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Sein H, Reinmets K, Peil K, Kristjuhan K, Värv S, Kristjuhan A. Rpb9-deficient cells are defective in DNA damage response and require histone H3 acetylation for survival. Sci Rep 2018; 8:2949. [PMID: 29440683 PMCID: PMC5811553 DOI: 10.1038/s41598-018-21110-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 01/29/2018] [Indexed: 11/09/2022] Open
Abstract
Rpb9 is a non-essential subunit of RNA polymerase II that is involved in DNA transcription and repair. In budding yeast, deletion of RPB9 causes several phenotypes such as slow growth and temperature sensitivity. We found that simultaneous mutation of multiple N-terminal lysines within histone H3 was lethal in rpb9Δ cells. Our results indicate that hypoacetylation of H3 leads to inefficient repair of DNA double-strand breaks, while activation of the DNA damage checkpoint regulators γH2A and Rad53 is suppressed in Rpb9-deficient cells. Combination of H3 hypoacetylation with the loss of Rpb9 leads to genomic instability, aberrant segregation of chromosomes in mitosis, and eventually to cell death. These results indicate that H3 acetylation becomes essential for efficient DNA repair and cell survival if a DNA damage checkpoint is defective.
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Affiliation(s)
- Henel Sein
- Department of Cell Biology, Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010, Tartu, Estonia
| | - Kristina Reinmets
- Department of Cell Biology, Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010, Tartu, Estonia
| | - Kadri Peil
- Department of Cell Biology, Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010, Tartu, Estonia
| | - Kersti Kristjuhan
- Department of Cell Biology, Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010, Tartu, Estonia
| | - Signe Värv
- Department of Cell Biology, Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010, Tartu, Estonia.,Department of Biosciences, Section for Biochemistry and Molecular Biology, University of Oslo, Blindernveien 31, 0371, Oslo, Norway
| | - Arnold Kristjuhan
- Department of Cell Biology, Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010, Tartu, Estonia.
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Martel A, Brar H, Mayer BF, Charron JB. Diversification of the Histone Acetyltransferase GCN5 through Alternative Splicing in Brachypodium distachyon. FRONTIERS IN PLANT SCIENCE 2017; 8:2176. [PMID: 29312415 PMCID: PMC5743026 DOI: 10.3389/fpls.2017.02176] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 12/12/2017] [Indexed: 06/07/2023]
Abstract
The epigenetic modulatory SAGA complex is involved in various developmental and stress responsive pathways in plants. Alternative transcripts of the SAGA complex's enzymatic subunit GCN5 have been identified in Brachypodium distachyon. These splice variants differ based on the presence and integrity of their conserved domain sequences: the histone acetyltransferase domain, responsible for catalytic activity, and the bromodomain, involved in acetyl-lysine binding and genomic loci targeting. GCN5 is the wild-type transcript, while alternative splice sites result in the following transcriptional variants: L-GCN5, which is missing the bromodomain and S-GCN5, which lacks the bromodomain as well as certain motifs of the histone acetyltransferase domain. Absolute mRNA quantification revealed that, across eight B. distachyon accessions, GCN5 was the dominant transcript isoform, accounting for up to 90% of the entire transcript pool, followed by L-GCN5 and S-GCN5. A cycloheximide treatment further revealed that the S-GCN5 splice variant was degraded through the nonsense-mediated decay pathway. All alternative BdGCN5 transcripts displayed similar transcript profiles, being induced during early exposure to heat and displaying higher levels of accumulation in the crown, compared to aerial tissues. All predicted protein isoforms localize to the nucleus, which lends weight to their purported epigenetic functions. S-GCN5 was incapable of forming an in vivo protein interaction with ADA2, the transcriptional adaptor that links the histone acetyltransferase subunit to the SAGA complex, while both GCN5 and L-GCN5 interacted with ADA2, which suggests that a complete histone acetyltransferase domain is required for BdGCN5-BdADA2 interaction in vivo. Thus, there has been a diversification in BdGCN5 through alternative splicing that has resulted in differences in conserved domain composition, transcript fate and in vivo protein interaction partners. Furthermore, our results suggest that B. distachyon may harbor compositionally distinct SAGA-like complexes that differ based on their histone acetyltransferase subunit.
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Zucconi BE, Cole PA. Allosteric regulation of epigenetic modifying enzymes. Curr Opin Chem Biol 2017; 39:109-115. [PMID: 28689145 DOI: 10.1016/j.cbpa.2017.05.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Accepted: 05/29/2017] [Indexed: 12/14/2022]
Abstract
Epigenetic enzymes including histone modifying enzymes are key regulators of gene expression in normal and disease processes. Many drug development strategies to target histone modifying enzymes have focused on ligands that bind to enzyme active sites, but allosteric pockets offer potentially attractive opportunities for therapeutic development. Recent biochemical studies have revealed roles for small molecule and peptide ligands binding outside of the active sites in modulating the catalytic activities of histone modifying enzymes. Here we highlight several examples of allosteric regulation of epigenetic enzymes and discuss the biological significance of these findings.
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Affiliation(s)
- Beth E Zucconi
- Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, 725 N. Wolfe St., Baltimore, MD 21205, USA.
| | - Philip A Cole
- Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, 725 N. Wolfe St., Baltimore, MD 21205, USA.
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Rösler SM, Kramer K, Finkemeier I, Humpf HU, Tudzynski B. The SAGA complex in the rice pathogenFusarium fujikuroi: structure and functional characterization. Mol Microbiol 2016; 102:951-974. [DOI: 10.1111/mmi.13528] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/10/2016] [Indexed: 12/11/2022]
Affiliation(s)
- Sarah M. Rösler
- Institute of Food Chemistry, Westfälische Wilhelms-Universität Münster; Corrensstraße 45 Münster 48149 Germany
- Institute of Plant Biology and Biotechnology, Westfälische Wilhelms-Universität Münster; Schlossplatz 7/8 Münster 48143 Germany
| | - Katharina Kramer
- Max Planck Institute for Plant Breeding Research, Plant Proteomics Group; Carl-von-Linne-Weg 10 Cologne 50829 Germany
| | - Iris Finkemeier
- Institute of Plant Biology and Biotechnology, Westfälische Wilhelms-Universität Münster; Schlossplatz 7/8 Münster 48143 Germany
- Max Planck Institute for Plant Breeding Research, Plant Proteomics Group; Carl-von-Linne-Weg 10 Cologne 50829 Germany
| | - Hans-Ulrich Humpf
- Institute of Food Chemistry, Westfälische Wilhelms-Universität Münster; Corrensstraße 45 Münster 48149 Germany
| | - Bettina Tudzynski
- Institute of Plant Biology and Biotechnology, Westfälische Wilhelms-Universität Münster; Schlossplatz 7/8 Münster 48143 Germany
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Appikonda S, Thakkar KN, Barton MC. Regulation of gene expression in human cancers by TRIM24. DRUG DISCOVERY TODAY. TECHNOLOGIES 2016; 19:57-63. [PMID: 27769359 DOI: 10.1016/j.ddtec.2016.05.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 05/15/2016] [Accepted: 05/19/2016] [Indexed: 01/21/2023]
Abstract
Tripartite Motif-containing protein 24 (TRIM24) functions as an E3 ligase targeting p53 for ubiquitination, a histone 'reader' that interacts with a specific signature of histone post-translational modifications and a co-regulator of nuclear receptor-regulated transcription. Although mouse models of Trim24 depletion suggest that TRIM24 may be a liver-specific tumor suppressor, several studies show that human TRIM24 is an oncogene when aberrantly over expressed. This review focuses on the mechanisms of TRIM24 functions in oncogenesis and metabolic reprogramming, which underlie recent interest in therapeutic targeting of aberrant TRIM24 in human cancers.
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Affiliation(s)
- Srikanth Appikonda
- Department of Epigenetics and Molecular Carcinogenesis, Center for Cancer Epigenetics, Houston, TX 77030, USA
| | - Kaushik N Thakkar
- Department of Epigenetics and Molecular Carcinogenesis, Center for Cancer Epigenetics, Houston, TX 77030, USA; University of Texas Graduate School of Biomedical Sciences at Houston, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Michelle Craig Barton
- Department of Epigenetics and Molecular Carcinogenesis, Center for Cancer Epigenetics, Houston, TX 77030, USA; University of Texas Graduate School of Biomedical Sciences at Houston, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
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ElBashir R, Vanselow JT, Kraus A, Janzen CJ, Siegel TN, Schlosser A. Fragment ion patchwork quantification for measuring site-specific acetylation degrees. Anal Chem 2016; 87:9939-45. [PMID: 26335048 DOI: 10.1021/acs.analchem.5b02517] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We introduce fragment ion patchwork quantification as a new mass spectrometry-based approach for the highly accurate quantification of site-specific acetylation degrees. This method combines (13)C1-acetyl derivatization on the protein level, proteolysis by low-specificity proteases and quantification on the fragment ion level. Acetylation degrees are determined from the isotope patterns of acetylated b and y ions. We show that this approach allows to determine site-specific acetylation degrees of all lysine residues for all core histones of Trypanosoma brucei. In addition, we demonstrate how this approach can be used to identify substrate sites of histone acetyltransferases.
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Affiliation(s)
| | | | | | - Christian J Janzen
- Department of Cell & Developmental Biology, Biocenter University of Wuerzburg , Am Hubland, 97074 Wuerzburg, Germany
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Sengupta D, Byrum SD, Avaritt NL, Davis L, Shields B, Mahmoud F, Reynolds M, Orr LM, Mackintosh SG, Shalin SC, Tackett AJ. Quantitative Histone Mass Spectrometry Identifies Elevated Histone H3 Lysine 27 (Lys27) Trimethylation in Melanoma. Mol Cell Proteomics 2016; 15:765-75. [PMID: 26621846 PMCID: PMC4813699 DOI: 10.1074/mcp.m115.053363] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 11/30/2015] [Indexed: 01/08/2023] Open
Abstract
Normal cell growth is characterized by a regulated epigenetic program that drives cellular activities such as gene transcription, DNA replication, and DNA damage repair. Perturbation of this epigenetic program can lead to events such as mis-regulation of gene transcription and diseases such as cancer. To begin to understand the epigenetic program correlated to the development of melanoma, we performed a novel quantitative mass spectrometric analysis of histone post-translational modifications mis-regulated in melanoma cell culture as well as patient tumors. Aggressive melanoma cell lines as well as metastatic melanoma were found to have elevated histone H3 Lys(27) trimethylation (H3K27me3) accompanied by overexpressed methyltransferase EZH2 that adds the specific modification. The altered epigenetic program that led to elevated H3K27me3 in melanoma cell culture was found to directly silence transcription of the tumor suppressor genes RUNX3 and E-cadherin. The EZH2-mediated silencing of RUNX3 and E-cadherin transcription was also validated in advanced stage human melanoma tissues. This is the first study focusing on the detailed epigenetic mechanisms leading to EZH2-mediated silencing of RUNX3 and E-cadherin tumor suppressors in melanoma. This study underscores the utility of using high resolution mass spectrometry to identify mis-regulated epigenetic programs in diseases such as cancer, which could ultimately lead to the identification of biological markers for diagnostic and prognostic applications.
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Affiliation(s)
| | | | | | - Lauren Davis
- From the ‡Department of Biochemistry and Molecular Biology
| | | | - Fade Mahmoud
- ¶Department of Hematology Oncology and Internal Medicine, and
| | | | - Lisa M Orr
- From the ‡Department of Biochemistry and Molecular Biology
| | | | - Sara C Shalin
- ‖Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205
| | - Alan J Tackett
- From the ‡Department of Biochemistry and Molecular Biology, ‖Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205
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Riss A, Scheer E, Joint M, Trowitzsch S, Berger I, Tora L. Subunits of ADA-two-A-containing (ATAC) or Spt-Ada-Gcn5-acetyltrasferase (SAGA) Coactivator Complexes Enhance the Acetyltransferase Activity of GCN5. J Biol Chem 2015; 290:28997-9009. [PMID: 26468280 DOI: 10.1074/jbc.m115.668533] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Indexed: 11/06/2022] Open
Abstract
Histone acetyl transferases (HATs) play a crucial role in eukaryotes by regulating chromatin architecture and locus specific transcription. GCN5 (KAT2A) is a member of the GNAT (Gcn5-related N-acetyltransferase) family of HATs. In metazoans this enzyme is found in two functionally distinct coactivator complexes, SAGA (Spt Ada Gcn5 acetyltransferase) and ATAC (Ada Two A-containing). These two multiprotein complexes comprise complex-specific and shared subunits, which are organized in functional modules. The HAT module of ATAC is composed of GCN5, ADA2a, ADA3, and SGF29, whereas in the SAGA HAT module ADA2b is present instead of ADA2a. To better understand how the activity of human (h) hGCN5 is regulated in the two related, but different, HAT complexes we carried out in vitro HAT assays. We compared the activity of hGCN5 alone with its activity when it was part of purified recombinant hATAC or hSAGA HAT modules or endogenous hATAC or hSAGA complexes using histone tail peptides and full-length histones as substrates. We demonstrated that the subunit environment of the HAT complexes into which GCN5 incorporates determines the enhancement of GCN5 activity. On histone peptides we show that all the tested GCN5-containing complexes acetylate mainly histone H3K14. Our results suggest a stronger influence of ADA2b as compared with ADA2a on the activity of GCN5. However, the lysine acetylation specificity of GCN5 on histone tails or full-length histones was not changed when incorporated in the HAT modules of ATAC or SAGA complexes. Our results thus demonstrate that the catalytic activity of GCN5 is stimulated by subunits of the ADA2a- or ADA2b-containing HAT modules and is further increased by incorporation of the distinct HAT modules in the ATAC or SAGA holo-complexes.
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Affiliation(s)
- Anne Riss
- From the Cellular Signaling and Nuclear Dynamics Program and
| | | | - Mathilde Joint
- Proteomics platform, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS UMR 7104, INSERM U964, Université de Strasbourg, BP 10142, 67404 Illkirch Cedex, CU de Strasbourg, France and
| | - Simon Trowitzsch
- EMBL Grenoble Outstation, 6 rue Jules Horowitz BP 181, F-38042 Grenoble Cedex, France and The School of Biochemistry, University of Bristol, University Walk, Clifton BS8 1TD, United Kingdom
| | - Imre Berger
- EMBL Grenoble Outstation, 6 rue Jules Horowitz BP 181, F-38042 Grenoble Cedex, France and The School of Biochemistry, University of Bristol, University Walk, Clifton BS8 1TD, United Kingdom
| | - László Tora
- From the Cellular Signaling and Nuclear Dynamics Program and
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60
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Nucleosome competition reveals processive acetylation by the SAGA HAT module. Proc Natl Acad Sci U S A 2015; 112:E5461-70. [PMID: 26401015 DOI: 10.1073/pnas.1508449112] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The Spt-Ada-Gcn5 acetyltransferase (SAGA) coactivator complex hyperacetylates histone tails in vivo in a manner that depends upon histone 3 lysine 4 trimethylation (H3K4me3), a histone mark enriched at promoters of actively transcribed genes. SAGA contains a separable subcomplex known as the histone acetyltransferase (HAT) module that contains the HAT, Gcn5, bound to Sgf29, Ada2, and Ada3. Sgf29 contains a tandem Tudor domain that recognizes H3K4me3-containing peptides and is required for histone hyperacetylation in vivo. However, the mechanism by which H3K4me3 recognition leads to lysine hyperacetylation is unknown, as in vitro studies show no effect of the H3K4me3 modification on histone peptide acetylation by Gcn5. To determine how H3K4me3 binding by Sgf29 leads to histone hyperacetylation by Gcn5, we used differential fluorescent labeling of histones to monitor acetylation of individual subpopulations of methylated and unmodified nucleosomes in a mixture. We find that the SAGA HAT module preferentially acetylates H3K4me3 nucleosomes in a mixture containing excess unmodified nucleosomes and that this effect requires the Tudor domain of Sgf29. The H3K4me3 mark promotes processive, multisite acetylation of histone H3 by Gcn5 that can account for the different acetylation patterns established by SAGA at promoters versus coding regions. Our results establish a model for Sgf29 function at gene promoters and define a mechanism governing crosstalk between histone modifications.
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61
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Chang P, Fan X, Chen J. Function and subcellular localization of Gcn5, a histone acetyltransferase in Candida albicans. Fungal Genet Biol 2015; 81:132-41. [DOI: 10.1016/j.fgb.2015.01.011] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2014] [Revised: 01/14/2015] [Accepted: 01/21/2015] [Indexed: 11/26/2022]
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Filleton F, Chuffart F, Nagarajan M, Bottin-Duplus H, Yvert G. The complex pattern of epigenomic variation between natural yeast strains at single-nucleosome resolution. Epigenetics Chromatin 2015; 8:26. [PMID: 26229551 PMCID: PMC4520285 DOI: 10.1186/s13072-015-0019-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 07/22/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Epigenomic studies on humans and model species have revealed substantial inter-individual variation in histone modification profiles. However, the pattern of this variation has not been precisely characterized, particularly regarding which genomic features are enriched for variability and whether distinct histone marks co-vary synergistically. Yeast allows us to investigate intra-species variation at high resolution while avoiding other sources of variation, such as cell type or subtype. RESULTS We profiled histone marks H3K4me3, H3K9ac, H3K14ac, H4K12ac and H3K4me1 in three unrelated wild strains of Saccharomyces cerevisiae at single-nucleosome resolution and analyzed inter-strain differences statistically. All five marks varied significantly at specific loci, but to different extents. The number of nucleosomes varying for a given mark between two strains ranged from 20 to several thousands; +1 nucleosomes were significantly less subject to variation. Genes with highly evolvable or responsive expression showed higher variability; however, the variation pattern could not be explained by known transcriptional differences between the strains. Synergistic variation of distinct marks was not systematic, with surprising differences between functionally related H3K9ac and H3K14ac. Interestingly, H3K14ac differences that persisted through transient hyperacetylation were supported by H3K4me3 differences, suggesting stabilization via cross talk. CONCLUSIONS Quantitative variation of histone marks among S. cerevisiae strains is abundant and complex. Its relation to functional characteristics is modular and seems modest, with partial association with gene expression divergences, differences between functionally related marks and partial co-variation between marks that may confer stability. Thus, the specific context of studies, such as which precise marks, individuals and genomic loci are investigated, is primordial in population epigenomics studies. The complexity found in this pilot survey in yeast suggests that high complexity can be anticipated among higher eukaryotes, including humans.
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Affiliation(s)
- Fabien Filleton
- Laboratoire de Biologie Moléculaire de la Cellule, Ecole Normale Supérieure de Lyon, CNRS, Université de Lyon, 46 Allée d'Italie, 69007 Lyon, France
| | - Florent Chuffart
- Laboratoire de Biologie Moléculaire de la Cellule, Ecole Normale Supérieure de Lyon, CNRS, Université de Lyon, 46 Allée d'Italie, 69007 Lyon, France
| | - Muniyandi Nagarajan
- Laboratoire de Biologie Moléculaire de la Cellule, Ecole Normale Supérieure de Lyon, CNRS, Université de Lyon, 46 Allée d'Italie, 69007 Lyon, France ; Department of Genomic Science, School of Biological Sciences, Central University of Kerala, Kerala, India
| | - Hélène Bottin-Duplus
- Laboratoire de Biologie Moléculaire de la Cellule, Ecole Normale Supérieure de Lyon, CNRS, Université de Lyon, 46 Allée d'Italie, 69007 Lyon, France
| | - Gaël Yvert
- Laboratoire de Biologie Moléculaire de la Cellule, Ecole Normale Supérieure de Lyon, CNRS, Université de Lyon, 46 Allée d'Italie, 69007 Lyon, France
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63
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Affiliation(s)
- He Huang
- Ben May Department of Cancer Research, The University of Chicago, Chicago, Illinois 60637, United States
| | - Shu Lin
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Benjamin A. Garcia
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Yingming Zhao
- Ben May Department of Cancer Research, The University of Chicago, Chicago, Illinois 60637, United States
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Xia J, Fang M, Wu X, Yang Y, Yu L, Xu H, Kong H, Tan Q, Wang H, Xie W, Xu Y. A2b adenosine signaling represses CIITA transcription via an epigenetic mechanism in vascular smooth muscle cells. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2015; 1849:665-76. [PMID: 25765819 DOI: 10.1016/j.bbagrm.2015.03.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2014] [Revised: 02/05/2015] [Accepted: 03/03/2015] [Indexed: 01/08/2023]
Abstract
Chronic inflammation plays a major role in the pathogenesis of atherosclerosis. Vascular smooth muscle cells (VSMC), by expressing and presenting major histocompatibility complex II (MHC II) molecules, help recruit T lymphocyte and initiate the inflammatory response within the vasculature. We have previously shown that VSMCs isolated from mice with deficient adenosine A2b receptor (A2b-null) exhibit higher expression of class II transactivator (CIITA), the master regulator of MHC II transcription, compared to wild type littermates. Here we report that activation of A2b adenosine signaling suppresses CIITA expression in human aortic smooth muscle cells. Down-regulation of CIITA expression was largely attributable to transcriptional repression of type III and IV promoters. Chromatin immunoprecipitation (ChIP) analyses revealed that A2b signaling repressed CIITA transcription by attenuating specific histone modifications on the CIITA promoters in a STAT1-dependent manner. STAT1 interacted with PCAF/GCN5, histone H3K9 acetyltransferases, and WDR5, a key component of the mammalian H3K4 methyltransferase complex, to activate CIITA transcription. A2b signaling prevented recruitment of PCAF/GCN5 and WDR5 to the CIITA promoters in a STAT1-dependent manner. In conclusion, our data suggest that adenosine A2b signaling represses CIITA transcription in VSMCs by manipulating the interaction between STAT1 and the epigenetic machinery.
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Affiliation(s)
- Jun Xia
- Department of Respiratory Medicine, the First Affiliated Hospital of Nanjing Medical University, China; Department of Respiratory Medicine, Jiangsu Province Hospital of Traditional Chinese Medicine, China
| | - Mingming Fang
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Pathophysiology, Nanjing Medical University, China; Department of Nursing, Jiangsu Jiankang Vocational University, Nanjing, China
| | - Xiaoyan Wu
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Pathophysiology, Nanjing Medical University, China
| | - Yuyu Yang
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Pathophysiology, Nanjing Medical University, China; State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China
| | - Liming Yu
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Pathophysiology, Nanjing Medical University, China
| | - Huihui Xu
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Pathophysiology, Nanjing Medical University, China
| | - Hui Kong
- Department of Respiratory Medicine, the First Affiliated Hospital of Nanjing Medical University, China
| | - Qi Tan
- Department of Respiratory Medicine, the First Affiliated Hospital of Nanjing Medical University, China
| | - Hong Wang
- Department of Respiratory Medicine, the First Affiliated Hospital of Nanjing Medical University, China.
| | - Weiping Xie
- Department of Respiratory Medicine, the First Affiliated Hospital of Nanjing Medical University, China.
| | - Yong Xu
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Pathophysiology, Nanjing Medical University, China.
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P Singh R, Brysbaert G, F Lensink M, Cleri F, Blossey R. Kinetic proofreading of chromatin remodeling: from gene activation to gene repression and back. AIMS BIOPHYSICS 2015. [DOI: 10.3934/biophy.2015.4.398] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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