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Lim YH, Park YJ, Lee J, Kim JH. Transcriptional corepressor activity of CtBP1 is regulated by ISG15 modification. Anim Cells Syst (Seoul) 2024; 28:66-74. [PMID: 38405356 PMCID: PMC10885760 DOI: 10.1080/19768354.2024.2321354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Accepted: 02/14/2024] [Indexed: 02/27/2024] Open
Abstract
C-terminal binding protein 1 (CtBP1) is a critical transcriptional corepressor of many tumor suppressor genes and plays diverse roles in the progression of cancers. The transcriptional repression function of CtBP1 is mediated by recruiting histone-modifying enzymes, such as histone deacetylases and histone methyltransferases, to target genes by binding with DNA-interacting factors. Several post-translational modifications of CtBP1 have been identified, including ubiquitination, phosphorylation, and SUMOylation. This paper reports that CtBP1 is conjugated by ISG15. Endogenous CtBP1 was modified by ISG15 after interferon-α treatment in HeLa cells. The ISGylation process of CtBP1 was regulated by deISGylation enzyme USP18 and ISG15 E3 ligase EFP. Interestingly, CtBP1 ISGylation affected the binding affinity between CtBP1 and some components of CtBP1-associated transcriptional complexes. HDAC1 and LSD1 bound more efficiently to ISG15-conjugated CtBP1 than non-conjugated CtBP1. On the other hand, binding between CtBP1 and HDAC4 was unaffected by ISG15 modification. Furthermore, ISG15 modification enhanced the transcriptional repression activity of CtBP1 on several target genes related to EMT and apoptosis. These findings suggest that the ISG15 modification of CtBP1 modulates the function and activity of CtBP1 and that CtBP1 ISGylation may provide a new insight for CtBP1-mediated cancers.
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Affiliation(s)
- Yun Hwan Lim
- Department of Biological Sciences, Inha University, Incheon, Korea
| | - Yoon Jin Park
- Department of Biological Sciences, Inha University, Incheon, Korea
| | - Jieun Lee
- Department of Biological Sciences, Inha University, Incheon, Korea
| | - Jung Hwa Kim
- Department of Biological Sciences, Inha University, Incheon, Korea
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2
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Causier B, McKay M, Hopes T, Lloyd J, Wang D, Harrison CJ, Davies B. The TOPLESS corepressor regulates developmental switches in the bryophyte Physcomitrium patens that were critical for plant terrestrialisation. Plant J 2023; 115:1331-1344. [PMID: 37243383 PMCID: PMC10953049 DOI: 10.1111/tpj.16322] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 04/27/2023] [Accepted: 05/23/2023] [Indexed: 05/28/2023]
Abstract
The plant-specific TOPLESS (TPL) family of transcriptional corepressors is integral to multiple angiosperm developmental processes. Despite this, we know little about TPL function in other plants. To address this gap, we investigated the roles TPL plays in the bryophyte Physcomitrium patens, which diverged from angiosperms approximately 0.5 billion years ago. Although complete loss of PpTPL function is lethal, transgenic lines with reduced PpTPL activity revealed that PpTPLs are essential for two fundamental developmental switches in this plant: the transitions from basal photosynthetic filaments (chloronemata) to specialised foraging filaments (caulonemata) and from two-dimensional (2D) to three-dimensional (3D) growth. Using a transcriptomics approach, we integrated PpTPL into the regulatory network governing 3D growth and we propose that PpTPLs represent another important class of regulators that are essential for the 2D-to-3D developmental switch. Transcriptomics also revealed a previously unknown role for PpTPL in the regulation of flavonoids. Intriguingly, 3D growth and the formation of caulonemata were crucial innovations that facilitated the colonisation of land by plants, a major transformative event in the history of life on Earth. We conclude that TPL, which existed before the land plants, was co-opted into new developmental pathways, enabling phytoterrestrialisation and the evolution of land plants.
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Affiliation(s)
- Barry Causier
- Centre for Plant Sciences, Faculty of Biological SciencesUniversity of LeedsLeedsLS2 9JTUK
| | - Mary McKay
- Centre for Plant Sciences, Faculty of Biological SciencesUniversity of LeedsLeedsLS2 9JTUK
| | - Tayah Hopes
- Centre for Plant Sciences, Faculty of Biological SciencesUniversity of LeedsLeedsLS2 9JTUK
- School of Molecular and Cellular Biology, Faculty of Biological SciencesUniversity of LeedsLeedsLS2 9JTUK
| | - James Lloyd
- Centre for Plant Sciences, Faculty of Biological SciencesUniversity of LeedsLeedsLS2 9JTUK
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular SciencesThe University of Western AustraliaPerthWA6009Australia
| | - Dapeng Wang
- LeedsOmicsUniversity of LeedsLeedsLS2 9JTUK
- National Heart and Lung Institute, Imperial College LondonLondonSW3 6LYUK
| | - C. Jill Harrison
- School of Biological SciencesUniversity of Bristol24 Tyndall AvenueBristolBS8 1TQUK
| | - Brendan Davies
- Centre for Plant Sciences, Faculty of Biological SciencesUniversity of LeedsLeedsLS2 9JTUK
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3
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Huang LJ, Wang Y, Lin Z, Jiang D, Luo Y, Li N. The role of corepressor HOS15-mediated epigenetic regulation of flowering. Front Plant Sci 2023; 13:1101912. [PMID: 36704168 PMCID: PMC9871556 DOI: 10.3389/fpls.2022.1101912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 12/21/2022] [Indexed: 06/18/2023]
Abstract
Regulation of gene expression underpins gene function and is essential for regulation of physiological roles. Epigenetic modifications regulate gene transcription by physically facilitating relaxation or condensation of target loci in chromatin. Transcriptional corepressors are involved in chromatin remodeling and regulate gene expression by establishing repressive complexes. Genetic and biochemical studies reveal that a member of the Groucho/Thymidine uptake 1 (Gro/Tup1) corepressor family, HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENE 15 (HOS15), is recruited via the evening complex (EC) to the GIGANTEA (GI) promoter to repress gene expression, and modulating flowering time. Therefore, HOS15 connects photoperiodic pathway and epigenetic mechanism to control flowering time in plants. In addition, growing body of evidence support a diverse roles of the epigenetic regulator HOS15 in fine-tuning plant development and growth by integrating intrinsic genetic components and various environmental signals.
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Affiliation(s)
- Li-Jun Huang
- State Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees, College of Forestry, Central South University of Forestry and Technology, Changsha, China
| | - Yukun Wang
- State Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees, College of Forestry, Central South University of Forestry and Technology, Changsha, China
| | - Zeng Lin
- State Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees, College of Forestry, Central South University of Forestry and Technology, Changsha, China
| | - Dong Jiang
- State Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees, College of Forestry, Central South University of Forestry and Technology, Changsha, China
| | - Yong Luo
- School of Chemistry and Environmental Science, Xiangnan University, Chenzhou, China
| | - Ning Li
- State Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees, College of Forestry, Central South University of Forestry and Technology, Changsha, China
- Key Laboratory of Forest Bio-resources and Integrated Pest Management for Higher Education in Hunan Province, Central South University of Forestry and Technology, Changsha, China
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4
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Saul J, Hirose T, Horvitz HR. The transcriptional corepressor CTBP-1 acts with the SOX family transcription factor EGL-13 to maintain AIA interneuron cell identity in Caenorhabditis elegans. eLife 2022; 11:74557. [PMID: 35119366 PMCID: PMC8816384 DOI: 10.7554/elife.74557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Accepted: 01/10/2022] [Indexed: 11/17/2022] Open
Abstract
Cell identity is characterized by a distinct combination of gene expression, cell morphology, and cellular function established as progenitor cells divide and differentiate. Following establishment, cell identities can be unstable and require active and continuous maintenance throughout the remaining life of a cell. Mechanisms underlying the maintenance of cell identities are incompletely understood. Here, we show that the gene ctbp-1, which encodes the transcriptional corepressor C-terminal binding protein-1 (CTBP-1), is essential for the maintenance of the identities of the two AIA interneurons in the nematode Caenorhabditis elegans. ctbp-1 is not required for the establishment of the AIA cell fate but rather functions cell-autonomously and can act in later larval stage and adult worms to maintain proper AIA gene expression, morphology and function. From a screen for suppressors of the ctbp-1 mutant phenotype, we identified the gene egl-13, which encodes a SOX family transcription factor. We found that egl-13 regulates AIA function and aspects of AIA gene expression, but not AIA morphology. We conclude that the CTBP-1 protein maintains AIA cell identity in part by utilizing EGL-13 to repress transcriptional activity in the AIAs. More generally, we propose that transcriptional corepressors like CTBP-1 might be critical factors in the maintenance of cell identities, harnessing the DNA-binding specificity of transcription factors like EGL-13 to selectively regulate gene expression in a cell-specific manner.
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Affiliation(s)
- Josh Saul
- Department of Biology, Massachusetts Institute of Technology, Howard Hughes Medical Institute, Cambridge, United States
| | - Takashi Hirose
- Department of Biology, Massachusetts Institute of Technology, Howard Hughes Medical Institute, Cambridge, United States
| | - H Robert Horvitz
- Department of Biology, Massachusetts Institute of Technology, Howard Hughes Medical Institute, Cambridge, United States
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5
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Marcum RD, Hsieh J, Giljen M, Justice E, Daffern N, Zhang Y, Radhakrishnan I. A Capped Tudor Domain within a Core Subunit of the Sin3L/Rpd3L Histone Deacetylase Complex Binds to Nucleic Acid G-Quadruplexes. J Biol Chem 2021; 298:101558. [PMID: 34979096 PMCID: PMC8800102 DOI: 10.1016/j.jbc.2021.101558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 12/28/2021] [Accepted: 12/29/2021] [Indexed: 12/04/2022] Open
Abstract
Chromatin-modifying complexes containing histone deacetylase (HDAC) activities play critical roles in the regulation of gene transcription in eukaryotes. These complexes are thought to lack intrinsic DNA-binding activity, but according to a well-established paradigm, they are recruited via protein–protein interactions by gene-specific transcription factors and posttranslational histone modifications to their sites of action on the genome. The mammalian Sin3L/Rpd3L complex, comprising more than a dozen different polypeptides, is an ancient HDAC complex found in diverse eukaryotes. The subunits of this complex harbor conserved domains and motifs of unknown structure and function. Here, we show that Sds3, a constitutively-associated subunit critical for the proper functioning of the Sin3L/Rpd3L complex, harbors a type of Tudor domain that we designate the capped Tudor domain. Unlike canonical Tudor domains that bind modified histones, the Sds3 capped Tudor domain binds to nucleic acids that can form higher-order structures such as G-quadruplexes and shares similarities with the knotted Tudor domain of the Esa1 histone acetyltransferase that was previously shown to bind single-stranded RNA. Our findings expand the range of macromolecules capable of recruiting the Sin3L/Rpd3L complex and draw attention to potentially new biological roles for this HDAC complex.
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Affiliation(s)
- Ryan Dale Marcum
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208-3500
| | - Joseph Hsieh
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208-3500
| | - Maksim Giljen
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208-3500
| | - Emily Justice
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208-3500
| | - Nicolas Daffern
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208-3500
| | - Yongbo Zhang
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208-3500
| | - Ishwar Radhakrishnan
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208-3500.
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Hu S, Chen Z, Gu J, Tan L, Zhang M, Lin W. TLE2 is associated with favorable prognosis and regulates cell growth and gemcitabine sensitivity in pancreatic cancer. Ann Transl Med 2020; 8:1017. [PMID: 32953817 PMCID: PMC7475492 DOI: 10.21037/atm-20-5492] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Background The transducin-like enhancer of split (TLE) proteins are a group of transcriptional corepressors. They play a crucial role in cellular homeostasis and are involved in various cancers. Compared with other TLE family members, little is known about the role and the underlying mechanism of TLE2 in human cancers. This study aimed to investigate the role of TLE2 in pancreatic ductal adenocarcinoma (PDAC) using in silico analysis and in vitro experiments. Methods Data were obtained from the Cancer Genome Atlas (TCGA) database to evaluate the prognostic value of TLE2 in PDAC. The MiaPaCa-2 cell line was transfected with siRNA to inhibit endogenous TLE2 expression, and a PANC-1 cell line with stable TLE2 overexpression was constructed using lentiviral transfection, which were confirmed by real-time polymerase chain reaction and western blotting. MTT assay, transwell invasion assays, and flow cytometry were carried out to assess cell viability, invasion, and apoptosis, respectively. TLE2 expression in PDAC cells was altered to evaluate their sensitivity to gemcitabine. Gene set enrichment analysis (GSEA) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were conducted to predict the biological role of TLE2. Results High expression of TLEs was significantly associated with increased overall survival (OS) and disease-free survival (DFS) in patients with PDAC. Among the PDAC cell lines, TLE2 expression was lowest and highest in PANC-1 cells and MiaPaCa-2 cells, respectively. TLE2 overexpression impaired the proliferation ability of PANC-1 cells and downregulation of TLE2 promoted the proliferation of MiaPaCa-2 cells. Upregulation of TLE2 in PANC-1 cells induced S-phase accumulation and sensitivity to gemcitabine. In contrast, the downregulation of TLE2 in MiaPaCa-2 cells promoted resistance to gemcitabine. Moreover, bioinformatics analysis also revealed the potential tumor suppressor role of TLE2 and uncovered a close relationship between TLE2 expression and cell cycle regulation. Conclusions Our results suggest that TLE2 expression is correlated with prognosis in patients with PDAC and show that TLE2 plays a central role in the regulation of cell proliferation, the cell cycle, and gemcitabine sensitivity. This study provides new insights and evidence that TLE2 functions as a tumor suppressor gene and prognostic marker in PDAC.
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Affiliation(s)
- Shixiong Hu
- The First Affiliated Hospital of Jinan University, Guangzhou, China.,Department of General Surgery, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Zhengbo Chen
- Department of General Surgery, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Jinling Gu
- Department of General Surgery, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Liyang Tan
- Department of General Surgery, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Meifeng Zhang
- Department of General Surgery, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Weidong Lin
- The Second People's Hospital of Foshan, Affiliated Foshan Hospital of Southern Medical University, Foshan, China
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7
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Steinauer N, Guo C, Zhang J. The transcriptional corepressor CBFA2T3 inhibits all- trans-retinoic acid-induced myeloid gene expression and differentiation in acute myeloid leukemia. J Biol Chem 2020; 295:8887-8900. [PMID: 32434928 PMCID: PMC7335779 DOI: 10.1074/jbc.ra120.013042] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 05/17/2020] [Indexed: 01/10/2023] Open
Abstract
CBFA2/RUNX1 partner transcriptional co-repressor 3 (CBFA2T3, also known as MTG16 or ETO2) is a myeloid translocation gene family protein that functions as a master transcriptional corepressor in hematopoiesis. Recently, it has been shown that CBFA2T3 maintains leukemia stem cell gene expression and promotes relapse in acute myeloid leukemia (AML). However, a role for CBFA2T3 in myeloid differentiation of AML has not been reported. Here, we show that CBFA2T3 represses retinoic acid receptor (RAR) target gene expression and inhibits all-trans-retinoic acid (ATRA)-induced myeloid differentiation of AML cells. ChIP-Seq revealed that CBFA2T3 targets the RARα/RXRα cistrome in U937 AML cells, predominantly at myeloid-specific enhancers associated with terminal differentiation. CRISPR/Cas9-mediated abrogation of CBFA2T3 resulted in spontaneous and ATRA-induced activation of myeloid-specific genes in a manner correlated with myeloid differentiation. Importantly, these effects were reversed by CBFA2T3 re-expression. Mechanistic studies showed that CBFA2T3 inhibits RAR target gene transcription by acting at an early step to regulate histone acetyltransferase recruitment, histone acetylation, and chromatin accessibility at RARα target sites, independently of the downstream, RAR-mediated steps of transcription. Finally, we validated the inhibitory effect of CBFA2T3 on RAR in multiple AML subtypes and patient samples. To our knowledge, this is the first study to show that CBFA2T3 down-regulation is both necessary and sufficient for enhancing ATRA-induced myeloid gene expression and differentiation of AML cells. Our findings suggest that CBFA2T3 can serve as a potential target for enhancing AML responsiveness to ATRA differentiation therapies.
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Affiliation(s)
- Nickolas Steinauer
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, St. Louis, Missouri, USA
| | - Chun Guo
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, St. Louis, Missouri, USA
| | - Jinsong Zhang
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, St. Louis, Missouri, USA.
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8
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Luo W, Chen I, Chen Y, Alkam D, Wang Y, Semenza GL. PRDX2 and PRDX4 are negative regulators of hypoxia-inducible factors under conditions of prolonged hypoxia. Oncotarget 2016; 7:6379-97. [PMID: 26837221 PMCID: PMC4872721 DOI: 10.18632/oncotarget.7142] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 01/27/2016] [Indexed: 12/14/2022] Open
Abstract
Hypoxia-inducible factors (HIFs) control the transcription of genes that are crucial for the pathogenesis of cancer and other human diseases. The transcriptional activity of HIFs is rapidly increased upon exposure to hypoxia, but expression of some HIF target genes decreases during prolonged hypoxia. However, the underlying mechanism for feedback inhibition is not completely understood. Here, we report that peroxiredoxin 2 (PRDX2) and PRDX4 interact with HIF-1α and HIF-2α in vitro and in hypoxic HeLa cells. Prolonged hypoxia increases the nuclear translocation of PRDX2 and PRDX4. As a result, PRDX2 and PRDX4 impair HIF-1 and HIF-2 binding to the hypoxia response elements of a subset of HIF target genes, thereby inhibiting gene transcription in cells exposed to prolonged hypoxia. PRDX2 and PRDX4 have no effect on the recruitment of p300 and RNA polymerase II to HIF target genes and the enzymatic activity of PRDX2 and PRDX4 is not required for inhibition of HIF-1 and HIF-2. We also demonstrate that PRDX2 is a direct HIF target gene and that PRDX2 expression is induced by prolonged hypoxia. These findings uncover a novel feedback mechanism for inhibition of HIF transcriptional activity under conditions of prolonged hypoxia.
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Affiliation(s)
- Weibo Luo
- Vascular Program, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Department of Pathology, UT Southwestern Medical Center, Dallas, TX, USA.,Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Ivan Chen
- Vascular Program, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Yan Chen
- Department of Pathology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Duah Alkam
- Department of Pathology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Yingfei Wang
- Department of Pathology, UT Southwestern Medical Center, Dallas, TX, USA.,Department of Neurology and Neurotherapeutics, UT Southwestern Medical Center, Dallas, TX, USA
| | - Gregg L Semenza
- Vascular Program, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Department of Radiation Oncology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Department of McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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9
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Sarmento OF, Svingen PA, Xiong Y, Sun Z, Bamidele AO, Mathison AJ, Smyrk TC, Nair AA, Gonzalez MM, Sagstetter MR, Baheti S, McGovern DPB, Friton JJ, Papadakis KA, Gautam G, Xavier RJ, Urrutia RA, Faubion WA. The Role of the Histone Methyltransferase Enhancer of Zeste Homolog 2 (EZH2) in the Pathobiological Mechanisms Underlying Inflammatory Bowel Disease (IBD). J Biol Chem 2016; 292:706-722. [PMID: 27909059 DOI: 10.1074/jbc.m116.749663] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 11/21/2016] [Indexed: 12/14/2022] Open
Abstract
Regulatory T (Treg) cells expressing the transcription factor FOXP3 play a pivotal role in maintaining immunologic self-tolerance. We and others have shown previously that EZH2 is recruited to the FOXP3 promoter and its targets in Treg cells. To further address the role for EZH2 in Treg cellular function, we have now generated mice that lack EZH2 specifically in Treg cells (EZH2Δ/ΔFOXP3+). We find that EZH2 deficiency in FOXP3+ T cells results in lethal multiorgan autoimmunity. We further demonstrate that EZH2Δ/ΔFOXP3+ T cells lack a regulatory phenotype in vitro and secrete proinflammatory cytokines. Of special interest, EZH2Δ/ΔFOXP3+ mice develop spontaneous inflammatory bowel disease. Guided by these results, we assessed the FOXP3 and EZH2 gene networks by RNA sequencing in isolated intestinal CD4+ T cells from patients with Crohn's disease. Gene network analysis demonstrates that these CD4+ T cells display a Th1/Th17-like phenotype with an enrichment of gene targets shared by FOXP3 and EZH2. Combined, these results suggest that the inflammatory milieu found in Crohn's disease could lead to or result from deregulation of FOXP3/EZH2-enforced T cell gene networks contributing to the underlying intestinal inflammation.
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Affiliation(s)
- Olga F Sarmento
- From the Epigenetics and Chromatin Dynamics Laboratory, Division of Gastroenterology and Hepatology and Translational Epigenomic Program, Center for Individualized Medicine
| | - Phyllis A Svingen
- From the Epigenetics and Chromatin Dynamics Laboratory, Division of Gastroenterology and Hepatology and Translational Epigenomic Program, Center for Individualized Medicine
| | - Yuning Xiong
- From the Epigenetics and Chromatin Dynamics Laboratory, Division of Gastroenterology and Hepatology and Translational Epigenomic Program, Center for Individualized Medicine
| | - Zhifu Sun
- Division of Biomedical Statistics and Informatics, and
| | - Adebowale O Bamidele
- From the Epigenetics and Chromatin Dynamics Laboratory, Division of Gastroenterology and Hepatology and Translational Epigenomic Program, Center for Individualized Medicine
| | - Angela J Mathison
- From the Epigenetics and Chromatin Dynamics Laboratory, Division of Gastroenterology and Hepatology and Translational Epigenomic Program, Center for Individualized Medicine
| | - Thomas C Smyrk
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota 55905
| | - Asha A Nair
- Division of Biomedical Statistics and Informatics, and
| | - Michelle M Gonzalez
- From the Epigenetics and Chromatin Dynamics Laboratory, Division of Gastroenterology and Hepatology and Translational Epigenomic Program, Center for Individualized Medicine
| | - Mary R Sagstetter
- From the Epigenetics and Chromatin Dynamics Laboratory, Division of Gastroenterology and Hepatology and Translational Epigenomic Program, Center for Individualized Medicine
| | | | - Dermot P B McGovern
- the F. Widjaja Foundation Inflammatory Bowel and Immunobiology Research Institute, Cedars-Sinai Hospital, Los Angeles, California 90048
| | - Jessica J Friton
- From the Epigenetics and Chromatin Dynamics Laboratory, Division of Gastroenterology and Hepatology and Translational Epigenomic Program, Center for Individualized Medicine
| | - Konstantinos A Papadakis
- From the Epigenetics and Chromatin Dynamics Laboratory, Division of Gastroenterology and Hepatology and Translational Epigenomic Program, Center for Individualized Medicine
| | - Goel Gautam
- the Gastrointestinal Unit and Center for the Study of Inflammatory Bowel Disease, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, and.,the Center for Computational and Integrative Biology, The Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142
| | - Ramnik J Xavier
- the Gastrointestinal Unit and Center for the Study of Inflammatory Bowel Disease, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, and.,the Center for Computational and Integrative Biology, The Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142
| | - Raul A Urrutia
- From the Epigenetics and Chromatin Dynamics Laboratory, Division of Gastroenterology and Hepatology and Translational Epigenomic Program, Center for Individualized Medicine
| | - William A Faubion
- From the Epigenetics and Chromatin Dynamics Laboratory, Division of Gastroenterology and Hepatology and Translational Epigenomic Program, Center for Individualized Medicine,
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10
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Wong KH, Struhl K. The Cyc8-Tup1 complex inhibits transcription primarily by masking the activation domain of the recruiting protein. Genes Dev 2011; 25:2525-39. [PMID: 22156212 PMCID: PMC3243062 DOI: 10.1101/gad.179275.111] [Citation(s) in RCA: 108] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Accepted: 10/14/2011] [Indexed: 12/22/2022]
Abstract
The yeast Tup1-Cyc8 corepressor complex is recruited to promoters by DNA-binding repressors, but the mechanisms by which it inhibits expression of genes involved in various stress pathways are poorly understood. Conditional and rapid depletion of Tup1 from the nucleus leads to concurrent nucleosome depletion and histone acetylation, recruitment of coactivators (Swi/Snf, SAGA, and Mediator), and increased transcriptional activity. Conversely, coactivator dissociation occurs rapidly upon rerepression by Cyc8-Tup1, although coactivator association and transcription can be blocked even in the absence of nucleosomes. The coactivators are recruited to the sites where Tup1 was located prior to depletion, indicating that the repressor proteins that recruit Tup1 function as activators in its absence. Last, Cyc8-Tup1 can interact with activation domains in vivo. Thus, Cyc8-Tup1 regulates transcription primarily by masking and inhibiting the transcriptional activation domains of the recruiting proteins, not by acting as a corepressor. We suggest that the corepressor function of Cyc8-Tup1 makes only a modest contribution to expression of target genes, specifically to keep expression levels below the nonactivated state.
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Affiliation(s)
| | - Kevin Struhl
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA
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11
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Ariyoshi M, Schwabe JWR. A conserved structural motif reveals the essential transcriptional repression function of Spen proteins and their role in developmental signaling. Genes Dev 2003; 17:1909-20. [PMID: 12897056 PMCID: PMC196244 DOI: 10.1101/gad.266203] [Citation(s) in RCA: 119] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Spen proteins regulate the expression of key transcriptional effectors in diverse signaling pathways. They are large proteins characterized by N-terminal RNA-binding motifs and a highly conserved C-terminal SPOC domain. The specific biological role of the SPOC domain (Spen paralog and ortholog C-terminal domain), and hence, the common function of Spen proteins, has been unclear to date. The Spen protein, SHARP (SMRT/HDAC1-associated repressor protein), was identified as a component of transcriptional repression complexes in both nuclear receptor and Notch/RBP-Jkappa signaling pathways. We have determined the 1.8 A crystal structure of the SPOC domain from SHARP. This structure shows that essentially all of the conserved surface residues map to a positively charged patch. Structure-based mutational analysis indicates that this conserved region is responsible for the interaction between SHARP and the universal transcriptional corepressor SMRT/NCoR (silencing mediator for retinoid and thyroid receptors/nuclear receptor corepressor. We demonstrate that this interaction involves a highly conserved acidic motif at the C terminus of SMRT/NCoR. These findings suggest that the conserved function of the SPOC domain is to mediate interaction with SMRT/NCoR corepressors, and that Spen proteins play an essential role in the repression complex.
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Affiliation(s)
- Mariko Ariyoshi
- Medical Research Council, Laboratory of Molecular Biology, Cambridge CB2 2QH, UK
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