You are here

Zhuang, Yuan

Overview:

Research in our laboratory focuses on molecular mechanism of lymphocyte development and genetic basis of lymphoid diseases such as leukemia and autoimmune disorders. We are using mouse models to investigate the role of E2A and other related transcription factors in lymphocyte development and immune function. We have shown that E2A plays an essential role in regulating both B and T cell development. Mice deficient for E2A cannot produce any B cell and exhibit high incidence of T cell leukemia. Separate studies also indicated that E2A is involved in the development of autoimmune disorders. Our current and future studies are to combine genetic, molecular biology, and immunology means to determine gene expression programs during lymphocyte development.

The mechanistic studies of gene function in animal models provide important clues in understanding relevant human diseases. It has been shown that about 20-30% of pediatric acute lymphocytic leukemias (ALL) are linked to chromosomal rearrangements at the E2A gene locus. Most of these genetic defects produce oncogenic forms of E2A proteins, which are the possible cause of leukemia. The use of animal models allows us to further define the molecular events underlying the disease development. Our long term goal is to provide molecular basis for early diagnosis and treatment of relevant lymphoid system diseases. 

Laboratory website:  http://sites.duke.edu/zhuanglab">Http://sites.duke.edu/zhuanglab. 

Positions:

Professor of Immunology

Immunology
School of Medicine

Director of Graduate Studies in the Department of Immunology

Immunology
School of Medicine

Professor of Molecular Genetics and Microbiology

Molecular Genetics and Microbiology
School of Medicine

Member of the Duke Cancer Institute

Duke Cancer Institute
School of Medicine

Education:

Ph.D. 1989

Ph.D. — Yale University

Grants:

Training Program in Developmental and Stem Cell Biology

Administered By
Basic Science Departments
AwardedBy
National Institutes of Health
Role
Mentor
Start Date
May 01, 2001
End Date
April 30, 2022

Organization and Function of Cellular Structure

Administered By
Basic Science Departments
AwardedBy
National Institutes of Health
Role
Mentor
Start Date
July 01, 1975
End Date
June 30, 2020

Basic Immunology Training Program

Administered By
Immunology
AwardedBy
National Institutes of Health
Role
Mentor
Start Date
July 01, 2002
End Date
June 30, 2019

Genetic dissection of Id3-mediated pathways in lineage development

Administered By
Immunology
AwardedBy
Fox Chase Cancer Center
Role
Principal Investigator
Start Date
May 01, 2017
End Date
April 30, 2018

E2A/HEB TRANSCRIPTION FACTORS IN T CELL DEVELOPMENT

Administered By
Immunology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
August 01, 1999
End Date
February 28, 2018

Training Program in Inflammatory and Immunological Diseases

Administered By
Medicine, Rheumatology and Immunology
AwardedBy
National Institutes of Health
Role
Preceptor
Start Date
September 30, 1980
End Date
August 31, 2017

A new approach to homeostatic maintenance of dendritic epidermal T cells

Administered By
Immunology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
May 01, 2014
End Date
April 30, 2017

A New Genetic Tool for Lineage Tracing of Mitotic Cells in Mice

Administered By
Immunology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
September 16, 2011
End Date
January 31, 2014

An episomal marking system for tracking cell proliferation

Administered By
Immunology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
August 15, 2009
End Date
January 31, 2012

Functions of E2A in B Lymphocyte Development

Administered By
Immunology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
January 01, 1997
End Date
February 28, 2011

Modeling Sjogrens Syndrome with Id3 Conditional Knockout Mice

Administered By
Immunology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
September 01, 2008
End Date
September 30, 2010

Orphan Nuclear Receptor in Thymocyte Differentiation

Administered By
Immunology
AwardedBy
National Institutes of Health
Role
Consultant
Start Date
August 28, 2002
End Date
July 31, 2007

The Functions Of E2a In B-Lymphocyte Development

Administered By
Immunology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
January 01, 1997
End Date
December 31, 1999

Cancer Center Core Support Grant

Administered By
Medicine, Medical Oncology
AwardedBy
National Institutes of Health
Role
Co-Principal Investigator
Start Date
September 01, 1976
End Date
December 31, 1998

Comprehensive Cancer Center Core Support Grant

Administered By
Medicine, Medical Oncology
AwardedBy
National Institutes of Health
Role
Co-Principal Investigator
Start Date
September 01, 1976
End Date
December 31, 1998
Show More

Awards:

AAAS Fellow. AAAS.

Type
National
Awarded By
AAAS
Date
January 01, 2013

Leukemia Society of America Scholarship. Leukemia Society of America (Leulemia and Lymphoma Society).

Type
National
Awarded By
Leukemia Society of America (Leulemia and Lymphoma Society)
Date
January 01, 1998

Whitehead Scholarship. Duke University.

Type
University
Awarded By
Duke University
Date
January 01, 1995

Leukemia Society of America Special Fellowship. Leukemia Society of America (Leulemia and Lymphoma Society).

Type
National
Awarded By
Leukemia Society of America (Leulemia and Lymphoma Society)
Date
January 01, 1994

Leukemia Research Institute Fellowship. Leukemia Research Institute.

Type
National
Awarded By
Leukemia Research Institute
Date
January 01, 1992

Damon Runyon-Walter Winchell Cancer Fund Fellowship. Damon Runyon-Walter Winchell Cancer Fund.

Type
National
Awarded By
Damon Runyon-Walter Winchell Cancer Fund
Date
January 01, 1990

Publications:

Tcrd Rearrangement Redirects a Processive Tcra Recombination Program to Expand the Tcra Repertoire.

Adaptive immunity depends on diverse T cell receptor repertoires generated by variable, diversity, and joining (V[D]J) recombination. Here, we define the principles by which combinatorial diversity is generated in the murine Tcra repertoire. Tcra and Tcrd gene segments share the Tcra-Tcrd locus, with interspersed Vα and Vδ segments undergoing Vδ-Dδ-Jδ rearrangement in CD4-CD8- thymocytes and then multiple rounds of Vα-Jα rearrangement in CD4+CD8+ thymocytes. We document stepwise, highly coordinated proximal-to-distal progressions of Vα and Jα use on individual Tcra alleles, limiting combinatorial diversity. This behavior is supported by an extended chromatin conformation in CD4+CD8+ thymocytes, with only nearby Vα and Jα segments contacting each other. Tcrd rearrangements can use distal Vδ segments due to a contracted Tcra-Tcrd conformation in CD4-CD8- thymocytes. These rearrangements expand the Tcra repertoire by truncating the Vα array to permit otherwise disfavored Vα-Jα combinations. Therefore, recombination events at two developmental stages with distinct chromatin conformations synergize to promote Tcra repertoire diversity.

Authors
Carico, ZM; Roy Choudhury, K; Zhang, B; Zhuang, Y; Krangel, MS
MLA Citation
Carico, ZM, Roy Choudhury, K, Zhang, B, Zhuang, Y, and Krangel, MS. "Tcrd Rearrangement Redirects a Processive Tcra Recombination Program to Expand the Tcra Repertoire." Cell reports 19.10 (June 2017): 2157-2173.
PMID
28591585
Source
epmc
Published In
Cell Reports
Volume
19
Issue
10
Publish Date
2017
Start Page
2157
End Page
2173
DOI
10.1016/j.celrep.2017.05.045

Enteropathy-associated T cell lymphoma subtypes are characterized by loss of function of SETD2.

Enteropathy-associated T cell lymphoma (EATL) is a lethal, and the most common, neoplastic complication of celiac disease. Here, we defined the genetic landscape of EATL through whole-exome sequencing of 69 EATL tumors. SETD2 was the most frequently silenced gene in EATL (32% of cases). The JAK-STAT pathway was the most frequently mutated pathway, with frequent mutations in STAT5B as well as JAK1, JAK3, STAT3, and SOCS1 We also identified mutations in KRAS, TP53, and TERT Type I EATL and type II EATL (monomorphic epitheliotropic intestinal T cell lymphoma) had highly overlapping genetic alterations indicating shared mechanisms underlying their pathogenesis. We modeled the effects of SETD2 loss in vivo by developing a T cell-specific knockout mouse. These mice manifested an expansion of γδ T cells, indicating novel roles for SETD2 in T cell development and lymphomagenesis. Our data render the most comprehensive genetic portrait yet of this uncommon but lethal disease and may inform future classification schemes.

Authors
Moffitt, AB; Ondrejka, SL; McKinney, M; Rempel, RE; Goodlad, JR; Teh, CH; Leppa, S; Mannisto, S; Kovanen, PE; Tse, E; Au-Yeung, RKH; Kwong, Y-L; Srivastava, G; Iqbal, J; Yu, J; Naresh, K; Villa, D; Gascoyne, RD; Said, J; Czader, MB; Chadburn, A; Richards, KL; Rajagopalan, D; Davis, NS; Smith, EC; Palus, BC; Tzeng, TJ; Healy, JA; Lugar, PL; Datta, J; Love, C; Levy, S; Dunson, DB; Zhuang, Y; Hsi, ED; Dave, SS
MLA Citation
Moffitt, AB, Ondrejka, SL, McKinney, M, Rempel, RE, Goodlad, JR, Teh, CH, Leppa, S, Mannisto, S, Kovanen, PE, Tse, E, Au-Yeung, RKH, Kwong, Y-L, Srivastava, G, Iqbal, J, Yu, J, Naresh, K, Villa, D, Gascoyne, RD, Said, J, Czader, MB, Chadburn, A, Richards, KL, Rajagopalan, D, Davis, NS, Smith, EC, Palus, BC, Tzeng, TJ, Healy, JA, Lugar, PL, Datta, J, Love, C, Levy, S, Dunson, DB, Zhuang, Y, Hsi, ED, and Dave, SS. "Enteropathy-associated T cell lymphoma subtypes are characterized by loss of function of SETD2." The Journal of experimental medicine 214.5 (May 2017): 1371-1386.
PMID
28424246
Source
epmc
Published In
The Journal of Experimental Medicine
Volume
214
Issue
5
Publish Date
2017
Start Page
1371
End Page
1386
DOI
10.1084/jem.20160894

The Histone Methyltransferase Ash1l is Required for Epidermal Homeostasis in Mice.

Epidermal homeostasis under normal and healing conditions are critical for the physical and functional maintenance of the skin barrier. It requires a proper balance between keratinocyte proliferation and differentiation under genetic and epigenetic regulations. Here we show that mice carrying a hypomorphic mutation of the histone methyltransferase Ash1l [(absent, small, or homeotic)-like (Drosophila)] develop epidermal hyperplasia and impaired epidermal stratification upon aging. In adult mutants, loss of Ash1l leads to more proliferative keratinocytes in disturbed differentiation stages. After wounding, Ash1l mutation leads to delayed re-epithlialization but increased keratinocyte proliferation at the wound edge. Elevated c-Myc expression could be observed in both aged and wounded mutant tissues. Taken together, these observations revealed an important role of the epigenetic regulator Ash1l in epidermal homeostasis.

Authors
Li, G; Ye, Z; Shi, C; Sun, L; Han, M; Zhuang, Y; Xu, T; Zhao, S; Wu, X
MLA Citation
Li, G, Ye, Z, Shi, C, Sun, L, Han, M, Zhuang, Y, Xu, T, Zhao, S, and Wu, X. "The Histone Methyltransferase Ash1l is Required for Epidermal Homeostasis in Mice." Scientific reports 7 (April 4, 2017): 45401-.
PMID
28374742
Source
epmc
Published In
Scientific Reports
Volume
7
Publish Date
2017
Start Page
45401
DOI
10.1038/srep45401

The Genetic Basis of Hepatosplenic T-cell Lymphoma.

Hepatosplenic T-cell lymphoma (HSTL) is a rare and lethal lymphoma; the genetic drivers of this disease are unknown. Through whole-exome sequencing of 68 HSTLs, we define recurrently mutated driver genes and copy-number alterations in the disease. Chromatin-modifying genes, including SETD2, INO80, and ARID1B, were commonly mutated in HSTL, affecting 62% of cases. HSTLs manifest frequent mutations in STAT5B (31%), STAT3 (9%), and PIK3CD (9%), for which there currently exist potential targeted therapies. In addition, we noted less frequent events in EZH2, KRAS, and TP53SETD2 was the most frequently silenced gene in HSTL. We experimentally demonstrated that SETD2 acts as a tumor suppressor gene. In addition, we found that mutations in STAT5B and PIK3CD activate critical signaling pathways important to cell survival in HSTL. Our work thus defines the genetic landscape of HSTL and implicates gene mutations linked to HSTL pathogenesis and potential treatment targets.Significance: We report the first systematic application of whole-exome sequencing to define the genetic basis of HSTL, a rare but lethal disease. Our work defines SETD2 as a tumor suppressor gene in HSTL and implicates genes including INO80 and PIK3CD in the disease. Cancer Discov; 7(4); 369-79. ©2017 AACR.See related commentary by Yoshida and Weinstock, p. 352This article is highlighted in the In This Issue feature, p. 339.

Authors
McKinney, M; Moffitt, AB; Gaulard, P; Travert, M; De Leval, L; Nicolae, A; Raffeld, M; Jaffe, ES; Pittaluga, S; Xi, L; Heavican, T; Iqbal, J; Belhadj, K; Delfau-Larue, MH; Fataccioli, V; Czader, MB; Lossos, IS; Chapman-Fredricks, JR; Richards, KL; Fedoriw, Y; Ondrejka, SL; Hsi, ED; Low, L; Weisenburger, D; Chan, WC; Mehta-Shah, N; Horwitz, S; Bernal-Mizrachi, L; Flowers, CR; Beaven, AW; Parihar, M; Baseggio, L; Parrens, M; Moreau, A; Sujobert, P; Pilichowska, M; Evens, AM; Chadburn, A et al.
MLA Citation
McKinney, M, Moffitt, AB, Gaulard, P, Travert, M, De Leval, L, Nicolae, A, Raffeld, M, Jaffe, ES, Pittaluga, S, Xi, L, Heavican, T, Iqbal, J, Belhadj, K, Delfau-Larue, MH, Fataccioli, V, Czader, MB, Lossos, IS, Chapman-Fredricks, JR, Richards, KL, Fedoriw, Y, Ondrejka, SL, Hsi, ED, Low, L, Weisenburger, D, Chan, WC, Mehta-Shah, N, Horwitz, S, Bernal-Mizrachi, L, Flowers, CR, Beaven, AW, Parihar, M, Baseggio, L, Parrens, M, Moreau, A, Sujobert, P, Pilichowska, M, Evens, AM, and Chadburn, A et al. "The Genetic Basis of Hepatosplenic T-cell Lymphoma." Cancer discovery 7.4 (April 2017): 369-379.
PMID
28122867
Source
epmc
Published In
Cancer Discovery
Volume
7
Issue
4
Publish Date
2017
Start Page
369
End Page
379
DOI
10.1158/2159-8290.cd-16-0330

Id2 Collaborates with Id3 To Suppress Invariant NKT and Innate-like Tumors.

Inhibitor of DNA binding (Id) proteins, including Id1-4, are transcriptional regulators involved in promoting cell proliferation and survival in various cell types. Although upregulation of Id proteins is associated with a broad spectrum of tumors, recent studies have identified that Id3 plays a tumor-suppressor role in the development of Burkitt's lymphoma in humans and hepatosplenic T cell lymphomas in mice. In this article, we report rapid lymphoma development in Id2/Id3 double-knockout mice that is caused by unchecked expansion of invariant NKT (iNKT) cells or a unique subset of innate-like CD1d-independent T cells. These populations began to expand in neonatal mice and, upon malignant transformation, resulted in mortality between 3 and 11 mo of age. The malignant cells also gave rise to lymphomas upon transfer to Rag-deficient and wild-type hosts, reaffirming their inherent tumorigenic potential. Microarray analysis revealed a significantly modified program in these neonatal iNKT cells that ultimately led to their malignant transformation. The lymphoma cells demonstrated chromosome instability along with upregulation of several signaling pathways, including the cytokine-cytokine receptor interaction pathway, which can promote their expansion and migration. Dysregulation of genes with reported driver mutations and the NF-κB pathway were found to be shared between Id2/Id3 double-knockout lymphomas and human NKT tumors. Our work identifies a distinct premalignant state and multiple tumorigenic pathways caused by loss of function of Id2 and Id3. Thus, conditional deletion of Id2 and Id3 in developing T cells establishes a unique animal model for iNKT and relevant innate-like lymphomas.

Authors
Li, J; Roy, S; Kim, Y-M; Li, S; Zhang, B; Love, C; Reddy, A; Rajagopalan, D; Dave, S; Diehl, AM; Zhuang, Y
MLA Citation
Li, J, Roy, S, Kim, Y-M, Li, S, Zhang, B, Love, C, Reddy, A, Rajagopalan, D, Dave, S, Diehl, AM, and Zhuang, Y. "Id2 Collaborates with Id3 To Suppress Invariant NKT and Innate-like Tumors." Journal of immunology (Baltimore, Md. : 1950) 198.8 (April 2017): 3136-3148.
PMID
28258199
Source
epmc
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
198
Issue
8
Publish Date
2017
Start Page
3136
End Page
3148
DOI
10.4049/jimmunol.1601935

Disruption of Gpr45 causes reduced hypothalamic POMC expression and obesity.

A rise in the occurrence of obesity has driven exploration of its underlying genetic basis and potential targets for intervention. GWAS studies have identified obesity susceptibility pathways involving several neuropeptides that control energy homeostasis, suggesting that variations in the genes that regulate food intake and energy expenditure may contribute to obesity. In this study, we identified 5 additional obesity loci, including a neuronal orphan GPCR called Gpr45, in a forward genetic screen of mutant mice generated by piggyBac insertional mutagenesis. Disruption of Gpr45 led to increased adiposity at the time of weaning and increases in body mass, fat content, glucose intolerance, and hepatic steatosis with advancing age. Mice with disruptions in Gpr45 also displayed a reduction in expression of the metabolic regulator POMC and less energy expenditure prior to the onset of obesity. Mechanistically, we determined that GPR45 regulates POMC expression via the JAK/STAT pathway in a cell-autonomous manner. Consistent with this finding, intraventricular administration of melanotan-2, an analog of the POMC derivative α-MSH, suppressed adult obesity in Gpr45 mutants. These results reveal that GPR45 is a regulator of POMC signaling and energy expenditure, which suggests that it may be a potential intervention target to combat obesity.

Authors
Cui, J; Ding, Y; Chen, S; Zhu, X; Wu, Y; Zhang, M; Zhao, Y; Li, T-RR; Sun, LV; Zhao, S; Zhuang, Y; Jia, W; Xue, L; Han, M; Xu, T; Wu, X
MLA Citation
Cui, J, Ding, Y, Chen, S, Zhu, X, Wu, Y, Zhang, M, Zhao, Y, Li, T-RR, Sun, LV, Zhao, S, Zhuang, Y, Jia, W, Xue, L, Han, M, Xu, T, and Wu, X. "Disruption of Gpr45 causes reduced hypothalamic POMC expression and obesity." The Journal of clinical investigation 126.9 (September 2016): 3192-3206.
PMID
27500489
Source
epmc
Published In
Journal of Clinical Investigation
Volume
126
Issue
9
Publish Date
2016
Start Page
3192
End Page
3206
DOI
10.1172/jci85676

Glimpse of natural selection of long-lived T-cell clones in healthy life.

Homeostatic maintenance of T cells with broad clonal diversity is influenced by both continuing output of young T cells from the thymus and ongoing turnover of preexisting clones in the periphery. In the absence of infection, self and commensal antigens are thought to play important roles in selection and homeostatic maintenance of the T-cell pool. Most naïve T cells are short-lived due to lack of antigen encounter, whereas antigen-experienced T cells may survive and persist as long-lived clones. Thus far, little is known about the homeostasis, antigenic specificity, and clonal diversity of long-lived T-cell clones in peripheral lymphoid organs under healthy living conditions. To identify long-lived T-cell clones in mice, we designed a lineage-tracing method to label a wave of T cells produced in the thymus of young mice. After aging the mice for 1.5 y, we found that lineage-tracked T cells consisted of primarily memory-like T cells and T regulatory cells. T-cell receptor repertoire analysis revealed that the lineage-tracked CD4 memory-like T cells and T regulatory cells exhibited age-dependent enrichment of shared clonotypes. Furthermore, these shared clonotypes were found across different mice maintained in the same housing condition. These findings suggest that nonrandom and shared antigens are involved in controlling selection, retention, and immune tolerance of long-lived T-cell clones under healthy living conditions.

Authors
Zhang, B; Jia, Q; Bock, C; Chen, G; Yu, H; Ni, Q; Wan, Y; Li, Q; Zhuang, Y
MLA Citation
Zhang, B, Jia, Q, Bock, C, Chen, G, Yu, H, Ni, Q, Wan, Y, Li, Q, and Zhuang, Y. "Glimpse of natural selection of long-lived T-cell clones in healthy life." Proceedings of the National Academy of Sciences of the United States of America 113.35 (August 17, 2016): 9858-9863.
PMID
27535935
Source
epmc
Published In
Proceedings of the National Academy of Sciences of USA
Volume
113
Issue
35
Publish Date
2016
Start Page
9858
End Page
9863
DOI
10.1073/pnas.1601634113

Generation of a Mouse Full-length Balancer with Versatile Cassette-shuttling Selection Strategy.

Balancer chromosomes are important tools for a variety of genetic manipulations in lower model organisms, owing to their ability to suppress recombination. In mouse, however, such effort has not been accomplished, mostly due to the size of the chromosomes and the complexity of multiple step chromosomal engineering. We developed an effective and versatile cassette-shuttling selection (CASS) strategy involving only two selection markers to achieve the sequential production of multiple large inversions along the chromosome. Using this strategy, we successfully generated the first full-length balancer in mice and showed that Balancer 17M-GFP can efficiently suppress recombination. Our study has not only generated a useful genetic resource, but also provided a strategy for constructing mammalian balancer chromosomes.

Authors
Ye, Z; Sun, L; Li, R; Han, M; Zhuang, Y; Wu, X; Xu, T
MLA Citation
Ye, Z, Sun, L, Li, R, Han, M, Zhuang, Y, Wu, X, and Xu, T. "Generation of a Mouse Full-length Balancer with Versatile Cassette-shuttling Selection Strategy." International journal of biological sciences 12.8 (January 2016): 911-916.
PMID
27489495
Source
epmc
Published In
International journal of biological sciences
Volume
12
Issue
8
Publish Date
2016
Start Page
911
End Page
916
DOI
10.7150/ijbs.15172

Differential Requirements of TCR Signaling in Homeostatic Maintenance and Function of Dendritic Epidermal T Cells.

Dendritic epidermal T cells (DETCs) are generated exclusively in the fetal thymus and maintained in the skin epithelium throughout postnatal life of the mouse. DETCs have restricted antigenic specificity as a result of their exclusive usage of a canonical TCR. Although the importance of the TCR in DETC development has been well established, the exact role of TCR signaling in DETC homeostasis and function remains incompletely defined. In this study, we investigated TCR signaling in fully matured DETCs by lineage-restricted deletion of the Lat gene, an essential signaling molecule downstream of the TCR. We found that Lat deletion impaired TCR-dependent cytokine gene activation and the ability of DETCs to undergo proliferative expansion. However, linker for activation of T cells-deficient DETCs were able to maintain long-term population homeostasis, although with a reduced proliferation rate. Mice with Lat deletion in DETCs exhibited delayed wound healing accompanied by impaired clonal expansion within the wound area. Our study revealed differential requirements for TCR signaling in homeostatic maintenance of DETCs and in their effector function during wound healing.

Authors
Zhang, B; Wu, J; Jiao, Y; Bock, C; Dai, M; Chen, B; Chao, N; Zhang, W; Zhuang, Y
MLA Citation
Zhang, B, Wu, J, Jiao, Y, Bock, C, Dai, M, Chen, B, Chao, N, Zhang, W, and Zhuang, Y. "Differential Requirements of TCR Signaling in Homeostatic Maintenance and Function of Dendritic Epidermal T Cells." Journal of immunology (Baltimore, Md. : 1950) 195.9 (November 2015): 4282-4291.
PMID
26408667
Source
epmc
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
195
Issue
9
Publish Date
2015
Start Page
4282
End Page
4291
DOI
10.4049/jimmunol.1501220

PP6 controls T cell development and homeostasis by negatively regulating distal TCR signaling.

T cell development and homeostasis are both regulated by TCR signals. Protein phosphorylation and dephosphorylation, which are catalyzed by protein kinases and phosphatases, respectively, serve as important switches controlling multiple downstream pathways triggered by TCR recognition of Ags. It has been well documented that protein tyrosine phosphatases are involved in negative regulation of proximal TCR signaling. However, how TCR signals are terminated or attenuated in the distal TCR signaling pathways is largely unknown. We investigated the function of Ser/Thr protein phosphatase (PP) 6 in TCR signaling. T cell lineage-specific ablation of PP6 in mice resulted in enhanced thymic positive and negative selection, and preferential expansion of fetal-derived, IL-17-producing Vγ6Vδ1(+) T cells. Both PP6-deficient peripheral CD4(+) helper and CD8(+) cytolytic cells could not maintain a naive state and became fast-proliferating and short-lived effector cells. PP6 deficiency led to profound hyperactivation of multiple distal TCR signaling molecules, including MAPKs, AKT, and NF-κB. Our studies demonstrate that PP6 acts as a critical negative regulator, not only controlling both αβ and γδ lineage development, but also maintaining naive T cell homeostasis by preventing their premature activation before Ag stimulation.

Authors
Ye, J; Shi, H; Shen, Y; Peng, C; Liu, Y; Li, C; Deng, K; Geng, J; Xu, T; Zhuang, Y; Zheng, B; Tao, W
MLA Citation
Ye, J, Shi, H, Shen, Y, Peng, C, Liu, Y, Li, C, Deng, K, Geng, J, Xu, T, Zhuang, Y, Zheng, B, and Tao, W. "PP6 controls T cell development and homeostasis by negatively regulating distal TCR signaling." Journal of immunology (Baltimore, Md. : 1950) 194.4 (February 2015): 1654-1664.
PMID
25609840
Source
epmc
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
194
Issue
4
Publish Date
2015
Start Page
1654
End Page
1664
DOI
10.4049/jimmunol.1401692

Orchestration of invariant natural killer T cell development by E and Id proteins.

Natural killer T (NKT) cells are αβ T cells that express a semi-invariant T-cell receptor (TCR) along with natural killer (NK) cell markers and have an innate cell-like ability to produce a myriad of cytokines very quickly upon antigen exposure and subsequent activation. These cells are diverted from conventional single positive (SP) T-cell fate at the double positive (DP) stage, where TCR-mediated recognition of a lipid antigen presented on a CD1d molecule promotes their selection into the NKT lineage. Although many key regulatory molecules have been shown to play important roles in the development of NKT cells, the mechanism of lineage specification and acquisition of effector functions in these cells still remain to be fully addressed. In this review, we specifically discuss the role of a family of class-I helix-loop-helix proteins known as E proteins, and their antagonists Id proteins in NKT celldevelopment. Recent work has shown that these proteins play key roles in invariant NKT (iNKT) development, from the invariant TCR rearrangement to terminal differentiation and maturation. Elucidating these roles provides an opportunity to uncover the transcriptional network that separates NKT cells from concurrently developed conventional αβ T cells.

Authors
Roy, S; Zhuang, Y
MLA Citation
Roy, S, and Zhuang, Y. "Orchestration of invariant natural killer T cell development by E and Id proteins." Critical reviews in immunology 35.1 (January 2015): 33-48. (Review)
PMID
25746046
Source
epmc
Published In
Critical Reviews in Immunology
Volume
35
Issue
1
Publish Date
2015
Start Page
33
End Page
48
DOI
10.1615/critrevimmunol.2015012207

Aberrant production of IL-13 by T cells promotes exocrinopathy in Id3 knockout mice.

Elevated levels of the cytokine IL-13 has been found to be associated with autoimmune diseases, including Sjögren's Syndrome. However, whether IL-13 plays a causative role in disease development is not known and cannot be easily studied in humans. Our previous work has shown that levels of IL-13 are elevated in Id3 knockout mice, which has been established as a model for primary Sjögren's Syndrome. Here, we utilized an IL-13 reporter to determine the source of the elevated IL-13 levels observed in Id3 knockout mice and assess its contribution to SS pathology. Our results indicate that T cells, notably CD4 and γδ T cells, in Id3 knockout mice acquire IL-13 competency at an elevated rate well before disease symptoms become apparent. We also show that T cells developing early in life are more predisposed to produce IL-13. Finally, analysis of Id3 and IL-13 double deficient mice demonstrated that IL-13 plays an essential role in the deterioration of gland function. Our study provides crucial genetic evidence that enhanced IL-13 production by T cells can play a causative role in the exocrinopathy observed in Id3 knockout mice.

Authors
Belle, I; Mahlios, J; McKenzie, A; Zhuang, Y
MLA Citation
Belle, I, Mahlios, J, McKenzie, A, and Zhuang, Y. "Aberrant production of IL-13 by T cells promotes exocrinopathy in Id3 knockout mice." Cytokine 69.2 (October 2014): 226-233.
PMID
25010390
Source
epmc
Published In
Cytokine
Volume
69
Issue
2
Publish Date
2014
Start Page
226
End Page
233
DOI
10.1016/j.cyto.2014.06.009

Mesenchymal high-grade glioma is maintained by the ID-RAP1 axis.

Authors
Niola, F; Zhao, X; Singh, D; Sullivan, R; Castano, A; Verrico, A; Zoppoli, P; Friedmann-Morvinski, D; Sulman, E; Barrett, L; Zhuang, Y; Verma, I; Benezra, R; Aldape, K; Iavarone, A; Lasorella, A
MLA Citation
Niola, F, Zhao, X, Singh, D, Sullivan, R, Castano, A, Verrico, A, Zoppoli, P, Friedmann-Morvinski, D, Sulman, E, Barrett, L, Zhuang, Y, Verma, I, Benezra, R, Aldape, K, Iavarone, A, and Lasorella, A. "Mesenchymal high-grade glioma is maintained by the ID-RAP1 axis." The Journal of clinical investigation 124.9 (September 2014): 4134-.
PMID
25083996
Source
epmc
Published In
Journal of Clinical Investigation
Volume
124
Issue
9
Publish Date
2014
Start Page
4134
DOI
10.1172/jci77927

A piggyBac insertion disrupts Foxl2 expression that mimics BPES syndrome in mice.

Blepharophimosis, ptosis, epicanthus inversus syndrome (BPES) is an autosomal dominant genetic disorder characterized by small palpebral fissures and other craniofacial malformations, often with (type I) but could also without (type II) premature ovarian failure. While mutations of the forkhead transcription factor FOXL2 are associated with and likely be responsible for many BPES cases, how FOXL2 affects craniofacial development remain to be understood. Through a large-scale piggyBac (PB) insertion mutagenesis, we have identified a mouse mutant carrying a PB insertion ∼160 kb upstream of the transcription start site (TSS) of Foxl2. The insertion reduces, but not eliminates, the expression of Foxl2. This mutant, but not its revertant, displays BPES-like conditions such as midface hypoplasia, eyelid abnormalities and female subfertility. Further analysis indicates that the mutation does not affect mandible, but causes premature fusion of the premaxilla-maxilla suture, smaller premaxilla and malformed maxilla during midface development. We further identified an evolutionarily conserved fragment near the insertion site and observed enhancer activity of this element in tissue culture cells. Analyses using DNase I hypersensitivity assay and chromosome conformation capture assay in developing maxillary and periocular tissues suggest that the DNA region near the insertion site likely interacts with Foxl2 TSS. Therefore, this mutant presents an excellent animal model for mechanistic study of BPES and regulation of Foxl2.

Authors
Shi, F; Ding, S; Zhao, S; Han, M; Zhuang, Y; Xu, T; Wu, X
MLA Citation
Shi, F, Ding, S, Zhao, S, Han, M, Zhuang, Y, Xu, T, and Wu, X. "A piggyBac insertion disrupts Foxl2 expression that mimics BPES syndrome in mice." Human molecular genetics 23.14 (July 2014): 3792-3800.
PMID
24565867
Source
epmc
Published In
Human Molecular Genetics
Volume
23
Issue
14
Publish Date
2014
Start Page
3792
End Page
3800
DOI
10.1093/hmg/ddu092

Rhbdd3 controls autoimmunity by suppressing the production of IL-6 by dendritic cells via K27-linked ubiquitination of the regulator NEMO.

Excessive activation of dendritic cells (DCs) leads to the development of autoimmune and inflammatory diseases, which has prompted a search for regulators of DC activation. Here we report that Rhbdd3, a member of the rhomboid family of proteases, suppressed the activation of DCs and production of interleukin 6 (IL-6) triggered by Toll-like receptors (TLRs). Rhbdd3-deficient mice spontaneously developed autoimmune diseases characterized by an increased abundance of the TH17 subset of helper T cells and decreased number of regulatory T cells due to the increase in IL-6 from DCs. Rhbdd3 directly bound to Lys27 (K27)-linked polyubiquitin chains on Lys302 of the modulator NEMO (IKKγ) via the ubiquitin-binding-association (UBA) domain in endosomes. Rhbdd3 further recruited the deubiquitinase A20 via K27-linked polyubiquitin chains on Lys268 to inhibit K63-linked polyubiquitination of NEMO and thus suppressed activation of the transcription factor NF-κB in DCs. Our data identify Rhbdd3 as a critical regulator of DC activation and indicate K27-linked polyubiquitination is a potent ubiquitin-linked pattern involved in the control of autoimmunity.

Authors
Liu, J; Han, C; Xie, B; Wu, Y; Liu, S; Chen, K; Xia, M; Zhang, Y; Song, L; Li, Z; Zhang, T; Ma, F; Wang, Q; Wang, J; Deng, K; Zhuang, Y; Wu, X; Yu, Y; Xu, T; Cao, X
MLA Citation
Liu, J, Han, C, Xie, B, Wu, Y, Liu, S, Chen, K, Xia, M, Zhang, Y, Song, L, Li, Z, Zhang, T, Ma, F, Wang, Q, Wang, J, Deng, K, Zhuang, Y, Wu, X, Yu, Y, Xu, T, and Cao, X. "Rhbdd3 controls autoimmunity by suppressing the production of IL-6 by dendritic cells via K27-linked ubiquitination of the regulator NEMO." Nature immunology 15.7 (July 2014): 612-622.
PMID
24859449
Source
epmc
Published In
Nature Immunology
Volume
15
Issue
7
Publish Date
2014
Start Page
612
End Page
622
DOI
10.1038/ni.2898

Id3 and Id2 act as a dual safety mechanism in regulating the development and population size of innate-like γδ T cells.

The innate-like T cells expressing Vγ1.1 and Vδ6.3 represent a unique T cell lineage sharing features with both the γδ T and the invariant NKT cells. The population size of Vγ1.1(+)Vδ6.3(+) T cells is tightly controlled and usually contributes to a very small proportion of thymic output, but the underlying mechanism remains enigmatic. Deletion of Id3, an inhibitor of E protein transcription factors, can induce an expansion of the Vγ1.1(+)Vδ6.3(+) T cell population. This phenotype is much stronger on the C57BL/6 background than on the 129/sv background. Using quantitative trait linkage analysis, we identified Id2, a homolog of Id3, to be the major modifier of Id3 in limiting Vγ1.1(+)Vδ6.3(+) T cell expansion. The Vγ1.1(+)Vδ6.3(+) phenotype is attributed to an intrinsic weakness of Id2 transcription from Id2 C57BL/6 allele, leading to an overall reduced dosage of Id proteins. However, complete removal of both Id2 and Id3 genes in developing T cells suppressed the expansion of Vγ1.1(+)Vδ6.3(+) T cells because of decreased proliferation and increased cell death. We showed that conditional knockout of Id2 alone is sufficient to promote a moderate expansion of γδ T cells. These regulatory effects of Id2 and Id3 on Vγ1.1(+)Vδ6.3(+) T cells are mediated by titration of E protein activity, because removing one or more copies of E protein genes can restore Vγ1.1(+)Vδ6.3(+) T cell expansion in Id2 and Id3 double conditional knockout mice. Our data indicated that Id2 and Id3 collaboratively control survival and expansion of the γδ lineage through modulating a proper threshold of E proteins.

Authors
Zhang, B; Lin, Y-Y; Dai, M; Zhuang, Y
MLA Citation
Zhang, B, Lin, Y-Y, Dai, M, and Zhuang, Y. "Id3 and Id2 act as a dual safety mechanism in regulating the development and population size of innate-like γδ T cells." J Immunol 192.3 (February 1, 2014): 1055-1063.
PMID
24379125
Source
pubmed
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
192
Issue
3
Publish Date
2014
Start Page
1055
End Page
1063
DOI
10.4049/jimmunol.1302694

Mst1/Mst2 regulate development and function of regulatory T cells through modulation of Foxo1/Foxo3 stability in autoimmune disease.

Foxp3 expression and regulatory T cell (Treg) development are critical for maintaining dominant tolerance and preventing autoimmune diseases. Human MST1 deficiency causes a novel primary immunodeficiency syndrome accompanied by autoimmune manifestations. However, the mechanism by which Mst1 controls immune regulation is unknown. In this article, we report that Mst1 regulates Foxp3 expression and Treg development/function and inhibits autoimmunity through modulating Foxo1 and Foxo3 (Foxo1/3) stability. We have found that Mst1 deficiency impairs Foxp3 expression and Treg development and function in mice. Mechanistic studies reveal that Mst1 enhances Foxo1/3 stability directly by phosphorylating Foxo1/3 and indirectly by attenuating TCR-induced Akt activation in peripheral T cells. Our studies have also shown that Mst1 deficiency does not affect Foxo1/3 cellular localization in CD4 T cells. In addition, we show that Mst1(-/-) mice are prone to autoimmune disease, and mutant phenotypes, such as overactivation of naive T cells, splenomegaly, and autoimmune pathological changes, are suppressed in Mst1(-/-) bone marrow chimera by cotransplanted wt Tregs. Finally, we demonstrate that Mst1 and Mst2 play a partially redundant role in Treg development and autoimmunity. Our findings not only identify Mst kinases as the long-searched-for factors that simultaneously activate Foxo1/3 and inhibit TCR-stimulated Akt downstream of TCR signaling to promote Foxp3 expression and Treg development, but also shed new light on understanding and designing better therapeutic strategies for MST1 deficiency-mediated human immunodeficiency syndrome.

Authors
Du, X; Shi, H; Li, J; Dong, Y; Liang, J; Ye, J; Kong, S; Zhang, S; Zhong, T; Yuan, Z; Xu, T; Zhuang, Y; Zheng, B; Geng, J-G; Tao, W
MLA Citation
Du, X, Shi, H, Li, J, Dong, Y, Liang, J, Ye, J, Kong, S, Zhang, S, Zhong, T, Yuan, Z, Xu, T, Zhuang, Y, Zheng, B, Geng, J-G, and Tao, W. "Mst1/Mst2 regulate development and function of regulatory T cells through modulation of Foxo1/Foxo3 stability in autoimmune disease." Journal of immunology (Baltimore, Md. : 1950) 192.4 (February 2014): 1525-1535.
PMID
24453252
Source
epmc
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
192
Issue
4
Publish Date
2014
Start Page
1525
End Page
1535
DOI
10.4049/jimmunol.1301060

E proteins in lymphocyte development and lymphoid diseases.

As members of the basic helix-loop-helix (bHLH) family of transcription factors, E proteins function in the immune system by directing and maintaining a vast transcriptional network that regulates cell survival, proliferation, differentiation, and function. Proper activity of this network is essential to the functionality of the immune system. Aberrations in E protein expression or function can cause numerous defects, ranging from impaired lymphocyte development and immunodeficiency to aberrant function, cancer, and autoimmunity. Additionally, disruption of inhibitor of DNA-binding (Id) proteins, natural inhibitors of E proteins, can induce additional defects in development and function. Although E proteins have been investigated for several decades, their study continues to yield novel and exciting insights into the workings of the immune system. The goal of this chapter is to discuss the various classical roles of E proteins in lymphocyte development and highlight new and ongoing research into how these roles, if compromised, can lead to disease.

Authors
Belle, I; Zhuang, Y
MLA Citation
Belle, I, and Zhuang, Y. "E proteins in lymphocyte development and lymphoid diseases." Current topics in developmental biology 110 (January 2014): 153-187. (Review)
PMID
25248476
Source
epmc
Published In
Current topics in developmental biology
Volume
110
Publish Date
2014
Start Page
153
End Page
187
DOI
10.1016/b978-0-12-405943-6.00004-x

Combined deletion of Id2 and Id3 genes reveals multiple roles for E proteins in invariant NKT cell development and expansion.

The invariant NKT (iNKT) cells represent a unique group of αβ T cells that have been classified based on their exclusive usage of the invariant Vα14Jα18 TCRα-chain and their innate-like effector function. Thus far, the transcriptional programs that control Vα14Jα18 TCRα rearrangements and the population size of iNKT cells are still incompletely defined. E protein transcription factors have been shown to play necessary roles in the development of multiple T cell lineages, including iNKT cells. In this study, we examined E protein functions in T cell development through combined deletion of genes encoding E protein inhibitors Id2 and Id3. Deletion of Id2 and Id3 in T cell progenitors resulted in a partial block at the pre-TCR selection checkpoint and a dramatic increase in numbers of iNKT cells. The increase in iNKT cells is accompanied with a biased rearrangement involving Vα14 to Jα18 recombination at the double-positive stage and enhanced proliferation of iNKT cells. We further demonstrate that a 50% reduction of E proteins can cause a dramatic switch from iNKT to innate-like γδ T cell fate in Id2- and Id3-deficient mice. Collectively, these findings suggest that Id2- and Id3-mediated inhibition of E proteins controls iNKT development by restricting lineage choice and population expansion.

Authors
Li, J; Wu, D; Jiang, N; Zhuang, Y
MLA Citation
Li, J, Wu, D, Jiang, N, and Zhuang, Y. "Combined deletion of Id2 and Id3 genes reveals multiple roles for E proteins in invariant NKT cell development and expansion." J Immunol 191.10 (November 15, 2013): 5052-5064.
PMID
24123680
Source
pubmed
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
191
Issue
10
Publish Date
2013
Start Page
5052
End Page
5064
DOI
10.4049/jimmunol.1301252

Tracking proliferative history in lymphocyte development with cre-mediated sister chromatid recombination.

Tracking and isolating live cells based on their proliferative history in live animals remains a technical challenge in animal studies. We have designed a genetic marking system for tracking the proliferative frequency and history of lymphocytes during their development and homeostatic maintenance. This system is based on activation of a fluorescent marker after Cre-dependent recombination between sister chromatids at a specially designed tandem loxP site, named Tlox. We have demonstrated the utility of the Tlox system in tracking proliferative windows of B and T lymphocyte development. We have further applied the Tlox system in the analysis of the proliferative behavior and homeostatic maintenance of Vγ1.1 positive γδ T cells. Our data show that Vγ1.1 T cells generated in neonatal but not adult life are able to expand in the thymus. The expanded Vγ1.1 T cells are preferentially maintained in the liver but not in lymphoid organs. It has been shown that numbers of Vγ1.1 T cells were dramatically increased in the lymphoid organs of Id3 deficient mice. By combining BrdU and Tlox assays we show that this phenotype is primarily due to enhanced neonatal expansion and subsequent retention of Vγ1.1 T cells. Thus, the Tlox system provides a new genetic tool to track clonal expansion within a defined cell population or tissue type in live animals.

Authors
Zhang, B; Dai, M; Li, Q-J; Zhuang, Y
MLA Citation
Zhang, B, Dai, M, Li, Q-J, and Zhuang, Y. "Tracking proliferative history in lymphocyte development with cre-mediated sister chromatid recombination." PLoS Genet 9.10 (October 2013): e1003887-.
PMID
24204301
Source
pubmed
Published In
PLoS genetics
Volume
9
Issue
10
Publish Date
2013
Start Page
e1003887
DOI
10.1371/journal.pgen.1003887

piggyBac as a high-capacity transgenesis and gene-therapy vector in human cells and mice.

The stable genomic integration and expression of a large transgene is a major hurdle in gene therapy. We show that the modified piggyBac (PB) transposon system can be used to introduce a 207 kb genomic DNA fragment containing the RORγ/γt locus into human cells and mice. PB-mediated transgenesis results in a single copy of a stably inherited and expressed transgene. These results indicate that PB could serve as an effective high-capacity vector for functional analysis of the mammalian genome and for gene therapy in human cells.

Authors
Li, R; Zhuang, Y; Han, M; Xu, T; Wu, X
MLA Citation
Li, R, Zhuang, Y, Han, M, Xu, T, and Wu, X. "piggyBac as a high-capacity transgenesis and gene-therapy vector in human cells and mice." Dis Model Mech 6.3 (May 2013): 828-833.
PMID
23519027
Source
pubmed
Published In
Disease models & mechanisms
Volume
6
Issue
3
Publish Date
2013
Start Page
828
End Page
833
DOI
10.1242/dmm.010827

PiggyBac Mutagenesis and Information Center

Authors
Sun, LV; Jin, K; Liu, Y; Yang, W; Xie, X; Ye, L; Wang, L; Zhu, L; Ding, S; Su, Y; Zhou, J; Han, M; Zhuang, Y; Xu, T; Wu, X; Gu, N; Zhong, Y
MLA Citation
Sun, LV, Jin, K, Liu, Y, Yang, W, Xie, X, Ye, L, Wang, L, Zhu, L, Ding, S, Su, Y, Zhou, J, Han, M, Zhuang, Y, Xu, T, Wu, X, Gu, N, and Zhong, Y. "PiggyBac Mutagenesis and Information Center." TRANSGENIC RESEARCH 22.1 (February 2013): 215-215.
Source
wos-lite
Published In
Transgenic Research
Volume
22
Issue
1
Publish Date
2013
Start Page
215
End Page
215

Mesenchymal high-grade glioma is maintained by the ID-RAP1 axis.

High-grade gliomas (HGGs) are incurable brain tumors that are characterized by the presence of glioma-initiating cells (GICs). GICs are essential to tumor aggressiveness and retain the capacity for self-renewal and multilineage differentiation as long as they reside in the perivascular niche. ID proteins are master regulators of stemness and anchorage to the extracellular niche microenvironment, suggesting that they may play a role in maintaining GICs. Here, we modeled the probable therapeutic impact of ID inactivation in HGG by selective ablation of Id in tumor cells and after tumor initiation in a new mouse model of human mesenchymal HGG. Deletion of 3 Id genes induced rapid release of GICs from the perivascular niche, followed by tumor regression. GIC displacement was mediated by derepression of Rap1gap and subsequent inhibition of RAP1, a master regulator of cell adhesion. We identified a signature module of 5 genes in the ID pathway, including RAP1GAP, which segregated 2 subgroups of glioma patients with markedly different clinical outcomes. The model-informed survival analysis together with genetic and functional studies establish that ID activity is required for the maintenance of mesenchymal HGG and suggest that pharmacological inactivation of ID proteins could serve as a therapeutic strategy.

Authors
Niola, F; Zhao, X; Singh, D; Sullivan, R; Castano, A; Verrico, A; Zoppoli, P; Friedmann-Morvinski, D; Sulman, E; Barrett, L; Zhuang, Y; Verma, I; Benezra, R; Aldape, K; Iavarone, A; Lasorella, A
MLA Citation
Niola, F, Zhao, X, Singh, D, Sullivan, R, Castano, A, Verrico, A, Zoppoli, P, Friedmann-Morvinski, D, Sulman, E, Barrett, L, Zhuang, Y, Verma, I, Benezra, R, Aldape, K, Iavarone, A, and Lasorella, A. "Mesenchymal high-grade glioma is maintained by the ID-RAP1 axis." J Clin Invest 123.1 (January 2013): 405-417.
PMID
23241957
Source
pubmed
Published In
Journal of Clinical Investigation
Volume
123
Issue
1
Publish Date
2013
Start Page
405
End Page
417
DOI
10.1172/JCI63811

Inner nuclear envelope proteins SUN1 and SUN2 play a prominent role in the DNA damage response.

The DNA damage response (DDR) and DNA repair are critical for maintaining genomic stability and evading many human diseases. Recent findings indicate that accumulation of SUN1, a nuclear envelope (NE) protein, is a significant pathogenic event in Emery-Dreifuss muscular dystrophy and Hutchinson-Gilford progeria syndrome, both caused by mutations in LMNA. However, roles of mammalian SUN proteins in mitotic cell division and genomic stability are unknown. Here we report that the inner NE proteins SUN1 and SUN2 may play a redundant role in DDR. Mouse embryonic fibroblasts from Sun1(-/-)Sun2(-/-) mice displayed premature proliferation arrest in S phase of cell cycle, increased apoptosis and DNA damage, and decreased perinuclear heterochromatin, indicating genome instability. Furthermore, activation of ATM and H2A.X, early events in DDR, were impaired in Sun1(-/-)Sun2(-/-) fibroblasts. A biochemical screen identified interactions between SUN1 and SUN2 and DNA-dependent protein kinase (DNAPK) complex that functions in DNA nonhomologous end joining repair and possibly in DDR. Knockdown of DNAPK reduced ATM activation in NIH 3T3 cells, consistent with a potential role of SUN1- and SUN2-DNAPK interaction during DDR. SUN1 and SUN2 could affect DDR by localizing certain nuclear factors to the NE or by mediating communication between nuclear and cytoplasmic events.

Authors
Lei, K; Zhu, X; Xu, R; Shao, C; Xu, T; Zhuang, Y; Han, M
MLA Citation
Lei, K, Zhu, X, Xu, R, Shao, C, Xu, T, Zhuang, Y, and Han, M. "Inner nuclear envelope proteins SUN1 and SUN2 play a prominent role in the DNA damage response." Curr Biol 22.17 (September 11, 2012): 1609-1615.
PMID
22863315
Source
pubmed
Published In
Current Biology
Volume
22
Issue
17
Publish Date
2012
Start Page
1609
End Page
1615
DOI
10.1016/j.cub.2012.06.043

Transcriptional regulator Id2 is required for the CD4 T cell immune response in the development of experimental autoimmune encephalomyelitis.

An effective immune response to Ag challenge is critically dependent on the size of the effector cell population generated from clonal activation of Ag-specific T cells. The transcription network involved in regulating the size of the effector population, particularly for CD4 Th cells, is poorly understood. In this study, we investigate the role of Id2, an inhibitor of E protein transcription factors, in the generation of CD4 effectors. Using a T cell-specific conditional Id2 knockout mouse model, we show that inhibitor of DNA binding (Id)2 is essential for the development of experimental autoimmune encephalomyelitis. Although Ag-specific and IL-17-producing CD4 T cells are produced in these mice, the activated CD4 T cells form a smaller pool of effector cells in the peripheral lymphoid organs, exhibit reduced proliferation and increased cell death, and are largely absent in the CNS. In the absence of Id2, E protein targets, including the proapoptotic protein Bim and SOCS3, are expressed at higher levels among activated CD4 T cells. This study reveals a critical role of Id2 in the control of effector CD4 T cell population size and the development of a Th17-mediated autoimmune disease.

Authors
Lin, Y-Y; Jones-Mason, ME; Inoue, M; Lasorella, A; Iavarone, A; Li, Q-J; Shinohara, ML; Zhuang, Y
MLA Citation
Lin, Y-Y, Jones-Mason, ME, Inoue, M, Lasorella, A, Iavarone, A, Li, Q-J, Shinohara, ML, and Zhuang, Y. "Transcriptional regulator Id2 is required for the CD4 T cell immune response in the development of experimental autoimmune encephalomyelitis." J Immunol 189.3 (August 1, 2012): 1400-1405.
PMID
22745378
Source
pubmed
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
189
Issue
3
Publish Date
2012
Start Page
1400
End Page
1405
DOI
10.4049/jimmunol.1200491

Generation of Dhx9-deficient clones in T-cell development with a mitotic recombination technique.

Mitotic recombination is an effective tool for generating mutant clones in somatic tissues. Because of difficulties associated with detecting and quantifying mutant clones in mice, this technique is limited to analysis of growth-related phenotypes induced by loss function of tumor suppressor genes. Here, we used the polymorphic CD45.1/CD45.2 alleles on chromosome 1 as pan-hematopoietic markers to track mosaic clones generated through mitotic recombination in developing T cells. We show that lineage-specific mitotic recombination can be induced and reliably detected as CD45.1 or CD45.2 homozygous clones from the CD45.1/CD45.2 heterozygous background. We have applied this system in the analysis of a lethal mutation in the Dhx9 gene. Mosaic analysis revealed a stage-specific role for Dhx9 during T-cell maturation. Thus, the experimental system described in this study offers a practical means for mosaic analysis of germline mutations in the hematopoietic system.

Authors
Zhu, Y; Liu, S; Yin, Q; Xu, T; Wu, X; Zhuang, Y
MLA Citation
Zhu, Y, Liu, S, Yin, Q, Xu, T, Wu, X, and Zhuang, Y. "Generation of Dhx9-deficient clones in T-cell development with a mitotic recombination technique." Genesis 50.7 (July 2012): 543-551.
PMID
22988576
Source
pubmed
Published In
Genesis: the Journal of Genetics and Development
Volume
50
Issue
7
Publish Date
2012
Start Page
543
End Page
551

Transcriptional regulator Id2 is required for the CD4 T cell immune response in the development of experimental autoimmune encephalomyelitis

Authors
Lin, Y-Y; Jones-Mason, M; Inoue, M; Iavarone, A; Lasorella, A; Shinohara, M; Zhuang, Y
MLA Citation
Lin, Y-Y, Jones-Mason, M, Inoue, M, Iavarone, A, Lasorella, A, Shinohara, M, and Zhuang, Y. "Transcriptional regulator Id2 is required for the CD4 T cell immune response in the development of experimental autoimmune encephalomyelitis." May 1, 2012.
Source
wos-lite
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
188
Publish Date
2012

Double knockout of Id2 & Id3 in developing T cells promotes the development of CD4-CD8-alpha beta T cell

Authors
Li, J; Zhuang, Y
MLA Citation
Li, J, and Zhuang, Y. "Double knockout of Id2 & Id3 in developing T cells promotes the development of CD4-CD8-alpha beta T cell." May 1, 2012.
Source
wos-lite
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
188
Publish Date
2012

Id proteins synchronize stemness and anchorage to the niche of neural stem cells.

Stem-cell functions require activation of stem-cell-intrinsic transcriptional programs and extracellular interaction with a niche microenvironment. How the transcriptional machinery controls residency of stem cells in the niche is unknown. Here we show that Id proteins coordinate stem-cell activities with anchorage of neural stem cells (NSCs) to the niche. Conditional inactivation of three Id genes in NSCs triggered detachment of embryonic and postnatal NSCs from the ventricular and vascular niche, respectively. The interrogation of the gene modules directly targeted by Id deletion in NSCs revealed that Id proteins repress bHLH-mediated activation of Rap1GAP, thus serving to maintain the GTPase activity of RAP1, a key mediator of cell adhesion. Preventing the elevation of the Rap1GAP level countered the consequences of Id loss on NSC-niche interaction and stem-cell identity. Thus, by preserving anchorage of NSCs to the extracellular environment, Id activity synchronizes NSC functions to residency in the specialized niche.

Authors
Niola, F; Zhao, X; Singh, D; Castano, A; Sullivan, R; Lauria, M; Nam, H-S; Zhuang, Y; Benezra, R; Di Bernardo, D; Iavarone, A; Lasorella, A
MLA Citation
Niola, F, Zhao, X, Singh, D, Castano, A, Sullivan, R, Lauria, M, Nam, H-S, Zhuang, Y, Benezra, R, Di Bernardo, D, Iavarone, A, and Lasorella, A. "Id proteins synchronize stemness and anchorage to the niche of neural stem cells. (Published online)" Nat Cell Biol 14.5 (April 22, 2012): 477-487.
PMID
22522171
Source
pubmed
Published In
Nature Cell Biology
Volume
14
Issue
5
Publish Date
2012
Start Page
477
End Page
487
DOI
10.1038/ncb2490

E protein transcription factors are required for the development of CD4(+) lineage T cells.

The double-positive (DP) to single-positive (SP) transition during T cell development is initiated by downregulation of the E protein transcription factors HEB and E2A. Here, we have demonstrated that in addition to regulating the onset of this transition, HEB and E2A also play a separate role in CD4(+) lineage choice. Deletion of HEB and E2A in DP thymocytes specifically blocked the development of CD4(+) lineage T cells. Furthermore, deletion of the E protein inhibitors Id2 and Id3 allowed CD4(+) T cell development but blocked CD8(+) lineage development. Analysis of the CD4(+) lineage transcriptional regulators ThPOK and Gata3 placed HEB and E2A upstream of CD4(+) lineage specification. These studies identify an important role for E proteins in the activation of CD4(+) lineage differentiation as thymocytes undergo the DP to SP transition.

Authors
Jones-Mason, ME; Zhao, X; Kappes, D; Lasorella, A; Iavarone, A; Zhuang, Y
MLA Citation
Jones-Mason, ME, Zhao, X, Kappes, D, Lasorella, A, Iavarone, A, and Zhuang, Y. "E protein transcription factors are required for the development of CD4(+) lineage T cells." Immunity 36.3 (March 23, 2012): 348-361.
PMID
22425249
Source
pubmed
Published In
Immunity
Volume
36
Issue
3
Publish Date
2012
Start Page
348
End Page
361
DOI
10.1016/j.immuni.2012.02.010

Contribution of IL-13 to early exocrinopathy in Id3-/- mice.

Id3-/- mice represent a model for T cell mediated primary Sjogren's syndrome (PSS). An intriguing feature of this disease model is the early appearance of impaired salivary function or exocrinopathy prior to lymphocytic infiltration of the salivary glands. This phenomenon prompted us to examine the role of cytokines produced by T cells in the systemic regulation of gland function. A comprehensive examination of serum cytokine profiles revealed elevated levels of IL-13 in Id3-/- mice. We found that the increase in serum IL-13 levels in Id3-/- mice was largely dependent on αβ T cells. Removal of αβ T cells in Id3-/- mice also eliminates disease symptoms, including lymphocytic infiltration in the gland tissues, and impaired saliva production. We further show that the number of mast cells in the salivary glands of Id3-/- mice is significantly increased, in a trend inversely related to the saliva production. This increase in the number of mast cells is also dependent on the presence of αβ T cells. Treatment of young Id3-/- mice with anti-IL-13 antibodies over a two-month period resulted in a reduction of both serum IL-13 levels and the number of mast cells in the salivary gland tissues, as well as correspondingly improved saliva production. These findings indicate a potentially important role for IL-13 in gland regulation and disease pathology.

Authors
Mahlios, J; Zhuang, Y
MLA Citation
Mahlios, J, and Zhuang, Y. "Contribution of IL-13 to early exocrinopathy in Id3-/- mice." Mol Immunol 49.1-2 (October 2011): 227-233.
PMID
21924496
Source
pubmed
Published In
Molecular Immunology
Volume
49
Issue
1-2
Publish Date
2011
Start Page
227
End Page
233
DOI
10.1016/j.molimm.2011.08.012

Stage-specific functions of E-proteins at the β-selection and T-cell receptor checkpoints during thymocyte development.

The E-protein transcription factors E2A and HEB function in a lineage- and stage-specific manner to orchestrate many critical events throughout lymphocyte development. The function of E-proteins in both B- and T-lymphocyte development has been extensively studied through the use of single-gene knockout animals. Unlike B cells, which rely primarily on E2A alone, T cells are regulated by the combinatorial expression of both E2A and HEB. Therefore, many of the roles of E-proteins during T-cell development may be masked in single-gene knockout studies due to the compensatory function of E2A and HEB. More recently, our laboratory has established double-conditional knockout models to eliminate both E2A and HEB in a stage-specific manner throughout T-cell development. These models, in combination with other complimentary genetic approaches, have identified new E-protein functions at each of the two major T-cell developmental checkpoints. Here, we will discuss how E-proteins function to regulate the expression of T-cell receptor components and cell cycle at the β-selection checkpoint, and how they control positive selection, survival, and lineage-specific gene expression at the subsequent T-cell receptor checkpoint.

Authors
Jones, ME; Zhuang, Y
MLA Citation
Jones, ME, and Zhuang, Y. "Stage-specific functions of E-proteins at the β-selection and T-cell receptor checkpoints during thymocyte development." Immunol Res 49.1-3 (April 2011): 202-215.
PMID
21128008
Source
pubmed
Published In
Immunologic Research
Volume
49
Issue
1-3
Publish Date
2011
Start Page
202
End Page
215
DOI
10.1007/s12026-010-8182-x

Modeling Sjögren's syndrome with Id3 conditional knockout mice.

The Id3 gene has been shown to play important roles in the development and function of broad tissue types including B and T cells. Id3 deficient mice develop autoimmune disease similar to human Sjögren's syndrome. Both B and T lymphocytes have been implicated to contribute to the disease phenotype in this disease model. In order to gain a better understanding of individual cell types in this disease model, we generated an Id3 conditional allele. An LckCre transgene was used to induce Id3 deletion in developing T cells. We showed that the Id3 gene was efficiently disrupted in early thymocyte development prior to T cell receptor (TCR)-mediated positive selection. Consequently, thymocyte maturation was impaired in the conditional knockout mice. These mice developed exocrinopathy starting at two months of age and subsequently exhibited high incidence of lymphocyte infiltration to salivary glands between eight and 12 months of age. This progressive feature of disease development is very similar to those observed in Id3 germline knockout mice. This study establishes a new model for investigating the relationship between T cell development and autoimmune disease. Our observation provides an experimental case that autoimmune disease may be induced by acquired mutation in developing T cells.

Authors
Guo, Z; Li, H; Han, M; Xu, T; Wu, X; Zhuang, Y
MLA Citation
Guo, Z, Li, H, Han, M, Xu, T, Wu, X, and Zhuang, Y. "Modeling Sjögren's syndrome with Id3 conditional knockout mice." Immunol Lett 135.1-2 (March 30, 2011): 34-42.
PMID
20932862
Source
pubmed
Published In
Immunology Letters
Volume
135
Issue
1-2
Publish Date
2011
Start Page
34
End Page
42
DOI
10.1016/j.imlet.2010.09.009

KASH protein Syne-2/Nesprin-2 and SUN proteins SUN1/2 mediate nuclear migration during mammalian retinal development.

Nuclear movement relative to cell bodies is a fundamental process during certain aspects of mammalian retinal development. During the generation of photoreceptor cells in the cell division cycle, the nuclei of progenitors oscillate between the apical and basal surfaces of the neuroblastic layer (NBL). This process is termed interkinetic nuclear migration (INM). Furthermore, newly formed photoreceptor cells migrate and form the outer nuclear layer (ONL). In the current study, we demonstrated that a KASH domain-containing protein, Syne-2/Nesprin-2, as well as SUN domain-containing proteins, SUN1 and SUN2, play critical roles during INM and photoreceptor cell migration in the mouse retina. A deletion mutation of Syne-2/Nesprin-2 or double mutations of Sun1 and Sun2 caused severe reduction of the thickness of the ONL, mislocalization of photoreceptor nuclei and profound electrophysiological dysfunction of the retina characterized by a reduction of a- and b-wave amplitudes. We also provide evidence that Syne-2/Nesprin-2 forms complexes with either SUN1 or SUN2 at the nuclear envelope to connect the nucleus with dynein/dynactin and kinesin molecular motors during the nuclear migrations in the retina. These key retinal developmental signaling results will advance our understanding of the mechanism of nuclear migration in the mammalian retina.

Authors
Yu, J; Lei, K; Zhou, M; Craft, CM; Xu, G; Xu, T; Zhuang, Y; Xu, R; Han, M
MLA Citation
Yu, J, Lei, K, Zhou, M, Craft, CM, Xu, G, Xu, T, Zhuang, Y, Xu, R, and Han, M. "KASH protein Syne-2/Nesprin-2 and SUN proteins SUN1/2 mediate nuclear migration during mammalian retinal development." Hum Mol Genet 20.6 (March 15, 2011): 1061-1073.
PMID
21177258
Source
pubmed
Published In
Human Molecular Genetics
Volume
20
Issue
6
Publish Date
2011
Start Page
1061
End Page
1073
DOI
10.1093/hmg/ddq549

Control of the differentiation of regulatory T cells and T(H)17 cells by the DNA-binding inhibitor Id3.

The molecular mechanisms that direct transcription of the gene encoding the transcription factor Foxp3 in CD4(+) T cells remain ill-defined. We show here that deletion of the DNA-binding inhibitor Id3 resulted in the defective generation of Foxp3(+) regulatory T cells (T(reg) cells). We identify two transforming growth factor-β1 (TGF-β1)-dependent mechanisms that were vital for activation of Foxp3 transcription and were defective in Id3(-/-) CD4(+) T cells. Enhanced binding of the transcription factor E2A to the Foxp3 promoter promoted Foxp3 transcription. Id3 was required for relief of inhibition by the transcription factor GATA-3 at the Foxp3 promoter. Furthermore, Id3(-/-) T cells showed greater differentiation into the T(H)17 subset of helper T cells in vitro and in a mouse asthma model. Therefore, a network of factors acts in a TGF-β-dependent manner to control Foxp3 expression and inhibit the development of T(H)17 cells.

Authors
Maruyama, T; Li, J; Vaque, JP; Konkel, JE; Wang, W; Zhang, B; Zhang, P; Zamarron, BF; Yu, D; Wu, Y; Zhuang, Y; Gutkind, JS; Chen, W
MLA Citation
Maruyama, T, Li, J, Vaque, JP, Konkel, JE, Wang, W, Zhang, B, Zhang, P, Zamarron, BF, Yu, D, Wu, Y, Zhuang, Y, Gutkind, JS, and Chen, W. "Control of the differentiation of regulatory T cells and T(H)17 cells by the DNA-binding inhibitor Id3." Nat Immunol 12.1 (January 2011): 86-95.
PMID
21131965
Source
pubmed
Published In
Nature Immunology
Volume
12
Issue
1
Publish Date
2011
Start Page
86
End Page
95
DOI
10.1038/ni.1965

Adam10 is essential for early embryonic cardiovascular development.

Notch pathway has been demonstrated to regulate cardiovascular development. One important step in Notch pathway is the cleavage of Notch receptor, during which an intracellular fragment of Notch protein is released to activate downstream genes. It is still uncertain whether Adam10, the mammalian homologue of Kuzbanian in Drosophila, is required to activate the Notch pathway during cardiovascular development. To further understand the physiological function of Adam10 in vascular and cardiac development, we generated mice lacking the Adam10 gene primarily in the endothelial compartment. We found that disruption of Adam10 in endothelial cells resulted in embryonic death after embryonic day 10.5 due to multiple cardiac and vascular defects similar to Notch1 mutants. We further showed that the expression of Notch target genes Snail and Bmp2 are impaired in Adam10-deficient cardiac tissues. Finally, we provide experimental evidence to support that Adam10 functions in a cell autonomous manner during mammalian cardiac development.

Authors
Zhang, C; Tian, L; Chi, C; Wu, X; Yang, X; Han, M; Xu, T; Zhuang, Y; Deng, K
MLA Citation
Zhang, C, Tian, L, Chi, C, Wu, X, Yang, X, Han, M, Xu, T, Zhuang, Y, and Deng, K. "Adam10 is essential for early embryonic cardiovascular development." Dev Dyn 239.10 (October 2010): 2594-2602.
PMID
20803506
Source
pubmed
Published In
Developmental Dynamics
Volume
239
Issue
10
Publish Date
2010
Start Page
2594
End Page
2602
DOI
10.1002/dvdy.22391

Generation and analysis of partially haploid cells with Cre-mediated chromosome deletion in the lymphoid system.

The fast accumulation of mutant mouse strains in recent years has provided an invaluable resource for phenotype-based genetic screens. However, study of lymphoid phenotypes can be obscured or impractical if homozygous mutations cause early embryonic defects. To aid phenotype screening of germ line mutations in the lymphoid system, we developed a method to induce loss of heterozygosity (LOH) in developing lymphocytes through chromosome deletion. Chromosome deletion was triggered by Cre/loxP-mediated inverse sister chromatid recombination in the G(2)/M phase of the cell cycle, leading to the generation of daughter cells missing part of or the entire recombinant chromosome. We show that the resulting cells were viable and capable of additional rounds of cell division, thus providing raw materials for subsequent phenotypic assessment. We used the recombination system to induce LOH at the E2A locus in developing B cells. A significant loss of pro-B and pre-B cells was observed when the wild-type allele was removed by chromosome deletion from the E2A heterozygous mice, a result consistent with the required role for E2A in B cell development. We also demonstrated the effectiveness of Cre-mediated chromosome deletion in the LOH assay for HEB function in T cell development. Thus, the Cre-mediated chromosome deletion provides a new and effective method for genome-wide assessment of germ line mutations in the lymphoid system.

Authors
Zhu, Y; Kim, Y-M; Li, S; Zhuang, Y
MLA Citation
Zhu, Y, Kim, Y-M, Li, S, and Zhuang, Y. "Generation and analysis of partially haploid cells with Cre-mediated chromosome deletion in the lymphoid system." J Biol Chem 285.34 (August 20, 2010): 26005-26012.
PMID
20551312
Source
pubmed
Published In
The Journal of biological chemistry
Volume
285
Issue
34
Publish Date
2010
Start Page
26005
End Page
26012
DOI
10.1074/jbc.M110.139196

Disruption of lysosome function promotes tumor growth and metastasis in Drosophila.

Lysosome function is essential to many physiological processes. It has been suggested that deregulation of lysosome function could contribute to cancer. Through a genetic screen in Drosophila, we have discovered that mutations disrupting lysosomal degradation pathway components contribute to tumor development and progression. Loss-of-function mutations in the Class C vacuolar protein sorting (VPS) gene, deep orange (dor), dramatically promote tumor overgrowth and invasion of the Ras(V12) cells. Knocking down either of the two other components of the Class C VPS complex, carnation (car) and vps16A, also renders Ras(V12) cells capable for uncontrolled growth and metastatic behavior. Finally, chemical disruption of the lysosomal function by feeding animals with antimalarial drugs, chloroquine or monensin, leads to malignant tumor growth of the Ras(V12) cells. Taken together, our data provide evidence for a causative role of lysosome dysfunction in tumor growth and invasion and indicate that members of the Class C VPS complex behave as tumor suppressors.

Authors
Chi, C; Zhu, H; Han, M; Zhuang, Y; Wu, X; Xu, T
MLA Citation
Chi, C, Zhu, H, Han, M, Zhuang, Y, Wu, X, and Xu, T. "Disruption of lysosome function promotes tumor growth and metastasis in Drosophila." J Biol Chem 285.28 (July 9, 2010): 21817-21823.
PMID
20418542
Source
pubmed
Published In
The Journal of biological chemistry
Volume
285
Issue
28
Publish Date
2010
Start Page
21817
End Page
21823
DOI
10.1074/jbc.M110.131714

Endothelial SUR-8 acts in an ERK-independent pathway during atrioventricular cushion development.

SUR-8, a conserved leucine-rich repeats protein, was first identified as a positive regulator of Ras pathway in Caenorhabditis elegans. Biochemical studies indicated that SUR-8 interacts with Ras and Raf, leading to the elevated ERK activity. However, the physiological role of SUR-8 during mammalian development remains unclear. Here we found that germline deletion of SUR-8 in mice resulted in early embryonic lethality. Inactivated SUR-8 specifically in mouse endothelial cells (ECs) revealed that SUR-8 is essential for embryonic heart development. SUR-8 deficiency in ECs resulted in late embryonic lethality, and the mutant mice displayed multiple cardiac defects. The reduced endothelial-mesenchymal transformation (EMT) and the reduced mesenchyme proliferation phase were observed in the atrioventricular canal (AVC) within the mutant hearts, leading to the formation of hypoplastic endocardial cushions. However, ERK activation did not appear to be affected in mutant ECs, suggesting that SUR-8 may act in an ERK-independent pathway to regulate AVC development.

Authors
Yi, J; Chen, M; Wu, X; Yang, X; Xu, T; Zhuang, Y; Han, M; Xu, R
MLA Citation
Yi, J, Chen, M, Wu, X, Yang, X, Xu, T, Zhuang, Y, Han, M, and Xu, R. "Endothelial SUR-8 acts in an ERK-independent pathway during atrioventricular cushion development." Dev Dyn 239.7 (July 2010): 2005-2013.
PMID
20549726
Source
pubmed
Published In
Developmental Dynamics
Volume
239
Issue
7
Publish Date
2010
Start Page
2005
End Page
2013
DOI
10.1002/dvdy.22343

SUN1/2 and Syne/Nesprin-1/2 complexes connect centrosome to the nucleus during neurogenesis and neuronal migration in mice.

Nuclear movement is critical during neurogenesis and neuronal migration, which are fundamental for mammalian brain development. Although dynein, Lis1, and other cytoplasmic proteins are known for their roles in connecting microtubules to the nucleus during interkinetic nuclear migration (INM) and nucleokinesis, the factors connecting dynein/Lis1 to the nuclear envelope (NE) remain to be determined. We report here that the SUN-domain proteins SUN1 and SUN2 and the KASH-domain proteins Syne-1/Nesprin-1 and Syne-2/Nesprin-2 play critical roles in neurogenesis and neuronal migration in mice. We show that SUN1 and SUN2 redundantly form complexes with Syne-2 to mediate the centrosome-nucleus coupling during both INM and radial neuronal migration in the cerebral cortex. Syne-2 is connected to the centrosome through interactions with both dynein/dynactin and kinesin complexes. Syne-2 mutants also display severe defects in learning and memory. These results fill an important gap in our understanding of the mechanism of nuclear movement during brain development.

Authors
Zhang, X; Lei, K; Yuan, X; Wu, X; Zhuang, Y; Xu, T; Xu, R; Han, M
MLA Citation
Zhang, X, Lei, K, Yuan, X, Wu, X, Zhuang, Y, Xu, T, Xu, R, and Han, M. "SUN1/2 and Syne/Nesprin-1/2 complexes connect centrosome to the nucleus during neurogenesis and neuronal migration in mice." Neuron 64.2 (October 29, 2009): 173-187.
PMID
19874786
Source
pubmed
Published In
Neuron
Volume
64
Issue
2
Publish Date
2009
Start Page
173
End Page
187
DOI
10.1016/j.neuron.2009.08.018

Ras promotes cell survival by antagonizing both JNK and Hid signals in the Drosophila eye.

BACKGROUND: Programmed cell death, or apoptosis, is a fundamental physiological process during normal development or in pathological conditions. The activation of apoptosis can be elicited by numerous signalling pathways. Ras is known to mediate anti-apoptotic signals by inhibiting Hid activity in the Drosophila eye. Here we report the isolation of a new loss-of-function ras allele, rasKP, which causes excessive apoptosis in the Drosophila eye. RESULTS: This new function is likely to be mediated through the JNK pathway since the inhibition of JNK signalling can significantly suppress rasKP-induced apoptosis, whereas the removal of hid only weakly suppresses the phenotype. Furthermore, the reduction of JNK signalling together with the expression of the baculovirus caspase inhibitor p35, which blocks Hid activity, strongly suppresses the rasKP cell death. In addition, we find a strong correlation between rasKP-induced apoptosis in the eye disc and the activation of JNK signalling. CONCLUSION: In the Drosophila eye, Ras may protect cells from apoptosis by inhibiting both JNK and Hid activities. Surprisingly, reducing Ras activity in the wing, however, does not cause apoptosis but rather affects cell and organ size. Thus, in addition to its requirement for cell viability, Ras appears to mediate different biological roles depending on the developmental context and on the level of its expression.

Authors
Wu, Y; Zhuang, Y; Han, M; Xu, T; Deng, K
MLA Citation
Wu, Y, Zhuang, Y, Han, M, Xu, T, and Deng, K. "Ras promotes cell survival by antagonizing both JNK and Hid signals in the Drosophila eye. (Published online)" BMC Dev Biol 9 (October 20, 2009): 53-.
PMID
19840402
Source
pubmed
Published In
BMC Developmental Biology
Volume
9
Publish Date
2009
Start Page
53
DOI
10.1186/1471-213X-9-53

A tamoxifen inducible knock-in allele for investigation of E2A function.

BACKGROUND: E-proteins are transcription factors important for the development of a variety of cell types, including neural, muscle and lymphocytes of the immune system. E2A, the best characterized E-protein family member in mammals, has been shown to have stage specific roles in cell differentiation, lineage commitment, proliferation, and survival. However, due to the complexity of E2A function, it is often difficult to separate these roles using conventional genetic approaches. Here, we have developed a new genetic model for reversible control of E2A protein activity at physiological levels. This system was created by inserting a tamoxifen-responsive region of the estrogen receptor (ER) at the carboxyl end of the tcfe2a gene to generate E2AER fusion proteins. We have characterized and analyzed the efficiency and kinetics of this inducible E2AER system in the context of B cell development. RESULTS: B cell development has been shown previously to be blocked at an early stage in E2A deficient animals. Our E2AER/ER mice demonstrated this predicted block in B cell development, and E2AER DNA binding activity was not detected in the absence of ligand. In vitro studies verified rapid induction of E2AER DNA binding activity upon tamoxifen treatment. While tamoxifen treatment of E2AER/ER mice showed inefficient rescue of B cell development in live animals, direct exposure of bone marrow cells to tamoxifen in an ex vivo culture was sufficient to rescue and support early B cell development from the pre-proB cell stage. CONCLUSION: The E2AER system provides inducible and reversible regulation of E2A function at the protein level. Many previous studies have utilized over-expression systems to induce E2A function, which are complicated by the toxicity often resulting from high levels of E2A. The E2AER model instead restores E2A activity at an endogenous level and in addition, allows for tight regulation of the timing of induction. These features make our E2AER ex vivo culture system attractive to study both immediate and gradual downstream E2A-mediated events.

Authors
Jones, ME; Kondo, M; Zhuang, Y
MLA Citation
Jones, ME, Kondo, M, and Zhuang, Y. "A tamoxifen inducible knock-in allele for investigation of E2A function. (Published online)" BMC Dev Biol 9 (October 12, 2009): 51-.
PMID
19822014
Source
pubmed
Published In
BMC Developmental Biology
Volume
9
Publish Date
2009
Start Page
51
DOI
10.1186/1471-213X-9-51

C-terminal deletion of the atrophin-1 protein results in growth retardation but not neurodegeneration in mice.

Dentatorubral-pallidoluysian atrophy (DRPLA) is a dominant hereditary neurodegenerative disorder caused by the expansion of a poly-glutamine (poly-Q) repeat in Atrophin-1 protein. Ectopic expression of a poly-Q expanded human Atrophin-1 is sufficient to induce DRPLA phenotypes in mice. However, it is still unclear whether the dominant effect of poly-Q expansion is due to the functional interference with wild-type Atrophin-1 proteins, which exist in both patients and transgenic mice. Here we report the generation and analysis of an Atrophin-1 targeting allele that expresses a truncated protein lacking both the poly-Q repeat and following C-terminal peptides. Homozygous mutants exhibit growth retardation and progressive male infertility, but no obvious signs of neurodegeneration. Moreover, the mutant allele neither blocked nor enhanced the neurodegenerative phenotypes caused by a poly-Q expanded transgene. These results support the model that poly-Q expanded Atrophin-1 proteins cause DRPLA in a manner independent of any functional interaction with wild-type Atrophin-1 proteins.

Authors
Yu, J; Ying, M; Zhuang, Y; Xu, T; Han, M; Wu, X; Xu, R
MLA Citation
Yu, J, Ying, M, Zhuang, Y, Xu, T, Han, M, Wu, X, and Xu, R. "C-terminal deletion of the atrophin-1 protein results in growth retardation but not neurodegeneration in mice." Dev Dyn 238.10 (October 2009): 2471-2478.
PMID
19681162
Source
pubmed
Published In
Developmental Dynamics
Volume
238
Issue
10
Publish Date
2009
Start Page
2471
End Page
2478
DOI
10.1002/dvdy.22063

A cell-intrinsic role for Mst1 in regulating thymocyte egress.

The MST1 kinase was recently identified as playing an essential role in the promotion of lymphocyte polarization and adhesion stimulated by chemokines and TCR signaling. However, the physiological relevance of the Mst1 pathway in thymocyte development is not completely understood. In this study, we analyzed the effect of Mst1 disruption on thymocyte development and migration. Mst1-deficient (Mst1(-/-)) mice displayed an accumulation of mature thymocytes in the thymus, a dramatic reduction of lymphocytes in blood and peripheral lymphoid tissues, and a decrease of homing ability to peripheral lymph nodes. Mst1(-/-) thymocytes were impaired in chemotactic response to chemokines, such as CCL19, but not to sphingosine-1-phosphate. Further analyses of Mst1(-/-) mice revealed a severe impairment in the egress of mature T cells from the thymus. T lineage-specific knockout of the Mst1 gene demonstrates a cell-intrinsic role for Mst1 in regulating T cell development. Our study indicates that Mst1 is crucial in controlling lymphocyte chemotaxis and thymocyte emigration.

Authors
Dong, Y; Du, X; Ye, J; Han, M; Xu, T; Zhuang, Y; Tao, W
MLA Citation
Dong, Y, Du, X, Ye, J, Han, M, Xu, T, Zhuang, Y, and Tao, W. "A cell-intrinsic role for Mst1 in regulating thymocyte egress." J Immunol 183.6 (September 15, 2009): 3865-3872.
PMID
19692642
Source
pubmed
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
183
Issue
6
Publish Date
2009
Start Page
3865
End Page
3872
DOI
10.4049/jimmunol.0900678

Pre-TCR signaling inactivates Notch1 transcription by antagonizing E2A.

Precise control of the timing and magnitude of Notch signaling is essential for the normal development of many tissues, but the feedback loops that regulate Notch are poorly understood. Developing T cells provide an excellent context to address this issue. Notch1 signals initiate T-cell development and increase in intensity during maturation of early T-cell progenitors (ETP) to the DN3 stage. As DN3 cells undergo beta-selection, during which cells expressing functionally rearranged TCRbeta proliferate and differentiate into CD4(+)CD8(+) progeny, Notch1 signaling is abruptly down-regulated. In this report, we investigate the mechanisms that control Notch1 expression during thymopoiesis. We show that Notch1 and E2A directly regulate Notch1 transcription in pre-beta-selected thymocytes. Following successful beta-selection, pre-TCR signaling rapidly inhibits Notch1 transcription via signals that up-regulate Id3, an E2A inhibitor. Consistent with a regulatory role for Id3 in Notch1 down-regulation, post-beta-selected Id3-deficient thymocytes maintain Notch1 transcription, whereas enforced Id3 expression decreases Notch1 expression and abrogates Notch1-dependent T-cell survival. These data provide new insights into Notch1 regulation in T-cell progenitors and reveal a direct link between pre-TCR signaling and Notch1 expression during thymocyte development. Our findings also suggest new strategies for inhibiting Notch1 signaling in pathologic conditions.

Authors
Yashiro-Ohtani, Y; He, Y; Ohtani, T; Jones, ME; Shestova, O; Xu, L; Fang, TC; Chiang, MY; Intlekofer, AM; Blacklow, SC; Zhuang, Y; Pear, WS
MLA Citation
Yashiro-Ohtani, Y, He, Y, Ohtani, T, Jones, ME, Shestova, O, Xu, L, Fang, TC, Chiang, MY, Intlekofer, AM, Blacklow, SC, Zhuang, Y, and Pear, WS. "Pre-TCR signaling inactivates Notch1 transcription by antagonizing E2A." Genes Dev 23.14 (July 15, 2009): 1665-1676.
PMID
19605688
Source
pubmed
Published In
Genes & development
Volume
23
Issue
14
Publish Date
2009
Start Page
1665
End Page
1676
DOI
10.1101/gad.1793709

SUN1 and SUN2 play critical but partially redundant roles in anchoring nuclei in skeletal muscle cells in mice.

How the nuclei in mammalian skeletal muscle fibers properly position themselves relative to the cell body is an interesting and important cell biology question. In the syncytial skeletal muscle cells, more than 100 nuclei are evenly distributed at the periphery of each cell, with 3-8 nuclei anchored beneath the neuromuscular junction (NMJ). Our previous studies revealed that the KASH domain-containing Syne-1/Nesprin-1 protein plays an essential role in anchoring both synaptic and nonsynaptic myonuclei in mice. SUN domain-containing proteins (SUN proteins) have been shown to interact with KASH domain-containing proteins (KASH proteins) at the nuclear envelope (NE), but their roles in nuclear positioning in mice are unknown. Here we show that the synaptic nuclear anchorage is partially perturbed in Sun1, but not in Sun2, knockout mice. Disruption of 3 or all 4 Sun1/2 wild-type alleles revealed a gene dosage effect on synaptic nuclear anchorage. The organization of nonsynaptic nuclei is disrupted in Sun1/2 double-knockout (DKO) mice as well. We further show that the localization of Syne-1 to the NE of muscle cells is disrupted in Sun1/2 DKO mice. These results clearly indicate that SUN1 and SUN2 function critically in skeletal muscle cells for Syne-1 localization at the NE, which is essential for proper myonuclear positioning.

Authors
Lei, K; Zhang, X; Ding, X; Guo, X; Chen, M; Zhu, B; Xu, T; Zhuang, Y; Xu, R; Han, M
MLA Citation
Lei, K, Zhang, X, Ding, X, Guo, X, Chen, M, Zhu, B, Xu, T, Zhuang, Y, Xu, R, and Han, M. "SUN1 and SUN2 play critical but partially redundant roles in anchoring nuclei in skeletal muscle cells in mice." Proc Natl Acad Sci U S A 106.25 (June 23, 2009): 10207-10212.
PMID
19509342
Source
pubmed
Published In
Proceedings of the National Academy of Sciences of USA
Volume
106
Issue
25
Publish Date
2009
Start Page
10207
End Page
10212
DOI
10.1073/pnas.0812037106

Id3 restricts the developmental potential of gamma delta lineage during thymopoiesis.

Most T cell progenitors develop into the alphabeta T cell lineage with the exception of a small fraction contributing to the gammadelta lineage throughout postnatal life. T cell progenitors usually commit to the alphabeta lineage upon the expression of a fully rearranged and functional TCRbeta gene, and most cells that fail to produce a functional TCRbeta-chain will die instead of adopting the alternative gammadelta T cell fate. What prevents these cells from continuing TCRgamma rearrangement and adopting the gammadelta T cell fate is not known. In this study, we show that functional loss of Id3 results in a significant increase of gammadelta T cell production from progenitor cells undergoing TCRbeta rearrangement. The enhanced gammadelta T cell development correlated with increased TCRgamma gene rearrangement involving primarily Vgamma1.1 in Id3 deficient mice. We further show that Id3 deficiency promotes gammadelta T cell production in a manner independent of TCRbeta-chain expression. Our data indicates that Id3 suppresses Vgamma1.1 rearrangement and gammadelta lineage potential among T cell progenitors that have completed TCRbeta gene rearrangement without producing a functional TCRbeta protein.

Authors
Ueda-Hayakawa, I; Mahlios, J; Zhuang, Y
MLA Citation
Ueda-Hayakawa, I, Mahlios, J, and Zhuang, Y. "Id3 restricts the developmental potential of gamma delta lineage during thymopoiesis." J Immunol 182.9 (May 1, 2009): 5306-5316.
PMID
19380777
Source
pubmed
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
182
Issue
9
Publish Date
2009
Start Page
5306
End Page
5316
DOI
10.4049/jimmunol.0804249

MEKK3 is essential for lymphopenia-induced T cell proliferation and survival.

T cell homeostasis is crucial for maintaining an efficient and balanced T cell immunity. The interaction between TCR and self peptide (sp) MHC ligands is known to be the key driving force in this process, and it is believed to be functionally and mechanistically different from that initiated by the antigenic TCR stimulation. Yet, very little is known about the downstream signaling events triggered by this TCR-spMHC interaction and how they differ from those triggered by antigenic TCR stimulation. In this study, we show that T cell conditional ablation of MEKK3, a Ser/Thr kinase in the MAPK cascade, causes a significant reduction in peripheral T cell numbers in the conditional knockout mice, but does not perturb thymic T cell development and maturation. Using an adoptive mixed transfer method, we show that MEKK3-deficient T cells are severely impaired in lymphopenia-induced cell proliferation and survival. Interestingly, the Ag-induced T cell proliferation proceeds normally in the absence of MEKK3. Finally, we found that the activity of ERK1/2, but not p38 MAPK, was attenuated during the lymphopenia-driven response in MEKK3-deficient T cells. Together, these data suggest that MEKK3 may play a crucial selective role for spMHC-mediated T cell homeostasis.

Authors
Wang, X; Chang, X; Facchinetti, V; Zhuang, Y; Su, B
MLA Citation
Wang, X, Chang, X, Facchinetti, V, Zhuang, Y, and Su, B. "MEKK3 is essential for lymphopenia-induced T cell proliferation and survival." J Immunol 182.6 (March 15, 2009): 3597-3608.
PMID
19265138
Source
pubmed
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
182
Issue
6
Publish Date
2009
Start Page
3597
End Page
3608
DOI
10.4049/jimmunol.0803738

Regulation of V(D)J recombination by E-protein transcription factors.

Extensive study of the E-proteins E2A and HEB duringlymphocyte development has revealed various functions for these bHLH transcription factors in regulating V(D)J recombination in both B- and T-cells. The study of E-proteins in mammals began with the identification of E2A by its ability to bind immunoglobulin heavy and light chain enhancers. Subsequent analysis has identified numerous roles for E2A and HEB at the immunoglobulin and T-cell receptor loci. E-protein targets also include the rag genes and other factors critical for recombination and for regulation of the developmental windows when cells undergo recombination. E-proteins appear to be master regulators that coordinate antigen receptor gene rearrangement and expression. This chapter focuses on how E-proteins regulate V(D)J recombination by activating transcription, initiating rearrangement and driving differentiation during B- and T-cell development.

Authors
Jones, ME; Zhuang, Y
MLA Citation
Jones, ME, and Zhuang, Y. "Regulation of V(D)J recombination by E-protein transcription factors." Adv Exp Med Biol 650 (2009): 148-156. (Review)
PMID
19731808
Source
pubmed
Published In
Advances in experimental medicine and biology
Volume
650
Publish Date
2009
Start Page
148
End Page
156

A large-scale functional approach to uncover human genes and pathways in Drosophila.

We demonstrate the feasibility of performing a systematic screen for human gene functions in Drosophila by assaying for their ability to induce overexpression phenotypes. Over 1 500 transgenic fly lines corresponding to 236 human genes have been established. In all, 51 lines are capable of eliciting a phenotype suggesting that the human genes are functional. These heterologous genes are functionally relevant as we have found a similar mutant phenotype caused either by a dominant negative mutant form of the human ribosomal protein L8 gene or by RNAi downregulation of the Drosophila RPL8. Significantly, the Drosophila RPL8 mutant can be rescued by wild-type human RPL8. We also provide genetic evidence that Drosophila RPL8 is a new member of the insulin signaling pathway. In summary, the functions of many human genes appear to be highly conserved, and the ability to identify them in Drosophila represents a powerful genetic tool for large-scale analysis of human transcripts in vivo.

Authors
Xu, R; Deng, K; Zhu, Y; Wu, Y; Ren, J; Wan, M; Zhao, S; Wu, X; Han, M; Zhuang, Y; Xu, T
MLA Citation
Xu, R, Deng, K, Zhu, Y, Wu, Y, Ren, J, Wan, M, Zhao, S, Wu, X, Han, M, Zhuang, Y, and Xu, T. "A large-scale functional approach to uncover human genes and pathways in Drosophila." Cell Res 18.11 (November 2008): 1114-1127.
PMID
18957936
Source
pubmed
Published In
Cell Research
Volume
18
Issue
11
Publish Date
2008
Start Page
1114
End Page
1127
DOI
10.1038/cr.2008.295

Transcription factor E2-2 is an essential and specific regulator of plasmacytoid dendritic cell development.

Plasmacytoid dendritic cells (PDCs) represent a unique immune cell type specialized in type I interferon (IFN) secretion in response to viral nucleic acids. The molecular control of PDC lineage specification has been poorly understood. We report that basic helix-loop-helix transcription factor (E protein) E2-2/Tcf4 is preferentially expressed in murine and human PDCs. Constitutive or inducible deletion of murine E2-2 blocked the development of PDCs but not of other lineages and abolished IFN response to unmethylated DNA. Moreover, E2-2 haploinsufficiency in mice and in human Pitt-Hopkins syndrome patients was associated with aberrant expression profile and impaired IFN response of the PDC. E2-2 directly activated multiple PDC-enriched genes, including transcription factors involved in PDC development (SpiB, Irf8) and function (Irf7). These results identify E2-2 as a specific transcriptional regulator of the PDC lineage in mice and humans and reveal a key function of E proteins in the innate immune system.

Authors
Cisse, B; Caton, ML; Lehner, M; Maeda, T; Scheu, S; Locksley, R; Holmberg, D; Zweier, C; den Hollander, NS; Kant, SG; Holter, W; Rauch, A; Zhuang, Y; Reizis, B
MLA Citation
Cisse, B, Caton, ML, Lehner, M, Maeda, T, Scheu, S, Locksley, R, Holmberg, D, Zweier, C, den Hollander, NS, Kant, SG, Holter, W, Rauch, A, Zhuang, Y, and Reizis, B. "Transcription factor E2-2 is an essential and specific regulator of plasmacytoid dendritic cell development." Cell 135.1 (October 3, 2008): 37-48.
PMID
18854153
Source
pubmed
Published In
Cell
Volume
135
Issue
1
Publish Date
2008
Start Page
37
End Page
48
DOI
10.1016/j.cell.2008.09.016

E proteins are required to activate germline transcription of the TCR Vbeta8.2 gene.

Each TCR Vbeta gene is regulated by an individual Vbeta promoter, which becomes active prior to V(D) J recombination and drives germline transcription. It has been shown that Vbeta gene locus activation and recombination are dependent on the Vbeta promoter. However, transcription factors that regulate Vbeta germline transcription remain largely undefined. A major challenge in studying Vbeta gene germline transcription is the quantitative assessment of relatively low-level transcripts in T-cell progenitors. Here we used the established Vbeta8.2(CD2) knock-in mouse model to assess functions of E-protein transcription factors in Vbeta8.2 germline transcription. We show that E proteins are required for the activation but not the maintenance of the Vbeta8.2 germline transcription during thymocyte development. The activation of Vbeta8.2 germline transcription depends more on the E proteins encoded by the E2A gene than by the HEB gene. We further show that IL-7 receptor (IL-7R)-mediated signals are essential for Vbeta8.2 germline transcription. We provide evidence that IL-7R expression is only partially controlled by E2A, suggesting a role for E2A in driving Vbeta8.2 germline transcription independent of IL-7R activation.

Authors
Jia, J; Dai, M; Zhuang, Y
MLA Citation
Jia, J, Dai, M, and Zhuang, Y. "E proteins are required to activate germline transcription of the TCR Vbeta8.2 gene." Eur J Immunol 38.10 (October 2008): 2806-2820.
PMID
18958875
Source
pubmed
Published In
European Journal of Immunology
Volume
38
Issue
10
Publish Date
2008
Start Page
2806
End Page
2820
DOI
10.1002/eji.200838144

ADAM10 is essential for proteolytic activation of Notch during thymocyte development.

Notch signaling pathway has been shown to play essential roles in T lymphocyte development. Activation of Notch requires a sequential proteolytic cleavage, which converts Notch from the full-length membrane-bound form to a transcriptionally active intracellular fragment. Studies in Drosophila showed that Kuzbanian (Kuz) is responsible for the enzymatic cleavage of extracellular S2 site upon Notch binding to its ligand Delta. Both a disintegrin and metalloprotease (ADAM) 10 and ADAM17, members of the ADAM family metalloproteases, have been indicated as the mammalian counterpart of Kuz in activating Notch in mammals. Here, we investigated functions of ADAM10 in Notch signaling during thymocyte development. We show that conditional disruption of the Adam10 gene in mouse thymocytes results in a developmental defect similar to the phenotypes previously described for T lineage-specific disruption of Notch1. We further show that the activation of Notch1 and its downstream target genes Deltex-1 and Pre-Ta are impaired in Adam10-deficient thymocytes. Our study demonstrates a T cell intrinsic role for Adam10 in activation of Notch1 during thymocyte development.

Authors
Tian, L; Wu, X; Chi, C; Han, M; Xu, T; Zhuang, Y
MLA Citation
Tian, L, Wu, X, Chi, C, Han, M, Xu, T, and Zhuang, Y. "ADAM10 is essential for proteolytic activation of Notch during thymocyte development." Int Immunol 20.9 (September 2008): 1181-1187.
PMID
18635581
Source
pubmed
Published In
International Immunology
Volume
20
Issue
9
Publish Date
2008
Start Page
1181
End Page
1187
DOI
10.1093/intimm/dxn076

Id3 controls the developmental window of gamma delta T Cells

Authors
Hayakawa, I; Zhuang, Y
MLA Citation
Hayakawa, I, and Zhuang, Y. "Id3 controls the developmental window of gamma delta T Cells." April 2008.
Source
wos-lite
Published In
Journal of Investigative Dermatology
Volume
128
Publish Date
2008
Start Page
S163
End Page
S163

HEB and E2A enforce TCR checkpoint in T lymphocyte development

Authors
Zhuang, Y; Jones, ME
MLA Citation
Zhuang, Y, and Jones, ME. "HEB and E2A enforce TCR checkpoint in T lymphocyte development." FASEB JOURNAL 22 (April 2008).
Source
wos-lite
Published In
The FASEB journal : official publication of the Federation of American Societies for Experimental Biology
Volume
22
Publish Date
2008

Id3 controls the developmental window of gamma delta T cells

Authors
Hayakawa, I; Zhuang, Y
MLA Citation
Hayakawa, I, and Zhuang, Y. "Id3 controls the developmental window of gamma delta T cells." FASEB JOURNAL 22 (April 2008).
Source
wos-lite
Published In
The FASEB journal : official publication of the Federation of American Societies for Experimental Biology
Volume
22
Publish Date
2008

A mitotic recombination system for mouse chromosome 17.

Mitotic recombination between homologous chromosomes is a genetic technique for mosaic analysis in model organisms. The general application of this technique in the mouse depends on establishment of effective recombination systems for individual chromosomes and reliable and sensitive methods for detection of recombination events. Here, we established a Cre/LoxP-mediated recombination system in mice for mosaic analysis of full-length chromosome 17. Cre-mediated germ-line recombination between the homologous chromosomes was observed with approximately 9% frequency in a progeny test. Mitotic recombination in somatic tissues was evaluated and scored in B and T lymphocytes with the aid of surface markers and fluorescent-activated cell sorting. We show that a lineage-specific Cre can induce mitotic recombination with a highly reproducible frequency of 0.5-1.0% in lymphoid progenitors. The recombination system established here allows for a simple and accurate detection and isolation of recombination events in live cells, making this system particularly attractive for mosaic analysis or mutagenesis studies in the immune system.

Authors
Sun, L; Wu, X; Han, M; Xu, T; Zhuang, Y
MLA Citation
Sun, L, Wu, X, Han, M, Xu, T, and Zhuang, Y. "A mitotic recombination system for mouse chromosome 17." Proc Natl Acad Sci U S A 105.11 (March 18, 2008): 4237-4241.
PMID
18326030
Source
pubmed
Published In
Proceedings of the National Academy of Sciences of USA
Volume
105
Issue
11
Publish Date
2008
Start Page
4237
End Page
4241
DOI
10.1073/pnas.0800798105

PBmice: an integrated database system of piggyBac (PB) insertional mutations and their characterizations in mice.

DNA transposon piggyBac (PB) is a newly established mutagen for large-scale mutagenesis in mice. We have designed and implemented an integrated database system called PBmice (PB Mutagenesis Information CEnter) for storing, retrieving and displaying the information derived from PB insertions (INSERTs) in the mouse genome. This system is centered on INSERTs with information including their genomic locations and flanking genomic sequences, the expression levels of the hit genes, and the expression patterns of the trapped genes if a trapping vector was used. It also archives mouse phenotyping data linked to INSERTs, and allows users to conduct quick and advanced searches for genotypic and phenotypic information relevant to a particular or a set of INSERT(s). Sequence-based information can be cross-referenced with other genomic databases such as Ensembl, BLAST and GBrowse tools used in PBmice offer enhanced search and display for additional information relevant to INSERTs. The total number and genomic distribution of PB INSERTs, as well as the availability of each PB insertional LINE can also be viewed with user-friendly interfaces. PBmice is freely available at http://www.idmshanghai.cn/PBmice or http://www.scbit.org/PBmice/.

Authors
Sun, LV; Jin, K; Liu, Y; Yang, W; Xie, X; Ye, L; Wang, L; Zhu, L; Ding, S; Su, Y; Zhou, J; Han, M; Zhuang, Y; Xu, T; Wu, X; Gu, N; Zhong, Y
MLA Citation
Sun, LV, Jin, K, Liu, Y, Yang, W, Xie, X, Ye, L, Wang, L, Zhu, L, Ding, S, Su, Y, Zhou, J, Han, M, Zhuang, Y, Xu, T, Wu, X, Gu, N, and Zhong, Y. "PBmice: an integrated database system of piggyBac (PB) insertional mutations and their characterizations in mice." Nucleic Acids Res 36.Database issue (January 2008): D729-D734.
PMID
17932058
Source
pubmed
Published In
Nucleic Acids Research
Volume
36
Issue
Database issue
Publish Date
2008
Start Page
D729
End Page
D734
DOI
10.1093/nar/gkm790

Acquisition of a functional T cell receptor during T lymphocyte development is enforced by HEB and E2A transcription factors.

The T cell receptor (TCR) is required for positive selection and the subsequent transition from the CD4(+)CD8(+) double-positive (DP) to the CD4(+) or CD8(+) single-positive (SP) stage of alphabeta T cell development. The molecular mechanism that maintains DP fate prior to the acquisition of a functional TCR is not clear. We have shown here that the structurally and functionally related transcription factors HEB and E2A work together to maintain DP fate and to control the DP to SP transition. Simultaneous deletion of HEB and E2A in DP thymocytes was sufficient for DP to SP transition independent of TCR. Loss of HEB and E2A allowed DP cells to bypass the requirement for TCR-mediated positive selection, downregulate DP-associated genes, and upregulate SP-specific genes. These results identify HEB and E2A as the gatekeepers that maintain cells at the DP stage of development until a functional alphabetaTCR is produced.

Authors
Jones, ME; Zhuang, Y
MLA Citation
Jones, ME, and Zhuang, Y. "Acquisition of a functional T cell receptor during T lymphocyte development is enforced by HEB and E2A transcription factors." Immunity 27.6 (December 2007): 860-870.
PMID
18093538
Source
pubmed
Published In
Immunity
Volume
27
Issue
6
Publish Date
2007
Start Page
860
End Page
870
DOI
10.1016/j.immuni.2007.10.014

B-lymphocyte depletion ameliorates Sjögren's syndrome in Id3 knockout mice.

Sjögren's syndrome is an autoimmune disease in which immune cells chronically attack the lachrymal and salivary glands. The Id3 knockout mouse is a newly established animal model for primary Sjögren's syndrome. To address the role of B cells in Sjögren's syndrome and autoimmune disease, we studied the effect of CD20 monoclonal antibody treatment on the disease in Id3 knockout mice. Antibody treatment at 2-month intervals led to efficient and sustained B-cell depletion in Id3 knockout mice. A significant improvement of histopathology was observed accompanied by the recovery of saliva secretory function after CD20 antibody treatment. We further show that serum immunoglobulin G3, which is abnormally high in untreated Id3 knockout mice, was reduced after CD20 antibody treatment. This study establishes a new animal model for immunotherapy of Sjögren's symptoms and suggests a possible link between immunoglobulin G3 and disease pathology in Id3 knockout mice.

Authors
Hayakawa, I; Tedder, TF; Zhuang, Y
MLA Citation
Hayakawa, I, Tedder, TF, and Zhuang, Y. "B-lymphocyte depletion ameliorates Sjögren's syndrome in Id3 knockout mice." Immunology 122.1 (September 2007): 73-79.
PMID
17472721
Source
pubmed
Published In
Immunology
Volume
122
Issue
1
Publish Date
2007
Start Page
73
End Page
79
DOI
10.1111/j.1365-2567.2007.02614.x

SUN1 is required for telomere attachment to nuclear envelope and gametogenesis in mice.

Prior to the pairing and recombination between homologous chromosomes during meiosis, telomeres attach to the nuclear envelope and form a transient cluster. However, the protein factors mediating meiotic telomere attachment to the nuclear envelope and the requirement of this attachment for homolog pairing and synapsis have not been determined in animals. Here we show that the inner nuclear membrane protein SUN1 specifically associates with telomeres between the leptotene and diplotene stages during meiotic prophase I. Disruption of Sun1 in mice prevents telomere attachment to the nuclear envelope, efficient homolog pairing, and synapsis formation in meiosis. Massive apoptotic events are induced in the mutant gonads, leading to the abolishment of both spermatogenesis and oogenesis. This study provides genetic evidence that SUN1-telomere interaction is essential for telomere dynamic movement and is required for efficient homologous chromosome pairing/synapsis during mammalian gametogenesis.

Authors
Ding, X; Xu, R; Yu, J; Xu, T; Zhuang, Y; Han, M
MLA Citation
Ding, X, Xu, R, Yu, J, Xu, T, Zhuang, Y, and Han, M. "SUN1 is required for telomere attachment to nuclear envelope and gametogenesis in mice." Dev Cell 12.6 (June 2007): 863-872.
PMID
17543860
Source
pubmed
Published In
Developmental Cell
Volume
12
Issue
6
Publish Date
2007
Start Page
863
End Page
872
DOI
10.1016/j.devcel.2007.03.018

Germline transcription from T-cell receptor Vbeta gene is uncoupled from allelic exclusion.

Allelic exclusion operates in B and T lymphocytes to ensure clonal expression of antigen receptors after V(D)J recombination. Germline transcription, which proceeds V(D)J recombination, has been postulated to provide an instructive signal for allelic exclusion. Here, we use a genetic marker to track germline transcription from a Vbeta gene within the TCRbeta locus. We find that developing thymocytes exhibit uniformed, bi-allelic activation of the Vbeta gene before V-DJ recombination, a process subject to allelic exclusion. We further show that V-DJ rearrangement promotes activation rather than silencing of germline transcription from the remaining Vbeta genes on either the functionally or non-functionally rearranged chromosome. Results presented here suggest that germline transcription, although necessary for V(D)J recombination, is not sufficient to instruct allelic exclusion.

Authors
Jia, J; Kondo, M; Zhuang, Y
MLA Citation
Jia, J, Kondo, M, and Zhuang, Y. "Germline transcription from T-cell receptor Vbeta gene is uncoupled from allelic exclusion." EMBO J 26.9 (May 2, 2007): 2387-2399.
PMID
17410206
Source
pubmed
Published In
EMBO Journal
Volume
26
Issue
9
Publish Date
2007
Start Page
2387
End Page
2399
DOI
10.1038/sj.emboj.7601671

E2A and HEB are required to block thymocyte proliferation prior to pre-TCR expression.

Thymocytes undergoing TCRbeta gene rearrangements are maintained in a low or nonproliferating state during early T cell development. This block in cell cycle progression is not released until the expression of a functional pre-TCR, which is composed of a successfully rearranged TCRbeta-chain and the Pre-Talpha-chain. The regulatory molecules responsible for the coordination of these differentiation and proliferation events are currently unknown. E2A and HEB are structurally and functionally related basic helix-loop-helix transcription factors involved in T cell development. To reveal the function of E2A and HEB through the stage of pre-TCR expression and alleviate functional compensation between E2A and HEB, we use a double-conditional knockout model. The simultaneous deletion of E2A and HEB in developing thymocytes leads to a severe developmental block before pre-TCR expression and a dramatic reduction of Pre-Talpha expression. These developmentally arrested thymocytes exhibit increased proliferation in vivo and dramatic expansion ex vivo in response to IL-7 signaling. These results suggest that E2A and HEB are not only critical for T cell differentiation but also necessary to retain developing thymocytes in cell cycle arrest before pre-TCR expression.

Authors
Wojciechowski, J; Lai, A; Kondo, M; Zhuang, Y
MLA Citation
Wojciechowski, J, Lai, A, Kondo, M, and Zhuang, Y. "E2A and HEB are required to block thymocyte proliferation prior to pre-TCR expression." J Immunol 178.9 (May 1, 2007): 5717-5726.
PMID
17442955
Source
pubmed
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
178
Issue
9
Publish Date
2007
Start Page
5717
End Page
5726

Syne-1 and Syne-2 play crucial roles in myonuclear anchorage and motor neuron innervation.

Proper nuclear positioning is important to cell function in many biological processes during animal development. In certain cells, the KASH-domain-containing proteins have been shown to be associated with the nuclear envelope, and to be involved in both nuclear anchorage and migration. We investigated the mechanism and function of nuclear anchorage in skeletal muscle cells by generating mice with single and double-disruption of the KASH-domain-containing genes Syne1 (also known as Syne-1) and Syne2 (also known as Syne-2). We showed that the deletion of the KASH domain of Syne-1 abolished the formation of clusters of synaptic nuclei and disrupted the organization of non-synaptic nuclei in skeletal muscle. Further analysis indicated that the loss of synaptic nuclei in Syne-1 KASH-knockout mice significantly affected the innervation sites and caused longer motor nerve branches. Although disruption of neither Syne-1 nor Syne-2 affected viability or fertility, Syne-1; Syne-2 double-knockout mice died of respiratory failure within 20 minutes of birth. These results suggest that the KASH-domain-containing proteins Syne-1 and Syne-2 play crucial roles in anchoring both synaptic and non-synaptic myonuclei that are important for proper motor neuron innervation and respiration.

Authors
Zhang, X; Xu, R; Zhu, B; Yang, X; Ding, X; Duan, S; Xu, T; Zhuang, Y; Han, M
MLA Citation
Zhang, X, Xu, R, Zhu, B, Yang, X, Ding, X, Duan, S, Xu, T, Zhuang, Y, and Han, M. "Syne-1 and Syne-2 play crucial roles in myonuclear anchorage and motor neuron innervation." Development 134.5 (March 2007): 901-908.
PMID
17267447
Source
pubmed
Published In
Development (Cambridge)
Volume
134
Issue
5
Publish Date
2007
Start Page
901
End Page
908
DOI
10.1242/dev.02783

Muscle atrophy in transgenic mice expressing a human TSC1 transgene.

Muscle mass is regulated by a wide range of hormonal and nutritional signals, such as insulin and IGF. Tuberous sclerosis complex (TSC) is an inherited hamartoma disease with tumor growth in numerous organs. TSC is caused by mutation in either TSC1 or TSC2 tumor suppressor genes that negatively regulate insulin-induced S6K activation and cell growth. Here we report that expression of human TSC1 (hTSC1) in mouse skeletal muscle leads to reduction of muscle mass. Expression of hTSC1 stabilizes endogenous TSC2 and leads to inhibition of the mTOR signaling. The hTSC1-mTSC2 hetero-complex and its downstream components remain sensitive to insulin stimulation and nutrition signals. This study suggests that an increase in the steady state level of resident TSC1-TSC2 complex is sufficient to reduce muscle mass and cause atrophy.

Authors
Wan, M; Wu, X; Guan, K-L; Han, M; Zhuang, Y; Xu, T
MLA Citation
Wan, M, Wu, X, Guan, K-L, Han, M, Zhuang, Y, and Xu, T. "Muscle atrophy in transgenic mice expressing a human TSC1 transgene." FEBS Lett 580.24 (October 16, 2006): 5621-5627.
PMID
16996505
Source
pubmed
Published In
FEBS Letters
Volume
580
Issue
24
Publish Date
2006
Start Page
5621
End Page
5627
DOI
10.1016/j.febslet.2006.09.008

E2A promotes the survival of precursor and mature B lymphocytes.

The basic helix-loop-helix transcription factor E2A is an essential regulator of B lymphocyte lineage commitment and is required to activate the expression of numerous B lineage-specific genes. Studies involving ectopic expression of Id proteins, which inhibit E2A as well as other basic helix-loop-helix proteins such as HEB, suggest additional roles of E2A at later stages of B cell development. We use E2A-deficient and E2A and HEB double-deficient pre-B cell lines to directly assess the function of E2A and HEB in B cell development after lineage commitment. We show that, in contrast to the established role of E2A in lineage commitment, elimination of E2A and HEB in pre-B cell lines has only a modest negative impact on B lineage gene expression. However, E2A single and E2A and HEB double-deficient but not HEB single-deficient cell lines show dramatically enhanced apoptosis upon growth arrest. To address the possible role of E2A in the regulation of B cell survival in vivo, we crossed IFN-inducible Cre-transgenic mice to E2A conditional mice. Cre-mediated E2A deletion resulted in a block in bone marrow B cell development and a significant reduction in the proportion and total number of splenic B cells in these mice. We show that Cre-mediated deletion of E2A in adoptively transferred mature B cells results in the rapid depletion of the transferred population within 24 h of Cre induction. These results reveal that E2A is not required to maintain B cell fate but is essential in promoting pre-B and B cell survival.

Authors
Lazorchak, AS; Wojciechowski, J; Dai, M; Zhuang, Y
MLA Citation
Lazorchak, AS, Wojciechowski, J, Dai, M, and Zhuang, Y. "E2A promotes the survival of precursor and mature B lymphocytes." J Immunol 177.4 (August 15, 2006): 2495-2504.
PMID
16888011
Source
pubmed
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
177
Issue
4
Publish Date
2006
Start Page
2495
End Page
2504

Sodium butyrate ameliorates histone hypoacetylation and neurodegenerative phenotypes in a mouse model for DRPLA.

Dentatorubral-pallidoluysian atrophy (DRPLA) is a progressive neurodegenerative disease caused by polyglutamine expansion within the Atrophin-1 protein. To study the mechanism of this disease and to test potential therapeutic methods, we established Atro-118Q transgenic mice, which express in neurons a mutant human Atrophin-1 protein that contains an expanded stretch of 118 glutamines. Consistent with the results from previous studies on transgenic mice that expressed mutant Atrophin-1 with 65 glutamines, Atro-118Q mice exhibited several neurodegenerative phenotypes that are commonly seen in DRPLA patients, including ataxia, tremors, and other motor defects. Overexpression of wild-type human Atrophin-1 could not rescue the motor and survival defects in Atro-118Q mice, indicating that the mutant protein with polyglutamine expansion does not simply function in a dominant negative manner. Biochemical analysis of Atro-118Q mice revealed hypoacetylation of histone H3 in brain tissues and thus suggested that global gene repression is an underlying mechanism for neurodegeneration in this mouse model. We further show that intraperitoneal administration of sodium butyrate, a histone deacetylase inhibitor, ameliorated the histone acetylation defects, significantly improved motor performance, and extended the average life span of Atro-118Q mice. These results support the hypothesis that transcription deregulation plays an important role in the pathogenesis of polyglutamine expansion diseases and suggest that reversion of transcription repression with small molecules such as sodium butyrate is a feasible approach to treating DRPLA symptoms.

Authors
Ying, M; Xu, R; Wu, X; Zhu, H; Zhuang, Y; Han, M; Xu, T
MLA Citation
Ying, M, Xu, R, Wu, X, Zhu, H, Zhuang, Y, Han, M, and Xu, T. "Sodium butyrate ameliorates histone hypoacetylation and neurodegenerative phenotypes in a mouse model for DRPLA." J Biol Chem 281.18 (May 5, 2006): 12580-12586.
PMID
16407196
Source
pubmed
Published In
The Journal of biological chemistry
Volume
281
Issue
18
Publish Date
2006
Start Page
12580
End Page
12586
DOI
10.1074/jbc.M511677200

E2A and IRF-4/Pip promote chromatin modification and transcription of the immunoglobulin kappa locus in pre-B cells.

The immunoglobulin kappa light chain (Igkappa) locus is regulated in a lineage- and stage-specific manner during B-cell development. The highly restricted timing of V to J gene recombination at the pre-B-cell stage is under the control of two enhancers, the intronic enhancer (kappaEi) and the 3' enhancer (kappaE3'), flanking the constant exon. E2A transcription factors have been indicated to be directly involved in the regulation of Igkappa locus activation. In this study, we utilize E2A-deficient pre-B cells to directly investigate the mechanism of E2A-mediated Igkappa activation. We demonstrate that Igkappa germ line transcription is severely impaired and recombination is blocked in the absence of E2A. Reconstitution of E2A-/- pre-B cells with inducible human E2A (E47R) is sufficient to promote chromatin modification of Igkappa and rescue Igkappa germ line transcription and Jkappa gene recombinase accessibility. Furthermore, we show that increased E2A recruitment to kappaEi and kappaE3' correlates with activation of Igkappa in pre-B cells and that recruitment of E2A to kappaE3' is in part dependent on the transcription factor IRF-4. Inhibition of IRF-4 expression in pre-B cells leads to a significant reduction of Igkappa germ line transcription and enhancer acetylation. In the absence of E2A, increased IRF-4 expression is not sufficient to promote Igkappa enhancer chromatin modification or transcription, suggesting that the sequential involvement of IRF-4 and E2A is necessary for the activation of the Igkappa locus. Finally, we provide genetic evidence in the mouse that E2A gene dosage can influence the development of pre-B cells during the phase of Igkappa gene activation.

Authors
Lazorchak, AS; Schlissel, MS; Zhuang, Y
MLA Citation
Lazorchak, AS, Schlissel, MS, and Zhuang, Y. "E2A and IRF-4/Pip promote chromatin modification and transcription of the immunoglobulin kappa locus in pre-B cells." Mol Cell Biol 26.3 (February 2006): 810-821.
PMID
16428437
Source
pubmed
Published In
Molecular and Cellular Biology
Volume
26
Issue
3
Publish Date
2006
Start Page
810
End Page
821
DOI
10.1128/MCB.26.3.810-821.2006

The KASH domain protein MSP-300 plays an essential role in nuclear anchoring during Drosophila oogenesis.

During late stages of Drosophila oogenesis, the cytoplasm of nurse cells in the egg chamber is rapidly transferred ("dumped") to oocytes, while the nurse cell nuclei are anchored by a mechanism that involves the actin cytoskeleton. The factors that mediate this interaction between nuclei and actin cytoskeleton are unknown. MSP-300 is the likely Drosophila ortholog of the mammalian Syne-1 and -2 and C. elegans ANC-1 proteins, contained both actin-binding and nuclear envelope localization domains. By using an antibody against C-terminus of MSP-300, we find that MSP-300 is distributed throughout the cytoplasm and accumulates at the nuclear envelope of nurse cells and the oocyte. A GFP fusion protein containing the C-terminal region of MSP-300 is also sufficient to localize protein on the nuclear envelope in oocytes. To eliminate the maternal gene activity during oogenesis, we generated homozygous germ-line clones of a loss-of-function mutation in msp-300 in otherwise heterozygous mothers. In the mutant egg chambers that develop from such clones, cytoplasmic dumping of nurse cells is severely disturbed. The nuclei of nurse cells and the oocyte are mislocalized and the usually well-organized actin structures are severely disrupted. These results indicate that maternal MSP-300 plays an important role in actin-dependent nuclear anchorage during cytoplasmic transport.

Authors
Yu, J; Starr, DA; Wu, X; Parkhurst, SM; Zhuang, Y; Xu, T; Xu, R; Han, M
MLA Citation
Yu, J, Starr, DA, Wu, X, Parkhurst, SM, Zhuang, Y, Xu, T, Xu, R, and Han, M. "The KASH domain protein MSP-300 plays an essential role in nuclear anchoring during Drosophila oogenesis." Dev Biol 289.2 (January 15, 2006): 336-345.
PMID
16337624
Source
pubmed
Published In
Developmental Biology
Volume
289
Issue
2
Publish Date
2006
Start Page
336
End Page
345
DOI
10.1016/j.ydbio.2005.10.027

Efficient transposition of the piggyBac (PB) transposon in mammalian cells and mice.

Transposable elements have been routinely used for genetic manipulation in lower organisms, including generating transgenic animals and insertional mutagenesis. In contrast, the usage of transposons in mice and other vertebrate systems is still limited due to the lack of an efficient transposition system. We have tested the ability of piggyBac (PB), a DNA transposon from the cabbage looper moth Trichoplusia ni, to transpose in mammalian systems. We show that PB elements carrying multiple genes can efficiently transpose in human and mouse cell lines and also in mice. PB permits the expression of the marker genes it carried. During germline transposition, PB could excise precisely from original insertion sites and transpose into the mouse genome at diverse locations, preferably transcription units. These data provide a first and critical step toward a highly efficient transposon system for a variety of genetic manipulations including transgenesis and insertional mutagenesis in mice and other vertebrates.

Authors
Ding, S; Wu, X; Li, G; Han, M; Zhuang, Y; Xu, T
MLA Citation
Ding, S, Wu, X, Li, G, Han, M, Zhuang, Y, and Xu, T. "Efficient transposition of the piggyBac (PB) transposon in mammalian cells and mice." Cell 122.3 (August 12, 2005): 473-483.
PMID
16096065
Source
pubmed
Published In
Cell
Volume
122
Issue
3
Publish Date
2005
Start Page
473
End Page
483
DOI
10.1016/j.cell.2005.07.013

New insights into E-protein function in lymphocyte development.

Lymphocyte development has long served as an experimental paradigm, revealing fundamental mechanisms of gene regulation and cellular differentiation in mammals. The study of E-protein-mediated transcriptional regulation in lymphocyte development provides a means to address these mechanistic issues. Both genetic and biochemical studies have defined many important regulatory events during lymphocyte development that are mediated by E-proteins. The E2A gene, one of the three known E-protein genes in mammals, has a particularly important role in B-lymphocyte development. Major progress has been made in recent years towards understanding the physiological targets of E2A during B-lymphocyte development. Most notably, new insights have been gained regarding the role of E2A in controlling lineage commitment and V(D)J recombination. This Review focuses primarily on E2A-mediated gene regulation during B-lymphocyte development.

Authors
Lazorchak, A; Jones, ME; Zhuang, Y
MLA Citation
Lazorchak, A, Jones, ME, and Zhuang, Y. "New insights into E-protein function in lymphocyte development." Trends Immunol 26.6 (June 2005): 334-338. (Review)
PMID
15922950
Source
pubmed
Published In
Trends in Immunology
Volume
26
Issue
6
Publish Date
2005
Start Page
334
End Page
338
DOI
10.1016/j.it.2005.03.011

Ubiquitous expression of mRFP1 in transgenic mice.

Fluorescent proteins provide a powerful means to track gene expression and cellular behaviors in the study of model organisms such as mice. Among the new generation of fluorescent protein markers, the monomeric red fluorescent protein mRFP1 is particularly attractive because of its rapid maturation and minimal interference with GFP and GFP-derived markers. Here we evaluate the utility of mRFP1 as a marker in transgenic mice. We show that high level and ubiquitous expression of mRFP1 does not affect mouse development, general physiology, or reproduction. mRFP1 expression can be readily detected with unaided eyes under daylight in transgenic mice on the albino background. The intensity of mRFP1 signals can be used to distinguish homozygous and heterozygous transgenic mice. Together, these features make mRFP1 an attractive marker for broad applications in transgenic research.

Authors
Zhu, H; Wang, G; Li, G; Han, M; Xu, T; Zhuang, Y; Wu, X
MLA Citation
Zhu, H, Wang, G, Li, G, Han, M, Xu, T, Zhuang, Y, and Wu, X. "Ubiquitous expression of mRFP1 in transgenic mice." Genesis 42.2 (June 2005): 86-90.
PMID
15880439
Source
pubmed
Published In
Genesis: the Journal of Genetics and Development
Volume
42
Issue
2
Publish Date
2005
Start Page
86
End Page
90
DOI
10.1002/gene.20129

Examining TCRVbeta germline transcription at single cell level during normal T cell development

Authors
Jia, JQ; Zhuang, Y
MLA Citation
Jia, JQ, and Zhuang, Y. "Examining TCRVbeta germline transcription at single cell level during normal T cell development." March 4, 2005.
Source
wos-lite
Published In
The FASEB journal : official publication of the Federation of American Societies for Experimental Biology
Volume
19
Issue
4
Publish Date
2005
Start Page
A15
End Page
A15

Erratum: Differential functions for the transcription factor E2A in positive and negative gene regulation in pre-B lymphocytes (The Journal of Biological Chemistry (2004) 279 (45028-45035))

Authors
Greenbaum, S; Lazorchak, AS; Zhuang, Y
MLA Citation
Greenbaum, S, Lazorchak, AS, and Zhuang, Y. "Erratum: Differential functions for the transcription factor E2A in positive and negative gene regulation in pre-B lymphocytes (The Journal of Biological Chemistry (2004) 279 (45028-45035))." Journal of Biological Chemistry 280.16 (2005): 16528--.
Source
scival
Published In
Journal of Biological Chemistry
Volume
280
Issue
16
Publish Date
2005
Start Page
16528-

Differential functions for the transcription factor E2A in positive and negative gene regulation in pre-B lymphocytes.

The transcription factors encoded by the E2A gene have been shown to play essential roles in the initiation and progression of lymphocyte development. However, there is still a lack of comprehensive understanding of E2A downstream genes in B-cell development. We previously developed a gene tagging-based chromatin immunoprecipitation (ChIP) system to directly evaluate E2A target genes in B-cell development. Here, we have improved this ChIP strategy and used it in conjunction with microarray analysis on E2A-deficient pre-B-cell lines to determine E2A target genes in lymphocyte development. Both microarray data and ChIP studies confirmed that E2A directly controls IgH gene expression. The microarray assay also revealed genes that were significantly up-regulated after E2A disruption. ChIP analysis showed that E2A was most likely to be directly involved in repression of some of these target genes such as Nfil3 and FGFR2. An inducible E2A reconstitution system further demonstrated that E2A-mediated repression of Nfil3 and FGFR2 was reversible. Collectively, these findings indicate that E2A is a positive regulator for one set of genes and a negative regulator for another set of genes in developing B lymphocytes.

Authors
Greenbaum, S; Lazorchak, AS; Zhuang, Y
MLA Citation
Greenbaum, S, Lazorchak, AS, and Zhuang, Y. "Differential functions for the transcription factor E2A in positive and negative gene regulation in pre-B lymphocytes." J Biol Chem 279.43 (October 22, 2004): 45028-45035.
PMID
15310760
Source
pubmed
Published In
The Journal of biological chemistry
Volume
279
Issue
43
Publish Date
2004
Start Page
45028
End Page
45035
DOI
10.1074/jbc.M400061200

A T cell intrinsic role of Id3 in a mouse model for primary Sjogren's syndrome.

Sjogren's syndrome is an autoimmune disease with clinical hallmarks of keratoconjunctivitis sicca (dry eyes) and xerostomia (dry mouth). The genetic basis of this autoimmune disease is poorly understood. Id3 is an immediate early-response gene in growth regulation and is involved in TCR-mediated T cell selection during T cell development. Here, we show that Id3-deficient mice develop many disease symptoms found in primary Sjogren's syndrome patients including dry eyes and mouth, lymphocyte infiltration in lachrymal and salivary glands, and development of anti-Ro and anti-La antibodies. Adoptive transfer experiment indicated a T cell intrinsic role for Id3 in the development of Sjogren's symptoms. Furthermore, genetic ablation of T cells or neonatal 3 day thymectomy in Id3-deficient mice showed a rescue of disease symptoms, suggesting a thymic origin of autoimmune T cells. Thus, this study establishes a critical connection between Id3-mediated T cell development and autoimmune diseases.

Authors
Li, H; Dai, M; Zhuang, Y
MLA Citation
Li, H, Dai, M, and Zhuang, Y. "A T cell intrinsic role of Id3 in a mouse model for primary Sjogren's syndrome." Immunity 21.4 (October 2004): 551-560.
PMID
15485632
Source
pubmed
Published In
Immunity
Volume
21
Issue
4
Publish Date
2004
Start Page
551
End Page
560
DOI
10.1016/j.immuni.2004.08.013

Regulation of E2A gene expression in B-lymphocyte development.

Biochemical and genetic studies have demonstrated that transcription factors encoded by the E2A gene are essential in regulating B lineage specific gene expression and B lineage commitment. However, the mechanism by which E2A regulates B lineage commitment is not known. It has been reported that E2A controls B lineage commitment in a dosage dependent manner. To further investigate this gene dosage effect, we analyzed E2A expression during normal B cell development in mice carrying a functional E2AGFP knockin allele. Mice carrying this fusion allele were examined for E2A gene expression during bone marrow B cell development. A dramatic upregulation of E2A is observed concomitant with the initiation of immunoglobulin heavy chain D-J rearrangement and the induction of Early B cell Factor (EBF) gene expression. We also show that this E2A upregulation does not occur in the absence of the EBF gene. These results indicate that E2A upregulation is a critical step in regulating B-lineage commitment. It further suggests that E2A gene dosage may be determined by a cross regulation between E2A and EBF during B lineage commitment.

Authors
Zhuang, Y; Jackson, A; Pan, L; Shen, K; Dai, M
MLA Citation
Zhuang, Y, Jackson, A, Pan, L, Shen, K, and Dai, M. "Regulation of E2A gene expression in B-lymphocyte development." Mol Immunol 40.16 (March 2004): 1165-1177.
PMID
15104122
Source
pubmed
Published In
Molecular Immunology
Volume
40
Issue
16
Publish Date
2004
Start Page
1165
End Page
1177

Altered T-dependent antigen responses and development of autoimmune symptoms in mice lacking E2A in T lymphocytes.

E2A has been shown to be an important transcription factor downstream of the T-cell receptor (TCR) signal during T-cell development. The TCR signal is known to elicit different cellular responses at different stages of T-cell development. Whether E2A is still required for normal TCR signalling in mature T cells is unknown. Here we examined T-cell function after disruption of the E2A gene exclusively in the T-cell lineage. The conditional E2A-deficient mice show enhanced humoral immunity to a T-dependent antigen. We further show that E2A is involved in regulating TCR-induced T-cell proliferation events. However, E2A seems to play opposite roles in naïve and effector T cells. In the absence of E2A, TCR-induced proliferation is increased in naïve T cells and decreased in effector T cells. At older ages, these mice frequently develop antinuclear antibodies and proteinuria. Our studies suggest that E2A regulates T-cell function and the loss of E2A may promote age-dependent autoimmune diseases.

Authors
Pan, L; Bradney, C; Zheng, B; Zhuang, Y
MLA Citation
Pan, L, Bradney, C, Zheng, B, and Zhuang, Y. "Altered T-dependent antigen responses and development of autoimmune symptoms in mice lacking E2A in T lymphocytes." Immunology 111.2 (February 2004): 147-154.
PMID
15027899
Source
pubmed
Published In
Immunology
Volume
111
Issue
2
Publish Date
2004
Start Page
147
End Page
154
DOI
10.1111/j.0019-2805.2003.01802.x

A conserved transcriptional enhancer regulates RAG gene expression in developing B cells.

Although expression of the RAG1 and RAG2 genes is essential for lymphocyte development, the mechanisms responsible for the lymphoid- and developmental stage-specific regulation of these genes are poorly understood. We have identified a novel, evolutionarily conserved transcriptional enhancer in the RAG locus, called Erag, which was essential for the expression of a chromosomal reporter gene driven by either RAG promoter. Targeted deletion of Erag in the mouse germline results in a partial block in B cell development associated with deficient V(D)J recombination, whereas T cell development appears unaffected. We found that E2A transcription factors bind to Erag in vivo and can transactivate Erag-dependent reporter constructs in cotransfected cell lines. These findings lead us to conclude that RAG transcription is regulated by distinct elements in developing B and T cells and that Erag is required for optimal levels of RAG expression in early B cell precursors but not in T cells.

Authors
Hsu, L-Y; Lauring, J; Liang, H-E; Greenbaum, S; Cado, D; Zhuang, Y; Schlissel, MS
MLA Citation
Hsu, L-Y, Lauring, J, Liang, H-E, Greenbaum, S, Cado, D, Zhuang, Y, and Schlissel, MS. "A conserved transcriptional enhancer regulates RAG gene expression in developing B cells." Immunity 19.1 (July 2003): 105-117.
PMID
12871643
Source
pubmed
Published In
Immunity
Volume
19
Issue
1
Publish Date
2003
Start Page
105
End Page
117

Regulation of E2A activities by histone acetyltransferases in B lymphocyte development.

Genetic studies have demonstrated that the basic helix-loop-helix protein E2A is an essential transcription factor in B lymphocyte lineage commitment and differentiation. However, the mechanism underlying E2A-mediated transcription regulation is not fully understood. Here, we investigated the physical and genetic interactions between E2A and co-activators histone acetyltransferases (HATs) in B cells. Gel filtration analysis of human pre-B cell nuclear extract showed that E2A co-elutes with the HATs p300, CBP, and PCAF. A co-immunoprecipitation assay further demonstrated that a fraction of endogenous E2A proteins is associated with each of the three HATs. We show that these HATs acetylate E2A in vitro, enhance E2A-mediated transcription activity, and promote nuclear retention of E2A proteins. A catalytic mutation of p300 completely abrogates the ability of p300 to acetylate E2A and to promote E2A nuclear retention in 293T cells. A breeding test between E2A heterozygous mice and p300 heterozygous mice demonstrated that these two genes interact for proper B cell development. Collectively, these results suggest that E2A and HATs collaboratively regulate B cell development.

Authors
Bradney, C; Hjelmeland, M; Komatsu, Y; Yoshida, M; Yao, T-P; Zhuang, Y
MLA Citation
Bradney, C, Hjelmeland, M, Komatsu, Y, Yoshida, M, Yao, T-P, and Zhuang, Y. "Regulation of E2A activities by histone acetyltransferases in B lymphocyte development." J Biol Chem 278.4 (January 24, 2003): 2370-2376.
PMID
12435739
Source
pubmed
Published In
The Journal of biological chemistry
Volume
278
Issue
4
Publish Date
2003
Start Page
2370
End Page
2376
DOI
10.1074/jbc.M211464200

Regulation of early lymphocyte development by E2A family proteins.

Lymphocytes develop from hematopoietic stem cells through a series of highly regulated differentiation events in the bone marrow and thymus. A number of transcription factors are known to collaborate in controlling the timing and specificity of gene expression required for these developmental processes to occur. The basic helix-loop-helix (bHLH) proteins encoded by the E2A gene have been shown to play particularly important roles in the initiation and progression of lymphocyte differentiation. Gene targeting experiments in mice have demonstrated a requirement for E2A proteins at the onset of B lymphocyte development. More recent studies have broadened our view on the function of E2A proteins at multiple stages of lymphopoiesis and in the regulation of lymphoid-specific gene expression. Here we review the mammalian E2A proteins and the accumulated evidence demonstrating central roles for E2A throughout early B and T lymphocyte development. We also speculate on the direction of future research on the mechanisms underlying the lineage and stage-specific functions of E2A in lymphopoiesis.

Authors
Greenbaum, S; Zhuang, Y
MLA Citation
Greenbaum, S, and Zhuang, Y. "Regulation of early lymphocyte development by E2A family proteins." Semin Immunol 14.6 (December 2002): 405-414. (Review)
PMID
12457613
Source
pubmed
Published In
Seminars in Immunology
Volume
14
Issue
6
Publish Date
2002
Start Page
405
End Page
414

Identification of E2A target genes in B lymphocyte development by using a gene tagging-based chromatin immunoprecipitation system.

The transcription factors encoded by the E2A gene are known to be essential for B lymphocyte development, and ectopic expression or gene inactivation studies have revealed several potential lineage-specific E2A target genes. However, it remains unknown whether these target genes are directly regulated by E2A at the transcriptional level. We therefore generated mice carrying an affinity-tagged E2A knock-in allele to provide a system for the direct elucidation of E2A target genes based on E2A binding to target regulatory regions. Abelson-transformed pre-B cell lines derived from these mice were used in chromatin immunoprecipitation experiments to identify regulatory sequences bound by E2A in the context of an early B lymphocyte environment. Significant E2A binding was detected at the promoters and enhancers of several essential B-lineage genes, including the Igkappa intronic and 3' enhancers, lambda5 and VpreB surrogate light chain promoters, the EBF locus promoter region, and the mb-1 (Igalpha) promoter. Low levels of E2A binding were observed at several other lymphoid-restricted regulatory regions including the Ig heavy chain (IgH) intronic enhancer, the IgH 3' enhancers hs3b/hs4, the RAG-2 enhancer, and the 5' regions of the B29 and TdT loci. An E2A target gene, the predicted butyrophilin-like gene NG9 (BTL-II), was also identified by using a chromatin immunoprecipitation-based cloning strategy. In summary, our studies have provided evidence that E2A is directly involved in the transcriptional regulation of a number of early B-lineage genes.

Authors
Greenbaum, S; Zhuang, Y
MLA Citation
Greenbaum, S, and Zhuang, Y. "Identification of E2A target genes in B lymphocyte development by using a gene tagging-based chromatin immunoprecipitation system." Proc Natl Acad Sci U S A 99.23 (November 12, 2002): 15030-15035.
PMID
12415115
Source
pubmed
Published In
Proceedings of the National Academy of Sciences of USA
Volume
99
Issue
23
Publish Date
2002
Start Page
15030
End Page
15035
DOI
10.1073/pnas.232299999

Disruption of Mekk2 in mice reveals an unexpected role for MEKK2 in modulating T-cell receptor signal transduction.

MEKK2 is a member of the mitogen-activated protein kinase (MAPK) kinase kinase gene family involved in regulating multiple MAPK signaling pathways. To elucidate the in vivo function of MEKK2, we generated mice carrying a targeted mutation in the Mekk2 locus. Mekk2(-/-) mice are viable and fertile. Major subsets of thymic and spleen T cells in Mekk2-deficient mice were indistinguishable from those in wild-type mice. B-cell development appeared to proceed similarly in the bone marrow of Mekk2-deficient and wild-type mice. However, Mekk2(-/-) T-cell proliferation was augmented in response to anti-CD3 monoclonal antibody (MAb) stimulation, and these T cells produced more interleukin 2 and gamma interferon than did the wild-type T cells, suggesting that MEKK2 may be involved in controlling the strength of T-cell receptor (TCR) signaling. Consistently, Mekk2(-/-) thymocytes were more susceptible than wild-type thymocytes to anti-CD3 MAb-induced cell death. Furthermore, TCR-mediated c-Jun N-terminal kinase activation was not blocked but moderately enhanced in Mekk2(-/-) T cells. Neither extracellular signal-regulated kinase nor p38 MAPK activation was affected in Mekk2(-/-) T cells. In conclusion, we found that MEKK2 may be required for controlling the strength of TCR/CD3 signaling.

Authors
Guo, Z; Clydesdale, G; Cheng, J; Kim, K; Gan, L; McConkey, DJ; Ullrich, SE; Zhuang, Y; Su, B
MLA Citation
Guo, Z, Clydesdale, G, Cheng, J, Kim, K, Gan, L, McConkey, DJ, Ullrich, SE, Zhuang, Y, and Su, B. "Disruption of Mekk2 in mice reveals an unexpected role for MEKK2 in modulating T-cell receptor signal transduction." Mol Cell Biol 22.16 (August 2002): 5761-5768.
PMID
12138187
Source
pubmed
Published In
Molecular and Cellular Biology
Volume
22
Issue
16
Publish Date
2002
Start Page
5761
End Page
5768

FKBP12 is the only FK506 binding protein mediating T-cell inhibition by the immunosuppressant FK506.

BACKGROUND: FK506-binding proteins (FKBP) are immunophilins that interact with the immunosuppressive drugs FK506 and rapamycin. Several FKBP family members such as FKBP12, FKBP12.6, and FKBP51 are expressed in T cells. It has been speculated that these FKBPs are possibly redundant in the immunosuppressant-induced T-cell inactivation. To determine the pharmacological relevance of multiple FKBP members in the immunosuppressant-induced T-cell inactivation, we have investigated the physiological responses of FKBP12-deficient and FKBP12.6-deficient mutant T cells to the immunosuppressive agent FK506. METHODS: FKBP12-deficient and FKBP12.6-deficient T cells were isolated from genetically engineered FKBP12-deficient and FKBP12.6-deficient mice, respectively. T-cell growth inhibitory assay was used to assess their responses to immunosuppressant FK506 treatments. RESULTS: We found that growth inhibition induced by FK506 is abolished in FKBP12-deficient cells but not in FKBP12.6-deficient cells. CONCLUSIONS: FKBP12 is the only FKBP family member that plays a key role in immunosuppressant-mediated immunosuppression.

Authors
Xu, X; Su, B; Barndt, RJ; Chen, H; Xin, H; Yan, G; Chen, L; Cheng, D; Heitman, J; Zhuang, Y; Fleischer, S; Shou, W
MLA Citation
Xu, X, Su, B, Barndt, RJ, Chen, H, Xin, H, Yan, G, Chen, L, Cheng, D, Heitman, J, Zhuang, Y, Fleischer, S, and Shou, W. "FKBP12 is the only FK506 binding protein mediating T-cell inhibition by the immunosuppressant FK506." Transplantation 73.11 (June 15, 2002): 1835-1838.
PMID
12085010
Source
pubmed
Published In
Transplantation
Volume
73
Issue
11
Publish Date
2002
Start Page
1835
End Page
1838

An analysis of T cell intrinsic roles of E2A by conditional gene disruption in the thymus.

The importance of E2A transcription factors in T cell development has been demonstrated in studies of E2A-deficient mice, which display abnormal T cell development and a high frequency of T cell lymphomas. Because E2A expression is not restricted to the T cell lineage, the primary cause of the T cell phenotype in E2A-deficient mice was not fully determined. To further investigate the role of E2A in T cell lineage, we generated mice with the E2A gene disrupted exclusively during thymocyte development using the Cre-lox system. We show that this system allows E2A gene disruption to occur throughout the double-negative stage of thymocyte development. E2A deletion appears to be completed before development reaches the double-positive stage. Consistent with the gene disruption, these mice reveal a T cell intrinsic role for E2A during the transition from the double-negative stage to the double-positive stage of thymocyte development. In contrast to germline E2A knockout mice, conditional E2A knockout mice do not develop T cell lymphoma. This work establishes a new model for further investigating E2A function in T cell development and leukemiogenesis.

Authors
Pan, L; Hanrahan, J; Li, J; Hale, LP; Zhuang, Y
MLA Citation
Pan, L, Hanrahan, J, Li, J, Hale, LP, and Zhuang, Y. "An analysis of T cell intrinsic roles of E2A by conditional gene disruption in the thymus." J Immunol 168.8 (April 15, 2002): 3923-3932.
PMID
11937548
Source
pubmed
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
168
Issue
8
Publish Date
2002
Start Page
3923
End Page
3932

E2A plays both T-lineage intrinsic and extrinsic roles in T cell development

Authors
Zhuang, Y; Pan, LH; Hanrahan, J; Li, J; Hale, LP; Zheng, B
MLA Citation
Zhuang, Y, Pan, LH, Hanrahan, J, Li, J, Hale, LP, and Zheng, B. "E2A plays both T-lineage intrinsic and extrinsic roles in T cell development." FASEB JOURNAL 15.5 (March 8, 2001): A1194-A1194.
Source
wos-lite
Published In
The FASEB journal : official publication of the Federation of American Societies for Experimental Biology
Volume
15
Issue
5
Publish Date
2001
Start Page
A1194
End Page
A1194

Functions of E2A-HEB heterodimers in T-cell development revealed by a dominant negative mutation of HEB.

Lymphocyte development and differentiation are regulated by the basic helix-loop-helix (bHLH) transcription factors encoded by the E2A and HEB genes. These bHLH proteins bind to E-box enhancers in the form of homodimers or heterodimers and, consequently, activate transcription of the target genes. E2A homodimers are the predominant bHLH proteins present in B-lineage cells and are shown genetically to play critical roles in B-cell development. E2A-HEB heterodimers, the major bHLH dimers found in thymocyte extracts, are thought to play a similar role in T-cell development. However, disruption of either the E2A or HEB gene led to only partial blocks in T-cell development. The exact role of E2A-HEB heterodimers and possibly the E2A and HEB homodimers in T-cell development cannot be distinguished in simple disruption analysis due to a functional compensation from the residual bHLH homodimers. To further define the function of E2A-HEB heterodimers, we generated and analyzed a dominant negative allele of HEB, which produces a physiological amount of HEB proteins capable of forming nonfunctional heterodimers with E2A proteins. Mice carrying this mutation show a stronger and earlier block in T-cell development than HEB complete knockout mice. The developmental block is specific to the alpha/beta T-cell lineage at a stage before the completion of V(D)J recombination at the TCRbeta gene locus. This defect is intrinsic to the T-cell lineage and cannot be rescued by expression of a functional T-cell receptor transgene. These results indicate that E2A-HEB heterodimers play obligatory roles both before and after TCRbeta gene rearrangement during the alpha/beta lineage T-cell development.

Authors
Barndt, RJ; Dai, M; Zhuang, Y
MLA Citation
Barndt, RJ, Dai, M, and Zhuang, Y. "Functions of E2A-HEB heterodimers in T-cell development revealed by a dominant negative mutation of HEB." Mol Cell Biol 20.18 (September 2000): 6677-6685.
PMID
10958665
Source
pubmed
Published In
Molecular and Cellular Biology
Volume
20
Issue
18
Publish Date
2000
Start Page
6677
End Page
6685

Developmental regulation of the E2A gene in lymphopoiesis revealed by an E2AGFP allele

Authors
Zhuang, Y
MLA Citation
Zhuang, Y. "Developmental regulation of the E2A gene in lymphopoiesis revealed by an E2AGFP allele." FASEB JOURNAL 14.6 (April 20, 2000): A1034-A1034.
Source
wos-lite
Published In
The FASEB journal : official publication of the Federation of American Societies for Experimental Biology
Volume
14
Issue
6
Publish Date
2000
Start Page
A1034
End Page
A1034

Mekk3 is essential for early embryonic cardiovascular development.

The early development of blood vessels consists of two phases, vasculogenesis and angiogenesis, which involve distinct and also overlapping molecular regulators, but the intracellular signal transduction pathways involved in these processes have not been well defined. We disrupted Map3k3 (also known as Mekk3), which encodes Mekk3, a member of the Mekk/Ste11 family, in mice. Map3k3-/- embryos died at approximately embryonic day (E) 11, displaying disruption of blood vessel development and the structural integrity of the yolk sac. Angiogenesis was blocked at approximately E9.5 in mutant embryos. Map3k3 disruption did not alter the expression of the genes encoding Vegf-1, angiopoietin or their receptors. The development of embryonic, but not maternal, blood vessels in the placentas of Map3k3-/- embryos was impaired, revealing an intrinsic defect in Map3k3-/- endothelial cells. Moreover, Mekk3 activated myocyte-specific enhancer factor 2C (Mef2c), a transcription factor crucial for early embryonic cardiovascular development through the p38 mitogen-activated protein kinase (Mapk) cascade. We conclude that Mekk3 is necessary for blood vessel development and may be a possible target for drugs that control angiogenesis.

Authors
Yang, J; Boerm, M; McCarty, M; Bucana, C; Fidler, IJ; Zhuang, Y; Su, B
MLA Citation
Yang, J, Boerm, M, McCarty, M, Bucana, C, Fidler, IJ, Zhuang, Y, and Su, B. "Mekk3 is essential for early embryonic cardiovascular development." Nat Genet 24.3 (March 2000): 309-313.
PMID
10700190
Source
pubmed
Published In
Nature Genetics
Volume
24
Issue
3
Publish Date
2000
Start Page
309
End Page
313
DOI
10.1038/73550

A genetic investigation of E2A function in lymphocyte development.

Lymphocytes are derived from hematopoietic stem cells (HSC) following a series of regulated differentiation events. Multipotent HSCs become committed to the B cell lineage in bone marrow and the T cell lineage in the thymus after receiving appropriate signals from the corresponding microenvironment. These committed lymphoid cells must then undergo V(D)J recombination at the immunoglobulin gene or T cell receptor gene locus resulting in clonal production of functional B or T lymphocytes, respectively. Lymphocyte commitment and differentiation are accompanied by programmed gene expression or repression events which are driven by lineage and stage specific transcription factors. The basic-helix-loop-helix (bHLH) transcription factors encoded by the E2A gene are involved in several differentiation events during B and T cell development, including lineage commitment, initiation of V(D)J recombination, and antigen receptor mediated proliferation and differentiation. Several recent reviews have provided a comprehensive discussion of biochemical, cellular, and genetic research on E2A function in lymphocyte development (1,2). Here, we only discuss some of the genetic approaches our laboratory (except where it is noted) has undertaken to investigate the molecular pathways mediated by E2A transcription factors in lymphocyte development.

Authors
Hanrahan, J; Pan, L; Greenbaum, S; Bradney, C; Hjelmeland, M; Dai, M; Zhuang, Y
MLA Citation
Hanrahan, J, Pan, L, Greenbaum, S, Bradney, C, Hjelmeland, M, Dai, M, and Zhuang, Y. "A genetic investigation of E2A function in lymphocyte development." Immunol Res 22.2-3 (2000): 211-222. (Review)
PMID
11339357
Source
pubmed
Published In
Immunologic Research
Volume
22
Issue
2-3
Publish Date
2000
Start Page
211
End Page
222

Id1 and Id3 are required for neurogenesis, angiogenesis and vascularization of tumour xenografts.

Id proteins may control cell differentiation by interfering with DNA binding of transcription factors. Here we show that targeted disruption of the dominant negative helix-loop-helix proteins Id1 and Id3 in mice results in premature withdrawal of neuroblasts from the cell cycle and expression of neural-specific differentiation markers. The Id1-Id3 double knockout mice also display vascular malformations in the forebrain and an absence of branching and sprouting of blood vessels into the neuroectoderm. As angiogenesis both in the brain and in tumours requires invasion of avascular tissue by endothelial cells, we examined the Id knockout mice for their ability to support the growth of tumour xenografts. Three different tumours failed to grow and/or metastasize in Id1+/- Id3-/- mice, and any tumour growth present showed poor vascularization and extensive necrosis. Thus, the Id genes are required to maintain the timing of neuronal differentiation in the embryo and invasiveness of the vasculature. Because the Id genes are expressed at very low levels in adults, they make attractive new targets for anti-angiogenic drug design.

Authors
Lyden, D; Young, AZ; Zagzag, D; Yan, W; Gerald, W; O'Reilly, R; Bader, BL; Hynes, RO; Zhuang, Y; Manova, K; Benezra, R
MLA Citation
Lyden, D, Young, AZ, Zagzag, D, Yan, W, Gerald, W, O'Reilly, R, Bader, BL, Hynes, RO, Zhuang, Y, Manova, K, and Benezra, R. "Id1 and Id3 are required for neurogenesis, angiogenesis and vascularization of tumour xenografts." Nature 401.6754 (October 14, 1999): 670-677.
PMID
10537105
Source
pubmed
Published In
Nature
Volume
401
Issue
6754
Publish Date
1999
Start Page
670
End Page
677
DOI
10.1038/44334

A novel role for HEB downstream or parallel to the pre-TCR signaling pathway during alpha beta thymopoiesis.

TCR gene rearrangement and expression are central to the development of clonal T lymphocytes. The pre-TCR complex provides the first signal instructing differentiation and proliferation events during the transition from CD4-CD8-TCR- double negative (DN) stage to CD4+CD8+ double positive (DP) stage. How the pre-TCR signal leads to downstream gene expression is not known. HeLa E-box binding protein (HEB), a basic helix-loop-helix transcription factor, is abundantly detected in thymocytes and is thought to regulate E-box sites present in many T cell-specific gene enhancers, including TCR-alpha, TCR-beta, and CD4. Targeted disruption of HEB results in a 5- to 10-fold reduction in thymic cellularity that can be accounted for by a developmental block at the DN to DP stage transition. Specifically, a dramatic increase in the CD4low/-CD8+CD5lowHSA+TCRlow/- immature single positive population and a concomitant decrease in the subsequent DP population are observed. Adoptive transfer test shows that this defect is cell-autonomous and restricted to the alpha beta T cell lineage. Introduction of an alpha beta TCR transgene into the HEBko/ko background is not sufficient to rescue the developmental delay. In vivo CD3 cross-linking analysis of thymocytes indicates that TCR signaling pathway in the HEBko/ko mice appears intact. These findings suggest an essential function of HEB in early T cell development, downstream or parallel to the pre-TCR signaling pathway.

Authors
Barndt, R; Dai, MF; Zhuang, Y
MLA Citation
Barndt, R, Dai, MF, and Zhuang, Y. "A novel role for HEB downstream or parallel to the pre-TCR signaling pathway during alpha beta thymopoiesis." J Immunol 163.6 (September 15, 1999): 3331-3343.
PMID
10477603
Source
pubmed
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
163
Issue
6
Publish Date
1999
Start Page
3331
End Page
3343

Impaired immune responses and B-cell proliferation in mice lacking the Id3 gene.

B-lymphocyte activation and proliferation induced by the B-cell receptor (BCR) signals are important steps in the initiation of humoral immune responses. How the BCR signals are translated by nuclear transcription factors into cell cycle progression is poorly understood. Id3 is an immediate-early gene responding to growth and mitogenic signals in many cell types including B cells. The primary function of the Id3 protein has been defined as that of inhibitor of basic-helix-loop-helix (bHLH) transcription factors. The interaction between Id3 and bHLH proteins, many of which are essential for cellular differentiation, has been proposed as a key regulatory event leading to cellular proliferation instead of differentiation. To further investigate the role of Id3 in tissue and embryo development and the mechanism of Id3-mediated growth regulation, we generated and analyzed Id3-deficient mice. While these mice display no overt abnormality in tissue and embryo development, their humoral immunity is compromised. The amounts of immunoglobulins produced in Id3-deficient mice immunized with a T-cell-dependent antigen and a type 2 T-cell-independent antigen are attenuated and severely impaired, respectively. Further analysis of lymphocytes isolated from Id3-deficient mice reveals a B-cell defect in their proliferation response to BCR cross-linking but not to lipopolysaccharide or a combination of BCR cross-linking and interleukin-4. Analyses of cultured lymphocytes also suggest involvement of Id3 in cytokine production in T cells and isotype switching in B cells. Finally, the proliferation defect in Id3-deficient B cells can be rescued by ectopic expression of Id1, a homologue of Id3. Taken together, these results define a necessary and specific role for Id3 in mediating signals from BCR to cell cycle progression during humoral immune responses.

Authors
Pan, L; Sato, S; Frederick, JP; Sun, XH; Zhuang, Y
MLA Citation
Pan, L, Sato, S, Frederick, JP, Sun, XH, and Zhuang, Y. "Impaired immune responses and B-cell proliferation in mice lacking the Id3 gene." Mol Cell Biol 19.9 (September 1999): 5969-5980.
PMID
10454544
Source
pubmed
Published In
Molecular and Cellular Biology
Volume
19
Issue
9
Publish Date
1999
Start Page
5969
End Page
5980

Targeted disruption of Smad3 reveals an essential role in transforming growth factor beta-mediated signal transduction.

The Smads are a family of nine related proteins which function as signaling intermediates for the transforming growth factor beta (TGF-beta) superfamily of ligands. To discern the in vivo functions of one of these Smads, Smad3, we generated mice harboring a targeted disruption of this gene. Smad3 null mice, although smaller than wild-type littermates, are viable, survive to adulthood, and exhibit an early phenotype of forelimb malformation. To study the cellular functions of Smad3, we generated Smad3 null mouse embryonic fibroblasts (MEFs) and dermal fibroblasts. We demonstrate that null MEFs have lost the ability to form Smad-containing DNA binding complexes and are unable to induce transcription from the TGF-beta-responsive promoter construct, p3TP-lux. Using the primary dermal fibroblasts, we also demonstrate that Smad3 is integral for induction of endogenous plasminogen activator inhibitor 1. We subsequently demonstrate that Smad3 null MEFs are partially resistant to TGF-beta's antiproliferative effect, thus firmly establishing a role for Smad3 in TGF-beta-mediated growth inhibition. We next examined cells in which Smad3 is most highly expressed, specifically cells of immune origin. Although no specific developmental defect was detected in the immune system of the Smad3 null mice, a functional defect was observed in the ability of TGF-beta to inhibit the proliferation of splenocytes activated by specific stimuli. In addition, primary splenocytes display defects in TGF-beta-mediated repression of cytokine production. These data, taken together, establish a role for Smad3 in mediating the antiproliferative effects of TGF-beta and implicate Smad3 as a potential effector for TGF-beta in modulating immune system function.

Authors
Datto, MB; Frederick, JP; Pan, L; Borton, AJ; Zhuang, Y; Wang, XF
MLA Citation
Datto, MB, Frederick, JP, Pan, L, Borton, AJ, Zhuang, Y, and Wang, XF. "Targeted disruption of Smad3 reveals an essential role in transforming growth factor beta-mediated signal transduction." Mol Cell Biol 19.4 (April 1999): 2495-2504.
PMID
10082515
Source
pubmed
Published In
Molecular and Cellular Biology
Volume
19
Issue
4
Publish Date
1999
Start Page
2495
End Page
2504

A dominant-negative approach to study the redundant function of bHLH genes.

Authors
Barndt, RJ; Zhuang, Y
MLA Citation
Barndt, RJ, and Zhuang, Y. "A dominant-negative approach to study the redundant function of bHLH genes." FASEB JOURNAL 13.4 (March 12, 1999): A619-A619.
Source
wos-lite
Published In
The FASEB journal : official publication of the Federation of American Societies for Experimental Biology
Volume
13
Issue
4
Publish Date
1999
Start Page
A619
End Page
A619

Impaired immune responses and B cell proliferation in mice lack of the Id3 gene

Authors
Pan, LH; Zhuang, Y
MLA Citation
Pan, LH, and Zhuang, Y. "Impaired immune responses and B cell proliferation in mice lack of the Id3 gene." FASEB JOURNAL 13.4 (March 12, 1999): A327-A327.
Source
wos-lite
Published In
The FASEB journal : official publication of the Federation of American Societies for Experimental Biology
Volume
13
Issue
4
Publish Date
1999
Start Page
A327
End Page
A327

Controlling lymphopoiesis with a combinatorial E-protein code.

Authors
Barndt, RJ; Zhuang, Y
MLA Citation
Barndt, RJ, and Zhuang, Y. "Controlling lymphopoiesis with a combinatorial E-protein code." Cold Spring Harb Symp Quant Biol 64 (1999): 45-50. (Review)
PMID
11232321
Source
pubmed
Published In
Cold Spring Harbor Laboratory: Symposia on Quantitative Biology
Volume
64
Publish Date
1999
Start Page
45
End Page
50

Functional replacement of the mouse E2A gene with a human HEB cDNA.

The mammalian E2A, HEB, and E2-2 genes encode a unique class of basic helix-loop-helix (bHLH) transcription factors that are evolutionarily conserved and essential for embryonic and postnatal development. While the structural and functional similarities among the gene products are well demonstrated, it is not clear why deletion of E2A, but not HEB or E2-2, leads to a complete arrest in B-lymphocyte development. To understand the molecular basis of the functional specificity between E2A and HEB/E2-2 in mammalian development, we generated and tested a panel of E2A knockin mutations including subtle mutations in the E12 and E47 exons and substitution of both E12 and E47 exons with a human HEB cDNA. We find that the alternatively spliced E12 and E47 bHLH proteins of the E2A gene play similar and additive roles in supporting B lymphopoiesis. Further, we find that HEB driven by the endogenous E2A promoter can functionally replace E2A in supporting B-cell commitment and differentiation toward completion. Finally, the postnatal lethality associated with E2A disruption is fully rescued by the addition of HEB. This study suggests that the functional divergence among E12, E47, and HEB in different cell types is partially defined by the context of gene expression.

Authors
Zhuang, Y; Barndt, RJ; Pan, L; Kelley, R; Dai, M
MLA Citation
Zhuang, Y, Barndt, RJ, Pan, L, Kelley, R, and Dai, M. "Functional replacement of the mouse E2A gene with a human HEB cDNA." Mol Cell Biol 18.6 (June 1998): 3340-3349.
PMID
9584174
Source
pubmed
Published In
Molecular and Cellular Biology
Volume
18
Issue
6
Publish Date
1998
Start Page
3340
End Page
3349

High incidence of T-cell tumors in E2A-null mice and E2A/Id1 double-knockout mice.

The basic-helix-loop-helix (bHLH) proteins encoded by the E2A gene are broadly expressed transcription regulators which function through binding to the E-box enhancer sequences. The DNA binding activities of E2A proteins are directly inhibited upon dimerization with the Id1 gene product. It has been shown that disruption of the E2A gene leads to a complete block in B-lymphocyte development and a high frequency of neonatal death. We report here that nearly half of the surviving E2A-null mice develop acute T-cell lymphoma between 3 to 10 months of age. We further show that disruption of the Id1 gene improves the chance of postnatal survival of E2A-null mice, indicating that Id1 is a canonical negative regulator of E2A and that the unbalanced ratio of E2A to Id1 may contribute to the postnatal death of the E2A-null mice. However, the E2A/Id1 double-knockout mice still develop T-cell tumors once they reach the age of 3 months. This result suggests that E2A may be essential for maintaining the homeostasis of T lymphocytes during their constant renewal in adult life.

Authors
Yan, W; Young, AZ; Soares, VC; Kelley, R; Benezra, R; Zhuang, Y
MLA Citation
Yan, W, Young, AZ, Soares, VC, Kelley, R, Benezra, R, and Zhuang, Y. "High incidence of T-cell tumors in E2A-null mice and E2A/Id1 double-knockout mice." Mol Cell Biol 17.12 (December 1997): 7317-7327.
PMID
9372963
Source
pubmed
Published In
Molecular and Cellular Biology
Volume
17
Issue
12
Publish Date
1997
Start Page
7317
End Page
7327

Analysis of the role of E2A-encoded proteins in insulin gene transcription.

Pancreatic beta-cell type-specific transcription of the insulin gene is mediated, in part, by factors in the basic helix-loop-helix (bHLH) family that act on a site within the insulin enhancer, termed the E1-box. Expression from this element is regulated by a heteromeric protein complex containing ubiquitous (i.e. the E2A- and HEB-encoded proteins) and islet-enriched members of the bHLH family. Recent studies indicate that the E2A- and HEB-encoded proteins contain a transactivation domain, termed AD2, that functions more efficiently in transfected beta-cell lines. In the present report, we extend this observation by demonstrating that expression of full-length E2A proteins (E47, E12, and E2/5) activates insulin E element-directed transcription in a beta-cell line-selective manner. Stimulation required functional interactions with other key insulin gene transcription factors, including its islet bHLH partner as well as those that act on the RIPE3b1 and RIPE3a2 elements of the insulin gene enhancer. The conserved AD2 domain in the E2A proteins was essential in this process. The effect of the E2A- and HEB-encoded proteins on insulin gene expression was also analyzed in mice lacking a functional E2A or HEB gene. There was no apparent difference in insulin production between wild type, heterozygote, and homozygous mutant E2A or HEB mice. These results suggest that neither the E2A- or HEB-encoded proteins are essential for insulin transcription and that one factor can substitute for the other to impart normal insulin E1 activator function in mutant animals.

Authors
Sharma, A; Henderson, E; Gamer, L; Zhuang, Y; Stein, R
MLA Citation
Sharma, A, Henderson, E, Gamer, L, Zhuang, Y, and Stein, R. "Analysis of the role of E2A-encoded proteins in insulin gene transcription." Mol Endocrinol 11.11 (October 1997): 1608-1617.
PMID
9328343
Source
pubmed
Published In
Molecular endocrinology (Baltimore, Md.)
Volume
11
Issue
11
Publish Date
1997
Start Page
1608
End Page
1617
DOI
10.1210/mend.11.11.0004

B-lymphocyte development is regulated by the combined dosage of three basic helix-loop-helix genes, E2A, E2-2, and HEB.

B-lymphocyte development requires the basic helix-loop-helix proteins encoded by the E2A gene. In this study, the control mechanism of E2A was further explored by disruption of the E2A-related genes, E2-2 and HEB. In contrast to E2A, E2-2 and HEB are not essential for the establishment of the B-cell lineage. However, both E2-2 and HEB are required for the generation of the normal numbers of pro-B cells in mouse embryos. Breeding tests among mice carrying different mutations revealed that E2-2 and HEB interact with E2A in many developmental processes including generation of B cells. Specifically, mice transheterozygous for any two mutations of these three genes produced fewer pro-B cells than the singly heterozygous littermates. This study indicates that B-cell development is dependent not only on an essential function provided by the E2A gene but also on a combined dosage set by E2A, E2-2, and HEB.

Authors
Zhuang, Y; Cheng, P; Weintraub, H
MLA Citation
Zhuang, Y, Cheng, P, and Weintraub, H. "B-lymphocyte development is regulated by the combined dosage of three basic helix-loop-helix genes, E2A, E2-2, and HEB." Mol Cell Biol 16.6 (June 1996): 2898-2905.
PMID
8649400
Source
pubmed
Published In
Molecular and Cellular Biology
Volume
16
Issue
6
Publish Date
1996
Start Page
2898
End Page
2905

Targeted deletion of 5'HS2 of the murine beta-globin LCR reveals that it is not essential for proper regulation of the beta-globin locus.

The beta-globin locus control region (LCR) is a complex regulatory element that is essential for the appropriate red cell-specific expression of all cis-linked beta-globin genes. Of the five hypersensitive sites that define the LCR, only 5'HS2 has been shown to augment gene expression in vitro in both transient and stable assays, as well as in transgenic mice. Thus, 5'HS2 has been assumed to be an important element for the function of the LCR in vivo. We have utilized homologous recombination in murine embryonic stem (ES) cells and phenotypic analysis in derived mice to investigate the function of 5'HS2 in its normal chromosomal position in the murine beta-globin locus. Replacement of 5'HS2 with a selectable marker gene (delta HS2 + neo) causes a 2-5-fold reduction in expression of all of the genes in the locus, and a more pronounced effect (10-12-fold) on the most 5' embryonic globin gene, Ey, when expression of this gene is first detectable during embryogenesis. The mutation produces no alterations in the developmental timing of expression of the globin genes. When homozygous, the deletion/replacement mutation is lethal in utero, with the embryos dying during the stage of yolk sac and early fetal liver erythropoiesis. To distinguish phenotypic effects resulting from the deletion of 5'HS2 from those attributable to insertion of the selectable marker, the selectable marker was removed by expressing the FLP site-specific recombinase in ES cells harboring the homologous recombination event. Mice derived from these ES cells (delta HS2 delta neo) demonstrated nearly full expression of all the beta-like globin genes on the mutated chromosome. These results indicate that although 5'HS2 demonstrates significant regulatory activities in a variety of assays, deletion of this element from the endogenous beta-globin locus has no significant effect on the timing or extent of expression of the locus. In addition, this result emphasizes that when using homologous recombination to analyze complex regulatory elements in vivo, the inserted selectable marker must be removed to avoid influencing the phenotype of the mutation.

Authors
Fiering, S; Epner, E; Robinson, K; Zhuang, Y; Telling, A; Hu, M; Martin, DI; Enver, T; Ley, TJ; Groudine, M
MLA Citation
Fiering, S, Epner, E, Robinson, K, Zhuang, Y, Telling, A, Hu, M, Martin, DI, Enver, T, Ley, TJ, and Groudine, M. "Targeted deletion of 5'HS2 of the murine beta-globin LCR reveals that it is not essential for proper regulation of the beta-globin locus." Genes Dev 9.18 (September 15, 1995): 2203-2213.
PMID
7557375
Source
pubmed
Published In
Genes & development
Volume
9
Issue
18
Publish Date
1995
Start Page
2203
End Page
2213

The helix-loop-helix gene E2A is required for B cell formation.

Heterodimers between tissue-specific basic-helix-loop-helix proteins and the gene products of E2A play major roles in determining tissue-specific cell fate. To understand the broad role of E2A in development, we have generated E2A mutant mice following homologous recombination in embryonic stem cells. Homozygous mutant mice develop to full term without apparent abnormalities, but then display a high rate of postnatal death. The surviving mice show retarded postnatal growth. Detailed examination of hematopoiesis reveals that the homozygous mutant mice contain no B cells while other lineages including T cell, granulocyte, macrophage, and erythroid are intact. The block to B cell differentiation occurs prior to immunoglobulin gene DH-JH rearrangement and the expression of the B lineage-specific marker B220. Surprisingly, heterozygous embryos contain, on average, about half as many B cells as wild-type embryos, suggesting the existence of a counting mechanism that translates levels of E2A into numbers of B cells.

Authors
Zhuang, Y; Soriano, P; Weintraub, H
MLA Citation
Zhuang, Y, Soriano, P, and Weintraub, H. "The helix-loop-helix gene E2A is required for B cell formation." Cell 79.5 (December 2, 1994): 875-884.
PMID
8001124
Source
pubmed
Published In
Cell
Volume
79
Issue
5
Publish Date
1994
Start Page
875
End Page
884

Helix-loop-helix transcription factors E12 and E47 are not essential for skeletal or cardiac myogenesis, erythropoiesis, chondrogenesis, or neurogenesis.

E12 and E47 are two non-tissue-specific helix-loop-helix (HLH) transcription factors encoded by the E2A gene. Previous studies suggested that they are involved in regulation of differentiation in many tissue types including muscle, blood, and nerve through direct heterodimer interactions with tissue-specific HLH proteins. To gain further genetic insight into the functions of E12 and E47 during cell differentiation, we mutated both copies of the E2A gene in mouse embryonic stem (ES) cells and then tested the effect on differentiation in vitro. We find that the ES cells lacking functional E12 and E47 are capable of differentiating into both skeletal and cardiac muscle, erythrocytes, neurons, and cartilage that the same extent as wild-type cells. These results indicate that the E2A gene is not essential for differentiation of these cell types and suggest that redundant genes may control these developmental pathways.

Authors
Zhuang, Y; Kim, CG; Bartelmez, S; Cheng, P; Groudine, M; Weintraub, H
MLA Citation
Zhuang, Y, Kim, CG, Bartelmez, S, Cheng, P, Groudine, M, and Weintraub, H. "Helix-loop-helix transcription factors E12 and E47 are not essential for skeletal or cardiac myogenesis, erythropoiesis, chondrogenesis, or neurogenesis." Proc Natl Acad Sci U S A 89.24 (December 15, 1992): 12132-12136.
PMID
1465450
Source
pubmed
Published In
Proceedings of the National Academy of Sciences of USA
Volume
89
Issue
24
Publish Date
1992
Start Page
12132
End Page
12136

The myoD gene family: Nodal point during specification of the muscle cell lineage

The myoD gene converts many differentiated cell types into muscle. MyoD is a member of the basic-helix-loophelix family of proteins; this 68-amino acid domain in MyoD is necessary and sufficient for myogenesis. MyoD binds cooperatively to muscle-specific enhancers and activates transcription. The helix-loop-helix motif is responsible for dimerization, and, depending on its dimerization partner, MyoD activity can be controlled. MyoD senses and integrates many facets of cell state. MyoD is expressed only in skeletal muscle and its precursors; in nonmuscle cells myoD is repressed by specific genes. MyoD activates its own transcription; this may stabilize commitment to myogenesis.

Authors
Weintraub, H; Davis, R; Tapscott, S; Thayer, M; Krause, M; Benezra, R; Blackwell, TK; Turner, D; Rupp, R; Hollenberg, S; Zhuang, Y; Lassar, A
MLA Citation
Weintraub, H, Davis, R, Tapscott, S, Thayer, M, Krause, M, Benezra, R, Blackwell, TK, Turner, D, Rupp, R, Hollenberg, S, Zhuang, Y, and Lassar, A. "The myoD gene family: Nodal point during specification of the muscle cell lineage." Science 251.4995 (1991): 761-766.
PMID
1846704
Source
scival
Published In
Science
Volume
251
Issue
4995
Publish Date
1991
Start Page
761
End Page
766

The conserved dinucleotide AG of the 3' splice site may be recognized twice during in vitro splicing of mammalian mRNA precursors.

We have previously used site-directed mutagenesis to introduce an additional branch site into the first intron of the human beta-globin gene at nt -24 between the natural branch site (nt -37) and the normal 3' splice site (nt -1). We found that either the upstream or downstream branch site could be used during in vitro splicing, depending on which site best matched the mammalian branch site consensus YURAC (R = purine; Y = pyrimidine). Here we show that introduction of an additional AG dinucleotide at nt -20 between the downstream branch site and the normal 3' splice site results in alternative 3' splicing. Splicing to the new AG uses the upstream branch site exclusively, presumably because the downstream branch site is only 4 nt from this 3' splice site. We were surprised, however, to find that the presence of the new AG also prevents the use of the upstream branch site for splicing to the normal 3' splice site. Analysis of additional mutants confirmed earlier work [Krainer et al.: Mechanisms of human beta-globin pre-mRNA splicing. In Berg, P. (Ed.), The Robert A. Welch Foundation Conferences on Chemical Research XXIX. Genetic Chemistry: The Molecular Basis of Heredity. Welch Foundation, Houston, TX, 1985, pp. 353-382] that the new AG cannot function by itself as a complete 3' splice site; rather, it appears that alternative 3' splicing initiates at the normal 3' splice site but then searches, once the reaction is underway, for the first AG downstream from the chosen branch site. Taken together, our data suggest that the conserved AG dinucleotide at the 3' splice site may be recognized twice during mammalian mRNA splicing in vitro.

Authors
Zhuang, Y; Weiner, AM
MLA Citation
Zhuang, Y, and Weiner, AM. "The conserved dinucleotide AG of the 3' splice site may be recognized twice during in vitro splicing of mammalian mRNA precursors." Gene 90.2 (June 15, 1990): 263-269.
PMID
2401404
Source
pubmed
Published In
Gene
Volume
90
Issue
2
Publish Date
1990
Start Page
263
End Page
269

A compensatory base change in human U2 snRNA can suppress a branch site mutation.

We have developed an assay to test whether U2 snRNA can base-pair with the branch site during mammalian mRNA splicing. The beta 110 point mutation (GG----AG) within the first intron of human beta-globin generates a new 3' splice site that is preferentially used. We show here that use of the normal 3' splice site can be restored either by improving the match of a cryptic branch site to the branch site consensus or by introducing mutant U2 snRNAs with greater complementarity to the cryptic branch site. These data indicate that human U2 snRNA can form base pairs with the mRNA precursor; however, base pairing appears to be optional because some mammalian branch sites do not match the consensus.

Authors
Zhuang, Y; Weiner, AM
MLA Citation
Zhuang, Y, and Weiner, AM. "A compensatory base change in human U2 snRNA can suppress a branch site mutation." Genes Dev 3.10 (October 1989): 1545-1552.
PMID
2612904
Source
pubmed
Published In
Genes & development
Volume
3
Issue
10
Publish Date
1989
Start Page
1545
End Page
1552

UACUAAC is the preferred branch site for mammalian mRNA splicing

The conserved branch-site sequence UACUAAC is known to form base pairs with the complementary sequence GUAGUA in U2 small nuclear RNA (snRNA) during mRNA splicing in the yeast Saccharomyces cerevisiae. Although the GUAGUA element is conserved in mammalian U2 snRNA, mammalian branch sites conform only weakly to a YURAC consensus and can even be deleted without obvious effects on the efficiency of splicing in vivo. To understand why the GUAGUA element of U2 is conserved in evolution but the branch site is not, we have devised two different competitive assays for branch-site selection using the first intron of the human β-globin gene. We find that a sequence resembling UACUAAC is the most efficient branch site for mammalian mRNA splicing both in vivo and in vitro. Our results suggest that in mammals (i) U2 snRNA can form base pairs with the branch site and (ii) the interaction between U2 and the branch site can be augmented or replaced by an interaction between the spliceosome and some other element of the intron or exons, perhaps the conserved polypyrimidine tract located immediately upstream from the 3' splice site.

Authors
Zhuang, Y; Goldstein, AM; Weiner, AM
MLA Citation
Zhuang, Y, Goldstein, AM, and Weiner, AM. "UACUAAC is the preferred branch site for mammalian mRNA splicing." Proceedings of the National Academy of Sciences of the United States of America 86.8 (1989): 2752-2756.
PMID
2704744
Source
scival
Published In
Proceedings of the National Academy of Sciences of the United States of America
Volume
86
Issue
8
Publish Date
1989
Start Page
2752
End Page
2756

The natural 5' splice site of simian virus 40 large T antigen can be improved by increasing the base complementarity to U1 RNA.

The use of alternative 5' splice sites in the simian virus 40 early-transcription unit controls the ratio of large T to small t antigen during viral infection. To study the regulation of these alternative 5' splice sites, we made two mutants which improve the match of the large-T-antigen 5' splice site to the 5' splice site consensus sequence. Whether these mutants were assayed in vitro or in vivo, we found that the efficiency of large-T splicing is increased by improving the match of the large-T-antigen 5' splice site to the consensus. We conclude that the match of a 5' splice site is an important determinant of 5' splice site utilization and that the simian virus 40 large-T-antigen 5' splice site is almost certainly recognized by the U1 small nuclear RNA component of the U1 small nuclear ribonucleoprotein particle.

Authors
Zhuang, Y; Leung, H; Weiner, AM
MLA Citation
Zhuang, Y, Leung, H, and Weiner, AM. "The natural 5' splice site of simian virus 40 large T antigen can be improved by increasing the base complementarity to U1 RNA." Mol Cell Biol 7.8 (August 1987): 3018-3020.
PMID
2823114
Source
pubmed
Published In
Molecular and Cellular Biology
Volume
7
Issue
8
Publish Date
1987
Start Page
3018
End Page
3020

A compensatory base change in U1 snRNA suppresses a 5' splice site mutation.

Indirect evidence suggests that the 5' end of U1 snRNA recognizes the 5' splice site in mRNA precursors by complementary base pairing. To test this hypothesis, we asked whether point mutations in the alternative 12S and 13S 5' splice sites of the adenovirus E1A gene can be suppressed by compensatory base changes in human U1 snRNA. When the mutant E1A and U1 genes are contransfected into HeLa cells, we observe efficient suppression of one mutation at position +5 in the 12S splice site, but exceedingly weak suppression of another mutation at position +3 in the 13S splice site. These and other results suggest that base pairing between U1 and the 5' splice site is necessary but not sufficient for the splicing of mRNA precursors.

Authors
Zhuang, Y; Weiner, AM
MLA Citation
Zhuang, Y, and Weiner, AM. "A compensatory base change in U1 snRNA suppresses a 5' splice site mutation." Cell 46.6 (September 12, 1986): 827-835.
PMID
3757028
Source
pubmed
Published In
Cell
Volume
46
Issue
6
Publish Date
1986
Start Page
827
End Page
835
Show More