1
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Manzo SG, Mazouzi A, Leemans C, van Schaik T, Neyazi N, van Ruiten MS, Rowland BD, Brummelkamp TR, van Steensel B. Chromatin protein complexes involved in gene repression in lamina-associated domains. EMBO J 2024:10.1038/s44318-024-00214-1. [PMID: 39322756 DOI: 10.1038/s44318-024-00214-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 08/05/2024] [Accepted: 08/07/2024] [Indexed: 09/27/2024] Open
Abstract
Lamina-associated domains (LADs) are large chromatin regions that are associated with the nuclear lamina (NL) and form a repressive environment for transcription. The molecular players that mediate gene repression in LADs are currently unknown. Here, we performed FACS-based whole-genome genetic screens in human cells using LAD-integrated fluorescent reporters to identify such regulators. Surprisingly, the screen identified very few NL proteins, but revealed roles for dozens of known chromatin regulators. Among these are the negative elongation factor (NELF) complex and interacting factors involved in RNA polymerase pausing, suggesting that regulation of transcription elongation is a mechanism to repress transcription in LADs. Furthermore, the chromatin remodeler complex BAF and the activation complex Mediator can work both as activators and repressors in LADs, depending on the local context and possibly by rewiring heterochromatin. Our data indicate that the fundamental regulators of transcription and chromatin remodeling, rather than interaction with NL proteins, play a major role in transcription regulation within LADs.
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Affiliation(s)
- Stefano G Manzo
- Division of Gene Regulation, Netherlands Cancer Institute, Amsterdam, the Netherlands
- Oncode Institute, Amsterdam, the Netherlands
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133, Milan, Italy
| | - Abdelghani Mazouzi
- Oncode Institute, Amsterdam, the Netherlands
- Division of Biochemistry, Netherlands Cancer Institute, Amsterdam, the Netherlands
| | - Christ Leemans
- Division of Gene Regulation, Netherlands Cancer Institute, Amsterdam, the Netherlands
- Oncode Institute, Amsterdam, the Netherlands
| | - Tom van Schaik
- Division of Gene Regulation, Netherlands Cancer Institute, Amsterdam, the Netherlands
- Oncode Institute, Amsterdam, the Netherlands
| | - Nadia Neyazi
- Division of Gene Regulation, Netherlands Cancer Institute, Amsterdam, the Netherlands
- Oncode Institute, Amsterdam, the Netherlands
| | - Marjon S van Ruiten
- Division of Cell Biology, Netherlands Cancer Institute, Amsterdam, the Netherlands
| | - Benjamin D Rowland
- Division of Cell Biology, Netherlands Cancer Institute, Amsterdam, the Netherlands
| | - Thijn R Brummelkamp
- Oncode Institute, Amsterdam, the Netherlands
- Division of Biochemistry, Netherlands Cancer Institute, Amsterdam, the Netherlands
| | - Bas van Steensel
- Division of Gene Regulation, Netherlands Cancer Institute, Amsterdam, the Netherlands.
- Oncode Institute, Amsterdam, the Netherlands.
- Division of Molecular Genetics, Netherlands Cancer Institute, Amsterdam, the Netherlands.
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2
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Czapiewski R, Schirmer EC. Enhancers on the edge - how the nuclear envelope controls gene regulatory elements. Curr Opin Genet Dev 2024; 87:102234. [PMID: 39047586 DOI: 10.1016/j.gde.2024.102234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 06/20/2024] [Accepted: 07/05/2024] [Indexed: 07/27/2024]
Abstract
Precise temporal and sequential control of gene expression during development and in response to environmental stimuli requires tight regulation of the physical contact between gene regulatory elements and promoters. Current models describing how the genome folds in 3D space to establish these interactions often ignore the role of the most stable structural nuclear feature - the nuclear envelope. While contributions of 3D folding within/between topologically associated domains (TADs) have been extensively described, mechanical contributions from the nuclear envelope can impact enhancer-promoter interactions both directly and indirectly through influencing intra/inter-TAD interactions. Importantly, these nuclear envelope contributions clearly link this mechanism to development and, when defective, to human disease. Here, we discuss evidence for nuclear envelope regulation of tissue-specific enhancer-promoter pairings, potential mechanisms for this regulation, exciting recent findings that other regulatory elements such as microRNAs and long noncoding RNAs are under nuclear envelope regulation, the possible involvement of condensates, and how disruption of this regulation can lead to disease.
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Affiliation(s)
- Rafal Czapiewski
- Institute of Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom; MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom.
| | - Eric C Schirmer
- Institute of Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom.
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3
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Dong S, Dimopoulos G. Aedes aegypti Argonaute 2 controls arbovirus infection and host mortality. Nat Commun 2023; 14:5773. [PMID: 37723154 PMCID: PMC10507101 DOI: 10.1038/s41467-023-41370-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 08/30/2023] [Indexed: 09/20/2023] Open
Abstract
Ae. aegypti mosquitoes transmit some of the most important human viral diseases that are responsible for a significant public health burden worldwide. The small interfering RNA (siRNA) pathway is considered the major antiviral defense system in insects. Here we show that siRNA pathway disruption by CRISPR/Cas9-based Ago2 knockout impaired the mosquitoes' ability to degrade arbovirus RNA leading to hyper-infection accompanied by cell lysis and tissue damage. Ago2 disruption impaired DNA repair mechanisms and the autophagy pathway by altering histone abundance. This compromised DNA repair and removal of damaged cellular organelles and dysfunctional aggregates promoted mosquito death. We also report that hyper-infection of Ago2 knockout mosquitoes stimulated a broad-spectrum antiviral immunity, including apoptosis, which may counteract infection. Taken together, our studies reveal novel roles for Ago2 in protecting mosquitoes from arbovirus infection and associated death.
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Affiliation(s)
- Shengzhang Dong
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, 615 N. Wolfe Street, Baltimore, MD, 21205-2179, USA
| | - George Dimopoulos
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, 615 N. Wolfe Street, Baltimore, MD, 21205-2179, USA.
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4
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Balasooriya GI, Spector DL. Allele pairing at Sun1-enriched domains at the nuclear periphery via T1A3 tandem DNA repeats. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.07.536031. [PMID: 37066204 PMCID: PMC10104147 DOI: 10.1101/2023.04.07.536031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/18/2023]
Abstract
Spatiotemporal gene regulation is fundamental to the biology of diploid cells. Therefore, effective communication between two alleles and their geometry in the nucleus is important. However, the mechanism that fine-tunes the expression from each of the two alleles of an autosome is enigmatic. Establishing an allele-specific gene expression visualization system in living cells, we show that alleles of biallelically expressed Cth and Ttc4 genes are paired prior to acquiring monoallelic expression. We found that active alleles of monoallelic genes are preferentially localized at Sun1-enriched domains at the nuclear periphery. These peripherally localized active DNA loci are enriched with adenine-thymidine-rich tandem repeats that interact with Hnrnpd and reside in a Hi-C-defined A compartment within the B compartment. Our results demonstrate the biological significance of T 1 A 3 tandem repeat sequences in genome organization and how the regulation of gene expression, at the level of individual alleles, relates to their spatial arrangement.
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5
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Pelletier D, Rivera B, Fabian MR, Foulkes WD. miRNA biogenesis and inherited disorders: clinico-molecular insights. Trends Genet 2023; 39:401-414. [PMID: 36863945 DOI: 10.1016/j.tig.2023.01.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 11/29/2022] [Accepted: 01/30/2023] [Indexed: 03/04/2023]
Abstract
MicroRNAs (miRNAs) play vital roles in the regulation of gene expression, a process known as miRNA-induced gene silencing. The human genome codes for many miRNAs, and their biogenesis relies on a handful of genes, including DROSHA, DGCR8, DICER1, and AGO1/2. Germline pathogenic variants (GPVs) in these genes cause at least three distinct genetic syndromes, with clinical manifestations that range from hyperplastic/neoplastic entities to neurodevelopmental disorders (NDDs). Over the past decade, DICER1 GPVs have been shown to lead to tumor predisposition. Moreover, recent findings have provided insight into the clinical consequences arising from GPVs in DGCR8, AGO1, and AGO2. Here we provide a timely update with respect to how GPVs in miRNA biogenesis genes alter miRNA biology and ultimately lead to their clinical manifestations.
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Affiliation(s)
- Dylan Pelletier
- Department of Human Genetics, Medicine, McGill University, Montreal, QC, Canada; Cancer Axis, Lady Davis Institute, Jewish General Hospital, Montreal, QC, Canada; Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Barbara Rivera
- Molecular Mechanisms and Experimental Therapy in Oncology Program - Oncobell, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain; Gerald Bronfman Department of Oncology, McGill University, Montreal, QC, Canada
| | - Marc R Fabian
- Cancer Axis, Lady Davis Institute, Jewish General Hospital, Montreal, QC, Canada; Gerald Bronfman Department of Oncology, McGill University, Montreal, QC, Canada; Division of Experimental Medicine, McGill University, Montreal, QC, Canada; Department of Biochemistry, McGill University, Montreal, QC, Canada
| | - William D Foulkes
- Department of Human Genetics, Medicine, McGill University, Montreal, QC, Canada; Cancer Axis, Lady Davis Institute, Jewish General Hospital, Montreal, QC, Canada; Gerald Bronfman Department of Oncology, McGill University, Montreal, QC, Canada; Cancer Research Program, Research Institute of the McGill University Health Center, Montreal, QC, Canada.
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6
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Griffin KN, Walters BW, Li H, Wang H, Biancon G, Tebaldi T, Kaya CB, Kanyo J, Lam TT, Cox AL, Halene S, Chung JJ, Lesch BJ. Widespread association of the Argonaute protein AGO2 with meiotic chromatin suggests a distinct nuclear function in mammalian male reproduction. Genome Res 2022; 32:1655-1668. [PMID: 36109149 PMCID: PMC9528986 DOI: 10.1101/gr.276578.122] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 07/21/2022] [Indexed: 11/25/2022]
Abstract
Argonaute 2 (AGO2) is a ubiquitously expressed protein critical for regulation of mRNA translation and vital to animal development. AGO2 protein is found in both cytoplasmic and nuclear compartments, and although its cytoplasmic role is well studied, the biological relevance of nuclear AGO2 is unclear. Here, we address this problem in vivo using spermatogenic cells as a model. We find that AGO2 transiently binds both chromatin and nucleus-specific mRNA transcripts of hundreds of genes required for sperm production during male meiosis in mice, and that germline conditional knockout (cKO) of Ago2 causes depletion of the encoded proteins. Correspondingly, Ago2 cKO males show abnormal sperm head morphology and reduced sperm count, along with reduced postnatal viability of offspring. Together, our data reveal an unexpected nuclear role for AGO2 in enhancing expression of developmentally important genes during mammalian male reproduction.
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Affiliation(s)
- Kimberly N Griffin
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | | | - Haixin Li
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | - Huafeng Wang
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | - Giulia Biancon
- Section of Hematology, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06510, USA
- Yale Comprehensive Cancer Center, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | - Toma Tebaldi
- Section of Hematology, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06510, USA
- Yale Comprehensive Cancer Center, Yale University School of Medicine, New Haven, Connecticut 06510, USA
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, 38123 Trento, Italy
| | - Carolyn B Kaya
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | - Jean Kanyo
- Keck MS & Proteomics Resource, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | - TuKiet T Lam
- Keck MS & Proteomics Resource, Yale University School of Medicine, New Haven, Connecticut 06510, USA
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520, USA
| | - Andy L Cox
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | - Stephanie Halene
- Section of Hematology, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06510, USA
- Yale Comprehensive Cancer Center, Yale University School of Medicine, New Haven, Connecticut 06510, USA
- Yale Stem Cell Center, Yale University School of Medicine, New Haven, Connecticut 06510, USA
- Yale Center for RNA Science and Medicine, Yale University School of Medicine, New Haven, Connecticut 06510, USA
- Department of Pathology, Gynecology & Reproductive Sciences, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | - Jean-Ju Chung
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut 06510, USA
- Department of Obstetrics, Gynecology & Reproductive Sciences, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | - Bluma J Lesch
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA
- Yale Comprehensive Cancer Center, Yale University School of Medicine, New Haven, Connecticut 06510, USA
- Department of Obstetrics, Gynecology & Reproductive Sciences, Yale University School of Medicine, New Haven, Connecticut 06510, USA
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7
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Chen S, Rosin LF, Pegoraro G, Moshkovich N, Murphy PJ, Yu G, Lei EP. NURF301 contributes to gypsy chromatin insulator-mediated nuclear organization. Nucleic Acids Res 2022; 50:7906-7924. [PMID: 35819192 PMCID: PMC9371915 DOI: 10.1093/nar/gkac600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 06/26/2022] [Accepted: 06/29/2022] [Indexed: 11/14/2022] Open
Abstract
Chromatin insulators are DNA-protein complexes that can prevent the spread of repressive chromatin and block communication between enhancers and promoters to regulate gene expression. In Drosophila, the gypsy chromatin insulator complex consists of three core proteins: CP190, Su(Hw), and Mod(mdg4)67.2. These factors concentrate at nuclear foci termed insulator bodies, and changes in insulator body localization have been observed in mutants defective for insulator function. Here, we identified NURF301/E(bx), a nucleosome remodeling factor, as a novel regulator of gypsy insulator body localization through a high-throughput RNAi imaging screen. NURF301 promotes gypsy-dependent insulator barrier activity and physically interacts with gypsy insulator proteins. Using ChIP-seq, we found that NURF301 co-localizes with insulator proteins genome-wide, and NURF301 promotes chromatin association of Su(Hw) and CP190 at gypsy insulator binding sites. These effects correlate with NURF301-dependent nucleosome repositioning. At the same time, CP190 and Su(Hw) both facilitate recruitment of NURF301 to chromatin. Finally, Oligopaint FISH combined with immunofluorescence revealed that NURF301 promotes 3D contact between insulator bodies and gypsy insulator DNA binding sites, and NURF301 is required for proper nuclear positioning of gypsy binding sites. Our data provide new insights into how a nucleosome remodeling factor and insulator proteins cooperatively contribute to nuclear organization.
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Affiliation(s)
- Shue Chen
- Nuclear Organization and Gene Expression Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA.,Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Leah F Rosin
- Nuclear Organization and Gene Expression Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA.,Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Gianluca Pegoraro
- High-Throughput Imaging Facility (HiTIF), Laboratory of Receptor Biology and Gene Expression, Center for Cancer Research, National Cancer Institute, Bethesda, MD, USA
| | - Nellie Moshkovich
- Nuclear Organization and Gene Expression Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA.,Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Patrick J Murphy
- Nuclear Organization and Gene Expression Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA.,Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Guoyun Yu
- Nuclear Organization and Gene Expression Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA.,Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Elissa P Lei
- Nuclear Organization and Gene Expression Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA.,Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
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8
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Chetverina D, Vorobyeva NE, Mazina MY, Fab LV, Lomaev D, Golovnina A, Mogila V, Georgiev P, Ziganshin RH, Erokhin M. Comparative interactome analysis of the PRE DNA-binding factors: purification of the Combgap-, Zeste-, Psq-, and Adf1-associated proteins. Cell Mol Life Sci 2022; 79:353. [PMID: 35676368 PMCID: PMC11072172 DOI: 10.1007/s00018-022-04383-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 04/14/2022] [Accepted: 05/08/2022] [Indexed: 01/08/2023]
Abstract
The Polycomb group (PcG) and Trithorax group (TrxG) proteins are key epigenetic regulators controlling the silenced and active states of genes in multicellular organisms, respectively. In Drosophila, PcG/TrxG proteins are recruited to the chromatin via binding to specific DNA sequences termed polycomb response elements (PREs). While precise mechanisms of the PcG/TrxG protein recruitment remain unknown, the important role is suggested to belong to sequence-specific DNA-binding factors. At the same time, it was demonstrated that the PRE DNA-binding proteins are not exclusively localized to PREs but can bind other DNA regulatory elements, including enhancers, promoters, and boundaries. To gain an insight into the PRE DNA-binding protein regulatory network, here, using ChIP-seq and immuno-affinity purification coupled to the high-throughput mass spectrometry, we searched for differences in abundance of the Combgap, Zeste, Psq, and Adf1 PRE DNA-binding proteins. While there were no conspicuous differences in co-localization of these proteins with other functional transcription factors, we show that Combgap and Zeste are more tightly associated with the Polycomb repressive complex 1 (PRC1), while Psq interacts strongly with the TrxG proteins, including the BAP SWI/SNF complex. The Adf1 interactome contained Mediator subunits as the top interactors. In addition, Combgap efficiently interacted with AGO2, NELF, and TFIID. Combgap, Psq, and Adf1 have architectural proteins in their networks. We further investigated the existence of direct interactions between different PRE DNA-binding proteins and demonstrated that Combgap-Adf1, Psq-Dsp1, and Pho-Spps can interact in the yeast two-hybrid assay. Overall, our data suggest that Combgap, Psq, Zeste, and Adf1 are associated with the protein complexes implicated in different regulatory activities and indicate their potential multifunctional role in the regulation of transcription.
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Affiliation(s)
- Darya Chetverina
- Group of Epigenetics, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, Moscow, 119334, Russia.
| | - Nadezhda E Vorobyeva
- Group of Dynamics of Transcriptional Complexes, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Marina Yu Mazina
- Group of Hormone-Dependent Transcriptional Regulation, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Lika V Fab
- Group of Chromatin Biology, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, Moscow, 119334, Russia
| | - Dmitry Lomaev
- Group of Epigenetics, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, Moscow, 119334, Russia
| | - Alexandra Golovnina
- Group of Epigenetics, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, Moscow, 119334, Russia
| | - Vladic Mogila
- Department of Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, Moscow, 119334, Russia
| | - Pavel Georgiev
- Department of Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, Moscow, 119334, Russia
| | - Rustam H Ziganshin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia
| | - Maksim Erokhin
- Group of Chromatin Biology, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, Moscow, 119334, Russia.
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9
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Nazer E. To be or not be (in the LAD): emerging roles of lamin proteins in transcriptional regulation. Biochem Soc Trans 2022; 50:1035-1044. [PMID: 35437578 PMCID: PMC9162450 DOI: 10.1042/bst20210858] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 03/29/2022] [Accepted: 03/30/2022] [Indexed: 12/21/2022]
Abstract
Lamins are components of the nuclear lamina, a protein meshwork that underlies the nuclear membrane. Lamins interact with chromatin in transcriptionally silent regions defined as lamina-associated-domains (LADs). However, recent studies have shown that lamins regulate active transcription inside LADs. In addition, ChIP-seq analysis has shown that lamins interact with lamin-dependent promoters and enhancers located in the interior of the nucleus. Moreover, functional studies suggest that lamins regulate transcription at associated-promoters and long-range chromatin interactions of key developmental gene programs. This review will discuss emerging, non-canonical functions of lamins in controlling non-silent genes located both inside and outside of LADs, focusing on transcriptional regulation and chromatin organization in Drosophila and mammals as metazoan model organisms.
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Affiliation(s)
- Ezequiel Nazer
- Universidad de Buenos Aires (UBA), Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular and CONICET-UBA, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Buenos Aires, Argentina
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10
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Yang N, Srivastav SP, Rahman R, Ma Q, Dayama G, Li S, Chinen M, Lei EP, Rosbash M, Lau NC. Transposable element landscapes in aging Drosophila. PLoS Genet 2022; 18:e1010024. [PMID: 35239675 PMCID: PMC8893327 DOI: 10.1371/journal.pgen.1010024] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 01/10/2022] [Indexed: 11/28/2022] Open
Abstract
Genetic mechanisms that repress transposable elements (TEs) in young animals decline during aging, as reflected by increased TE expression in aged animals. Does increased TE expression during aging lead to more genomic TE copies in older animals? To address this question, we quantified TE Landscapes (TLs) via whole genome sequencing of young and aged Drosophila strains of wild-type and mutant backgrounds. We quantified TLs in whole flies and dissected brains and validated the feasibility of our approach in detecting new TE insertions in aging Drosophila genomes when small RNA and RNA interference (RNAi) pathways are compromised. We also describe improved sequencing methods to quantify extra-chromosomal DNA circles (eccDNAs) in Drosophila as an additional source of TE copies that accumulate during aging. Lastly, to combat the natural progression of aging-associated TE expression, we show that knocking down PAF1, a conserved transcription elongation factor that antagonizes RNAi pathways, may bolster suppression of TEs during aging and extend lifespan. Our study suggests that in addition to a possible influence by different genetic backgrounds, small RNA and RNAi mechanisms may mitigate genomic TL expansion despite the increase in TE transcripts during aging. Transposable elements, also called transposons, are genetic parasites found in all animal genomes. Normally, transposons are compacted away in silent chromatin in young animals. But, as animals age and transposon-silencing defense mechanisms break down, transposon RNAs accumulate to significant levels in old animals like fruit flies. An open question is whether the increased levels of transposon RNAs in older animals also correspond to increased genomic copies of transposons. This study approached this question by sequencing the whole genomes of young and old wild-type and mutant flies lacking a functional RNA interference (RNAi) pathway, which naturally silences transposon RNAs. Although the wild-type flies with intact RNAi activity had little new accumulation of transposon copies, the sequencing approach was able to detect several transposon accumulation occurrences in some RNAi mutants. In addition, we found that some fly transposon families can also accumulate as extra-chromosomal circular DNA copies. Lastly, we showed that genetically augmenting the expression of RNAi factors can counteract the rising transposon RNA levels in aging and promote longevity. This study improves our understanding of the animal host genome relationship with transposons during natural aging processes.
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Affiliation(s)
- Nachen Yang
- Boston University School of Medicine, Department of Biochemistry, Boston, Massachusetts, United States of America
| | - Satyam P. Srivastav
- Boston University School of Medicine, Department of Biochemistry, Boston, Massachusetts, United States of America
| | - Reazur Rahman
- Brandeis University, Department of Biology and Howard Hughes Medical Institute, Waltham, Massachusetts, United States of America
| | - Qicheng Ma
- Boston University School of Medicine, Department of Biochemistry, Boston, Massachusetts, United States of America
| | - Gargi Dayama
- Boston University School of Medicine, Department of Biochemistry, Boston, Massachusetts, United States of America
| | - Sizheng Li
- Boston University School of Medicine, Department of Biochemistry, Boston, Massachusetts, United States of America
| | - Madoka Chinen
- Nuclear Organization and Gene Expression Section, NIDDK, NIH, Bethesda, Maryland, United States of America
| | - Elissa P. Lei
- Nuclear Organization and Gene Expression Section, NIDDK, NIH, Bethesda, Maryland, United States of America
| | - Michael Rosbash
- Brandeis University, Department of Biology and Howard Hughes Medical Institute, Waltham, Massachusetts, United States of America
| | - Nelson C. Lau
- Boston University School of Medicine, Department of Biochemistry, Boston, Massachusetts, United States of America
- Boston University Genome Science Institute, Boston, Massachusetts, United States of America
- * E-mail:
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11
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Kitzman SC, Duan T, Pufall MA, Geyer PK. Checkpoint activation drives global gene expression changes in Drosophila nuclear lamina mutants. G3 (BETHESDA, MD.) 2022; 12:6459172. [PMID: 34893833 PMCID: PMC9210273 DOI: 10.1093/g3journal/jkab408] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 11/22/2021] [Indexed: 11/25/2022]
Abstract
The nuclear lamina (NL) lines the inner nuclear membrane. This extensive protein network organizes chromatin and contributes to the regulation of transcription, DNA replication, and repair. Lap2-emerin-MAN1 domain (LEM-D) proteins are key members of the NL, representing proteins that connect the NL to the genome through shared interactions with the chromatin-binding protein Barrier-to-Autointegration Factor (BAF). Functions of the LEM-D protein emerin and BAF are essential during Drosophila melanogaster oogenesis. Indeed, loss of either emerin or BAF blocks germ cell development and causes loss of germline stem cells, defects linked to the deformation of NL structure, and non-canonical activation of Checkpoint kinase 2 (Chk2). Here, we investigate the contributions of emerin and BAF to gene expression in the ovary. Profiling RNAs from emerin and baf mutant ovaries revealed that nearly all baf misregulated genes were shared with emerin mutants, defining a set of NL-regulated genes. Strikingly, loss of Chk2 restored the expression of most NL-regulated genes, identifying a large class of Chk2-dependent genes (CDGs). Nonetheless, some genes remained misexpressed upon Chk2 loss, identifying a smaller class of emerin-dependent genes (EDGs). Properties of EDGs suggest a shared role for emerin and BAF in the repression of developmental genes. Properties of CDGs demonstrate that Chk2 activation drives global misexpression of genes in the emerin and baf mutant backgrounds. Notably, CDGs were found upregulated in lamin-B mutant backgrounds. These observations predict that Chk2 activation might have a general role in gene expression changes found in NL-associated diseases, such as laminopathies.
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Affiliation(s)
| | - Tingting Duan
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA
| | - Miles A Pufall
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA
| | - Pamela K Geyer
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA
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12
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Nazer E, Gómez Acuña L, Kornblihtt AR. Seeking the truth behind the myth: Argonaute tales from "nuclearland". Mol Cell 2021; 82:503-513. [PMID: 34856122 DOI: 10.1016/j.molcel.2021.11.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 10/29/2021] [Accepted: 11/03/2021] [Indexed: 12/19/2022]
Abstract
Argonaute proteins have been traditionally characterized as a highly evolutionary conserved family engaged in post-transcriptional gene silencing pathways. The Argonaute family is mainly grouped into the AGO and PIWI clades. The canonical role of Argonaute proteins relies on their ability to bind small-RNAs that recognize complementary sequences on target mRNAs to induce either mRNA degradation or translational repression. However, there is an increasing amount of evidence supporting that Argonaute proteins also exert multiple nuclear functions that subsequently regulate gene expression. In this line, genome-wide studies showed that members from the AGO clade regulate transcription, 3D chromatin organization, and splicing of active loci located within euchromatin. Here, we discuss recent work based on high-throughput technologies that have significantly contributed to shed light on the multivariate nuclear functions of AGO proteins in different model organisms. We also analyze data supporting that AGO proteins are able to execute these nuclear functions independently from small RNA pathways. Finally, we integrate these mechanistic insights with recent reports highlighting the clinical importance of AGO in breast and prostate cancer development.
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Affiliation(s)
- Ezequiel Nazer
- Universidad de Buenos Aires (UBA), Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular and CONICET-UBA, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Buenos Aires, Argentina.
| | - Luciana Gómez Acuña
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, UK
| | - Alberto R Kornblihtt
- Universidad de Buenos Aires (UBA), Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular and CONICET-UBA, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Buenos Aires, Argentina
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13
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Chen D, McManus CE, Radmanesh B, Matzat LH, Lei EP. Temporal inhibition of chromatin looping and enhancer accessibility during neuronal remodeling. Nat Commun 2021; 12:6366. [PMID: 34737269 PMCID: PMC8568962 DOI: 10.1038/s41467-021-26628-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 10/14/2021] [Indexed: 11/24/2022] Open
Abstract
During development, looping of an enhancer to a promoter is frequently observed in conjunction with temporal and tissue-specific transcriptional activation. The chromatin insulator-associated protein Alan Shepard (Shep) promotes Drosophila post-mitotic neuronal remodeling by repressing transcription of master developmental regulators, such as brain tumor (brat), specifically in maturing neurons. Since insulator proteins can promote looping, we hypothesized that Shep antagonizes brat promoter interaction with an as yet unidentified enhancer. Using chromatin conformation capture and reporter assays, we identified two enhancer regions that increase in looping frequency with the brat promoter specifically in pupal brains after Shep depletion. The brat promoters and enhancers function independently of Shep, ruling out direct repression of these elements. Moreover, ATAC-seq in isolated neurons demonstrates that Shep restricts chromatin accessibility of a key brat enhancer as well as other enhancers genome-wide in remodeling pupal but not larval neurons. These enhancers are enriched for chromatin targets of Shep and are located at Shep-inhibited genes, suggesting direct Shep inhibition of enhancer accessibility and gene expression during neuronal remodeling. Our results provide evidence for temporal regulation of chromatin looping and enhancer accessibility during neuronal maturation.
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Affiliation(s)
- Dahong Chen
- Nuclear Organization and Gene Expression Section, Bethesda, MD, USA
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD, 20892, USA
| | - Catherine E McManus
- Nuclear Organization and Gene Expression Section, Bethesda, MD, USA
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD, 20892, USA
| | - Behram Radmanesh
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD, USA
| | - Leah H Matzat
- Nuclear Organization and Gene Expression Section, Bethesda, MD, USA
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD, USA
| | - Elissa P Lei
- Nuclear Organization and Gene Expression Section, Bethesda, MD, USA.
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD, 20892, USA.
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14
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Tchurikov NA, Klushevskaya ES, Fedoseeva DM, Alembekov IR, Kravatskaya GI, Chechetkin VR, Kravatsky YV, Kretova OV. Dynamics of Whole-Genome Contacts of Nucleoli in Drosophila Cells Suggests a Role for rDNA Genes in Global Epigenetic Regulation. Cells 2020; 9:cells9122587. [PMID: 33287227 PMCID: PMC7761670 DOI: 10.3390/cells9122587] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 11/27/2020] [Accepted: 11/30/2020] [Indexed: 01/06/2023] Open
Abstract
Chromosomes are organized into 3D structures that are important for the regulation of gene expression and differentiation. Important role in formation of inter-chromosome contacts play rDNA clusters that make up nucleoli. In the course of differentiation, heterochromatization of rDNA units in mouse cells is coupled with the repression or activation of different genes. Furthermore, the nucleoli of human cells shape the direct contacts with genes that are involved in differentiation and cancer. Here, we identified and categorized the genes located in the regions where rDNA clusters make frequent contacts. Using a 4C approach, we demonstrate that in Drosophila S2 cells, rDNA clusters form contacts with genes that are involved in chromosome organization and differentiation. Heat shock treatment induces changes in the contacts between nucleoli and hundreds of genes controlling morphogenesis. We show that nucleoli form contacts with regions that are enriched with active or repressive histone marks and where small non-coding RNAs are mapped. These data indicate that rDNA contacts are involved in the repression and activation of gene expression and that rDNA clusters orchestrate large groups of Drosophila genes involved in differentiation.
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15
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Gómez Acuña LI, Nazer E, Rodríguez-Seguí SA, Pozzi B, Buggiano V, Marasco LE, Agirre E, He C, Alló M, Kornblihtt AR. Nuclear role for human Argonaute-1 as an estrogen-dependent transcription coactivator. J Cell Biol 2020; 219:e201908097. [PMID: 32673398 PMCID: PMC7480116 DOI: 10.1083/jcb.201908097] [Citation(s) in RCA: 4] [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: 08/12/2019] [Revised: 04/20/2020] [Accepted: 05/20/2020] [Indexed: 01/07/2023] Open
Abstract
In mammals, argonaute (AGO) proteins have been characterized for their roles in small RNA-mediated posttranscriptional and also in transcriptional gene silencing. Here, we report a different role for AGO1 in estradiol-triggered transcriptional activation in human cells. We show that in MCF-7 mammary gland cells, AGO1 associates with transcriptional enhancers of estrogen receptor α (ERα) and that this association is up-regulated by treating the cells with estrogen (E2), displaying a positive correlation with the activation of these enhancers. Moreover, we show that AGO1 interacts with ERα and that this interaction is also increased by E2 treatment, but occurs in the absence of RNA. We show that AGO1 acts positively as a coactivator in estradiol-triggered transcription regulation by promoting ERα binding to its enhancers. Consistently, AGO1 depletion decreases long-range contacts between ERα enhancers and their target promoters. Our results point to a role of AGO1 in transcriptional regulation in human cells that is independent from small RNA binding.
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Affiliation(s)
- Luciana I Gómez Acuña
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular and Consejo Nacional de Investigaciones Científicas y Técnicas of Argentina, Instituto de Fisiología, Biología Molecular y Neurociencias, Buenos Aires, Argentina
| | - Ezequiel Nazer
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular and Consejo Nacional de Investigaciones Científicas y Técnicas of Argentina, Instituto de Fisiología, Biología Molecular y Neurociencias, Buenos Aires, Argentina
| | - Santiago A Rodríguez-Seguí
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular and Consejo Nacional de Investigaciones Científicas y Técnicas of Argentina, Instituto de Fisiología, Biología Molecular y Neurociencias, Buenos Aires, Argentina
| | - Berta Pozzi
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular and Consejo Nacional de Investigaciones Científicas y Técnicas of Argentina, Instituto de Fisiología, Biología Molecular y Neurociencias, Buenos Aires, Argentina
| | - Valeria Buggiano
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular and Consejo Nacional de Investigaciones Científicas y Técnicas of Argentina, Instituto de Fisiología, Biología Molecular y Neurociencias, Buenos Aires, Argentina
| | - Luciano E Marasco
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular and Consejo Nacional de Investigaciones Científicas y Técnicas of Argentina, Instituto de Fisiología, Biología Molecular y Neurociencias, Buenos Aires, Argentina
| | | | - Cody He
- Pritzker School of Medicine, University of Chicago, Chicago, IL
| | - Mariano Alló
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular and Consejo Nacional de Investigaciones Científicas y Técnicas of Argentina, Instituto de Fisiología, Biología Molecular y Neurociencias, Buenos Aires, Argentina
| | - Alberto R Kornblihtt
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular and Consejo Nacional de Investigaciones Científicas y Técnicas of Argentina, Instituto de Fisiología, Biología Molecular y Neurociencias, Buenos Aires, Argentina
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16
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Li X, Wang X, Cheng Z, Zhu Q. AGO2 and its partners: a silencing complex, a chromatin modulator, and new features. Crit Rev Biochem Mol Biol 2020; 55:33-53. [DOI: 10.1080/10409238.2020.1738331] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Xiaojing Li
- Xiangya School of Pharmaceutical Sciences, Central South University, Changsha, Hunan, China
| | - Xueying Wang
- Xiangya School of Pharmaceutical Sciences, Central South University, Changsha, Hunan, China
| | - Zeneng Cheng
- Xiangya School of Pharmaceutical Sciences, Central South University, Changsha, Hunan, China
| | - Qubo Zhu
- Xiangya School of Pharmaceutical Sciences, Central South University, Changsha, Hunan, China
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17
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Argonaute2 attenuates active transcription by limiting RNA Polymerase II elongation in Drosophila melanogaster. Sci Rep 2018; 8:15685. [PMID: 30356106 PMCID: PMC6200757 DOI: 10.1038/s41598-018-34115-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 10/08/2018] [Indexed: 12/21/2022] Open
Abstract
Increasing lines of evidence support that Argonaute2 (AGO2) harbors several nuclear functions in metazoa. In particular, Drosophila AGO2 modulates transcription of developmentally regulated genes; however, the molecular mechanisms behind AGO2 recruitment into chromatin and its function in transcription have not been deeply explored. In this study, we show that Drosophila AGO2 chromatin association depends on active transcription. In order to gain insight into how AGO2 controls transcription, we performed differential ChIP-seq analysis for RNA Polymerase II (Pol II) upon depletion of AGO2. Remarkably, we find specific accumulation of the elongating but not initiating form of Pol II after AGO2 knockdown, suggesting that AGO2 impairs transcription elongation. Finally, AGO2 also affects Negative Elongation Factor (NELF) chromatin association but not the Cyclin Dependent Kinase 9 (CDK9). Altogether, these results provide key insights into the molecular role of AGO2 in attenuating elongation of certain actively transcribed genes.
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