1
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Tamburri S, Rustichelli S, Amato S, Pasini D. Navigating the complexity of Polycomb repression: Enzymatic cores and regulatory modules. Mol Cell 2024:S1097-2765(24)00628-2. [PMID: 39178860 DOI: 10.1016/j.molcel.2024.07.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2024] [Revised: 07/12/2024] [Accepted: 07/30/2024] [Indexed: 08/26/2024]
Abstract
Polycomb proteins are a fundamental repressive system that plays crucial developmental roles by orchestrating cell-type-specific transcription programs that govern cell identity. Direct alterations of Polycomb activity are indeed implicated in human pathologies, including developmental disorders and cancer. General Polycomb repression is coordinated by three distinct activities that regulate the deposition of two histone post-translational modifications: tri-methylation of histone H3 lysine 27 (H3K27me3) and histone H2A at lysine 119 (H2AK119ub1). These activities exist in large and heterogeneous multiprotein ensembles consisting of common enzymatic cores regulated by heterogeneous non-catalytic modules composed of a large number of accessory proteins with diverse biochemical properties. Here, we have analyzed the current molecular knowledge, focusing on the functional interaction between the core enzymatic activities and their regulation mediated by distinct accessory modules. This provides a comprehensive analysis of the molecular details that control the establishment and maintenance of Polycomb repression, examining their underlying coordination and highlighting missing information and emerging new features of Polycomb-mediated transcriptional control.
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Affiliation(s)
- Simone Tamburri
- IEO, European Institute of Oncology IRCCS, Department of Experimental Oncology, Via Adamello 16, 20139 Milan, Italy; University of Milan, Department of Health Sciences, Via A. di Rudinì 8, 20142 Milan, Italy.
| | - Samantha Rustichelli
- IEO, European Institute of Oncology IRCCS, Department of Experimental Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Simona Amato
- IEO, European Institute of Oncology IRCCS, Department of Experimental Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Diego Pasini
- IEO, European Institute of Oncology IRCCS, Department of Experimental Oncology, Via Adamello 16, 20139 Milan, Italy; University of Milan, Department of Health Sciences, Via A. di Rudinì 8, 20142 Milan, Italy.
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2
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Dror I, Tan T, Plath K. A critical role for X-chromosome architecture in mammalian X-chromosome dosage compensation. Curr Opin Genet Dev 2024; 87:102235. [PMID: 39053028 DOI: 10.1016/j.gde.2024.102235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2024] [Revised: 07/02/2024] [Accepted: 07/05/2024] [Indexed: 07/27/2024]
Abstract
To regulate gene expression, the macromolecular components of the mammalian interphase nucleus are spatially organized into a myriad of functional compartments. Over the past decade, increasingly sophisticated genomics, microscopy, and functional approaches have probed this organization in unprecedented detail. These investigations have linked chromatin-associated noncoding RNAs to specific nuclear compartments and uncovered mechanisms by which these RNAs establish such domains. In this review, we focus on the long non-coding RNA Xist and summarize new evidence demonstrating the significance of chromatin reconfiguration in creating the inactive X-chromosome compartment. Differences in chromatin compaction correlate with distinct levels of gene repression on the X-chromosome, potentially explaining how human XIST can induce chromosome-wide dampening and silencing of gene expression at different stages of human development.
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Affiliation(s)
- Iris Dror
- Department of Biological Chemistry, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Tiao Tan
- Department of Biological Chemistry, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Kathrin Plath
- Department of Biological Chemistry, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, CA 90095, USA; Molecular Biology Institute, Jonsson Comprehensive Cancer Center, Brain Research Institute, Graduate Program in the Biosciences, Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California Los Angeles, Los Angeles, CA 90095, USA.
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3
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Uckelmann M, Levina V, Taveneau C, Ng XH, Pandey V, Martinez J, Mendiratta S, Houx J, Boudes M, Venugopal H, Trépout S, Zhang Q, Flanigan S, Li M, Sierecki E, Gambin Y, Das PP, Bell O, de Marco A, Davidovich C. Dynamic PRC1-CBX8 stabilizes a porous structure of chromatin condensates. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.05.08.539931. [PMID: 38405976 PMCID: PMC10888862 DOI: 10.1101/2023.05.08.539931] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
The compaction of chromatin is a prevalent paradigm in gene repression. Chromatin compaction is commonly thought to repress transcription by restricting chromatin accessibility. However, the spatial organisation and dynamics of chromatin compacted by gene-repressing factors are unknown. Using cryo-electron tomography, we solved the three-dimensional structure of chromatin condensed by the Polycomb Repressive Complex 1 (PRC1) in a complex with CBX8. PRC1-condensed chromatin is porous and stabilised through multivalent dynamic interactions of PRC1 with chromatin. Mechanistically, positively charged residues on the internally disordered regions (IDRs) of CBX8 mask negative charges on the DNA to stabilize the condensed state of chromatin. Within condensates, PRC1 remains dynamic while maintaining a static chromatin structure. In differentiated mouse embryonic stem cells, CBX8-bound chromatin remains accessible. These findings challenge the idea of rigidly compacted polycomb domains and instead provides a mechanistic framework for dynamic and accessible PRC1-chromatin condensates.
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4
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Bauwens M, Celik E, Zur D, Lin S, Quinodoz M, Michaelides M, Webster AR, Van Den Broeck F, Leroy BP, Rizel L, Moye AR, Meunier A, Tran HV, Moulin AP, Mahieu Q, Van Heetvelde M, Arno G, Rivolta C, De Baere E, Ben-Yosef T. Mutations in SAMD7 cause autosomal-recessive macular dystrophy with or without cone dysfunction. Am J Hum Genet 2024; 111:393-402. [PMID: 38272031 PMCID: PMC10870129 DOI: 10.1016/j.ajhg.2024.01.001] [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: 09/11/2023] [Revised: 01/03/2024] [Accepted: 01/03/2024] [Indexed: 01/27/2024] Open
Abstract
Sterile alpha motif domain containing 7 (SAMD7) is a component of the Polycomb repressive complex 1, which inhibits transcription of many genes, including those activated by the transcription factor Cone-Rod Homeobox (CRX). Here we report bi-allelic mutations in SAMD7 as a cause of autosomal-recessive macular dystrophy with or without cone dysfunction. Four of these mutations affect splicing, while another mutation is a missense variant that alters the repressive effect of SAMD7 on CRX-dependent promoter activity, as shown by in vitro assays. Immunostaining of human retinal sections revealed that SAMD7 is localized in the nuclei of both rods and cones, as well as in those of cells belonging to the inner nuclear layer. These results place SAMD7 as a gene crucial for human retinal function and demonstrate a significant difference in the role of SAMD7 between the human and the mouse retina.
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Affiliation(s)
- Miriam Bauwens
- Center for Medical Genetics, Ghent University Hospital, 9000 Ghent, Belgium; Department of Biomolecular Medicine, Ghent University, 9000 Ghent, Belgium
| | - Elifnaz Celik
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), 4031 Basel, Switzerland; Department of Ophthalmology, University Hospital Basel, 4031 Basel, Switzerland
| | - Dinah Zur
- Ophthalmology Division, Tel Aviv Sourasky Medical Center, Tel Aviv 6423906, Israel; Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Siying Lin
- National Institute of Health Research Biomedical Research Centre at Moorfields Eye Hospital and the Institute of Ophthalmology, London, UK; Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | - Mathieu Quinodoz
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), 4031 Basel, Switzerland; Department of Ophthalmology, University Hospital Basel, 4031 Basel, Switzerland; Department of Genetics and Genome Biology, University of Leicester, Leicester LE1 7RH, UK
| | - Michel Michaelides
- National Institute of Health Research Biomedical Research Centre at Moorfields Eye Hospital and the Institute of Ophthalmology, London, UK; Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | - Andrew R Webster
- National Institute of Health Research Biomedical Research Centre at Moorfields Eye Hospital and the Institute of Ophthalmology, London, UK; Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | - Filip Van Den Broeck
- Center for Medical Genetics, Ghent University Hospital, 9000 Ghent, Belgium; Department of Head & Skin, Ghent University, 9000 Ghent, Belgium
| | - Bart P Leroy
- Center for Medical Genetics, Ghent University Hospital, 9000 Ghent, Belgium; Department of Head & Skin, Ghent University, 9000 Ghent, Belgium; Department of Ophthalmology, Ghent University Hospital, 9000 Ghent, Belgium; The Division of Ophthalmology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Leah Rizel
- The Ruth & Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel
| | - Abigail R Moye
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), 4031 Basel, Switzerland; Department of Ophthalmology, University Hospital Basel, 4031 Basel, Switzerland
| | - Audrey Meunier
- Department of Ophthalmology, Centre Hospitalier Universitaire Saint-Pierre, 1000 Brussels, Belgium
| | - Hoai Viet Tran
- Jules-Gonin Eye Hospital, Fondation Asile des Aveugles, University of Lausanne, 1004 Lausanne, Switzerland; Centre for Gene Therapy and Regenerative Medicine, King's College London, London, UK
| | - Alexandre P Moulin
- Jules-Gonin Eye Hospital, Fondation Asile des Aveugles, University of Lausanne, 1004 Lausanne, Switzerland
| | - Quinten Mahieu
- Center for Medical Genetics, Ghent University Hospital, 9000 Ghent, Belgium; Department of Biomolecular Medicine, Ghent University, 9000 Ghent, Belgium
| | - Mattias Van Heetvelde
- Center for Medical Genetics, Ghent University Hospital, 9000 Ghent, Belgium; Department of Biomolecular Medicine, Ghent University, 9000 Ghent, Belgium
| | - Gavin Arno
- National Institute of Health Research Biomedical Research Centre at Moorfields Eye Hospital and the Institute of Ophthalmology, London, UK; Institute of Ophthalmology, University College London, London EC1V 9EL, UK; North Thames Genomic Laboratory Hub, Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3BH, UK
| | - Carlo Rivolta
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), 4031 Basel, Switzerland; Department of Ophthalmology, University Hospital Basel, 4031 Basel, Switzerland; Department of Genetics and Genome Biology, University of Leicester, Leicester LE1 7RH, UK
| | - Elfride De Baere
- Center for Medical Genetics, Ghent University Hospital, 9000 Ghent, Belgium; Department of Biomolecular Medicine, Ghent University, 9000 Ghent, Belgium
| | - Tamar Ben-Yosef
- The Ruth & Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel.
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5
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Wang J, Chen Y, Xiao Z, Liu X, Liu C, Huang K, Chen H. Phase Separation of Chromatin Structure-related Biomolecules: A Driving Force for Epigenetic Regulations. Curr Protein Pept Sci 2024; 25:553-566. [PMID: 38551058 DOI: 10.2174/0113892037296216240301074253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 02/12/2024] [Accepted: 02/16/2024] [Indexed: 07/25/2024]
Abstract
Intracellularly, membrane-less organelles are formed by spontaneous fusion and fission of macro-molecules in a process called phase separation, which plays an essential role in cellular activities. In certain disease states, such as cancers and neurodegenerative diseases, aberrant phase separations take place and participate in disease progression. Chromatin structure-related proteins, based on their characteristics and upon external stimuli, phase separate to exert functions like genome assembly, transcription regulation, and signal transduction. Moreover, many chromatin structure-related proteins, such as histones, histone-modifying enzymes, DNA-modifying enzymes, and DNA methylation binding proteins, are involved in epigenetic regulations through phase separation. This review introduces phase separation and how phase separation affects epigenetics with a focus on chromatin structure-related molecules.
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Affiliation(s)
- Jiao Wang
- Wuhan No.1 Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430000, China
| | - Yuchen Chen
- Tongji School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Zixuan Xiao
- ISA Wenhua Wuhan High School, Fenglin Road, Junshan New Town, Wuhan Economics & Technological Development Zone, Wuhan, Hubei 430119, China
| | - Xikai Liu
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Chengyu Liu
- Wuhan No.1 Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430000, China
| | - Kun Huang
- Tongji School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Hong Chen
- Tongji School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
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6
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Lu G, Li P. PHF1 compartmentalizes PRC2 via phase separation. Biochem J 2023; 480:1833-1844. [PMID: 37888776 DOI: 10.1042/bcj20230040] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Revised: 10/25/2023] [Accepted: 10/26/2023] [Indexed: 10/28/2023]
Abstract
Polycomb repressive complex 2 (PRC2) is central to polycomb repression as it trimethylates lysine 27 on histone H3 (H3K27me3). How PRC2 is recruited to its targets to deposit H3K27me3 remains an open question. Polycomb-like (PCL) proteins, a group of conserved PRC2 accessory proteins, can direct PRC2 to its targets. In this report, we demonstrate that a PCL protein named PHF1 forms phase-separated condensates at H3K27me3 loci that recruit PRC2. Combining cellular observation and biochemical reconstitution, we show that the N-terminal domains of PHF1 cooperatively mediate target recognition, the chromo-like domain recruits PRC2, and the intrinsically disordered region (IDR) drives phase separation. Moreover, we reveal that the condensates compartmentalize PRC2, DNA, and nucleosome arrays by phase separation. Luciferase reporter assays confirm that PHF1 phase separation promotes transcription repression, further supporting a role of the condensates in polycomb repression. Based on our findings, we propose that these condensates create favorable microenvironments at the target loci for PRC2 to function.
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Affiliation(s)
- Genzhe Lu
- Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Joint Center for Life Sciences, Beijing 100084, China
- Tsinghua Xuetang Life Science Program, Tsinghua University, Beijing 100084, China
| | - Pilong Li
- Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Joint Center for Life Sciences, Beijing 100084, China
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7
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Li R, Huang D, Zhao Y, Yuan Y, Sun X, Dai Z, Huo D, Liu X, Helin K, Li MJ, Wu X. PR-DUB safeguards Polycomb repression through H2AK119ub1 restriction. Cell Prolif 2023; 56:e13457. [PMID: 36959757 PMCID: PMC10542648 DOI: 10.1111/cpr.13457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 03/01/2023] [Accepted: 03/11/2023] [Indexed: 03/25/2023] Open
Abstract
Polycomb group (PcG) proteins are critical chromatin regulators for cell fate control. The mono-ubiquitylation on histone H2AK119 (H2AK119ub1) is one of the well-recognized mechanisms for Polycomb repressive complex 1 (PRC1)-mediated transcription repression. Unexpectedly, the specific H2AK119 deubiquitylation complex composed by additional sex comb-like proteins and BAP1 has also been genetically characterized as Polycomb repressive deubiquitnase (PR-DUB) for unclear reasons. However, it remains a mystery whether and how PR-DUB deficiency affects chromatin states and cell fates through impaired PcG silencing. Here through a careful epigenomic analysis, we demonstrate that a bulk of H2AK119ub1 is diffusely distributed away from promoter regions and their enrichment is positively correlated with PRC1 occupancy. Upon deletion of Asxl2 in mouse embryonic stem cells (ESCs), a pervasive gain of H2AK119ub1 is coincident with increased PRC1 sampling at chromatin. Accordingly, PRC1 is significantly lost from a subset of highly occupied promoters, leading to impaired silencing of associated genes before and after lineage differentiation of Asxl2-null ESCs. Therefore, our study highlights the importance of genome-wide H2AK119ub1 restriction by PR-DUB in safeguarding robust PRC1 deposition and its roles in developmental regulation.
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Affiliation(s)
- Rui Li
- State Key Laboratory of Experimental Hematology, The Province and Ministry Co‐sponsored Collaborative Innovation Center for Medical Epigenetics, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Department of Cell Biology, School of Basic Medical SciencesTianjin Medical UniversityTianjin300070China
| | - Dandan Huang
- Wuxi School of MedicineJiangnan UniversityWuxi214000China
| | - Yingying Zhao
- State Key Laboratory of Experimental Hematology, The Province and Ministry Co‐sponsored Collaborative Innovation Center for Medical Epigenetics, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Department of Cell Biology, School of Basic Medical SciencesTianjin Medical UniversityTianjin300070China
| | - Ye Yuan
- State Key Laboratory of Experimental Hematology, The Province and Ministry Co‐sponsored Collaborative Innovation Center for Medical Epigenetics, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Department of Cell Biology, School of Basic Medical SciencesTianjin Medical UniversityTianjin300070China
| | - Xiaoyu Sun
- State Key Laboratory of Experimental Hematology, The Province and Ministry Co‐sponsored Collaborative Innovation Center for Medical Epigenetics, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Department of Cell Biology, School of Basic Medical SciencesTianjin Medical UniversityTianjin300070China
| | - Zhongye Dai
- State Key Laboratory of Experimental Hematology, The Province and Ministry Co‐sponsored Collaborative Innovation Center for Medical Epigenetics, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Department of Cell Biology, School of Basic Medical SciencesTianjin Medical UniversityTianjin300070China
| | - Dawei Huo
- State Key Laboratory of Experimental Hematology, The Province and Ministry Co‐sponsored Collaborative Innovation Center for Medical Epigenetics, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Department of Cell Biology, School of Basic Medical SciencesTianjin Medical UniversityTianjin300070China
| | - Xiaozhi Liu
- Pediatric Center, Tianjin Key Laboratory of Epigenetics for Organ Development of Premature InfantsThe Fifth Central Hospital of TianjinTianjin300450China
| | - Kristian Helin
- Biotech Research and Innovation CentreUniversity of CopenhagenCopenhagenDenmark
- The Institute of Cancer Research (ICR)LondonUK
| | - Mulin Jun Li
- Department of Bioinformatics, School of Basic Medical SciencesTianjin Medical UniversityTianjin300070China
- Department of Epidemiology and Biostatistics, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and HospitalTianjin Medical UniversityTianjin300070China
| | - Xudong Wu
- State Key Laboratory of Experimental Hematology, The Province and Ministry Co‐sponsored Collaborative Innovation Center for Medical Epigenetics, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), Department of Cell Biology, School of Basic Medical SciencesTianjin Medical UniversityTianjin300070China
- Department of OrthopedicsTianjin Medical University General HospitalTianjin300052China
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8
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Soroczynski J, Risca VI. Technological advances in probing 4D genome organization. Curr Opin Cell Biol 2023; 84:102211. [PMID: 37556867 PMCID: PMC10588670 DOI: 10.1016/j.ceb.2023.102211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Revised: 05/13/2023] [Accepted: 06/29/2023] [Indexed: 08/11/2023]
Abstract
The last two decades of work on chromosome conformation in eukaryotic nuclei have revealed a complex and highly regulated hierarchy of architectural features, from self-associating domains and compartmental interactions to locus-specific loops. Recent findings have shown that these structures are dynamic and heterogeneous, with emerging insights into the factors that shape them and implications for the control of transcription and other nuclear processes. Here, we review the latest advances in the DNA sequencing- and microscopy-based technologies for probing these features in space and time (4D) and discuss how they have been combined with complementary approaches such as genetic perturbations, protein and RNA measurements, and modeling to gain mechanistic insights about genome regulation across space and time.
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Affiliation(s)
- Jan Soroczynski
- Laboratory of Genome Architecture and Dynamics, The Rockefeller University, 1230 York Ave., Box 176, New York, NY 10065, USA; David Rockefeller Graduate Program in Bioscience, The Rockefeller University, 1230 York Ave., New York, NY 10065, USA
| | - Viviana I Risca
- Laboratory of Genome Architecture and Dynamics, The Rockefeller University, 1230 York Ave., Box 176, New York, NY 10065, USA.
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9
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Wang H, Langlais D, Nijnik A. Histone H2A deubiquitinases in the transcriptional programs of development and hematopoiesis: a consolidated analysis. Int J Biochem Cell Biol 2023; 157:106384. [PMID: 36738766 DOI: 10.1016/j.biocel.2023.106384] [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: 08/11/2022] [Accepted: 01/31/2023] [Indexed: 02/05/2023]
Abstract
Monoubiquitinated lysine 119 of histone H2A (H2AK119ub) is a highly abundant epigenetic mark, associated with gene repression and deposited on chromatin by the polycomb repressor complex 1 (PRC1), which is an essential regulator of diverse transcriptional programs in mammalian development and tissue homeostasis. While multiple deubiquitinases (DUBs) with catalytic activity for H2AK119ub (H2A-DUBs) have been identified, we lack systematic analyses of their roles and cross-talk in transcriptional regulation. Here, we address H2A-DUB functions in epigenetic regulation of mammalian development and tissue maintenance by conducting a meta-analysis of 248 genomics datasets from 32 independent studies, focusing on the mouse model and covering embryonic stem cells (ESCs), hematopoietic, and immune cell lineages. This covers all the publicly available datasets that map genomic H2A-DUB binding and H2AK119ub distributions (ChIP-Seq), and all datasets assessing dysregulation in gene expression in the relevant H2A-DUB knockout models (RNA-Seq). Many accessory datasets for PRC1-2 and DUB-interacting proteins are also analyzed and interpreted, as well as further data assessing chromatin accessibility (ATAC-Seq) and transcriptional activity (RNA-seq). We report co-localization in the binding of H2A-DUBs BAP1, USP16, and to a lesser extent others that is conserved across different cell-types, and also the enrichment of antagonistic PRC1-2 protein complexes at the same genomic locations. Such conserved sites enriched for the H2A-DUBs and PRC1-2 are proximal to transcriptionally active genes that engage in housekeeping cellular functions. Nevertheless, they exhibit H2AK119ub levels significantly above the genomic average that can undergo further increase with H2A-DUB knockout. This indicates a cooperation between H2A-DUBs and PRC1-2 in the modulation of housekeeping transcriptional programs, conserved across many cell types, likely operating through their antagonistic effects on H2AK119ub and the regulation of local H2AK119ub turnover. Our study further highlights existing knowledge gaps and discusses important directions for future work.
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Affiliation(s)
- HanChen Wang
- Department of Physiology, McGill University, Montreal, QC, Canada; McGill University Research Centre on Complex Traits, McGill University, QC, Canada
| | - David Langlais
- McGill University Research Centre on Complex Traits, McGill University, QC, Canada; Department of Human Genetics, McGill University, Montreal, QC, Canada; McGill Genome Centre, Montreal, QC, Canada.
| | - Anastasia Nijnik
- Department of Physiology, McGill University, Montreal, QC, Canada; McGill University Research Centre on Complex Traits, McGill University, QC, Canada.
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10
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Nepita I, Piazza S, Ruglioni M, Cristiani S, Bosurgi E, Salvadori T, Vicidomini G, Diaspro A, Castello M, Cerase A, Bianchini P, Storti B, Bizzarri R. On the Advent of Super-Resolution Microscopy in the Realm of Polycomb Proteins. BIOLOGY 2023; 12:374. [PMID: 36979066 PMCID: PMC10044799 DOI: 10.3390/biology12030374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 02/23/2023] [Accepted: 02/24/2023] [Indexed: 03/02/2023]
Abstract
The genomes of metazoans are organized at multiple spatial scales, ranging from the double helix of DNA to whole chromosomes. The intermediate genomic scale of kilobases to megabases, which corresponds to the 50-300 nm spatial scale, is particularly interesting, as the 3D arrangement of chromatin is implicated in multiple regulatory mechanisms. In this context, polycomb group (PcG) proteins stand as major epigenetic modulators of chromatin function, acting prevalently as repressors of gene transcription by combining chemical modifications of target histones with physical crosslinking of distal genomic regions and phase separation. The recent development of super-resolution microscopy (SRM) has strongly contributed to improving our comprehension of several aspects of nano-/mesoscale (10-200 nm) chromatin domains. Here, we review the current state-of-the-art SRM applied to PcG proteins, showing that the application of SRM to PcG activity and organization is still quite limited and mainly focused on the 3D assembly of PcG-controlled genomic loci. In this context, SRM approaches have mostly been applied to multilabel fluorescence in situ hybridization (FISH). However, SRM data have complemented the maps obtained from chromosome capture experiments and have opened a new window to observe how 3D chromatin topology is modulated by PcGs.
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Affiliation(s)
- Irene Nepita
- Nanoscopy, Istituto Italiano di Tecnologia, Via E. Melen 83, 16152 Genova, Italy
| | - Simonluca Piazza
- Molecular Microscopy and Spectroscopy, Istituto Italiano di Tecnologia, Via E. Melen 83, 16152 Genova, Italy
- R&D Department, Genoa Instruments s.r.l., Via E. Melen 83, 16152 Genova, Italy
| | - Martina Ruglioni
- Department of Surgical, Medical and Molecular Pathology, and Critical Care Medicine, University of Pisa, Via Roma 65, 56126 Pisa, Italy
| | - Sofia Cristiani
- Department of Surgical, Medical and Molecular Pathology, and Critical Care Medicine, University of Pisa, Via Roma 65, 56126 Pisa, Italy
| | - Emanuele Bosurgi
- Department of Surgical, Medical and Molecular Pathology, and Critical Care Medicine, University of Pisa, Via Roma 65, 56126 Pisa, Italy
| | - Tiziano Salvadori
- Department of Surgical, Medical and Molecular Pathology, and Critical Care Medicine, University of Pisa, Via Roma 65, 56126 Pisa, Italy
| | - Giuseppe Vicidomini
- Molecular Microscopy and Spectroscopy, Istituto Italiano di Tecnologia, Via E. Melen 83, 16152 Genova, Italy
| | - Alberto Diaspro
- Nanoscopy, Istituto Italiano di Tecnologia, Via E. Melen 83, 16152 Genova, Italy
- DIFILAB, Dipartimento di Fisica, Università degli Studi di Genova, Via Dodecaneso 33, 16146 Genova, Italy
| | - Marco Castello
- Nanoscopy, Istituto Italiano di Tecnologia, Via E. Melen 83, 16152 Genova, Italy
- R&D Department, Genoa Instruments s.r.l., Via E. Melen 83, 16152 Genova, Italy
| | - Andrea Cerase
- Unit of Cell and Developmental Biology, Department of Biology, University of Pisa, Strada Statale dell’Abetone Brennero 4, 56123 Pisa, Italy
| | - Paolo Bianchini
- Nanoscopy, Istituto Italiano di Tecnologia, Via E. Melen 83, 16152 Genova, Italy
- DIFILAB, Dipartimento di Fisica, Università degli Studi di Genova, Via Dodecaneso 33, 16146 Genova, Italy
| | - Barbara Storti
- NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR, Piazza San Silvestro 12, 56127 Pisa, Italy
| | - Ranieri Bizzarri
- Nanoscopy, Istituto Italiano di Tecnologia, Via E. Melen 83, 16152 Genova, Italy
- Department of Surgical, Medical and Molecular Pathology, and Critical Care Medicine, University of Pisa, Via Roma 65, 56126 Pisa, Italy
- NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR, Piazza San Silvestro 12, 56127 Pisa, Italy
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11
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Waters PD, Graves JAM, Whiteley SL, Georges A, Ruiz-Herrera A. Three dimensions of thermolabile sex determination. Bioessays 2023; 45:e2200123. [PMID: 36529688 DOI: 10.1002/bies.202200123] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Revised: 10/14/2022] [Accepted: 12/05/2022] [Indexed: 12/23/2022]
Abstract
The molecular mechanism of temperature-dependent sex determination (TSD) is a long-standing mystery. How is the thermal signal sensed, captured and transduced to regulate key sex genes? Although there is compelling evidence for pathways via which cells capture the temperature signal, there is no known mechanism by which cells transduce those thermal signals to affect gene expression. Here we propose a novel hypothesis we call 3D-TSD (the three dimensions of thermolabile sex determination). We postulate that the genome has capacity to remodel in response to temperature by changing 3D chromatin conformation, perhaps via temperature-sensitive transcriptional condensates. This could rewire enhancer-promoter interactions to alter the expression of key sex-determining genes. This hypothesis can accommodate monogenic or multigenic thermolabile sex-determining systems, and could be combined with upstream thermal sensing and transduction to the epigenome to commit gonadal fate.
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Affiliation(s)
- Paul D Waters
- Faculty of Science, School of Biotechnology and Biomolecular Science, UNSW Sydney, Sydney, NSW, Australia
| | - Jennifer A Marshall Graves
- Department of Environment and Genetics, La Trobe University, Bundoora, Australia.,Institute for Applied Ecology, University of Canberra, Canberra, Australia
| | - Sarah L Whiteley
- Institute for Applied Ecology, University of Canberra, Canberra, Australia
| | - Arthur Georges
- Institute for Applied Ecology, University of Canberra, Canberra, Australia
| | - Aurora Ruiz-Herrera
- Departament de Biologia Cellular, Fisiologia i Immunologia, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain.,Genome Integrity and Instability Group, Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain
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12
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Hanot M, Raby L, Völkel P, Le Bourhis X, Angrand PO. The Contribution of the Zebrafish Model to the Understanding of Polycomb Repression in Vertebrates. Int J Mol Sci 2023; 24:ijms24032322. [PMID: 36768643 PMCID: PMC9916924 DOI: 10.3390/ijms24032322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 01/20/2023] [Accepted: 01/21/2023] [Indexed: 01/26/2023] Open
Abstract
Polycomb group (PcG) proteins are highly conserved proteins assembled into two major types of complexes, PRC1 and PRC2, involved in the epigenetic silencing of a wide range of gene expression programs regulating cell fate and tissue development. The crucial role of PRC1 and PRC2 in the fundamental cellular processes and their involvement in human pathologies such as cancer attracted intense attention over the last few decades. Here, we review recent advancements regarding PRC1 and PRC2 function using the zebrafish model. We point out that the unique characteristics of the zebrafish model provide an exceptional opportunity to increase our knowledge of the role of the PRC1 and PRC2 complexes in tissue development, in the maintenance of organ integrity and in pathology.
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Affiliation(s)
- Mariette Hanot
- Univ. Lille, CNRS, Inserm, CHU Lille, UMR9020-U1277-CANTHER-Cancer Heterogeneity Plasticity and Resistance to Therapies, F-59000 Lille, France
| | - Ludivine Raby
- Univ. Lille, CNRS, Inserm, CHU Lille, UMR9020-U1277-CANTHER-Cancer Heterogeneity Plasticity and Resistance to Therapies, F-59000 Lille, France
| | - Pamela Völkel
- Univ. Lille, CNRS, Inserm, CHU Lille, UMR9020-U1277-CANTHER-Cancer Heterogeneity Plasticity and Resistance to Therapies, F-59000 Lille, France
| | - Xuefen Le Bourhis
- Univ. Lille, CNRS, Inserm, CHU Lille, UMR9020-U1277-CANTHER-Cancer Heterogeneity Plasticity and Resistance to Therapies, F-59000 Lille, France
| | - Pierre-Olivier Angrand
- Univ. Lille, CNRS, Inserm, CHU Lille, UMR9020-U1277-CANTHER-Cancer Heterogeneity Plasticity and Resistance to Therapies, F-59000 Lille, France
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13
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RINGs, DUBs and Abnormal Brain Growth-Histone H2A Ubiquitination in Brain Development and Disease. EPIGENOMES 2022; 6:epigenomes6040042. [PMID: 36547251 PMCID: PMC9778336 DOI: 10.3390/epigenomes6040042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 11/29/2022] [Accepted: 11/30/2022] [Indexed: 12/03/2022] Open
Abstract
During mammalian neurodevelopment, signaling pathways converge upon transcription factors (TFs) to establish appropriate gene expression programmes leading to the production of distinct neural and glial cell types. This process is partially regulated by the dynamic modulation of chromatin states by epigenetic systems, including the polycomb group (PcG) family of co-repressors. PcG proteins form multi-subunit assemblies that sub-divide into distinct, yet functionally related families. Polycomb repressive complexes 1 and 2 (PRC1 and 2) modify the chemical properties of chromatin by covalently modifying histone tails via H2A ubiquitination (H2AK119ub1) and H3 methylation, respectively. In contrast to the PRCs, the Polycomb repressive deubiquitinase (PR-DUB) complex removes H2AK119ub1 from chromatin through the action of the C-terminal hydrolase BAP1. Genetic screening has identified several PcG mutations that are causally associated with a range of congenital neuropathologies associated with both localised and/or systemic growth abnormalities. As PRC1 and PR-DUB hold opposing functions to control H2AK119ub1 levels across the genome, it is plausible that such neurodevelopmental disorders arise through a common mechanism. In this review, we will focus on advancements regarding the composition and opposing molecular functions of mammalian PRC1 and PR-DUB, and explore how their dysfunction contributes to the emergence of neurodevelopmental disorders.
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14
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Mansisidor AR, Risca VI. Chromatin accessibility: methods, mechanisms, and biological insights. Nucleus 2022; 13:236-276. [PMID: 36404679 PMCID: PMC9683059 DOI: 10.1080/19491034.2022.2143106] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 10/23/2022] [Accepted: 10/30/2022] [Indexed: 11/22/2022] Open
Abstract
Access to DNA is a prerequisite to the execution of essential cellular processes that include transcription, replication, chromosomal segregation, and DNA repair. How the proteins that regulate these processes function in the context of chromatin and its dynamic architectures is an intensive field of study. Over the past decade, genome-wide assays and new imaging approaches have enabled a greater understanding of how access to the genome is regulated by nucleosomes and associated proteins. Additional mechanisms that may control DNA accessibility in vivo include chromatin compaction and phase separation - processes that are beginning to be understood. Here, we review the ongoing development of accessibility measurements, we summarize the different molecular and structural mechanisms that shape the accessibility landscape, and we detail the many important biological functions that are linked to chromatin accessibility.
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Affiliation(s)
- Andrés R. Mansisidor
- Laboratory of Genome Architecture and Dynamics, The Rockefeller University, New York, NY
| | - Viviana I. Risca
- Laboratory of Genome Architecture and Dynamics, The Rockefeller University, New York, NY
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15
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Rong Y, Zhu YZ, Yu JL, Wu YW, Ji SY, Zhou Y, Jiang Y, Jin J, Fan HY, Shen L, Sha QQ. USP16-mediated histone H2A lysine-119 deubiquitination during oocyte maturation is a prerequisite for zygotic genome activation. Nucleic Acids Res 2022; 50:5599-5616. [PMID: 35640597 PMCID: PMC9178006 DOI: 10.1093/nar/gkac468] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 05/12/2022] [Accepted: 05/17/2022] [Indexed: 12/12/2022] Open
Abstract
Maternal-to-zygotic transition (MZT) is the first and key step in the control of animal development and intimately related to changes in chromatin structure and histone modifications. H2AK119ub1, an important epigenetic modification in regulating chromatin configuration and function, is primarily catalyzed by PRC1 and contributes to resistance to transcriptional reprogramming in mouse embryos. In this study, the genome-wide dynamic distribution of H2AK119ub1 during MZT in mice was investigated using chromosome immunoprecipitation and sequencing. The results indicated that H2AK119ub1 accumulated in fully grown oocytes and was enriched at the TSSs of maternal genes, but was promptly declined after meiotic resumption at genome-wide including the TSSs of early zygotic genes, by a previously unidentified mechanism. Genetic evidences indicated that ubiquitin-specific peptidase 16 (USP16) is the major deubiquitinase for H2AK119ub1 in mouse oocytes. Conditional knockout of Usp16 in oocytes did not impair their survival, growth, or meiotic maturation. However, oocytes lacking USP16 have defects when undergoing zygotic genome activation or gaining developmental competence after fertilization, potentially associated with high levels of maternal H2AK119ub1 deposition on the zygotic genomes. Taken together, H2AK119ub1 level is declined during oocyte maturation by an USP16-dependent mechanism, which ensures zygotic genome reprogramming and transcriptional activation of essential early zygotic genes.
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Affiliation(s)
- Yan Rong
- Key Laboratory of Reproductive Dysfunction Management of Zhejiang Province; Assisted Reproduction Unit, Department of Obstetrics and Gynecology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou 310016, China
- MOE Key Laboratory for Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network, Life Sciences Institute, Zhejiang University, Hangzhou 310058, China
| | - Ye-Zhang Zhu
- MOE Key Laboratory for Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network, Life Sciences Institute, Zhejiang University, Hangzhou 310058, China
| | - Jia-li Yu
- MOE Key Laboratory for Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network, Life Sciences Institute, Zhejiang University, Hangzhou 310058, China
| | - Yun-Wen Wu
- MOE Key Laboratory for Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network, Life Sciences Institute, Zhejiang University, Hangzhou 310058, China
| | - Shu-Yan Ji
- MOE Key Laboratory for Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network, Life Sciences Institute, Zhejiang University, Hangzhou 310058, China
| | - Yong Zhou
- Fertility Preservation Laboratory, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou 510317, China
| | - Yu Jiang
- MOE Key Laboratory for Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network, Life Sciences Institute, Zhejiang University, Hangzhou 310058, China
| | - Jin Jin
- MOE Key Laboratory for Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network, Life Sciences Institute, Zhejiang University, Hangzhou 310058, China
| | - Heng-Yu Fan
- MOE Key Laboratory for Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network, Life Sciences Institute, Zhejiang University, Hangzhou 310058, China
| | - Li Shen
- MOE Key Laboratory for Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network, Life Sciences Institute, Zhejiang University, Hangzhou 310058, China
| | - Qian-Qian Sha
- Fertility Preservation Laboratory, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou 510317, China
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16
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Henriques-Pons A, Beghini DG, Silva VDS, Iwao Horita S, da Silva FAB. Pulmonary Mesenchymal Stem Cells in Mild Cases of COVID-19 Are Dedicated to Proliferation; In Severe Cases, They Control Inflammation, Make Cell Dispersion, and Tissue Regeneration. Front Immunol 2022; 12:780900. [PMID: 35095855 PMCID: PMC8793136 DOI: 10.3389/fimmu.2021.780900] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 12/17/2021] [Indexed: 12/29/2022] Open
Abstract
Mesenchymal stem cells (MSCs) are multipotent adult stem cells present in virtually all tissues; they have potent self-renewal capacity and differentiate into multiple cell types. For many reasons, these cells are a promising therapeutic alternative to treat patients with severe COVID-19 and pulmonary post-COVID sequelae. These cells are not only essential for tissue regeneration; they can also alter the pulmonary environment through the paracrine secretion of several mediators. They can control or promote inflammation, induce other stem cells differentiation, restrain the virus load, and much more. In this work, we performed single-cell RNA-seq data analysis of MSCs in bronchoalveolar lavage samples from control individuals and COVID-19 patients with mild and severe clinical conditions. When we compared samples from mild cases with control individuals, most genes transcriptionally upregulated in COVID-19 were involved in cell proliferation. However, a new set of genes with distinct biological functions was upregulated when we compared severely affected with mild COVID-19 patients. In this analysis, the cells upregulated genes related to cell dispersion/migration and induced the γ-activated sequence (GAS) genes, probably triggered by IFNGR1 and IFNGR2. Then, IRF-1 was upregulated, one of the GAS target genes, leading to the interferon-stimulated response (ISR) and the overexpression of many signature target genes. The MSCs also upregulated genes involved in the mesenchymal-epithelial transition, virus control, cell chemotaxis, and used the cytoplasmic RNA danger sensors RIG-1, MDA5, and PKR. In a non-comparative analysis, we observed that MSCs from severe cases do not express many NF-κB upstream receptors, such as Toll-like (TLRs) TLR-3, -7, and -8; tumor necrosis factor (TNFR1 or TNFR2), RANK, CD40, and IL-1R1. Indeed, many NF-κB inhibitors were upregulated, including PPP2CB, OPTN, NFKBIA, and FHL2, suggesting that MSCs do not play a role in the "cytokine storm" observed. Therefore, lung MSCs in COVID-19 sense immune danger and act protectively in concert with the pulmonary environment, confirming their therapeutic potential in cell-based therapy for COVID-19. The transcription of MSCs senescence markers is discussed.
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Affiliation(s)
- Andrea Henriques-Pons
- Fundação Oswaldo Cruz, Instituto Oswaldo Cruz, Laboratório de Inovações em Terapias, Ensino e Bioprodutos, Rio de Janeiro, Brazil
| | - Daniela Gois Beghini
- Fundação Oswaldo Cruz, Instituto Oswaldo Cruz, Laboratório de Inovações em Terapias, Ensino e Bioprodutos, Rio de Janeiro, Brazil
| | | | - Samuel Iwao Horita
- Fundação Oswaldo Cruz, Instituto Oswaldo Cruz, Laboratório de Inovações em Terapias, Ensino e Bioprodutos, Rio de Janeiro, Brazil
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17
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Mahmood SR, El Said NH, Percipalle P. The Role of Nuclear Actin in Genome Organization and Gene Expression Regulation During Differentiation. Results Probl Cell Differ 2022; 70:607-624. [PMID: 36348124 DOI: 10.1007/978-3-031-06573-6_22] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
In the cell nucleus, actin participates in numerous essential processes. Actin is involved in chromatin as part of specific ATP-dependent chromatin remodeling complexes and associates with the RNA polymerase machinery to regulate transcription at multiple levels. Emerging evidence has also shown that the nuclear actin pool controls the architecture of the mammalian genome playing an important role in its hierarchical organization into transcriptionally active and repressed compartments, contributing to the clustering of RNA polymerase II into transcriptional hubs. Here, we review the most recent literature and discuss how actin involvement in genome organization impacts the regulation of gene programs that are activated or repressed during differentiation and development. As in the cytoplasm, we propose that nuclear actin is involved in key nuclear tasks in complex with different types of actin-binding proteins that regulate actin function and bridge interactions between actin and various nuclear components.
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Affiliation(s)
- Syed Raza Mahmood
- Center for Genomics and Systems Biology, New York University Abu Dhabi (NYUAD), Abu Dhabi, United Arab Emirates
- Department of Biology, New York University, New York, NY, USA
| | - Nadine Hosny El Said
- Program in Biology, Division of Science and Mathematics, New York University Abu Dhabi (NYUAD), Abu Dhabi, United Arab Emirates
| | - Piergiorgio Percipalle
- Center for Genomics and Systems Biology, New York University Abu Dhabi (NYUAD), Abu Dhabi, United Arab Emirates.
- Department of Biology, New York University, New York, NY, USA.
- Program in Biology, Division of Science and Mathematics, New York University Abu Dhabi (NYUAD), Abu Dhabi, United Arab Emirates.
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18
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Markaki Y, Gan Chong J, Wang Y, Jacobson EC, Luong C, Tan SYX, Jachowicz JW, Strehle M, Maestrini D, Banerjee AK, Mistry BA, Dror I, Dossin F, Schöneberg J, Heard E, Guttman M, Chou T, Plath K. Xist nucleates local protein gradients to propagate silencing across the X chromosome. Cell 2021; 184:6174-6192.e32. [PMID: 34813726 PMCID: PMC8671326 DOI: 10.1016/j.cell.2021.10.022] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 07/29/2021] [Accepted: 10/11/2021] [Indexed: 02/08/2023]
Abstract
The lncRNA Xist forms ∼50 diffraction-limited foci to transcriptionally silence one X chromosome. How this small number of RNA foci and interacting proteins regulate a much larger number of X-linked genes is unknown. We show that Xist foci are locally confined, contain ∼2 RNA molecules, and nucleate supramolecular complexes (SMACs) that include many copies of the critical silencing protein SPEN. Aggregation and exchange of SMAC proteins generate local protein gradients that regulate broad, proximal chromatin regions. Partitioning of numerous SPEN molecules into SMACs is mediated by their intrinsically disordered regions and essential for transcriptional repression. Polycomb deposition via SMACs induces chromatin compaction and the increase in SMACs density around genes, which propagates silencing across the X chromosome. Our findings introduce a mechanism for functional nuclear compartmentalization whereby crowding of transcriptional and architectural regulators enables the silencing of many target genes by few RNA molecules.
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Affiliation(s)
- Yolanda Markaki
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA.
| | - Johnny Gan Chong
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Yuying Wang
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Elsie C Jacobson
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Christy Luong
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Shawn Y X Tan
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Joanna W Jachowicz
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Mackenzie Strehle
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Davide Maestrini
- Department of Computational Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Abhik K Banerjee
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Bhaven A Mistry
- Department of Computational Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA; Claremont McKenna College, Claremont, CA 91711, USA
| | - Iris Dror
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Francois Dossin
- European Molecular Biology Laboratory, Director's Unit, Heidelberg 69117, Germany
| | - Johannes Schöneberg
- Departments of Pharmacology & Chemistry and Biochemistry, University of California San Diego, San Diego, CA 92093, USA
| | - Edith Heard
- European Molecular Biology Laboratory, Director's Unit, Heidelberg 69117, Germany
| | - Mitchell Guttman
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Tom Chou
- Department of Computational Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA.
| | - Kathrin Plath
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA.
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19
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Bieluszewski T, Xiao J, Yang Y, Wagner D. PRC2 activity, recruitment, and silencing: a comparative perspective. TRENDS IN PLANT SCIENCE 2021; 26:1186-1198. [PMID: 34294542 DOI: 10.1016/j.tplants.2021.06.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 06/08/2021] [Accepted: 06/16/2021] [Indexed: 05/22/2023]
Abstract
Polycomb repressive complex (PRC)-mediated gene silencing is vital for cell identity and development in both the plant and the animal kingdoms. It also modulates responses to stress. Two major protein complexes, PRC1 and PRC2, execute conserved nuclear functions in metazoans and plants through covalent modification of histones and by compacting chromatin. While a general requirement for Polycomb complexes in mitotically heritable gene repression in the context of chromatin is well established, recent studies have brought new insights into the regulation of Polycomb complex activity and recruitment. Here, we discuss these recent advances with emphasis on PRC2.
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Affiliation(s)
- Tomasz Bieluszewski
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19103, USA
| | - Jun Xiao
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China; Centre of Excellence for Plant and Microbial Science (CEPAMS), the John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Yiman Yang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China; College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Doris Wagner
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19103, USA.
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20
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Tamburri S, Conway E, Pasini D. Polycomb-dependent histone H2A ubiquitination links developmental disorders with cancer. Trends Genet 2021; 38:333-352. [PMID: 34426021 DOI: 10.1016/j.tig.2021.07.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 07/21/2021] [Accepted: 07/26/2021] [Indexed: 12/18/2022]
Abstract
Cell identity is tightly controlled by specific transcriptional programs which require post-translational modifications of histones. These histone modifications allow the establishment and maintenance of active and repressed chromatin domains. Histone H2A lysine 119 ubiquitination (H2AK119ub1) has an essential role in building repressive chromatin domains during development. It is regulated by the counteracting activities of the Polycomb repressive complex 1 (PRC1) and the Polycomb repressive-deubiquitinase (PR-DUB) complexes, two multi-subunit ensembles that write and erase this modification, respectively. We have catalogued the recurrent genetic alterations in subunits of the PRC1 and PR-DUB complexes in both neurodevelopmental disorders and cancer. These genetic lesions are often shared across disorders, and we highlight common mechanisms of H2AK119ub1 dysregulation and how they affect development in multiple disease contexts.
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Affiliation(s)
- Simone Tamburri
- European Institute of Oncology (IEO), Istituto Di Ricovero e Cura a Carattere Scientifico (IRCCS), Department of Experimental Oncology, Via Adamello 16, 20139 Milan, Italy; University of Milan, Department of Health Sciences, Via Antonio di Rudinì 8, 20142 Milan, Italy.
| | - Eric Conway
- European Institute of Oncology (IEO), Istituto Di Ricovero e Cura a Carattere Scientifico (IRCCS), Department of Experimental Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Diego Pasini
- European Institute of Oncology (IEO), Istituto Di Ricovero e Cura a Carattere Scientifico (IRCCS), Department of Experimental Oncology, Via Adamello 16, 20139 Milan, Italy; University of Milan, Department of Health Sciences, Via Antonio di Rudinì 8, 20142 Milan, Italy.
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21
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Nuclear compartmentalization as a mechanism of quantitative control of gene expression. Nat Rev Mol Cell Biol 2021; 22:653-670. [PMID: 34341548 DOI: 10.1038/s41580-021-00387-1] [Citation(s) in RCA: 123] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/28/2021] [Indexed: 01/08/2023]
Abstract
Gene regulation requires the dynamic coordination of hundreds of regulatory factors at precise genomic and RNA targets. Although many regulatory factors have specific affinity for their nucleic acid targets, molecular diffusion and affinity models alone cannot explain many of the quantitative features of gene regulation in the nucleus. One emerging explanation for these quantitative properties is that DNA, RNA and proteins organize within precise, 3D compartments in the nucleus to concentrate groups of functionally related molecules. Recently, nucleic acids and proteins involved in many important nuclear processes have been shown to engage in cooperative interactions, which lead to the formation of condensates that partition the nucleus. In this Review, we discuss an emerging perspective of gene regulation, which moves away from classic models of stoichiometric interactions towards an understanding of how spatial compartmentalization can lead to non-stoichiometric molecular interactions and non-linear regulatory behaviours. We describe key mechanisms of nuclear compartment formation, including emerging roles for non-coding RNAs in facilitating their formation, and discuss the functional role of nuclear compartments in transcription regulation, co-transcriptional and post-transcriptional RNA processing, and higher-order chromatin regulation. More generally, we discuss how compartmentalization may explain important quantitative aspects of gene regulation.
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22
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De Novo Polycomb Recruitment: Lessons from Latent Herpesviruses. Viruses 2021; 13:v13081470. [PMID: 34452335 PMCID: PMC8402699 DOI: 10.3390/v13081470] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/22/2021] [Accepted: 07/24/2021] [Indexed: 12/11/2022] Open
Abstract
The Human Herpesviruses persist in the form of a latent infection in specialized cell types. During latency, the herpesvirus genomes associate with cellular histone proteins and the viral lytic genes assemble into transcriptionally repressive heterochromatin. Although there is divergence in the nature of heterochromatin on latent herpesvirus genomes, in general, the genomes assemble into forms of heterochromatin that can convert to euchromatin to permit gene expression and therefore reactivation. This reversible form of heterochromatin is known as facultative heterochromatin and is most commonly characterized by polycomb silencing. Polycomb silencing is prevalent on the cellular genome and plays a role in developmentally regulated and imprinted genes, as well as X chromosome inactivation. As herpesviruses initially enter the cell in an un-chromatinized state, they provide an optimal system to study how de novo facultative heterochromatin is targeted to regions of DNA and how it contributes to silencing. Here, we describe how polycomb-mediated silencing potentially assembles onto herpesvirus genomes, synergizing what is known about herpesvirus latency with facultative heterochromatin targeting to the cellular genome. A greater understanding of polycomb silencing of herpesviruses will inform on the mechanism of persistence and reactivation of these pathogenic human viruses and provide clues regarding how de novo facultative heterochromatin forms on the cellular genome.
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23
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Venit T, El Said NH, Mahmood SR, Percipalle P. A dynamic actin-dependent nucleoskeleton and cell identity. J Biochem 2021; 169:243-257. [PMID: 33351909 DOI: 10.1093/jb/mvaa133] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Accepted: 10/27/2020] [Indexed: 12/19/2022] Open
Abstract
Actin is an essential regulator of cellular functions. In the eukaryotic cell nucleus, actin regulates chromatin as a bona fide component of chromatin remodelling complexes, it associates with nuclear RNA polymerases to regulate transcription and is involved in co-transcriptional assembly of nascent RNAs into ribonucleoprotein complexes. Actin dynamics are, therefore, emerging as a major regulatory factor affecting diverse cellular processes. Importantly, the involvement of actin dynamics in nuclear functions is redefining the concept of nucleoskeleton from a rigid scaffold to a dynamic entity that is likely linked to the three-dimensional organization of the nuclear genome. In this review, we discuss how nuclear actin, by regulating chromatin structure through phase separation may contribute to the architecture of the nuclear genome during cell differentiation and facilitate the expression of specific gene programs. We focus specifically on mitochondrial genes and how their dysregulation in the absence of actin raises important questions about the role of cytoskeletal proteins in regulating chromatin structure. The discovery of a novel pool of mitochondrial actin that serves as 'mitoskeleton' to facilitate organization of mtDNA supports a general role for actin in genome architecture and a possible function of distinct actin pools in the communication between nucleus and mitochondria.
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Affiliation(s)
- Tomas Venit
- Science Division, Biology Program, New York University Abu Dhabi (NYUAD), PO Box 129188, Abu Dhabi United Arab Emirates
| | - Nadine Hosny El Said
- Science Division, Biology Program, New York University Abu Dhabi (NYUAD), PO Box 129188, Abu Dhabi United Arab Emirates
| | - Syed Raza Mahmood
- Science Division, Biology Program, New York University Abu Dhabi (NYUAD), PO Box 129188, Abu Dhabi United Arab Emirates.,Department of Biology, New York University, 100 Washington Square East, 1009 Silver Center, New York, NY 10003, USA
| | - Piergiorgio Percipalle
- Science Division, Biology Program, New York University Abu Dhabi (NYUAD), PO Box 129188, Abu Dhabi United Arab Emirates.,Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Svante Arrhenius väg 20C, 114 18 Stockholm, Sweden
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24
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Huang Y, Sicar S, Ramirez-Prado JS, Manza-Mianza D, Antunez-Sanchez J, Brik-Chaouche R, Rodriguez-Granados NY, An J, Bergounioux C, Mahfouz MM, Hirt H, Crespi M, Concia L, Barneche F, Amiard S, Probst AV, Gutierrez-Marcos J, Ariel F, Raynaud C, Latrasse D, Benhamed M. Polycomb-dependent differential chromatin compartmentalization determines gene coregulation in Arabidopsis. Genome Res 2021; 31:1230-1244. [PMID: 34083408 PMCID: PMC8256866 DOI: 10.1101/gr.273771.120] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 05/20/2021] [Indexed: 11/24/2022]
Abstract
In animals, distant H3K27me3-marked Polycomb targets can establish physical interactions forming repressive chromatin hubs. In plants, growing evidence suggests that H3K27me3 acts directly or indirectly to regulate chromatin interactions, although how this histone modification modulates 3D chromatin architecture remains elusive. To decipher the impact of the dynamic deposition of H3K27me3 on the Arabidopsis thaliana nuclear interactome, we combined genetics, transcriptomics, and several 3D epigenomic approaches. By analyzing mutants defective for histone H3K27 methylation or demethylation, we uncovered the crucial role of this chromatin mark in short- and previously unnoticed long-range chromatin loop formation. We found that a reduction in H3K27me3 levels led to a decrease in the interactions within Polycomb-associated repressive domains. Regions with lower H3K27me3 levels in the H3K27 methyltransferase clf mutant established new interactions with regions marked with H3K9ac, a histone modification associated with active transcription, indicating that a reduction in H3K27me3 levels induces a global reconfiguration of chromatin architecture. Altogether, our results reveal that the 3D genome organization is tightly linked to reversible histone modifications that govern chromatin interactions. Consequently, nuclear organization dynamics shapes the transcriptional reprogramming during plant development and places H3K27me3 as a key feature in the coregulation of distant genes.
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Affiliation(s)
- Ying Huang
- Université Paris-Saclay, CNRS, INRAE, Univ Evry, Institute of Plant Sciences Paris-Saclay (IPS2), 91405, Orsay, France
| | - Sanchari Sicar
- Université Paris-Saclay, CNRS, INRAE, Univ Evry, Institute of Plant Sciences Paris-Saclay (IPS2), 91405, Orsay, France
| | - Juan S Ramirez-Prado
- Université Paris-Saclay, CNRS, INRAE, Univ Evry, Institute of Plant Sciences Paris-Saclay (IPS2), 91405, Orsay, France
| | - Deborah Manza-Mianza
- Université Paris-Saclay, CNRS, INRAE, Univ Evry, Institute of Plant Sciences Paris-Saclay (IPS2), 91405, Orsay, France
| | | | - Rim Brik-Chaouche
- Université Paris-Saclay, CNRS, INRAE, Univ Evry, Institute of Plant Sciences Paris-Saclay (IPS2), 91405, Orsay, France
| | - Natalia Y Rodriguez-Granados
- Université Paris-Saclay, CNRS, INRAE, Univ Evry, Institute of Plant Sciences Paris-Saclay (IPS2), 91405, Orsay, France
| | - Jing An
- Université Paris-Saclay, CNRS, INRAE, Univ Evry, Institute of Plant Sciences Paris-Saclay (IPS2), 91405, Orsay, France
| | - Catherine Bergounioux
- Université Paris-Saclay, CNRS, INRAE, Univ Evry, Institute of Plant Sciences Paris-Saclay (IPS2), 91405, Orsay, France
| | - Magdy M Mahfouz
- Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Heribert Hirt
- Université Paris-Saclay, CNRS, INRAE, Univ Evry, Institute of Plant Sciences Paris-Saclay (IPS2), 91405, Orsay, France
- Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Martin Crespi
- Université Paris-Saclay, CNRS, INRAE, Univ Evry, Institute of Plant Sciences Paris-Saclay (IPS2), 91405, Orsay, France
| | - Lorenzo Concia
- Université Paris-Saclay, CNRS, INRAE, Univ Evry, Institute of Plant Sciences Paris-Saclay (IPS2), 91405, Orsay, France
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), ENS, CNRS UMR8197, INSERM U1024, PSL Research University, 75005, Paris, France
| | - Fredy Barneche
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), ENS, CNRS UMR8197, INSERM U1024, PSL Research University, 75005, Paris, France
| | - Simon Amiard
- GReD, Université Clermont Auvergne, CNRS, INSERM, BP 38, 63001, Clermont-Ferrand, France
| | - Aline V Probst
- GReD, Université Clermont Auvergne, CNRS, INSERM, BP 38, 63001, Clermont-Ferrand, France
| | | | - Federico Ariel
- Instituto de Agrobiotecnología del Litoral, CONICET, Universidad Nacional del Litoral, 3000, Santa Fe, Argentina
| | - Cécile Raynaud
- Université Paris-Saclay, CNRS, INRAE, Univ Evry, Institute of Plant Sciences Paris-Saclay (IPS2), 91405, Orsay, France
| | - David Latrasse
- Université Paris-Saclay, CNRS, INRAE, Univ Evry, Institute of Plant Sciences Paris-Saclay (IPS2), 91405, Orsay, France
| | - Moussa Benhamed
- Université Paris-Saclay, CNRS, INRAE, Univ Evry, Institute of Plant Sciences Paris-Saclay (IPS2), 91405, Orsay, France
- Université de Paris, Institute of Plant Sciences Paris-Saclay (IPS2), F-75006 Paris, France
- Institut Universitaire de France (IUF)
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25
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Polycomb-group proteins in the initiation and progression of cancer. J Genet Genomics 2021; 48:433-443. [PMID: 34266781 DOI: 10.1016/j.jgg.2021.03.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 03/23/2021] [Accepted: 03/28/2021] [Indexed: 12/13/2022]
Abstract
The Polycomb group (PcG) proteins are a family of chromatin regulators and critical for the maintenance of cellular identity. The PcG machinery can be categorized into at least three multi-protein complexes, namely Polycomb Repressive Complex 1 (PRC1), PRC2, and Polycomb Repressive DeUBiquitinase (PR-DUB). Their deregulation has been associated with human cancer initiation and progression. Here we review the updated understanding for PcG proteins in transcription regulation and DNA damage repair and highlight increasing links to the hallmarks in cancer. Accordingly, we discuss some of the recent advances in drug development or strategies against cancers caused by the gain or loss of PcG functions.
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26
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Tetraarsenic oxide affects non-coding RNA transcriptome through deregulating polycomb complexes in MCF7 cells. Adv Biol Regul 2021; 80:100809. [PMID: 33932728 DOI: 10.1016/j.jbior.2021.100809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 03/30/2021] [Accepted: 04/08/2021] [Indexed: 11/23/2022]
Abstract
Non-coding RNAs (ncRNAs) play important and diverse roles in mammalian cell biology and pathology. Although the functions of an increasing number of ncRNAs have been identified, the mechanisms underlying ncRNA gene expression remain elusive and are incompletely understood. Here, we investigated ncRNA gene expression in Michigan cancer foundation 7 (MCF7), a malignant breast cancer cell line, on treatment of tetraarsenic oxide (TAO), a potential anti-cancer drug. Our genomic analyses found that TAO up- or down-regulated ncRNA genes genome-wide. A subset of identified ncRNAs with critical biological and clinical functions were validated by real-time quantitative polymerase chain reaction. Intriguingly, these TAO-regulated genes included CDKN2B-AS, HOXA11-AS, SHH, and DUSP5 that are known to interact with or be targeted by polycomb repressive complexes (PRCs). In addition, the PRC subunits were enriched in these TAO-regulated ncRNA genes and TAO treatment deregulated the expression of PRC subunits. Strikingly, TAO decreased the cellular and gene-specific levels of EZH2 expression and H3K27me3. In particular, TAO reduced EZH2 and H3K27me3 and increased transcription at MALAT1 gene. Inhibiting the catalytic activity of EZH2 using GSK343 increased representative TAO-inducible ncRNA genes. Together, our findings suggest that the expression of a subset of ncRNA genes is regulated by PRC2 and that TAO could be a potent epigenetic regulator through PRCs to modulate the ncRNA gene expression in MCF7 cells.
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27
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Baumann C, Zhang X, De La Fuente R. Loss of CBX2 induces genome instability and senescence-associated chromosomal rearrangements. J Cell Biol 2021; 219:152063. [PMID: 32870972 PMCID: PMC7594495 DOI: 10.1083/jcb.201910149] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 06/08/2020] [Accepted: 08/02/2020] [Indexed: 01/05/2023] Open
Abstract
The polycomb group protein CBX2 is an important epigenetic reader involved in cell proliferation and differentiation. While CBX2 overexpression occurs in a wide range of human tumors, targeted deletion results in homeotic transformation, proliferative defects, and premature senescence. However, its cellular function(s) and whether it plays a role in maintenance of genome stability remain to be determined. Here, we demonstrate that loss of CBX2 in mouse fibroblasts induces abnormal large-scale chromatin structure and chromosome instability. Integrative transcriptome analysis and ATAC-seq revealed a significant dysregulation of transcripts involved in DNA repair, chromocenter formation, and tumorigenesis in addition to changes in chromatin accessibility of genes involved in lateral sclerosis, basal transcription factors, and folate metabolism. Notably, Cbx2−/− cells exhibit prominent decondensation of satellite DNA sequences at metaphase and increased sister chromatid recombination events leading to rampant chromosome instability. The presence of extensive centromere and telomere defects suggests a prominent role for CBX2 in heterochromatin homeostasis and the regulation of nuclear architecture.
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Affiliation(s)
- Claudia Baumann
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, GA.,Regenerative Bioscience Center, University of Georgia, Athens, GA
| | - Xiangyu Zhang
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, GA.,Regenerative Bioscience Center, University of Georgia, Athens, GA
| | - Rabindranath De La Fuente
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, GA.,Regenerative Bioscience Center, University of Georgia, Athens, GA
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28
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Xie X, Mahmood SR, Gjorgjieva T, Percipalle P. Emerging roles of cytoskeletal proteins in regulating gene expression and genome organization during differentiation. Nucleus 2020; 11:53-65. [PMID: 32212905 PMCID: PMC7289583 DOI: 10.1080/19491034.2020.1742066] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
In the eukaryotic cell nucleus, cytoskeletal proteins are emerging as essential players in nuclear function. In particular, actin regulates chromatin as part of ATP-dependent chromatin remodeling complexes, it modulates transcription and it is incorporated into nascent ribonucleoprotein complexes, accompanying them from the site of transcription to polyribosomes. The nuclear actin pool is undistinguishable from the cytoplasmic one in terms of its ability to undergo polymerization and it has also been implicated in the dynamics of chromatin, regulating heterochromatin segregation at the nuclear lamina and maintaining heterochromatin levels in the nuclear interiors. One of the next frontiers is, therefore, to determine a possible involvement of nuclear actin in the functional architecture of the cell nucleus by regulating the hierarchical organization of chromatin and, thus, genome organization. Here, we discuss the repertoire of these potential actin functions and how they are likely to play a role in the context of cellular differentiation.
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Affiliation(s)
- Xin Xie
- Science Division, Biology Program, New York University Abu Dhabi (NYUAD), Abu Dhabi, United Arab Emirates
| | - S Raza Mahmood
- Science Division, Biology Program, New York University Abu Dhabi (NYUAD), Abu Dhabi, United Arab Emirates.,Department of Biology, New York University, New York, NY, USA
| | - Tamara Gjorgjieva
- Science Division, Biology Program, New York University Abu Dhabi (NYUAD), Abu Dhabi, United Arab Emirates
| | - Piergiorgio Percipalle
- Science Division, Biology Program, New York University Abu Dhabi (NYUAD), Abu Dhabi, United Arab Emirates.,Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
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29
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No Easy Way Out for EZH2: Its Pleiotropic, Noncanonical Effects on Gene Regulation and Cellular Function. Int J Mol Sci 2020; 21:ijms21249501. [PMID: 33327550 PMCID: PMC7765048 DOI: 10.3390/ijms21249501] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 12/04/2020] [Accepted: 12/08/2020] [Indexed: 12/14/2022] Open
Abstract
Enhancer of zeste homolog 2 (EZH2) plays critical roles in a range of biological processes including organ development and homeostasis, epigenomic and transcriptomic regulation, gene repression and imprinting, and DNA damage repair. A widely known function of EZH2 is to serve as an enzymatic subunit of Polycomb repressive complex 2 (PRC2) and catalyze trimethylation of histone H3 lysine 27 (H3K27me3) for repressing target gene expression. However, an increasing body of evidence demonstrates that EZH2 has many "non-conventional" functions that go beyond H3K27 methylation as a Polycomb factor. First, EZH2 can methylate a number of nonhistone proteins, thereby regulating cellular processes in an H3K27me3-independent fashion. Furthermore, EZH2 relies on both methyltransferase-dependent and methyltransferase-independent mechanisms for modulating gene-expression programs and/or epigenomic patterns of cells. Importantly, independent of PRC2, EZH2 also forms physical interactions with a number of DNA-binding factors and transcriptional coactivators to context-dependently influence gene expression. The purpose of this review is to detail the complex, noncanonical roles of EZH2, which are generally less appreciated in gene and (epi)genome regulation. Because EZH2 deregulation is prevalent in human diseases such as cancer, there is increased dependency on its noncanonical function, which shall have important implications in developing more effective therapeutics.
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30
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Saponaro F, Rutigliano G, Sestito S, Bandini L, Storti B, Bizzarri R, Zucchi R. ACE2 in the Era of SARS-CoV-2: Controversies and Novel Perspectives. Front Mol Biosci 2020; 7:588618. [PMID: 33195436 PMCID: PMC7556165 DOI: 10.3389/fmolb.2020.588618] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 09/04/2020] [Indexed: 12/23/2022] Open
Abstract
Angiotensin-converting enzyme 2 (ACE2) is related to ACE but turned out to counteract several pathophysiological actions of ACE. ACE2 exerts antihypertensive and cardioprotective effects and reduces lung inflammation. ACE2 is subjected to extensive transcriptional and post-transcriptional modulation by epigenetic mechanisms and microRNAs. Also, ACE2 expression is regulated post-translationally by glycosylation, phosphorylation, and shedding from the plasma membrane. ACE2 protein is ubiquitous across mammalian tissues, prominently in the cardiovascular system, kidney, and intestine. ACE2 expression in the respiratory tract is of particular interest, in light of the discovery that ACE2 serves as the initial cellular target of severe acute respiratory syndrome (SARS)-coronaviruses, including the recent SARS-CoV2, responsible of the COronaVIrus Disease 2019 (COVID-19). Since the onset of the COVID-19 pandemic, an intense effort has been made to elucidate the biochemical determinants of SARS-CoV2-ACE2 interaction. It has been determined that SARS-CoV2 engages with ACE2 through its spike (S) protein, which consists of two subunits: S1, that mediates binding to the host receptor; S2, that induces fusion of the viral envelope with the host cell membrane and delivery of the viral genome. Owing to the role of ACE2 in SARS-CoV2 pathogenicity, it has been speculated that medical conditions, i.e., hypertension, and/or drugs, i.e., ACE inhibitors and angiotensin receptor blockers, known to influence ACE2 density could alter the fate of SARS-CoV-2 infection. The debate is still open and will only be solved when results of properly designed experimental and clinical investigations will be made public. An interesting observation is, however that, upon infection, ACE2 activity is reduced either by downregulation or by shedding. These events might precipitate the so-called "cytokine storm" that characterizes the most severe COVID-19 forms. As evidence accumulates, ACE2 appears a druggable target in the attempt to limit virus entry and replication. Strategies aimed at blocking ACE2 with antibodies, small molecules or peptides, or at neutralizing the virus by competitive binding with exogenously administered ACE2, are currently under investigations. In this review, we will present an overview of the state-of-the-art knowledge on ACE2 biochemistry and pathophysiology, outlining open issues in the context of COVID-19 disease and potential experimental and clinical developments.
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Affiliation(s)
| | | | - Simona Sestito
- Department of Pathology, University of Pisa, Pisa, Italy
- Department of Chemistry and Pharmacy, University of Sassari, Sassari, Italy
| | | | - Barbara Storti
- NEST, Scuola Normale Superiore and CNR-NANO, Pisa, Italy
| | - Ranieri Bizzarri
- Department of Pathology, University of Pisa, Pisa, Italy
- NEST, Scuola Normale Superiore and CNR-NANO, Pisa, Italy
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Abstract
The interaction between polycomb-repressive complexes 1/2 (PRC1/2) and long non-coding RNA (lncRNA), such as the X inactive specific transcript Xist and the HOX transcript antisense RNA (HOTAIR), has been the subject of intense debate. While cross-linking, immuno-precipitation and super-resolution microscopy argue against direct interaction of Polycomb with some lncRNAs, there is increasing evidence supporting the ability of both PRC1 and PRC2 to functionally associate with RNA. Recent data indicate that these interactions are in most cases spurious, but nonetheless crucial for a number of cellular activities. In this review, we suggest that while PRC1/2 recruitment by HOTAIR might be direct, in the case of Xist, it might occur indirectly and, at least in part, through the process of liquid-liquid phase separation. We present recent models of lncRNA-mediated PRC1/2 recruitment to their targets and describe potential RNA-mediated roles in the three-dimensional organization of the nucleus.
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Affiliation(s)
- Andrea Cerase
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AT, UK
| | - Gian Gaetano Tartaglia
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Dr. Aiguader 88, 08003 Barcelona, Spain.,Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain.,Institucio Catalana de Recerca i Estudis Avançats (ICREA), 23 Passeig Lluis Companys, 08010 Barcelona, Spain.,Department of Biology 'Charles Darwin', Sapienza University of Rome, P.le A. Moro 5, Rome 00185, Italy.,Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia (IIT), Via Morego 30, 16163, Genoa, Italy
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32
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Almeida M, Bowness JS, Brockdorff N. The many faces of Polycomb regulation by RNA. Curr Opin Genet Dev 2020; 61:53-61. [PMID: 32403014 PMCID: PMC7653676 DOI: 10.1016/j.gde.2020.02.023] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 02/12/2020] [Accepted: 02/22/2020] [Indexed: 02/06/2023]
Abstract
Many intricate pathways contribute to the timely control of gene expression during development. Polycomb repressive complexes (PRC1 and PRC2) and long non-coding RNAs (lncRNAs) are players associated with gene repression in various developmental processes such as X chromosome inactivation (XCI) and genomic imprinting. Historically, lncRNAs were proposed to directly recruit PRC2. However, recent evidence suggests that promiscuous interactions between PRC2 and RNA fine-tune the function of the complex through a multiplicity of mechanisms. A PRC2-recruitment model was definitively overturned in the paradigm of XCI by Xist RNA, being replaced by a novel mechanism which puts PRC1 in the spotlight. This review focuses on these recent advances in understanding the interplay between RNA and Polycomb complexes for gene expression control.
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Affiliation(s)
- Mafalda Almeida
- Developmental Epigenetics, Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Joseph S Bowness
- Developmental Epigenetics, Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Neil Brockdorff
- Developmental Epigenetics, Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom.
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33
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Venit T, Mahmood SR, Endara-Coll M, Percipalle P. Nuclear actin and myosin in chromatin regulation and maintenance of genome integrity. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2020; 355:67-108. [DOI: 10.1016/bs.ircmb.2020.05.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/06/2022]
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