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Aysola V, Abd C, Kuo AH, Gupta N. Ezrin Promotes Antigen Receptor Diversity during B Cell Development by Supporting Ig H Chain Variable Gene Recombination. Immunohorizons 2022; 6:722-729. [DOI: 10.4049/immunohorizons.2100103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/02/2023] Open
Abstract
Abstract
Genome-level rearrangements of Ig genes during B cell development are critical for generation of a diverse repertoire of BCRs that bind to a multitude of foreign Ags and some self Ags. Bone marrow B cell development involves a variety of cell–cell interactions, cell migration, and receptor signaling that likely benefit from the activity of membrane-cytoskeletal reorganizing proteins. However, the specific contribution of such proteins toward BCR repertoire diversification is poorly understood. Ezrin is a membrane-cytoskeletal linker protein that regulates mature B cell activation through spatial organization of the BCR. We employed next-generation sequencing to investigate whether Ezrin plays a role in IgH rearrangements and generation of BCR diversity in developing bone marrow B cells. BCR repertoire development occurred stochastically in B cell progenitors from both control and B cell conditional Ezrin-deficient mice. However, the loss of Ezrin resulted in fewer unique CDRs (CDR3s) in the BCRs and reduced Shannon entropy. Ezrin-deficient pre-B cells revealed similar utilization of joining (J) genes but significantly fewer variable (V) genes, thereby decreasing V-J combinatorial diversity. V-J junctional diversity, measured by CDR3 length and nucleotide additions and deletions, was not altered in Ezrin-deficient pre-B cells. Mechanistically, Ezrin-deficient cells showed a marked decrease in RAG1 gene expression, indicating a less efficient DNA recombination machinery. Overall, our results demonstrate that Ezrin shapes the BCR repertoire through combinatorial diversification.
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Affiliation(s)
- Varun Aysola
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH
| | - Christina Abd
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH
| | - Alexander H. Kuo
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH
| | - Neetu Gupta
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH
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Roychowdhury T, Chattopadhyay S. Chemical Decorations of "MARs" Residents in Orchestrating Eukaryotic Gene Regulation. Front Cell Dev Biol 2020; 8:602994. [PMID: 33409278 PMCID: PMC7779526 DOI: 10.3389/fcell.2020.602994] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 11/19/2020] [Indexed: 01/19/2023] Open
Abstract
Genome organization plays a crucial role in gene regulation, orchestrating multiple cellular functions. A meshwork of proteins constituting a three-dimensional (3D) matrix helps in maintaining the genomic architecture. Sequences of DNA that are involved in tethering the chromatin to the matrix are called scaffold/matrix attachment regions (S/MARs), and the proteins that bind to these sequences and mediate tethering are termed S/MAR-binding proteins (S/MARBPs). The regulation of S/MARBPs is important for cellular functions and is altered under different conditions. Limited information is available presently to understand the structure–function relationship conclusively. Although all S/MARBPs bind to DNA, their context- and tissue-specific regulatory roles cannot be justified solely based on the available information on their structures. Conformational changes in a protein lead to changes in protein–protein interactions (PPIs) that essentially would regulate functional outcomes. A well-studied form of protein regulation is post-translational modification (PTM). It involves disulfide bond formation, cleavage of precursor proteins, and addition or removal of low-molecular-weight groups, leading to modifications like phosphorylation, methylation, SUMOylation, acetylation, PARylation, and ubiquitination. These chemical modifications lead to varied functional outcomes by mechanisms like modifying DNA–protein interactions and PPIs, altering protein function, stability, and crosstalk with other PTMs regulating subcellular localizations. S/MARBPs are reported to be regulated by PTMs, thereby contributing to gene regulation. In this review, we discuss the current understanding, scope, disease implications, and future perspectives of the diverse PTMs regulating functions of S/MARBPs.
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Affiliation(s)
- Tanaya Roychowdhury
- Department of Biological Sciences, Birla Institute of Technology & Science, Pilani, India.,Cancer Biology and Inflammatory Disorder Division, Indian Institute of Chemical Biology, Kolkata, India
| | - Samit Chattopadhyay
- Department of Biological Sciences, Birla Institute of Technology & Science, Pilani, India.,Cancer Biology and Inflammatory Disorder Division, Indian Institute of Chemical Biology, Kolkata, India
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Ratliff ML, Mishra M, Frank MB, Guthridge JM, Webb CF. The Transcription Factor ARID3a Is Important for In Vitro Differentiation of Human Hematopoietic Progenitors. THE JOURNAL OF IMMUNOLOGY 2015; 196:614-23. [PMID: 26685208 DOI: 10.4049/jimmunol.1500355] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 11/10/2015] [Indexed: 12/12/2022]
Abstract
We recently reported that the transcription factor ARID3a is expressed in a subset of human hematopoietic progenitor stem cells in both healthy individuals and in patients with systemic lupus erythematosus. Numbers of ARID3a(+) lupus hematopoietic stem progenitor cells were associated with increased production of autoreactive Abs when those cells were introduced into humanized mouse models. Although ARID3a/Bright knockout mice died in utero, they exhibited decreased numbers of hematopoietic stem cells and erythrocytes, indicating that ARID3a is functionally important for hematopoiesis in mice. To explore the requirement for ARID3a for normal human hematopoiesis, hematopoietic stem cell progenitors from human cord blood were subjected to both inhibition and overexpression of ARID3a in vitro. Inhibition of ARID3a resulted in decreased B lineage cell production accompanied by increases in cells with myeloid lineage markers. Overexpression of ARID3a inhibited both myeloid and erythroid differentiation. Additionally, inhibition of ARID3a in hematopoietic stem cells resulted in altered expression of transcription factors associated with hematopoietic lineage decisions. These results suggest that appropriate regulation of ARID3a is critical for normal development of both myeloid and B lineage pathways.
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Affiliation(s)
| | - Meenu Mishra
- Walter Reed Army Institute of Research, Silver Spring, MD 20910
| | - Mark B Frank
- Oklahoma Medical Research Foundation, Oklahoma City, OK 73104
| | | | - Carol F Webb
- Oklahoma Medical Research Foundation, Oklahoma City, OK 73104; Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104; and Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104
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Xu Y, Zong W, Hou X, Yao J, Liu H, Li X, Zhao Y, Xiong L. OsARID3, an AT-rich Interaction Domain-containing protein, is required for shoot meristem development in rice. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 83:806-817. [PMID: 26121094 DOI: 10.1111/tpj.12927] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Revised: 06/23/2015] [Accepted: 06/24/2015] [Indexed: 06/04/2023]
Abstract
The shoot apical meristem (SAM) produces all of the plant's aerial organs. The SAM is established either during embryogenesis or experimentally in in vitro tissue culture. Although several factors including the Class I KNOTTED1-LIKE HOMEOBOX (KNOXI) proteins, auxin, and cytokinin are known to play essential roles in SAM development, the underlying mechanisms of SAM formation and maintenance are still largely not understood. Herein we demonstrate that OsARID3, a member of the rice (Oryza sativa) AT-rich Interaction Domain (ARID) family, is required for SAM development. Disruption of OsARID3 leads to a defective SAM, early seedling lethality, and impaired capacity of in vitro shoot regeneration. We show that the expression levels of several KNOXI genes and the biosynthetic genes for auxin and cytokinin are significantly altered in the Osarid3 mutant calli. Moreover, we determine that auxin concentrations are increased, whereas cytokinin levels are decreased, in Osarid3 calli. Furthermore, chromatin immunoprecipitation results demonstrate that OsARID3 binds directly to the KNOXI gene OSH71, the auxin biosynthetic genes OsYUC1 and OsYUC6, and the cytokinin biosynthetic genes OsIPT2 and OsIPT7. We also show through electrophoretic mobility shift assays that OsARID3 specifically binds to the AT-rich DNA sequences of the identified target genes. We conclude that OsARID3 is an AT-rich specific DNA-binding protein and that it plays a major role in SAM development in rice.
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Affiliation(s)
- Yan Xu
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China
| | - Wei Zong
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China
| | - Xin Hou
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA
| | - Jialing Yao
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China
| | - Hongbo Liu
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China
| | - Xianghua Li
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China
| | - Yunde Zhao
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China
- Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA, 92093-0116, USA
| | - Lizhong Xiong
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China
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Yokota T, Sudo T, Ishibashi T, Doi Y, Ichii M, Orirani K, Kanakura Y. Complementary regulation of early B-lymphoid differentiation by genetic and epigenetic mechanisms. Int J Hematol 2013; 98:382-9. [PMID: 23999941 DOI: 10.1007/s12185-013-1424-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Revised: 08/21/2013] [Accepted: 08/23/2013] [Indexed: 02/02/2023]
Abstract
Although B lymphopoiesis is one of the best-defined paradigms in cell differentiation, our knowledge of the regulatory mechanisms underlying its earliest processes, in which hematopoietic stem cells (HSCs) enter the B lineage, is limited. However, recent methodological advances in sorting progenitor cells and monitoring their epigenetic features have increased our understanding of HSC activities. It is now known that even the highly enriched HSC fraction is heterogeneous in terms of lymphopoietic potential. While surface markers and reporter proteins provide information on the sequential differentiation of B-lineage progenitors, complex interactions between transcription factors have also been shown to play a major role in this process. Epigenetic regulation of histones, nucleosomes, and chromatin appears to play a crucial background role in this elaborate transcription network. In this review, we summarize recent findings on the physiological processes of early B-lineage differentiation, which provides a new paradigm for understanding the harmonious action of genetic and epigenetic mechanisms.
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Affiliation(s)
- Takafumi Yokota
- Department of Hematology and Oncology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka, 565-0871, Japan,
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Oldham AL, Miner CA, Wang HC, Webb CF. The transcription factor Bright plays a role in marginal zone B lymphocyte development and autoantibody production. Mol Immunol 2011; 49:367-79. [PMID: 21963220 DOI: 10.1016/j.molimm.2011.09.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2011] [Revised: 09/07/2011] [Accepted: 09/12/2011] [Indexed: 10/17/2022]
Abstract
Previous data suggested that constitutive expression of the transcription factor Bright (B cell regulator of immunoglobulin heavy chain transcription), normally tightly regulated during B cell differentiation, was associated with autoantibody production. Here we show that constitutive Bright expression results in skewing of mature B lineage subpopulations toward marginal zone cells at the expense of the follicular subpopulation. C57Bl/6 transgenic mice constitutively expressing Bright in B lineage cells generated autoantibodies that were not the result of global increases in immunoglobulin or of breaches in key tolerance checkpoints typically defective in other autoimmune mouse models. Rather, autoimmunity correlated with increased numbers of marginal zone B cells and alterations in the phenotype and gene expression profiles of lymphocytes within the follicular B cell compartment. These data suggest a novel role for Bright in the normal development of mature B cell subsets and in autoantibody production.
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Affiliation(s)
- Athenia L Oldham
- Immunobiology and Cancer Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
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The herpes simplex virus immediate-early ubiquitin ligase ICP0 induces degradation of the ICP0 repressor protein E2FBP1. J Virol 2011; 85:3356-66. [PMID: 21248039 DOI: 10.1128/jvi.02105-10] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
E2FBP1/hDRIL1, a DNA-binding A/T-rich interaction domain (ARID) family transcription factor, is expressed ubiquitously in human tissues and plays an essential role in maintaining the proliferation potential of passage-limited human fibroblasts by dissociating promyelocytic leukemia nuclear bodies (PML-NBs). This effect on PML-NBs is similar to that of viral immediate-early gene products, such as infected cellular protein 0 (ICP0) from human herpes simplex virus 1 (HSV-1), which also disrupts PML-NBs to override the intrinsic cellular defense. Here we report that E2FBP1 inhibits accumulation of ICP0 RNA and, at the same time, is degraded via ICP0's herpes ubiquitin ligase 2 (HUL-2) activity upon HSV-1 infection. These reciprocal regulatory roles of ICP0 and E2FBP1 are linked in an ARID-dependent fashion. Our results suggest that E2FBP1 functions as an intrinsic cellular defense factor in spite of its PML-NB dissociation function.
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Wang TY, Han ZM, Chai YR, Zhang JH. A mini review of MAR-binding proteins. Mol Biol Rep 2010; 37:3553-60. [PMID: 20174991 DOI: 10.1007/s11033-010-0003-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2009] [Accepted: 02/08/2010] [Indexed: 02/08/2023]
Abstract
Genomic DNA encompasses several levels of organization, the nuclear matrix mediates the formation of DNA loop domains that are anchored to matrix attachment regions (MARs). By means of specific interaction with MAR binding proteins (MARBPs), MAR plays an important regulation role in enhancing transgene expression, decreasing expression variation among individuals of different transformants and serving as the replication origin. Through these years, some MARBPs have been identified and characterized from humans, plants, animals and algae so far and the list is growing. Most of MARBPs exist in a co-repressor/co-activator complex and involve in chromosome folding, regulation of gene expression, influencing cell development and inducing cell apoptosis. This review covers recent advances that have contributed to our understanding of MARBPs.
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Affiliation(s)
- Tian-Yun Wang
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Jinsui Road, Xinxiang, Henan, 453003, People's Republic of China.
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Garin G, Zibara K, Aguilar F, Lo M, Hurlstone A, Poston R, Mcgregor JL. 6A3-5/Osa2 is an early activated gene implicated in the control of vascular smooth muscle cell functions. J Biomed Biotechnol 2007; 2006:97287. [PMID: 17489020 PMCID: PMC1698265 DOI: 10.1155/jbb/2006/97287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Vascular smooth muscle cells (VSMC) growth plays a key role in the pathophysiology of vascular diseases. However, the molecular mechanisms controlling gene transcription in VSMC remain poorly understood. We previously identified, by differential display, a new gene (6A3-5) overexpressed in proliferating rat VSMC. In this study, we have cloned the full-length cDNA by screening a rat foetal brain cDNA library and investigated its functions. The 6A3-5 protein shows 4 putative conserved functional motifs: a DNA binding domain called ARID (AT-rich interaction domain), two recently described motifs (Osa Homology Domain), and a nuclear localization signal. The deduced protein sequence was observed to be 85% identical to the recently described human Osa2 gene. Immunolabelling, using an anti-6A3-5/Osa2 monoclonal antibody, showed a nuclear localization of the 6A3-5/Osa2 protein. In addition, PDGF upregulated 6A3-5/Osa2 expression at both the transcript and protein levels in a dose and time-dependent fashion. The pattern of upregulation by PDGF was reminiscent of the early responsive gene c-fos. The PDGF-induced upregulation of 6A3-5/Osa2 and proliferation of VSMC were significantly inhibited in a dose and sequence-dependent fashion by an antisense, but not by sense, scrambled or mismatched oligonucleotides directed against 6A3-5/Osa2. In VSMC of aortas derived from hypertensive (LH) rats, 6A3-5/Osa2 is overexpressed as compared to that in normotensive (LL) rats. The 6A3-5/Osa2-gene expression is downregulated by an ACE inhibitor and upregulated by exogenous AngiotensinII in LH rats. In summary, these results indicate that 6A3-5/Osa2 is an early activated gene that belongs to a new family of proteins involved in the control of VSMC growth.
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Affiliation(s)
- Gwenaele Garin
- INSERM XR331, Faculté of Médicine Laënnec, Lyon 69372, France
- Genomics and Atherothrombosis, Thrombosis Research Institute, London SW3 6LR, UK
| | - Kazem Zibara
- INSERM XR331, Faculté of Médicine Laënnec, Lyon 69372, France
- Genomics and Atherothrombosis, Thrombosis Research Institute, London SW3 6LR, UK
| | - Frederick Aguilar
- Département de Physiologie et Pharmacologie Clinique, Faculté de Pharmacie, Université Lyon 1, Lyon, France
| | - Ming Lo
- Département de Physiologie et Pharmacologie Clinique, Faculté de Pharmacie, Université Lyon 1, Lyon, France
| | - Adam Hurlstone
- Hubrecht Laboratory, Netherlands Institute for Developmental Biology, Utrecht, The Netherlands
| | - Robin Poston
- Center for Cardiovascular Biology and Medicine, King's College, University of London, UK
| | - John L. Mcgregor
- INSERM XR331, Faculté of Médicine Laënnec, Lyon 69372, France
- Genomics and Atherothrombosis, Thrombosis Research Institute, London SW3 6LR, UK
- Center for Cardiovascular Biology and Medicine, King's College, University of London, UK
- *John L. Mcgregor:
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Shankar M, Nixon JC, Maier S, Workman J, Farris AD, Webb CF. Anti-nuclear antibody production and autoimmunity in transgenic mice that overexpress the transcription factor Bright. THE JOURNAL OF IMMUNOLOGY 2007; 178:2996-3006. [PMID: 17312145 PMCID: PMC2705967 DOI: 10.4049/jimmunol.178.5.2996] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The B cell-restricted transcription factor, B cell regulator of Ig(H) transcription (Bright), up-regulates Ig H chain transcription 3- to 7-fold in activated B cells in vitro. Bright function is dependent upon both active Bruton's tyrosine kinase and its substrate, the transcription factor, TFII-I. In mouse and human B lymphocytes, Bright transcription is down-regulated in mature B cells, and its expression is tightly regulated during B cell differentiation. To determine how Bright expression affects B cell development, transgenic mice were generated that express Bright constitutively in all B lineage cells. These mice exhibited increases in total B220(+) B lymphocyte lineage cells in the bone marrow, but the relative percentages of the individual subpopulations were not altered. Splenic immature transitional B cells were significantly expanded both in total cell numbers and as increased percentages of cells relative to other B cell subpopulations. Serum Ig levels, particularly IgG isotypes, were increased slightly in the Bright-transgenic mice compared with littermate controls. However, immunization studies suggest that responses to all foreign Ags were not increased globally. Moreover, 4-wk-old Bright-transgenic mice produced anti-nuclear Abs. Older animals developed Ab deposits in the kidney glomeruli, but did not succumb to further autoimmune sequelae. These data indicate that enhanced Bright expression results in failure to maintain B cell tolerance and suggest a previously unappreciated role for Bright regulation in immature B cells. Bright is the first B cell-restricted transcription factor demonstrated to induce autoimmunity. Therefore, the Bright transgenics provide a novel model system for future analyses of B cell autoreactivity.
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Affiliation(s)
- Malini Shankar
- Immunobiology and Cancer, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Jamee C. Nixon
- Immunobiology and Cancer, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Shannon Maier
- Arthritis and Immunology Programs, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Jennifer Workman
- Arthritis and Immunology Programs, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - A. Darise Farris
- Arthritis and Immunology Programs, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- Oklahoma Medical Research Foundation, Department of Microbiology and Immunobiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Carol F. Webb
- Immunobiology and Cancer, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- Oklahoma Medical Research Foundation, Department of Microbiology and Immunobiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- Cell Biology Department, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
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Zhang X, Azhar G, Zhong Y, Wei JY. Zipzap/p200 is a novel zinc finger protein contributing to cardiac gene regulation. Biochem Biophys Res Commun 2006; 346:794-801. [PMID: 16782067 DOI: 10.1016/j.bbrc.2006.05.211] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2006] [Accepted: 05/29/2006] [Indexed: 10/24/2022]
Abstract
Serum response factor (SRF) plays an important role in the regulation of immediate-early genes and muscle-specific genes, while SRF cofactors may contribute significantly to assist in tissue-specific, development-stage related regulation of SRF-target genes. We recently cloned a novel SRF cofactor, termed zipzap/p200, which is a zinc finger protein yet to be characterized. We determined that zipzap/p200 is a 200-kDa protein with two classic C2H2 zinc fingers at the carboxyl terminus where the nucleotide sequence was highly conserved among human, mouse, and rat. The zipzap gene was expressed in multiple tissues and at multiple ages, including the fetal and adult heart. The zipzap protein interacted with SRF in vivo and was found in protein complexes containing SRF and other SRF cofactors, including p49/strap and Nkx2.5. Zipzap/p200 activated the promoter of cardiac genes and potentiated the effect of myocardin on ANF promoter activity. Therefore, zipzap may serve as a transcription co-activator for the regulation of cardiac gene expression. Our data support the notion that a number of SRF cofactors may participate in gene regulation and thereby contribute to the delicate control of gene expression in complex biological processes.
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Affiliation(s)
- Xiaomin Zhang
- Donald W. Reynolds Department of Geriatrics, The University of Arkansas for Medical Sciences and Geriatric Research, Education, and Clinical Center, Central Arkansas Veterans Healthcare System, Little Rock, AR 72205, USA.
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Fukuyo Y, Mogi K, Tsunematsu Y, Nakajima T. E2FBP1/hDril1 modulates cell growth through downregulation of promyelocytic leukemia bodies. Cell Death Differ 2004; 11:747-59. [PMID: 15017387 DOI: 10.1038/sj.cdd.4401412] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Promyelocytic leukemia nuclear bodies (PML-NBs) comprise multiple regulatory factors and play crucial roles in the maintenance of cellular integrity, while unregulated activation of PML-NBs induces death and premature senescence. Hence, the function of PML-NBs must be directed properly; however, the mechanism that regulates PML-NBs remains unclear. In this paper, we show that PML-NBs are disintegrated by an AT-rich interaction domain family protein E2FBP1/hDril1 through specific desumoylation of promyelocytic leukemia protein (PML) in vivo and in vitro. RNA interference-mediated downregulation of E2FBP1/hDril1 results in hyperplasis of PML-NBs and consequent commitment to PML-dependent premature senescence. Thus, the function of E2FBP1/hDril1 is required for maintenance of survival potential of the cells. Our data suggest a novel mechanism to govern cellular integrity through the modulation of nuclear depots.
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Affiliation(s)
- Y Fukuyo
- Department of Molecular Cellular Oncology and Microbiology, Graduate School, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan
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Lutzko C, Senadheera D, Skelton D, Petersen D, Kohn DB. Lentivirus vectors incorporating the immunoglobulin heavy chain enhancer and matrix attachment regions provide position-independent expression in B lymphocytes. J Virol 2003; 77:7341-51. [PMID: 12805432 PMCID: PMC164820 DOI: 10.1128/jvi.77.13.7341-7351.2003] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In the present studies we developed lentivirus vectors with regulated, consistent transgene expression in B lymphocytes by incorporating the immunoglobulin heavy chain enhancer (E micro ) with and without associated matrix attachment regions (E micro MAR) into lentivirus vectors. Incorporation of these fragments upstream of phosphoglycerate kinase (PGK) or cytomegalovirus promoters resulted in a two- to threefold increase in enhanced green fluorescent protein (EGFP) mean fluorescence intensity (MFI) in B-lymphoid but not T-lymphoid, myeloid, fibroblast, or carcinoma cell lines. A 1-log increase in EGFP expression was observed in B-lymphoid cells (but not myeloid cells) differentiated from human CD34(+) progenitors in vitro transduced with E micro - and E micro MAR-containing lentivectors. Lastly, we evaluated the expression from the E micro MAR element in mice 2 to 24 weeks posttransplant with transduced hematopoietic stem cells. In mice receiving vectors with the E micro and E micro MAR elements upstream of the PGK promoter, there was a 2- to 10-fold increase in EGFP expression in B cells (but not other cell types). Evaluation of the coefficient of variation of expression among different cell types demonstrated that consistent, position-independent transgene expression was observed exclusively in B cells transduced with the E micro MAR-containing vector and not other cells types or vectors. Proviral genomes with the E micro MAR element had increased chromatin accessibility, which likely contributed to the position independence of expression in B lymphocytes. In summary, incorporation of the E micro MAR element in lentivirus vectors resulted in enhanced, position-independent expression in primary B lymphocytes. These vectors provide a useful tool for the study of B-lymphocyte biology and the development of gene therapy for disorders affecting B lymphocytes, such as immune deficiencies.
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Affiliation(s)
- Carolyn Lutzko
- Division of Research Immunology and Bone Marrow Transplantation at Childrens Hospital Los Angeles, California 90027, USA
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