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Ito S, Umehara T, Koseki H. Polycomb-mediated histone modifications and gene regulation. Biochem Soc Trans 2024; 52:151-161. [PMID: 38288743 DOI: 10.1042/bst20230336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 01/03/2024] [Accepted: 01/05/2024] [Indexed: 02/29/2024]
Abstract
Polycomb repressive complexes 1 and 2 (PRC1 and PRC2) are transcriptional repressor complexes that play a fundamental role in epigenomic regulation and the cell-fate decision; these complexes are widely conserved in multicellular organisms. PRC1 is an E3 ubiquitin (ub) ligase that generates histone H2A ubiquitinated at lysine (K) 119 (H2AK119ub1), whereas PRC2 is a histone methyltransferase that specifically catalyzes tri-methylation of histone H3K27 (H3K27me3). Genome-wide analyses have confirmed that these two key epigenetic marks highly overlap across the genome and contribute to gene repression. We are now beginning to understand the molecular mechanisms that enable PRC1 and PRC2 to identify their target sites in the genome and communicate through feedback mechanisms to create Polycomb chromatin domains. Recently, it has become apparent that PRC1-induced H2AK119ub1 not only serves as a docking site for PRC2 but also affects the dynamics of the H3 tail, both of which enhance PRC2 activity, suggesting that trans-tail communication between H2A and H3 facilitates the formation of the Polycomb chromatin domain. In this review, we discuss the emerging principles that define how PRC1 and PRC2 establish the Polycomb chromatin domain and regulate gene expression in mammals.
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Affiliation(s)
- Shinsuke Ito
- Laboratory of Developmental Genetics, RIKEN Center for Integrative Medical Sciences, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - Takashi Umehara
- Laboratory of Developmental Genetics, RIKEN Center for Integrative Medical Sciences, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
- Laboratory for Epigenetics Drug Discovery, RIKEN Center for Biosystems Dynamics Research, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - Haruhiko Koseki
- Laboratory of Developmental Genetics, RIKEN Center for Integrative Medical Sciences, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
- Department of Cellular and Molecular Medicine, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan
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Phuengmaung P, Khiewkamrop P, Makjaroen J, Issara-Amphorn J, Boonmee A, Benjaskulluecha S, Ritprajak P, Nita-Lazar A, Palaga T, Hirankarn N, Leelahavanichkul A. Less Severe Sepsis in Cecal Ligation and Puncture Models with and without Lipopolysaccharide in Mice with Conditional Ezh2-Deleted Macrophages (LysM-Cre System). Int J Mol Sci 2023; 24:ijms24108517. [PMID: 37239864 DOI: 10.3390/ijms24108517] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Revised: 05/02/2023] [Accepted: 05/07/2023] [Indexed: 05/28/2023] Open
Abstract
Despite a previous report on less inflammatory responses in mice with an absence of the enhancer of zeste homologue 2 (Ezh2), a histone lysine methyltransferase of epigenetic regulation, using a lipopolysaccharide (LPS) injection model, proteomic analysis and cecal ligation and puncture (CLP), a sepsis model that more resembles human conditions was devised. As such, analysis of cellular and secreted protein (proteome and secretome) after a single LPS activation and LPS tolerance in macrophages from Ezh2 null (Ezh2flox/flox; LysM-Crecre/-) mice (Ezh2 null) and the littermate control mice (Ezh2fl/fl; LysM-Cre-/-) (Ezh2 control) compared with the unstimulated cells from each group indicated fewer activities in Ezh2 null macrophages, especially by the volcano plot analysis. Indeed, supernatant IL-1β and expression of genes in pro-inflammatory M1 macrophage polarization (IL-1β and iNOS), TNF-α, and NF-κB (a transcription factor) were lower in Ezh2 null macrophages compared with the control. In LPS tolerance, downregulated NF-κB compared with the control was also demonstrated in Ezh2 null cells. In CLP sepsis mice, those with CLP alone and CLP at 2 days after twice receiving LPS injection, representing sepsis and sepsis after endotoxemia, respectively, symptoms were less severe in Ezh2 null mice, as indicated by survival analysis and other biomarkers. However, the Ezh2 inhibitor improved survival only in CLP, but not LPS with CLP. In conclusion, an absence of Ezh2 in macrophages resulted in less severe sepsis, and the use of an Ezh2 inhibitor might be beneficial in sepsis.
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Affiliation(s)
- Pornpimol Phuengmaung
- Center of Excellence in Translational Research in Inflammation and Immunology (CETRII), Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
- Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
| | - Phuriwat Khiewkamrop
- Center of Excellence in Immunology and Immune-Mediated Diseases, Chulalongkorn University, Bangkok 10330, Thailand
- Medical Microbiology, Interdisciplinary and International Program, Graduate School, Chulalongkorn University, Bangkok 10330, Thailand
| | - Jiradej Makjaroen
- Center of Excellence in Systems Biology, Research Affairs, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
| | - Jiraphorn Issara-Amphorn
- Functional Cellular Networks Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Atsadang Boonmee
- Department of Microbiology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Salisa Benjaskulluecha
- Department of Microbiology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Patcharee Ritprajak
- Research Unit in Integrative Immuno-Microbial Biochemistry and Bioresponsive Nanomaterials, Department of Microbiology, Faculty of Dentistry, Chulalongkorn University, Bangkok 10330, Thailand
| | - Aleksandra Nita-Lazar
- Functional Cellular Networks Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Tanapat Palaga
- Center of Excellence in Immunology and Immune-Mediated Diseases, Chulalongkorn University, Bangkok 10330, Thailand
- Department of Microbiology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Nattiya Hirankarn
- Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
- Center of Excellence in Immunology and Immune-Mediated Diseases, Chulalongkorn University, Bangkok 10330, Thailand
| | - Asada Leelahavanichkul
- Center of Excellence in Translational Research in Inflammation and Immunology (CETRII), Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
- Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
- Division of Nephrology, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
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3
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The Regulatory Roles of Ezh2 in Response to Lipopolysaccharide (LPS) in Macrophages and Mice with Conditional Ezh2 Deletion with LysM-Cre System. Int J Mol Sci 2023; 24:ijms24065363. [PMID: 36982437 PMCID: PMC10049283 DOI: 10.3390/ijms24065363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 03/07/2023] [Accepted: 03/08/2023] [Indexed: 03/14/2023] Open
Abstract
The responses of macrophages to lipopolysaccharide (LPS) might determine the direction of clinical manifestations of sepsis, which is the immune response against severe infection. Meanwhile, the enhancer of zeste homologue 2 (Ezh2), a histone lysine methyltransferase of epigenetic regulation, might interfere with LPS response. Transcriptomic analysis on LPS-activated wild-type macrophages demonstrated an alteration of several epigenetic enzymes. Although the Ezh2-silencing macrophages (RAW264.7), using small interfering RNA (siRNA), indicated a non-different response to the control cells after a single LPS stimulation, the Ezh2-reducing cells demonstrated a less severe LPS tolerance, after two LPS stimulations, as determined by the higher supernatant TNF-α. With a single LPS stimulation, Ezh2 null (Ezh2flox/flox; LysM-Crecre/−) macrophages demonstrated lower supernatant TNF-α than Ezh2 control (Ezh2fl/fl; LysM-Cre−/−), perhaps due to an upregulation of Socs3, which is a suppressor of cytokine signaling 3, due to the loss of the Ezh2 gene. In LPS tolerance, Ezh2 null macrophages indicated higher supernatant TNF-α and IL-6 than the control, supporting an impact of the loss of the Ezh2 inhibitory gene. In parallel, Ezh2 null mice demonstrated lower serum TNF-α and IL-6 than the control mice after an LPS injection, indicating a less severe LPS-induced hyper-inflammation in Ezh2 null mice. On the other hand, there were similar serum cytokines after LPS tolerance and the non-reduction of serum cytokines after the second dose of LPS, indicating less severe LPS tolerance in Ezh2 null mice compared with control mice. In conclusion, an absence of Ezh2 in macrophages resulted in less severe LPS-induced inflammation, as indicated by low serum cytokines, with less severe LPS tolerance, as demonstrated by higher cytokine production, partly through the upregulated Socs3.
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Ito S, Das ND, Umehara T, Koseki H. Factors and Mechanisms That Influence Chromatin-Mediated Enhancer–Promoter Interactions and Transcriptional Regulation. Cancers (Basel) 2022; 14:cancers14215404. [PMID: 36358822 PMCID: PMC9659172 DOI: 10.3390/cancers14215404] [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] [Received: 10/06/2022] [Revised: 10/28/2022] [Accepted: 11/01/2022] [Indexed: 11/06/2022] Open
Abstract
Simple Summary The physical interactions between enhancers and promoters create chromatin conformations involved in gene regulation. In cancer cells, the chromatin conformations can be altered with uncontrolled deposition of histone marks resulting in varied gene expression. Although it is not entirely comprehensive how chromatin-mediated enhancer–promoter (E–P) interactions with various histone marks can affect gene expression, this proximity has been observed in multiple systems at multiple loci and is thought to be essential to control gene expression. In this review, we focus on emerging views of chromatin conformations associated with the E–P interactions and factors that establish or maintain such interactions, which may regulate gene expression. Abstract Eukaryotic gene expression is regulated through chromatin conformation, in which enhancers and promoters physically interact (E–P interactions). How such chromatin-mediated E–P interactions affect gene expression is not yet fully understood, but the roles of histone acetylation and methylation, pioneer transcription factors, and architectural proteins such as CCCTC binding factor (CTCF) and cohesin have recently attracted attention. Moreover, accumulated data suggest that E–P interactions are mechanistically involved in biophysical events, including liquid–liquid phase separation, and in biological events, including cancers. In this review, we discuss various mechanisms that regulate eukaryotic gene expression, focusing on emerging views regarding chromatin conformations that are involved in E–P interactions and factors that establish and maintain them.
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Affiliation(s)
- Shinsuke Ito
- Laboratory for Developmental Genetics, RIKEN Center for Integrative Medical Sciences, Yokohama 230-0045, Japan
- Correspondence: ; Tel.: +81-45-503-9690
| | - Nando Dulal Das
- Laboratory for Epigenetics Drug Discovery, RIKEN Center for Biosystems Dynamics Research, Yokohama 230-0045, Japan
| | - Takashi Umehara
- Laboratory for Epigenetics Drug Discovery, RIKEN Center for Biosystems Dynamics Research, Yokohama 230-0045, Japan
| | - Haruhiko Koseki
- Laboratory for Developmental Genetics, RIKEN Center for Integrative Medical Sciences, Yokohama 230-0045, Japan
- Immune Regulation, Advanced Research Departments, Graduate School of Medicine, Chiba University, Chiba 260-8677, Japan
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Lan X, Ding S, Zhang T, Yi Y, Li C, Jin W, Chen J, Liang K, Wang H, Jiang W. PCGF6 controls neuroectoderm specification of human pluripotent stem cells by activating SOX2 expression. Nat Commun 2022; 13:4601. [PMID: 35933409 PMCID: PMC9357003 DOI: 10.1038/s41467-022-32295-z] [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] [Received: 09/30/2021] [Accepted: 07/25/2022] [Indexed: 11/28/2022] Open
Abstract
Polycomb group (PcG) proteins are known to repress developmental genes during embryonic development and tissue homeostasis. Here, we report that PCGF6 controls neuroectoderm specification of human pluripotent stem cells (PSCs) by activating SOX2 gene. Human PSCs with PCGF6 depletion display impaired neuroectoderm differentiation coupled with increased mesendoderm outcomes. Transcriptome analysis reveals that de-repression of the WNT/β-catenin signaling pathway is responsible for the differentiation of PSC toward the mesendodermal lineage. Interestingly, PCGF6 and MYC directly interact and co-occupy a distal regulatory element of SOX2 to activate SOX2 expression, which likely accounts for the regulation in neuroectoderm differentiation. Supporting this notion, genomic deletion of the SOX2-regulatory element phenocopies the impaired neuroectoderm differentiation, while overexpressing SOX2 rescues the neuroectoderm phenotype caused by PCGF6-depletion. Together, our study reveals that PCGF6 can function as lineage switcher between mesendoderm and neuroectoderm in human PSCs by both suppression and activation mechanisms. Variant Polycomb complexes can have tissue-specific roles during development. Here they show that PCGF6 controls lineage-specification in human PSCs by promoting neuroectoderm differentiation and repressing mesendoderm differentiation via distinct downstream targets.
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Affiliation(s)
- Xianchun Lan
- Department of Biological Repositories, Frontier Science Center for Immunology and Metabolism, Medical Research Institute, RNA Institute, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, 430071, China
| | - Song Ding
- Department of Biological Repositories, Frontier Science Center for Immunology and Metabolism, Medical Research Institute, RNA Institute, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, 430071, China
| | - Tianzhe Zhang
- Department of Biological Repositories, Frontier Science Center for Immunology and Metabolism, Medical Research Institute, RNA Institute, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, 430071, China
| | - Ying Yi
- Department of Biological Repositories, Frontier Science Center for Immunology and Metabolism, Medical Research Institute, RNA Institute, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, 430071, China
| | - Conghui Li
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Wenwen Jin
- Department of Biological Repositories, Frontier Science Center for Immunology and Metabolism, Medical Research Institute, RNA Institute, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, 430071, China
| | - Jian Chen
- Chinese Institute for Brain Research (Beijing), Research Unit of Medical Neurobiology, Chinese Academy of Medical Sciences, 102206, Beijing, China
| | - Kaiwei Liang
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Hengbin Wang
- Department of Internal Medicine, Division of Hematology, Oncology, and Palliative Care, Massey Cancer Center, Virginia Commonwealth University, Richmond, VA, 23298, USA
| | - Wei Jiang
- Department of Biological Repositories, Frontier Science Center for Immunology and Metabolism, Medical Research Institute, RNA Institute, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, 430071, China. .,Human Genetics Resource Preservation Center of Wuhan University, Wuhan, China. .,Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan, China.
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6
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Chen J, Zhao Y, Zhang F, Li J, Boland JA, Cheng NC, Liu K, Tiffen JC, Bertolino P, Bowen DG, Krueger A, Lisowski L, Alexander IE, Vadas MA, El-Omar E, Gamble JR, McCaughan GW. Liver-specific deletion of miR-181ab1 reduces liver tumour progression via upregulation of CBX7. Cell Mol Life Sci 2022; 79:443. [PMID: 35867177 PMCID: PMC9307539 DOI: 10.1007/s00018-022-04452-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 06/23/2022] [Accepted: 06/26/2022] [Indexed: 11/30/2022]
Abstract
MiR-181 expression levels increased in hepatocellular carcinoma (HCC) compared to non-cancerous tissues. MiR-181 has been widely reported as a possible driver of tumourigenesis but also acts as a tumour suppressor. In addition, the miR-181 family regulates the development and function of immune and vascular cells, which play vital roles in the progression of tumours. More complicatedly, many genes have been identified as miR-181 targets to mediate the effects of miR-181. However, the role of miR-181 in the development of primary tumours remains largely unexplored. We aimed to examine the function of miR-181 and its vital mediators in the progression of diethylnitrosamine-induced primary liver cancers in mice. The size of liver tumours was significantly reduced by 90% in global (GKO) or liver-specific (LKO) 181ab1 knockout mice but not in hematopoietic and endothelial lineage-specific knockout mice, compared to WT mice. In addition, the number of tumours was significantly reduced by 50% in GKO mice. Whole-genome RNA-seq analysis and immunohistochemistry showed that epithelial-mesenchymal transition was partially reversed in GKO tumours compared to WT tumours. The expression of CBX7, a confirmed miR-181 target, was up-regulated in GKO compared to WT tumours. Stable CBX7 expression was achieved with an AAV/Transposase Hybrid-Vector System and up-regulated CBX7 expression inhibited liver tumour progression in WT mice. Hepatic CBX7 deletion restored the progression of LKO liver tumours. MiR-181a expression was the lowest and CBX7 expression the highest in iClust2 and 3 subclasses of human HCC compared to iClust1. Gene expression profiles of GKO tumours overlapped with low-proliferative peri-portal-type HCCs. Liver-specific loss of miR-181ab1 inhibited primary liver tumour progression via up-regulating CBX7 expression, but tumour induction requires both hepatic and non-hepatic miR-181. Also, miR-181ab1-deficient liver tumours may resemble low-proliferative periportal-type human HCC.
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Affiliation(s)
- Jinbiao Chen
- Liver Injury and Cancer Program Centenary Institute and Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, 2050, Australia
| | - Yang Zhao
- Vascular Biology Program Centenary Institute and Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, 2050, Australia.,School of Medicine and Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, People's Republic of China
| | - Fan Zhang
- UNSW Microbiome Research Centre, School of Clinical Medicine, UNSW Medicine and Health, St George and Sutherland Clinical Campuses, Kogarah, NSW, 2217, Australia
| | - Jia Li
- Vascular Biology Program Centenary Institute and Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, 2050, Australia.,Centre for Motor Neuron Disease, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - Jade A Boland
- Liver Injury and Cancer Program Centenary Institute and Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, 2050, Australia
| | - Ngan Ching Cheng
- Liver Injury and Cancer Program Centenary Institute and Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, 2050, Australia.,Vascular Biology Program Centenary Institute and Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, 2050, Australia
| | - Ken Liu
- Liver Injury and Cancer Program Centenary Institute and Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, 2050, Australia.,Royal Prince Alfred Hospital, Missenden Road, Camperdown, NSW, 2050, Australia
| | - Jessamy C Tiffen
- Melanoma Epigenetics Lab Centenary Institute and Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, 2050, Australia
| | - Patrick Bertolino
- Liver Immunology Program Centenary Institute and Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, 2050, Australia
| | - David G Bowen
- Royal Prince Alfred Hospital, Missenden Road, Camperdown, NSW, 2050, Australia.,Liver Immunology Program Centenary Institute and Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, 2050, Australia
| | - Andreas Krueger
- Molecular Immunology, Faculty of Biology and Chemistry, Justus Liebig University Gießen, Schubertstr 81, 35392, Giessen, Germany.,Institute for Molecular Medicine, Frankfurt Cancer Institute, Goethe-University, Frankfurt, Germany
| | - Leszek Lisowski
- Translational Vectorology Research Unit, Children's Medical Research Institute, The University of Sydney, Westmead, NSW, 2145, Australia.,Laboratory of Molecular Oncology and Innovative Therapies, Military Institute of Medicine, Warsaw, Poland
| | - Ian E Alexander
- Gene Therapy Research Unit, Children's Medical Research Institute, Faculty of Medicine and Health, The University of Sydney and Sydney Children's Hospitals Network, Westmead, NSW, 2145, Australia
| | - Mathew A Vadas
- Vascular Biology Program Centenary Institute and Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, 2050, Australia
| | - Emad El-Omar
- UNSW Microbiome Research Centre, School of Clinical Medicine, UNSW Medicine and Health, St George and Sutherland Clinical Campuses, Kogarah, NSW, 2217, Australia
| | - Jennifer R Gamble
- Vascular Biology Program Centenary Institute and Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, 2050, Australia
| | - Geoffrey W McCaughan
- Liver Injury and Cancer Program Centenary Institute and Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, 2050, Australia. .,Royal Prince Alfred Hospital, Missenden Road, Camperdown, NSW, 2050, Australia.
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7
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Abstract
Predicting regulatory potential from primary DNA sequences or transcription factor binding patterns is not possible. However, the annotation of the genome by chromatin proteins, histone modifications, and differential compaction is largely sufficient to reveal the locations of genes and their differential activity states. The Polycomb Group (PcG) and Trithorax Group (TrxG) proteins are the central players in this cell type-specific chromatin organization. PcG function was originally viewed as being solely repressive and irreversible, as observed at the homeotic loci in flies and mammals. However, it is now clear that modular and reversible PcG function is essential at most developmental genes. Focusing mainly on recent advances, we review evidence for how PcG and TrxG patterns change dynamically during cell type transitions. The ability to implement cell type-specific transcriptional programming with exquisite fidelity is essential for normal development.
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Affiliation(s)
- Mitzi I Kuroda
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA; ,
| | - Hyuckjoon Kang
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA; ,
| | - Sandip De
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA; ,
| | - Judith A Kassis
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA; ,
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8
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Cohen I, Bar C, Ezhkova E. Activity of PRC1 and Histone H2AK119 Monoubiquitination: Revising Popular Misconceptions. Bioessays 2020; 42:e1900192. [PMID: 32196702 PMCID: PMC7585675 DOI: 10.1002/bies.201900192] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 02/12/2020] [Indexed: 12/21/2022]
Abstract
Polycomb group proteins are evolutionary conserved chromatin-modifying complexes, essential for the regulation of developmental and cell-identity genes. Polycomb-mediated transcriptional regulation is provided by two multi-protein complexes known as Polycomb repressive complex 1 (PRC1) and 2 (PRC2). Recent studies positioned PRC1 as a foremost executer of Polycomb-mediated transcriptional control. Mammalian PRC1 complexes can form multiple sub-complexes that vary in their core and accessory subunit composition, leading to fascinating and diverse transcriptional regulatory mechanisms employed by PRC1 complexes. These mechanisms include PRC1-catalytic activity toward monoubiquitination of histone H2AK119, a well-established hallmark of PRC1 complexes, whose importance has been long debated. In this review, the central roles that PRC1-catalytic activity plays in transcriptional repression are emphasized and the recent evidence supporting a role for PRC1 complexes in gene activation is discussed.
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Affiliation(s)
- Idan Cohen
- The Shraga Segal Department of Microbiology, Immunology and Genetics; Faculty of Health Science; Ben-Gurion University of the Negev; Beer Sheva 84105; Israel
- These authors contributed equally to this work
| | - Carmit Bar
- Black Family Stem Cell Institute, Department of Cell, Developmental, and Regenerative Biology; Icahn School of Medicine at Mount Sinai; 1 Gustave L. Levy Place, New York, NY 10029; USA
- These authors contributed equally to this work
| | - Elena Ezhkova
- The Shraga Segal Department of Microbiology, Immunology and Genetics; Faculty of Health Science; Ben-Gurion University of the Negev; Beer Sheva 84105; Israel
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9
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Ham L, Brackston RD, Stumpf MPH. Extrinsic Noise and Heavy-Tailed Laws in Gene Expression. PHYSICAL REVIEW LETTERS 2020; 124:108101. [PMID: 32216388 DOI: 10.1103/physrevlett.124.108101] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 02/12/2020] [Indexed: 06/10/2023]
Abstract
Noise in gene expression is one of the hallmarks of life at the molecular scale. Here we derive analytical solutions to a set of models describing the molecular mechanisms underlying transcription of DNA into RNA. Our ansatz allows us to incorporate the effects of extrinsic noise-encompassing factors external to the transcription of the individual gene-and discuss the ramifications for heterogeneity in gene product abundance that has been widely observed in single cell data. Crucially, we are able to show that heavy-tailed distributions of RNA copy numbers cannot result from the intrinsic stochasticity in gene expression alone, but must instead reflect extrinsic sources of variability.
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Affiliation(s)
- Lucy Ham
- School of BioSciences and School of Mathematics and Statistics, University of Melbourne, Parkville VIC 3010, Australia
| | - Rowan D Brackston
- Department Life Sciences, Imperial College London, SW7 2AZ, United Kingdom
| | - Michael P H Stumpf
- School of BioSciences and School of Mathematics and Statistics, University of Melbourne, Parkville VIC 3010, Australia
- Department Life Sciences, Imperial College London, SW7 2AZ, United Kingdom
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10
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Bmi1 restricts the adipogenic differentiation of bone marrow stromal cells to maintain the integrity of the hematopoietic stem cell niche. Exp Hematol 2019; 76:24-37. [PMID: 31408689 DOI: 10.1016/j.exphem.2019.07.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Accepted: 07/30/2019] [Indexed: 02/03/2023]
Abstract
The polycomb group protein Bmi1 maintains hematopoietic stem cell (HSC) functions. We previously reported that Bmi1-deficient mice exhibited progressive fatty changes in bone marrow (BM). A large portion of HSCs reside in the perivascular niche created partly by endothelial cells and leptin receptor+ (LepR+) BM stromal cells. To clarify how Bmi1 regulates the HSC niche, we specifically deleted Bmi1 in LepR+ cells in mice. The Bmi1 deletion promoted the adipogenic differentiation of LepR+ stromal cells and caused progressive fatty changes in the BM of limb bones with age, resulting in reductions in the numbers of HSCs and progenitors in BM and enhanced extramedullary hematopoiesis. This adipogenic change was also evident during BM regeneration after irradiation. Several adipogenic regulator genes appeared to be regulated by Bmi1. Our results indicate that Bmi1 keeps the adipogenic differentiation program repressed in BM stromal cells to maintain the integrity of the HSC niche.
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11
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Ezh1 Targets Bivalent Genes to Maintain Self-Renewing Stem Cells in Ezh2-Insufficient Myelodysplastic Syndrome. iScience 2018; 9:161-174. [PMID: 30396150 PMCID: PMC6223231 DOI: 10.1016/j.isci.2018.10.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 10/09/2018] [Accepted: 10/09/2018] [Indexed: 11/25/2022] Open
Abstract
Polycomb repressive complex (PRC) 2 represses transcription through histone H3K27 trimethylation (H3K27me3). We previously reported that the hematopoietic-cell-specific deletion of Ezh2, encoding a PRC2 enzyme, induced myelodysplastic syndrome (MDS) in mice, whereas the concurrent Ezh1 deletion depleted hematopoietic stem and progenitor cells (HSPCs). We herein demonstrated that mice with only one Ezh1 allele (Ezh1+/-Ezh2Δ/Δ) maintained HSPCs. A chromatin immunopreciptation sequence analysis revealed that residual PRC2 preferentially targeted genes with high levels of H3K27me3 and H2AK119 monoubiquitination (H2AK119ub1) in HSPCs (designated as Ezh1 core target genes), which were mostly developmental regulators, and maintained H3K27me3 levels in Ezh1+/-Ezh2Δ/Δ HSPCs. Even upon the complete depletion of Ezh1 and Ezh2, H2AK119ub1 levels were largely retained, and only a minimal number of Ezh1 core targets were de-repressed. These results indicate that genes marked with high levels of H3K27me3 and H2AK119ub1 are the core targets of polycomb complexes in HSPCs as well as MDS stem cells. One allele of Ezh1 is enough to maintain self-renewing HSCs and MDS stem cells Ezh1 core targets are marked with high levels of H3K27me3 and H2AK119ub1 in HSPCs Ezh1 core targets are mostly bivalent developmental regulators and critical for HSCs
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Abstract
Epigenetic complexes regulate chromatin dynamics via binding to and assembling on chromatin. However, the mechanisms of chromatin binding and assembly of epigenetic complexes within cells remain incompletely understood, partly due to technical challenges. Here, we present a new approach termed single-molecule chromatin immunoprecipitation imaging (Sm-ChIPi) that enables to assess the cellular assembly stoichiometry of epigenetic complexes on chromatin. Sm-ChIPi was developed based on chromatin immunoprecipitation followed by single-molecule fluorescence microscopy imaging. In this method, an epigenetic complex subunit fused with a gene coding for a fluorescent protein is stably expressed in its corresponding knockout cells. Nucleosomes associated with epigenetic complexes are isolated from cells at native conditions and incubated with biotinylated antibodies. The resulting complexes are immobilized on a quartz slide that had been passivated and functionalized with NeutrAvidin. Image stacks are then acquired by using single-molecule TIRF microscopy. The individual spots imaged by TIRF microscopy represent single protein-nucleosome complexes. The number of copies of the protein complexes on a nucleosome is inferred from the fluorescence photobleaching measurements. Sm-ChIPi is a sensitive and direct method that can quantify the cellular assembly stoichiometry of epigenetic complexes on chromatin.
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Affiliation(s)
- Roubina Tatavosian
- Department of Chemistry, University of Colorado Denver, Denver, CO, 80217-3364, USA
| | - Xiaojun Ren
- Department of Chemistry, University of Colorado Denver, Renovated Science Building, Rm 3071, 1151 Arapahoe Street, Denver, CO, 80204, USA.
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Abe K, Misaka T. Food functionality research as a new national project in special reference to improvement of cognitive and locomotive abilities. Biosci Biotechnol Biochem 2018; 82:573-583. [PMID: 29316856 DOI: 10.1080/09168451.2017.1412249] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In Japan, where a super-aging society is realized, we are most concerned about healthy longevity, which would ascertain the wellness of people by improving their quality of life (QOL). In 2014, the Cabinet Office proposed a strategic innovation promotion programme, launching a national project for the development of the agricultural-forestry-fisheries food products with new functionalities for the next generation. In addition to focusing on a conventional prevention of lifestyle-associated metabolic syndromes, the project targets the scientific evidence of the activation of brain cognitive ability and the improvement of bodily locomotive function. The project also involves the analysis of the foods-sports interrelation of chronic importance, and the development of devices for the verification of QOL-associated maintenance of homeostasis. In this review, we provide an overview of these studies, with special reference to cognition as a case of the gut-brain axis which the author is particularly interested in.
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Affiliation(s)
- Keiko Abe
- a Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences , The University of Tokyo , Tokyo , Japan.,b Group for Food Functionality Assessment , Kanagawa Institute of Industrial Science and Technology (KISTEC) , Kawasaki , Japan
| | - Takumi Misaka
- a Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences , The University of Tokyo , Tokyo , Japan
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Yakushiji-Kaminatsui N, Kondo T, Hironaka KI, Sharif J, Endo TA, Nakayama M, Masui O, Koseki Y, Kondo K, Ohara O, Vidal M, Morishita Y, Koseki H. Variant PRC1 competes with retinoic acid-related signals to repress Meis2 in distal forelimb bud. Development 2018; 145:dev.166348. [DOI: 10.1242/dev.166348] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 08/28/2018] [Indexed: 12/12/2022]
Abstract
Suppression of Meis genes in the distal limb bud is required for Proximal-Distal (PD) specification of the forelimb. Polycomb group (PcG) factors play a role in downregulation of retinoic acid (RA)-related signals in the distal forelimb bud, causing Meis repression. It is, however, not known if downregulation of RA-related signals and PcG-mediated proximal genes repression are functionally linked. Here, we reveal that PcG factors and RA-related signals antagonize each other to polarize Meis2 expression along the PD axis. With mathematical modeling and simulation, we propose that PcG factors are required to adjust the threshold for RA-related signaling to regulate Meis2 expression. Finally, we show that a variant Polycomb repressive complex 1 (PRC1), incorporating PCGF3 and PCGF5, represses Meis2 expression in the distal limb bud. Taken together, we reveal a previously unknown link between PcG proteins and downregulation of RA-related signals to mediate the phase transition of Meis2 transcriptional status during forelimb specification.
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Affiliation(s)
- Nayuta Yakushiji-Kaminatsui
- Laboratory for Developmental Genetics, RIKEN Center for Integrative Medical Sciences (RIKEN-IMS), 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Takashi Kondo
- Laboratory for Developmental Genetics, RIKEN Center for Integrative Medical Sciences (RIKEN-IMS), 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
- CREST, Japan Science and Technology Agency, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
- KAST, Project on Health and Anti-aging, 3-25-13 Tonomachi, Kawasaki-ku, Kawasaki 210-0821, Japan
| | - Ken-ichi Hironaka
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 113-0033, Japan
| | - Jafar Sharif
- Laboratory for Developmental Genetics, RIKEN Center for Integrative Medical Sciences (RIKEN-IMS), 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
- CREST, Japan Science and Technology Agency, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Takaho A. Endo
- Laboratory for Integrative Genomics, RIKEN-IMS, 1-7-22 Suehirocho, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Manabu Nakayama
- Department of Technology Development, Kazusa DNA Research Institute, 2-6-7 Kazusa-Kamatari, Kisarazu, Chiba 292-0818, Japan
| | - Osamu Masui
- Laboratory for Developmental Genetics, RIKEN Center for Integrative Medical Sciences (RIKEN-IMS), 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
- CREST, Japan Science and Technology Agency, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Yoko Koseki
- Laboratory for Developmental Genetics, RIKEN Center for Integrative Medical Sciences (RIKEN-IMS), 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
- CREST, Japan Science and Technology Agency, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Kaori Kondo
- Laboratory for Developmental Genetics, RIKEN Center for Integrative Medical Sciences (RIKEN-IMS), 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
- CREST, Japan Science and Technology Agency, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
- KAST, Project on Health and Anti-aging, 3-25-13 Tonomachi, Kawasaki-ku, Kawasaki 210-0821, Japan
| | - Osamu Ohara
- Laboratory for Integrative Genomics, RIKEN-IMS, 1-7-22 Suehirocho, Tsurumi-ku, Yokohama 230-0045, Japan
- Department of Technology Development, Kazusa DNA Research Institute, 2-6-7 Kazusa-Kamatari, Kisarazu, Chiba 292-0818, Japan
| | - Miguel Vidal
- Centro de Investigaciones Biológicas, Department of Cellular and Molecular Biology, Ramiro de Maeztu 9, Madrid 28040, Spain
| | - Yoshihiro Morishita
- Laboratory for Developmental Morphogeometry, RIKEN Center for Biosystems Dynamics Research, 2-2-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047, Japan
| | - Haruhiko Koseki
- Laboratory for Developmental Genetics, RIKEN Center for Integrative Medical Sciences (RIKEN-IMS), 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
- CREST, Japan Science and Technology Agency, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
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Zhao W, Huang Y, Zhang J, Liu M, Ji H, Wang C, Cao N, Li C, Xia Y, Jiang Q, Qin J. Polycomb group RING finger proteins 3/5 activate transcription via an interaction with the pluripotency factor Tex10 in embryonic stem cells. J Biol Chem 2017; 292:21527-21537. [PMID: 29054931 DOI: 10.1074/jbc.m117.804054] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 10/11/2017] [Indexed: 11/06/2022] Open
Abstract
Polycomb group (PcG) proteins are epigenetic transcriptional repressors that orchestrate numerous developmental processes and have been implicated in the maintenance of embryonic stem (ES) cell state. More recent evidence suggests that a subset of PcG proteins engages in transcriptional activation in some cellular contexts, but how this property is exerted remains largely unknown. Here, we generated ES cells with single or combined disruption of polycomb group RING finger protein 3 (Pcgf3) and Pcgf5 with the CRISPR-Cas9 technique. We report that although these mutant cells maintained their self-renewal and colony-forming capacity, they displayed severe defects in mesoderm differentiation in vitro and in vivo Using RNA-seq to analyze transcriptional profiles of ES cells with single or combined Pcgf3/5 deficiencies, we found that in contrast to the canonical role of the related polycomb repressive complex 1 (PRC1) in gene repression, Pcgf3/5 mainly function as transcriptional activators driving expression of many genes involved in mesoderm differentiation. Proteomic approaches and promoter occupancy analyses helped to establish an extended Pcgf3/5 interactome and identified several novel Pcgf3/5 interactors. These included testis-expressed 10 (Tex10), which may directly contribute to transcriptional activation via the transcriptional co-activator p300. Furthermore, Pcgf3/5 deletion in ES cells substantially reduced the occupancy of Tex10 and p300 at target genes. Finally, we demonstrated that Pcgf3/5 are essential for regulating global levels of the histone modifier H2AK119ub1 in ES cells. Our findings establish Pcgf3/5 as transcriptional activators that interact with Tex10 and p300 in ES cells and point to redundant activity of Pcgf3/5 in pluripotency maintenance.
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Affiliation(s)
- Wukui Zhao
- From the MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing Biomedical Research Institute, Nanjing University, 12 Xuefu Road, Nanjing, Jiangsu 210061
| | - Yikai Huang
- From the MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing Biomedical Research Institute, Nanjing University, 12 Xuefu Road, Nanjing, Jiangsu 210061
| | - Jingzi Zhang
- From the MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing Biomedical Research Institute, Nanjing University, 12 Xuefu Road, Nanjing, Jiangsu 210061
| | - Mengjie Liu
- From the MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing Biomedical Research Institute, Nanjing University, 12 Xuefu Road, Nanjing, Jiangsu 210061
| | - Haijing Ji
- the College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210014
| | - Congcong Wang
- From the MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing Biomedical Research Institute, Nanjing University, 12 Xuefu Road, Nanjing, Jiangsu 210061
| | - Ning Cao
- From the MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing Biomedical Research Institute, Nanjing University, 12 Xuefu Road, Nanjing, Jiangsu 210061
| | - Chaojun Li
- From the MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing Biomedical Research Institute, Nanjing University, 12 Xuefu Road, Nanjing, Jiangsu 210061
| | - Yin Xia
- the School of Biomedical Sciences, Chinese University of Hong Kong, Hong Kong, and
| | - Qing Jiang
- the Department of Sports Medicine and Adult Reconstructive Surgery, Nanjing Drum Tower Hospital, Medical School of Nanjing University, Nanjing 21008, China
| | - Jinzhong Qin
- From the MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing Biomedical Research Institute, Nanjing University, 12 Xuefu Road, Nanjing, Jiangsu 210061,
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16
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Cruz-Molina S, Respuela P, Tebartz C, Kolovos P, Nikolic M, Fueyo R, van Ijcken WF, Grosveld F, Frommolt P, Bazzi H, Rada-Iglesias A. PRC2 Facilitates the Regulatory Topology Required for Poised Enhancer Function during Pluripotent Stem Cell Differentiation. Cell Stem Cell 2017; 20:689-705.e9. [DOI: 10.1016/j.stem.2017.02.004] [Citation(s) in RCA: 151] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2016] [Revised: 12/19/2016] [Accepted: 02/07/2017] [Indexed: 01/28/2023]
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Sashida G, Iwama A. Multifaceted role of the polycomb-group gene EZH2 in hematological malignancies. Int J Hematol 2016; 105:23-30. [PMID: 27830540 DOI: 10.1007/s12185-016-2124-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 10/26/2016] [Accepted: 11/01/2016] [Indexed: 12/22/2022]
Abstract
Polycomb repressive complex (PRC) is a critical regulator of normal tissue homeostasis as well as tumorigenesis. EZH2, an enzymatic subunit of PRC2, is a histone H3K27 methyltransferase that functions in the regulation of gene silencing. EZH2 overexpression was first identified in prostate and breast cancers and is associated with poor clinical outcome. Subsequently, gain- and loss-of-function mutations of EZH2 have been identified in various tumors, including hematological malignancies, implicating EZH2 as either an oncogene or a tumor suppressor gene, depending on the cancer type. Molecular mechanisms underlying the multifaceted function of EZH2 have been analyzed extensively. However, because EZH2 dysregulation is functionally integrated with multiple other epigenetic events in a context-dependent manner, the precise manner in which EZH2 dysregulation impacts the pathogenesis of hematological malignancies remains to be clarified. In this perspective, we describe recent findings in pathogenic role of EZH2 in hematological malignancies, which may provide insights into the treatment of with cancers with EZH2 dysregulation and the development of novel therapies targeting epigenetic regulators.
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Affiliation(s)
- Goro Sashida
- International Research Center for Medical Sciences, Kumamoto University, 2-2-1 Honjo, Chuo-ku, Kumamoto, 860-0811, Japan.
| | - Atsushi Iwama
- Department of Cellular and Molecular Medicine, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan
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18
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Beagrie RA, Pombo A. Gene activation by metazoan enhancers: Diverse mechanisms stimulate distinct steps of transcription. Bioessays 2016; 38:881-93. [PMID: 27452946 DOI: 10.1002/bies.201600032] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Enhancers can stimulate transcription by a number of different mechanisms which control different stages of the transcription cycle of their target genes, from recruitment of the transcription machinery to elongation by RNA polymerase. These mechanisms may not be mutually exclusive, as a single enhancer may act through different pathways by binding multiple transcription factors. Multiple enhancers may also work together to regulate transcription of a shared target gene. Most of the evidence supporting different enhancer mechanisms comes from the study of single genes, but new high-throughput experimental frameworks offer the opportunity to integrate and generalize disparate mechanisms identified at single genes. This effort is especially important if we are to fully understand how sequence variation within enhancers contributes to human disease.
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Affiliation(s)
- Robert A Beagrie
- Epigenetic Regulation and Chromatin Architecture Group, Berlin Institute for Medical Systems Biology, Max-Delbrück Centre for Molecular Medicine, Berlin-Buch, Germany
| | - Ana Pombo
- Epigenetic Regulation and Chromatin Architecture Group, Berlin Institute for Medical Systems Biology, Max-Delbrück Centre for Molecular Medicine, Berlin-Buch, Germany
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19
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Entrevan M, Schuettengruber B, Cavalli G. Regulation of Genome Architecture and Function by Polycomb Proteins. Trends Cell Biol 2016; 26:511-525. [PMID: 27198635 DOI: 10.1016/j.tcb.2016.04.009] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Revised: 04/19/2016] [Accepted: 04/21/2016] [Indexed: 12/13/2022]
Abstract
Polycomb group (PcG) proteins dynamically define cellular identities through the epigenetic repression of key developmental regulatory genes. PcG proteins are recruited to specific regulatory elements to modify the chromatin surrounding them. In addition, they regulate the organization of their target genes in the 3D space of the nucleus, and this regulatory function of the 3D genome architecture is involved in cell differentiation and the maintenance of cellular memory. In this review we discuss recent advances in our understanding of how PcG proteins are recruited to chromatin to induce local and global changes in chromosome conformation and regulate their target genes.
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Affiliation(s)
- Marianne Entrevan
- Institute of Human Genetics, CNRS UPR1142 and University of Montpellier, 141 Rue de la Cardonille, 34396, Montpellier Cedex 5, France
| | - Bernd Schuettengruber
- Institute of Human Genetics, CNRS UPR1142 and University of Montpellier, 141 Rue de la Cardonille, 34396, Montpellier Cedex 5, France.
| | - Giacomo Cavalli
- Institute of Human Genetics, CNRS UPR1142 and University of Montpellier, 141 Rue de la Cardonille, 34396, Montpellier Cedex 5, France.
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20
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Neuman N. The Complex Macromolecular Complex. Trends Biochem Sci 2015; 41:1-3. [PMID: 26699226 DOI: 10.1016/j.tibs.2015.11.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Accepted: 11/11/2015] [Indexed: 10/22/2022]
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