101
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Yadav RP, Mäkelä JA, Hyssälä H, Cisneros-Montalvo S, Kotaja N. DICER regulates the expression of major satellite repeat transcripts and meiotic chromosome segregation during spermatogenesis. Nucleic Acids Res 2020; 48:7135-7153. [PMID: 32484548 PMCID: PMC7367195 DOI: 10.1093/nar/gkaa460] [Citation(s) in RCA: 12] [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: 02/20/2020] [Revised: 04/23/2020] [Accepted: 05/22/2020] [Indexed: 12/16/2022] Open
Abstract
Constitutive heterochromatin at the pericentric regions of chromosomes undergoes dynamic changes in its epigenetic and spatial organization during spermatogenesis. Accurate control of pericentric heterochromatin is required for meiotic cell divisions and production of fertile and epigenetically intact spermatozoa. In this study, we demonstrate that pericentric heterochromatin is expressed during mouse spermatogenesis to produce major satellite repeat (MSR) transcripts. We show that the endonuclease DICER localizes to the pericentric heterochromatin in the testis. Furthermore, DICER forms complexes with MSR transcripts, and their processing into small RNAs is compromised in Dicer1 knockout mice leading to an elevated level of MSR transcripts in meiotic cells. We also show that defective MSR forward transcript processing in Dicer1 cKO germ cells is accompanied with reduced recruitment of SUV39H2 and H3K9me3 to the pericentric heterochromatin and meiotic chromosome missegregation. Altogether, our results indicate that the physiological role of DICER in maintenance of male fertility extends to the regulation of pericentric heterochromatin through direct targeting of MSR transcripts.
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Affiliation(s)
- Ram Prakash Yadav
- Institute of Biomedicine, Integrative Physiology and Pharmacology Unit, University of Turku, Finland
| | - Juho-Antti Mäkelä
- Institute of Biomedicine, Integrative Physiology and Pharmacology Unit, University of Turku, Finland
| | - Hanna Hyssälä
- Institute of Biomedicine, Integrative Physiology and Pharmacology Unit, University of Turku, Finland
| | - Sheyla Cisneros-Montalvo
- Institute of Biomedicine, Integrative Physiology and Pharmacology Unit, University of Turku, Finland
| | - Noora Kotaja
- To whom correspondence should be addressed. Tel: +358 44 2539225;
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102
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Prendergast L, McClurg UL, Hristova R, Berlinguer-Palmini R, Greener S, Veitch K, Hernandez I, Pasero P, Rico D, Higgins JMG, Gospodinov A, Papamichos-Chronakis M. Resolution of R-loops by INO80 promotes DNA replication and maintains cancer cell proliferation and viability. Nat Commun 2020; 11:4534. [PMID: 32913330 PMCID: PMC7484789 DOI: 10.1038/s41467-020-18306-x] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 08/18/2020] [Indexed: 02/04/2023] Open
Abstract
Collisions between the DNA replication machinery and co-transcriptional R-loops can impede DNA synthesis and are a major source of genomic instability in cancer cells. How cancer cells deal with R-loops to proliferate is poorly understood. Here we show that the ATP-dependent chromatin remodelling INO80 complex promotes resolution of R-loops to prevent replication-associated DNA damage in cancer cells. Depletion of INO80 in prostate cancer PC3 cells leads to increased R-loops. Overexpression of the RNA:DNA endonuclease RNAse H1 rescues the DNA synthesis defects and suppresses DNA damage caused by INO80 depletion. R-loops co-localize with and promote recruitment of INO80 to chromatin. Artificial tethering of INO80 to a LacO locus enabled turnover of R-loops in cis. Finally, counteracting R-loops by INO80 promotes proliferation and averts DNA damage-induced death in cancer cells. Our work suggests that INO80-dependent resolution of R-loops promotes DNA replication in the presence of transcription, thus enabling unlimited proliferation in cancers.
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Affiliation(s)
- Lisa Prendergast
- Cancer Research UK Newcastle Drug Discovery Unit, Newcastle University Centre for Cancer, Newcastle University, Paul O'Gorman Building, Newcastle upon Tyne, NE2 4HH, UK
- Drug Discovery Unit, Cancer Research UK Manchester Institute, The University of Manchester, Alderley Park, SK10 4TG, Manchester, UK
| | - Urszula L McClurg
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Rossitsa Hristova
- Roumen Tsanev Institute of Molecular Biology, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | | | - Sarah Greener
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Katie Veitch
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Inmaculada Hernandez
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
- CNAG-CRG, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, 08028, Spain
| | - Philippe Pasero
- Institute of Human Genetics, CNRS UMR9002 and University of Montpellier, Equipe Labéllisée Ligue Contre le Cancer, 34090, Montpellier, France
| | - Daniel Rico
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | | | - Anastas Gospodinov
- Roumen Tsanev Institute of Molecular Biology, Bulgarian Academy of Sciences, Sofia, Bulgaria.
| | - Manolis Papamichos-Chronakis
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, UK.
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle Upon Tyne, NE2 4HH, UK.
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103
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Lambo S, von Hoff K, Korshunov A, Pfister SM, Kool M. ETMR: a tumor entity in its infancy. Acta Neuropathol 2020; 140:249-266. [PMID: 32601913 PMCID: PMC7423804 DOI: 10.1007/s00401-020-02182-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 06/04/2020] [Accepted: 06/18/2020] [Indexed: 12/18/2022]
Abstract
Embryonal tumor with Multilayered Rosettes (ETMR) is a relatively rare but typically deadly type of brain tumor that occurs mostly in infants. Since the discovery of the characteristic chromosome 19 miRNA cluster (C19MC) amplification a decade ago, the methods for diagnosing this entity have improved and many new insights in the molecular landscape of ETMRs have been acquired. All ETMRs, despite their highly heterogeneous histology, are characterized by specific high expression of the RNA-binding protein LIN28A, which is, therefore, often used as a diagnostic marker for these tumors. ETMRs have few recurrent genetic aberrations, mainly affecting the miRNA pathway and including amplification of C19MC (embryonal tumor with multilayered rosettes, C19MC-altered) and mutually exclusive biallelic DICER1 mutations of which the first hit is typically inherited through the germline (embryonal tumor with multilayered rosettes, DICER1-altered). Identification of downstream pathways affected by the deregulated miRNA machinery has led to several proposed potential therapeutical vulnerabilities including targeting the WNT, SHH, or mTOR pathways, MYCN or chromosomal instability. However, despite those findings, treatment outcomes have only marginally improved, since the initial description of this tumor entity. Many patients do not survive longer than a year after diagnosis and the 5-year overall survival rate is still lower than 30%. Thus, there is an urgent need to translate the new insights in ETMR biology into more effective treatments. Here, we present an overview of clinical and molecular characteristics of ETMRs and the current progress on potential targeted therapies.
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Affiliation(s)
- Sander Lambo
- Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany
- Division of Pediatric Neurooncology, German Cancer Research Center (DKFZ), German Cancer Consortium (DKTK), Heidelberg, Germany
| | - Katja von Hoff
- Department of Pediatric Oncology/Hematology, Charité University Medicine, Berlin, Germany
| | - Andrey Korshunov
- Department of Neuropathology, Heidelberg University Hospital, Heidelberg, Germany
- Clinical Cooperation Unit Neuropathology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Stefan M Pfister
- Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany
- Division of Pediatric Neurooncology, German Cancer Research Center (DKFZ), German Cancer Consortium (DKTK), Heidelberg, Germany
- Department of Pediatric Oncology, Hematology and Immunology, University Hospital Heidelberg, Heidelberg, Germany
| | - Marcel Kool
- Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany.
- Division of Pediatric Neurooncology, German Cancer Research Center (DKFZ), German Cancer Consortium (DKTK), Heidelberg, Germany.
- Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands.
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104
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Ghosh S, Guimaraes JC, Lanzafame M, Schmidt A, Syed AP, Dimitriades B, Börsch A, Ghosh S, Mittal N, Montavon T, Correia AL, Danner J, Meister G, Terracciano LM, Pfeffer S, Piscuoglio S, Zavolan M. Prevention of dsRNA-induced interferon signaling by AGO1x is linked to breast cancer cell proliferation. EMBO J 2020; 39:e103922. [PMID: 32812257 PMCID: PMC7507497 DOI: 10.15252/embj.2019103922] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 06/27/2020] [Accepted: 07/07/2020] [Indexed: 01/05/2023] Open
Abstract
Translational readthrough, i.e., elongation of polypeptide chains beyond the stop codon, was initially reported for viral RNA, but later found also on eukaryotic transcripts, resulting in proteome diversification and protein‐level modulation. Here, we report that AGO1x, an evolutionarily conserved translational readthrough isoform of Argonaute 1, is generated in highly proliferative breast cancer cells, where it curbs accumulation of double‐stranded RNAs (dsRNAs) and consequent induction of interferon responses and apoptosis. In contrast to other mammalian Argonaute protein family members with primarily cytoplasmic functions, AGO1x exhibits nuclear localization in the vicinity of nucleoli. We identify AGO1x interaction with the polyribonucleotide nucleotidyltransferase 1 (PNPT1) and show that the depletion of this protein further augments dsRNA accumulation. Our study thus uncovers a novel function of an Argonaute protein in buffering the endogenous dsRNA‐induced interferon responses, different than the canonical function of AGO proteins in the miRNA effector pathway. As AGO1x expression is tightly linked to breast cancer cell proliferation, our study thus suggests a new direction for limiting tumor growth.
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Affiliation(s)
- Souvik Ghosh
- Computational and Systems Biology, Biozentrum, University of Basel, Basel, Switzerland
| | - Joao C Guimaraes
- Computational and Systems Biology, Biozentrum, University of Basel, Basel, Switzerland
| | - Manuela Lanzafame
- Institute of Pathology, University Hospital Basel, Basel, Switzerland
| | - Alexander Schmidt
- Proteomics Core Facility, Biozentrum, University of Basel, Basel, Switzerland
| | - Afzal Pasha Syed
- Computational and Systems Biology, Biozentrum, University of Basel, Basel, Switzerland
| | - Beatrice Dimitriades
- Computational and Systems Biology, Biozentrum, University of Basel, Basel, Switzerland
| | - Anastasiya Börsch
- Computational and Systems Biology, Biozentrum, University of Basel, Basel, Switzerland
| | - Shreemoyee Ghosh
- Computational and Systems Biology, Biozentrum, University of Basel, Basel, Switzerland
| | - Nitish Mittal
- Computational and Systems Biology, Biozentrum, University of Basel, Basel, Switzerland
| | - Thomas Montavon
- Architecture et Réactivité de l'ARN, Institut de biologie moléculaire et cellulaire du CNRS, Université de Strasbourg, Strasbourg, France
| | - Ana Luisa Correia
- Department of Biomedicine, University of Basel/University Hospital Basel, Basel, Switzerland
| | - Johannes Danner
- Department of Biochemistry, Department of Biology and Preclinical Medicine, University of Regensburg, Regensburg, Germany
| | - Gunter Meister
- Department of Biochemistry, Department of Biology and Preclinical Medicine, University of Regensburg, Regensburg, Germany
| | | | - Sébastien Pfeffer
- Architecture et Réactivité de l'ARN, Institut de biologie moléculaire et cellulaire du CNRS, Université de Strasbourg, Strasbourg, France
| | - Salvatore Piscuoglio
- Institute of Pathology, University Hospital Basel, Basel, Switzerland.,Department of Biomedicine, University of Basel/University Hospital Basel, Basel, Switzerland
| | - Mihaela Zavolan
- Computational and Systems Biology, Biozentrum, University of Basel, Basel, Switzerland
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105
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Richard P, Feng S, Tsai YL, Li W, Rinchetti P, Muhith U, Irizarry-Cole J, Stolz K, Sanz LA, Hartono S, Hoque M, Tadesse S, Seitz H, Lotti F, Hirano M, Chédin F, Tian B, Manley JL. SETX (senataxin), the helicase mutated in AOA2 and ALS4, functions in autophagy regulation. Autophagy 2020; 17:1889-1906. [PMID: 32686621 DOI: 10.1080/15548627.2020.1796292] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
SETX (senataxin) is an RNA/DNA helicase that has been implicated in transcriptional regulation and the DNA damage response through resolution of R-loop structures. Mutations in SETX result in either of two distinct neurodegenerative disorders. SETX dominant mutations result in a juvenile form of amyotrophic lateral sclerosis (ALS) called ALS4, whereas recessive mutations are responsible for ataxia called ataxia with oculomotor apraxia type 2 (AOA2). How mutations in the same protein can lead to different phenotypes is still unclear. To elucidate AOA2 disease mechanisms, we first examined gene expression changes following SETX depletion. We observed the effects on both transcription and RNA processing, but surprisingly observed decreased R-loop accumulation in SETX-depleted cells. Importantly, we discovered a strong connection between SETX and the macroautophagy/autophagy pathway, reflecting a direct effect on transcription of autophagy genes. We show that SETX depletion inhibits the progression of autophagy, leading to an accumulation of ubiquitinated proteins, decreased ability to clear protein aggregates, as well as mitochondrial defects. Analysis of AOA2 patient fibroblasts also revealed a perturbation of the autophagy pathway. Our work has thus identified a novel function for SETX in the regulation of autophagy, whose modulation may have a therapeutic impact for AOA2.Abbreviations: 3'READS: 3' region extraction and deep sequencing; ACTB: actin beta; ALS4: amyotrophic lateral sclerosis type 4; AOA2: ataxia with oculomotor apraxia type 2; APA: alternative polyadenylation; AS: alternative splicing; ATG7: autophagy-related 7; ATP6V0D2: ATPase H+ transporting V0 subunit D2; BAF: bafilomycin A1; BECN1: beclin 1; ChIP: chromatin IP; Chloro: chloroquine; CPT: camptothecin; DDR: DNA damage response; DNMT1: DNA methyltransferase 1; DRIP: DNA/RNA IP; DSBs: double strand breaks; EBs: embryoid bodies; FTD: frontotemporal dementia; GABARAP: GABA type A receptor-associated protein; GO: gene ontology; HR: homologous recombination; HTT: huntingtin; IF: immunofluorescence; IP: immunoprecipitation; iPSCs: induced pluripotent stem cells; KD: knockdown; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MN: motor neuron; MTORC1: mechanistic target of rapamycin kinase complex 1; PASS: PolyA Site Supporting; PFA: paraformaldehyde; RNAPII: RNA polymerase II; SCA: spinocerebellar ataxia; SETX: senataxin; SMA: spinal muscular atrophy; SMN1: survival of motor neuron 1, telomeric; SQSTM1/p62: sequestosome 1; TFEB: transcription factor EB; TSS: transcription start site; TTS: transcription termination site; ULK1: unc-51 like autophagy activating kinase 1; WB: western blot; WIPI2: WD repeat domain, phosphoinositide interacting 2; XRN2: 5'-3' exoribonuclease 2.
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Affiliation(s)
- Patricia Richard
- Department of Biological Sciences, Columbia University, New York, NY, USA.,Stellate Therapeutics, JLABS @ NYC, New York, NY, USA
| | | | - Yueh-Lin Tsai
- Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Wencheng Li
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School, Newark, NJ, USA
| | - Paola Rinchetti
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY, USA.,Dino Ferrari Centre, Department of Pathophysiology and Transplantation (DEPT), University of Milan, Milan, Italy
| | - Ubayed Muhith
- Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Juan Irizarry-Cole
- Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Katharine Stolz
- Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Lionel A Sanz
- Department of Molecular and Cellular Biology and Genome Center, University of California, Davis, CA, USA
| | - Stella Hartono
- Department of Molecular and Cellular Biology and Genome Center, University of California, Davis, CA, USA
| | - Mainul Hoque
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School, Newark, NJ, USA
| | - Saba Tadesse
- Department of Neurology, Columbia University Irving Medical Center, New York, NY, USA
| | - Hervé Seitz
- Institut de Génétique Humaine, UMR 9002 CNRS and Université de Montpellier, Montpellier, France
| | - Francesco Lotti
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY, USA
| | - Michio Hirano
- Department of Neurology, Columbia University Irving Medical Center, New York, NY, USA
| | - Frédéric Chédin
- Department of Molecular and Cellular Biology and Genome Center, University of California, Davis, CA, USA
| | - Bin Tian
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School, Newark, NJ, USA.,Gene Expression and Regulation Program, and Center for Systems and Computational Biology, The Wistar Institute, Philadelphia, PA, USA
| | - James L Manley
- Department of Biological Sciences, Columbia University, New York, NY, USA
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106
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Dou P, Li Y, Sun H, Xie W, Zhang X, Zhang X, Zhang D, Qiao S, Ci Y, Nie H, Han F, Li Y. C1orf109L binding DHX9 promotes DNA damage depended on the R-loop accumulation and enhances camptothecin chemosensitivity. Cell Prolif 2020; 53:e12875. [PMID: 32761833 PMCID: PMC7507383 DOI: 10.1111/cpr.12875] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 06/14/2020] [Accepted: 06/17/2020] [Indexed: 12/15/2022] Open
Abstract
Objectives R‐loop is a three‐stranded nucleic acid structure of RNA/DNA hybrid, which occurs naturally during transcription, and more R‐loop accumulation can trigger serious DNA damage. There has been increasing attention to the issue of R‐loop accumulation acted as a target for cancer therapy. However, the regulation of R‐loop‐associated proteins is poorly explored. Material and method Quantitative real‐time PCR and Western blot were used to measure the expression of C1orf109 in cell lines. In addition, C1orf109L (C1orf109 longest isoform) protein binding partner was identified and validated using immunoprecipitation‐mass spectrometric (IP‐MS) and immunoprecipitation assays. DNA‐RNA immunoprecipitation (DR‐IP) and immunofluorescence determined the C1orf109L location on R‐loop. R‐loop accumulation was determined by immunofluorescence. Cell cycle was determined by flow cytometry. Finally, time‐lapse assay and cell counting were conducted to determined cell survival in response to camptothecin (CPT). Results We found that C1orf109L could mediate cell cycle arrest in the G2/M phase and DNA damage depended on R‐loop accumulation. Meanwhile, C1orf109L could bind with DHX9 to trigger R‐loop accumulation. And C1orf109L was competitive with PARP1 binding to DHX9, which would block the function of DHX9‐PARP1 to prevent the R‐loop accumulation. Furthermore, C1orf109L could enhance the chemosensitivity of CPT, a chemotherapeutic drug capable of promoting R‐loop formation. Conclusions Our data demonstrate that C1orf109L triggers R‐loop accumulation and DNA damage to arrest cell cycle.
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Affiliation(s)
- Peng Dou
- School of Life Science and Technology, Harbin Institute of Technology, Harbin City, China
| | - Yiqun Li
- School of Life Science and Technology, Harbin Institute of Technology, Harbin City, China
| | - Haoxiu Sun
- School of Life Science and Technology, Harbin Institute of Technology, Harbin City, China
| | - Wanqiu Xie
- School of Life Science and Technology, Harbin Institute of Technology, Harbin City, China
| | - Xiaoqing Zhang
- School of Life Science and Technology, Harbin Institute of Technology, Harbin City, China
| | - Xiaohan Zhang
- School of Life Science and Technology, Harbin Institute of Technology, Harbin City, China
| | - Dandan Zhang
- School of Life Science and Technology, Harbin Institute of Technology, Harbin City, China
| | - Shupei Qiao
- School of Life Science and Technology, Harbin Institute of Technology, Harbin City, China
| | - Yanpeng Ci
- School of Life Science and Technology, Harbin Institute of Technology, Harbin City, China
| | - Huan Nie
- School of Life Science and Technology, Harbin Institute of Technology, Harbin City, China
| | - Fang Han
- School of Life Science and Technology, Harbin Institute of Technology, Harbin City, China
| | - Yu Li
- School of Life Science and Technology, Harbin Institute of Technology, Harbin City, China
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107
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Leng X, Thomas Q, Rasmussen SH, Marquardt S. A G(enomic)P(ositioning)S(ystem) for Plant RNAPII Transcription. TRENDS IN PLANT SCIENCE 2020; 25:744-764. [PMID: 32673579 DOI: 10.1016/j.tplants.2020.03.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 02/24/2020] [Accepted: 03/10/2020] [Indexed: 06/11/2023]
Abstract
Post-translational modifications (PTMs) of histone residues shape the landscape of gene expression by modulating the dynamic process of RNA polymerase II (RNAPII) transcription. The contribution of particular histone modifications to the definition of distinct RNAPII transcription stages remains poorly characterized in plants. Chromatin immunoprecipitation combined with next-generation sequencing (ChIP-seq) resolves the genomic distribution of histone modifications. Here, we review histone PTM ChIP-seq data in Arabidopsis thaliana and find support for a Genomic Positioning System (GPS) that guides RNAPII transcription. We review the roles of histone PTM 'readers', 'writers', and 'erasers', with a focus on the regulation of gene expression and biological functions in plants. The distinct functions of RNAPII transcription during the plant transcription cycle may rely, in part, on the characteristic histone PTM profiles that distinguish transcription stages.
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Affiliation(s)
- Xueyuan Leng
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Bülowsvej 34, 1870 Frederiksberg C, Denmark
| | - Quentin Thomas
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Bülowsvej 34, 1870 Frederiksberg C, Denmark
| | - Simon Horskjær Rasmussen
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Bülowsvej 34, 1870 Frederiksberg C, Denmark
| | - Sebastian Marquardt
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Bülowsvej 34, 1870 Frederiksberg C, Denmark.
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108
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Tanaka H, Watanabe T. Mechanisms Underlying Recurrent Genomic Amplification in Human Cancers. Trends Cancer 2020; 6:462-477. [PMID: 32383436 PMCID: PMC7285850 DOI: 10.1016/j.trecan.2020.02.019] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 02/20/2020] [Accepted: 02/24/2020] [Indexed: 12/17/2022]
Abstract
Focal copy-number increases (genomic amplification) pinpoint oncogenic driver genes and therapeutic targets in cancer genomes. With the advent of genomic technologies, recurrent genomic amplification has been mapped throughout the genome. Recurrent amplification could be solely due to positive selection for the tumor-promoting effects of amplified gene products. Alternatively, recurrence could result from the susceptibility of the loci to amplification. Distinguishing between these possibilities requires a full understanding of the amplification mechanisms. Two mechanisms, the formation of double minute (DM) chromosomes and breakage-fusion-bridge (BFB) cycles, have been repeatedly linked to genomic amplification, and the impact of both mechanisms has been confirmed in cancer genomics data. We review the details of these mechanisms and discuss the mechanisms underlying recurrence.
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Affiliation(s)
- Hisashi Tanaka
- Department of Surgery, Cedars-Sinai Medical Center, West Hollywood, CA 90046, USA; Biomedical Sciences, Cedars-Sinai Medical Center, West Hollywood, CA 90046, USA; Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center, West Hollywood, CA 90046, USA.
| | - Takaaki Watanabe
- Department of Surgery, Cedars-Sinai Medical Center, West Hollywood, CA 90046, USA; Molecular Life Science, Tokai University School of Medicine, Kanagawa, Japan
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109
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Li Y, Song Y, Xu W, Li Q, Wang X, Li K, Wang J, Liu Z, Velychko S, Ye R, Xia Q, Wang L, Guo R, Dong X, Zheng Z, Dai Y, Li H, Yao M, Xue Y, Schöler HR, Sun Q, Yao H. R-loops coordinate with SOX2 in regulating reprogramming to pluripotency. SCIENCE ADVANCES 2020; 6:eaba0777. [PMID: 32704541 PMCID: PMC7360481 DOI: 10.1126/sciadv.aba0777] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Accepted: 04/09/2020] [Indexed: 05/06/2023]
Abstract
R-loops modulate genome stability and regulate gene expression, but the functions and the regulatory mechanisms of R-loops in stem cell biology are still unclear. Here, we profiled R-loops during somatic cell reprogramming and found that dynamic changes in R-loops are essential for reprogramming and occurred before changes in gene expression. Disrupting the homeostasis of R-loops by depleting RNaseH1 or catalytic inactivation of RNaseH1 at D209 (RNaseH1D209N) blocks reprogramming. Sox2, but not any other factor in the Yamanaka cocktail, overcomes the inhibitory effects of RNaseH1 activity loss on reprogramming. Sox2 interacts with the reprogramming barrier factor Ddx5 and inhibits the resolvase activity of Ddx5 on R-loops and thus facilitates reprogramming. Furthermore, reprogramming efficiency can be modulated by dCas9-mediated RNaseH1/RNaseH1D209N targeting the specific R-loop regions. Together, these results show that R-loops play important roles in reprogramming and shed light on the regulatory module of Sox2/Ddx5 on R-loops during reprogramming.
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Affiliation(s)
- Yaoyi Li
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou 510530, China
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China
- Guangzhou Regenerative Medicine and Health GuangDong Laboratory (GRMH-GDL), Guangzhou 510005, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Institute of Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China
| | - Yawei Song
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou 510530, China
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China
- Guangzhou Regenerative Medicine and Health GuangDong Laboratory (GRMH-GDL), Guangzhou 510005, China
- Institute of Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China
| | - Wei Xu
- Tsinghua-Peking Joint Center for Life Sciences and Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Qin Li
- Tsinghua-Peking Joint Center for Life Sciences and Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Xinxiu Wang
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou 510530, China
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China
- Guangzhou Regenerative Medicine and Health GuangDong Laboratory (GRMH-GDL), Guangzhou 510005, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Institute of Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China
| | - Kuan Li
- Tsinghua-Peking Joint Center for Life Sciences and Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Juehan Wang
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou 510530, China
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China
- Guangzhou Regenerative Medicine and Health GuangDong Laboratory (GRMH-GDL), Guangzhou 510005, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Institute of Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China
| | - Zicong Liu
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou 510530, China
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China
- Guangzhou Regenerative Medicine and Health GuangDong Laboratory (GRMH-GDL), Guangzhou 510005, China
- Institute of Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China
| | - Sergiy Velychko
- Department of Cell and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Medical Faculty, University of Muenster, Münster 48149, Germany
| | - Rong Ye
- Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Qing Xia
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou 510530, China
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China
- Guangzhou Regenerative Medicine and Health GuangDong Laboratory (GRMH-GDL), Guangzhou 510005, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Institute of Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China
| | - Lei Wang
- Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Rong Guo
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou 510530, China
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China
- Guangzhou Regenerative Medicine and Health GuangDong Laboratory (GRMH-GDL), Guangzhou 510005, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Institute of Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiaotao Dong
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou 510530, China
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China
- Guangzhou Regenerative Medicine and Health GuangDong Laboratory (GRMH-GDL), Guangzhou 510005, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Institute of Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China
| | - Zhikai Zheng
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou 510530, China
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China
- Guangzhou Regenerative Medicine and Health GuangDong Laboratory (GRMH-GDL), Guangzhou 510005, China
- Institute of Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China
| | - Yushuang Dai
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou 510530, China
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China
- Guangzhou Regenerative Medicine and Health GuangDong Laboratory (GRMH-GDL), Guangzhou 510005, China
- Institute of Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China
| | - Haojie Li
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou 510530, China
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China
- Guangzhou Regenerative Medicine and Health GuangDong Laboratory (GRMH-GDL), Guangzhou 510005, China
- Institute of Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China
| | - Mingze Yao
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou 510530, China
| | - Yuanchao Xue
- Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Hans R. Schöler
- Department of Cell and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Medical Faculty, University of Muenster, Münster 48149, Germany
- Medical Faculty, University of Muenster, Domagkstrasse 3, 48149 Muenster, Germany
| | - Qianwen Sun
- Tsinghua-Peking Joint Center for Life Sciences and Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Corresponding author. (Q.S.); (H.Y.)
| | - Hongjie Yao
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou Medical University, Guangzhou 510530, China
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China
- Guangzhou Regenerative Medicine and Health GuangDong Laboratory (GRMH-GDL), Guangzhou 510005, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Institute of Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China
- Corresponding author. (Q.S.); (H.Y.)
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110
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New insight into the biology of R-loops. Mutat Res 2020; 821:111711. [PMID: 32516653 DOI: 10.1016/j.mrfmmm.2020.111711] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 05/22/2020] [Accepted: 05/23/2020] [Indexed: 11/24/2022]
Abstract
R-loops form when RNA hybridizes with its template DNA generating a three-stranded structure leaving a displaced single strand non-template DNA. During transcription negative supercoiling of DNA behind the advancing RNA polymerase will facilitate the formation of R-loops by the nascent RNA as the DNA is under wound to facilitate transcription. In theory R-loops are classified into pathological and non-pathological depending on the context of its formation. R-loop which are formed normally in various physiological events like in gene regulation and at immunoglobulin class switch regions are considered non-pathological, whereas abnormally stable R-loop which leads to genomic instability are considered pathological. Although pathological R-loop formation is a rare event but once formed completely blocks transcription, mRNA export, elevates mutagenesis, and inhibits gene expression. Hence, R-loop either prevents or induces genomic instability indirectly and are potentially an endogenous source of DNA lesion. Although the existence of R-loop has been reported few decades ago, but only recently we have gained knowledge about its formation and resolution in cells due to the availability of reagents. R-loop biology has generated immense interest in past few years since it connects the important biological processes such as transcription, mRNA splicing, DNA replication, recombination and repair. In this review I will focus on the recent progress made about formation and resolution of R-loop, based on the methodologies that are currently available to study R-loop using biochemical, cell biology and molecular biology approaches.
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111
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Ui A, Chiba N, Yasui A. Relationship among DNA double-strand break (DSB), DSB repair, and transcription prevents genome instability and cancer. Cancer Sci 2020; 111:1443-1451. [PMID: 32232911 PMCID: PMC7226179 DOI: 10.1111/cas.14404] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 01/29/2020] [Accepted: 02/01/2020] [Indexed: 12/28/2022] Open
Abstract
DNA double‐strand break (DSB) is a serious type of DNA damage and is known to trigger multiple responses within cells. In these responses, novel relationships among DSB, DSB repair, and transcription machineries are created. First, transcription is repressed if DSB occurs near or at the transcription site, termed DSB‐induced transcriptional repression, which contributes to DSB repair with the aid of DNA damage‐signaling pathways, ATM‐ or DNA‐PKcs‐signaling pathways. DSB‐induced transcriptional repression is also regulated by transcriptional factors TLP1, NELF, and ENL, as well as chromatin remodeling and organizing factors ZMYND8, CDYL1, PBAF, and cohesin. Second, transcription and RNA promote DSB repair for genome integrity. Transcription factors such as LEDGF, SETD2, and transcriptionally active histone modification, H3K36, facilitate homologous recombination to overcome DSB. At transcriptional active sites, DNA:RNA hybrids, termed R‐loops, which are formed by DSB, are processed by RAD52 and XPG leading to an activation of the homologous recombination pathway. Even in a transcriptionally inactive non‐genic sites, noncoding RNAs that are produced by RNA polymerase II, DICER, and DROSHA, help to recruit DSB repair proteins at the DSB sites. Third, transcriptional activation itself, however, can induce DSB. Transcriptional activation often generates specific DNA structures such as R‐loops and topoisomerase‐induced DSBs, which cause genotoxic stress and may lead to genome instability and consequently to cancer. Thus, transcription and DSB repair machineries interact and cooperate to prevent genome instability and cancer.
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Affiliation(s)
- Ayako Ui
- Genome Regulation and Molecular Pharmacogenomics, School of Bioscience and Biotechnology, Tokyo University of Technology, Hachijoji, Japan.,Department of Molecular Oncology, Institute of Development, Aging, and Cancer, Tohoku University, Sendai, Japan.,Division of Dynamic Proteome in Cancer and Aging, Institute of Development, Aging, and Cancer, Tohoku University, Sendai, Japan
| | - Natsuko Chiba
- Department of Cancer Biology, Institute of Development, Aging, and Cancer, Tohoku University, Sendai, Japan
| | - Akira Yasui
- Division of Dynamic Proteome in Cancer and Aging, Institute of Development, Aging, and Cancer, Tohoku University, Sendai, Japan
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112
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Wu W, Bhowmick R, Vogel I, Özer Ö, Ghisays F, Thakur RS, Sanchez de Leon E, Richter PH, Ren L, Petrini JH, Hickson ID, Liu Y. RTEL1 suppresses G-quadruplex-associated R-loops at difficult-to-replicate loci in the human genome. Nat Struct Mol Biol 2020; 27:424-437. [PMID: 32398827 DOI: 10.1038/s41594-020-0408-6] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 02/26/2020] [Indexed: 12/14/2022]
Abstract
Oncogene activation during tumorigenesis generates DNA replication stress, a known driver of genome rearrangements. In response to replication stress, certain loci, such as common fragile sites and telomeres, remain under-replicated during interphase and subsequently complete locus duplication in mitosis in a process known as 'MiDAS'. Here, we demonstrate that RTEL1 (regulator of telomere elongation helicase 1) has a genome-wide role in MiDAS at loci prone to form G-quadruplex-associated R-loops, in a process that is dependent on its helicase function. We reveal that SLX4 is required for the timely recruitment of RTEL1 to the affected loci, which in turn facilitates recruitment of other proteins required for MiDAS, including RAD52 and POLD3. Our findings demonstrate that RTEL1 is required for MiDAS and suggest that RTEL1 maintains genome stability by resolving conflicts that can arise between the replication and transcription machineries.
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Affiliation(s)
- Wei Wu
- Center for Chromosome Stability, University of Copenhagen, Copenhagen, Denmark
| | - Rahul Bhowmick
- Center for Chromosome Stability, University of Copenhagen, Copenhagen, Denmark
| | - Ivan Vogel
- Center for Chromosome Stability, University of Copenhagen, Copenhagen, Denmark
| | - Özgün Özer
- Center for Chromosome Stability, University of Copenhagen, Copenhagen, Denmark
- Institute of Cancer Research, London, UK
| | - Fiorella Ghisays
- Laboratory of Chromosome Biology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA
| | - Roshan S Thakur
- Center for Chromosome Stability, University of Copenhagen, Copenhagen, Denmark
| | - Esther Sanchez de Leon
- Laboratory of Chromosome Biology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA
| | - Philipp H Richter
- Center for Chromosome Stability, University of Copenhagen, Copenhagen, Denmark
| | - Liqun Ren
- Center for Chromosome Stability, University of Copenhagen, Copenhagen, Denmark
- The Basic Medical Research Institute, Chengde Medical University, Chengde, China
| | - John H Petrini
- Laboratory of Chromosome Biology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA
| | - Ian D Hickson
- Center for Chromosome Stability, University of Copenhagen, Copenhagen, Denmark.
| | - Ying Liu
- Center for Chromosome Stability, University of Copenhagen, Copenhagen, Denmark.
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113
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Xu W, Li K, Li S, Hou Q, Zhang Y, Liu K, Sun Q. The R-Loop Atlas of Arabidopsis Development and Responses to Environmental Stimuli. THE PLANT CELL 2020; 32:888-903. [PMID: 32075864 PMCID: PMC7145480 DOI: 10.1105/tpc.19.00802] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 01/31/2020] [Accepted: 02/19/2020] [Indexed: 05/19/2023]
Abstract
R-loops are a common chromatin feature with essential functions in multiple cellular processes and diseases. However, little is known about the dynamic patterns of R-loops in a given organism. Here, using our recently developed genome-wide R-loop profiling method, we generated a comprehensive atlas quantifying the R-loop patterns of Arabidopsis (Arabidopsis thaliana) in 53 samples during development and during responses to environmental stimuli. The R-loop patterns were fairly stable in plants at the vegetative stage and in response to different light spectra and other environmental stimuli. Notably, the R-loops showed turnover during the plant life cycle, with patterns switching between generations. Importantly, R-loop dynamics was not strongly associated with RNA abundance, indicating that the mechanisms regulating R-loop formation and RNA accumulation are independent. We also observed enrichment of R-loops in transcription factor binding regions, suggesting that R-loops could function as potential cis-transcriptional regulators. This study provides an overview of R-loop dynamics in Arabidopsis during development and stress responses, highlights the unique dynamics of R-loops in the flowering plant Arabidopsis, and lays the groundwork for elucidating the functions of R-loops.
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Affiliation(s)
- Wei Xu
- Tsinghua-Peking Joint Center for Life Sciences and Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Kuan Li
- Tsinghua-Peking Joint Center for Life Sciences and Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Shuai Li
- Tsinghua-Peking Joint Center for Life Sciences and Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Quancan Hou
- Tsinghua-Peking Joint Center for Life Sciences and Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yushun Zhang
- Tsinghua-Peking Joint Center for Life Sciences and Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Kunpeng Liu
- Tsinghua-Peking Joint Center for Life Sciences and Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Qianwen Sun
- Tsinghua-Peking Joint Center for Life Sciences and Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
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114
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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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115
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Zhang LH, Zhang XY, Hu T, Chen XY, Li JJ, Raida M, Sun N, Luo Y, Gao X. The SUMOylated METTL8 Induces R-loop and Tumorigenesis via m3C. iScience 2020; 23:100968. [PMID: 32199293 PMCID: PMC7082549 DOI: 10.1016/j.isci.2020.100968] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 02/08/2020] [Accepted: 03/03/2020] [Indexed: 01/26/2023] Open
Abstract
R-loops, three-stranded DNA-DNA:RNA hybrid structures, are best known for their deleterious effects on genome stability. The regulatory factors of this fundamental genetic structure remain unclear. Here, we reveal an epigenetic factor that controls R-loop stability. METTL8, a member of the methyltransferase-like protein family that methylates 3-methylcytidine (m3C), is a key factor in the R-loop regulating methyltransferase complex. Biochemical studies show that METTL8 forms a large SUMOylated nuclear RNA-binding protein complex (∼0.8 mega daltons) that contains well-reported R-loop related factors. Genetic ablation of METTL8 results in an overall reduction of R-loops in cells. Interaction assays indicated METTL8 binds to RNAs and is responsible for R-loop stability on selected gene regions. Our results demonstrate that the SUMOylated METTL8 promotes tumorigenesis by affecting genetic organization primarily in, or in close proximity to, the nucleolus and impacts the formation of regulatory R-loops through its methyltransferase activity on m3C. DNA:RNA hybrid structures are regulated by RNA methyltransferase via 3-methylcytidine SUMOylation stabilizes the RNA methyltransferase complex in the nucleus Dysregulation of DNA:RNA hybrids may induce tumorigenesis in mammalian cells
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Affiliation(s)
- Li-Hong Zhang
- Department of Biochemistry and Cancer Institute of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, China; Key Laboratory of Cancer Prevention and Intervention of China National Ministry of Education, Hangzhou 310009, China
| | - Xue-Yun Zhang
- Department of Biochemistry and Cancer Institute of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, China; Key Laboratory of Cancer Prevention and Intervention of China National Ministry of Education, Hangzhou 310009, China
| | - Tao Hu
- Department of Spine Surgery, Shanghai East Hospital, Tongji University, Shanghai 200092, China
| | - Xin-Yun Chen
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Jing-Jia Li
- Department of Biochemistry and Cancer Institute of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, China; Key Laboratory of Cancer Prevention and Intervention of China National Ministry of Education, Hangzhou 310009, China
| | - Manfred Raida
- Life Sciences Institute, National University of Singapore, Singapore 117456, Singapore
| | - Ning Sun
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Yan Luo
- Department of Biochemistry and Cancer Institute of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, China; Key Laboratory of Cancer Prevention and Intervention of China National Ministry of Education, Hangzhou 310009, China.
| | - Xiang Gao
- Department of Biochemistry and Cancer Institute of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, China; Key Laboratory of Cancer Prevention and Intervention of China National Ministry of Education, Hangzhou 310009, China.
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116
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O'Neill RJ. Seq'ing identity and function in a repeat-derived noncoding RNA world. Chromosome Res 2020; 28:111-127. [PMID: 32146545 PMCID: PMC7393779 DOI: 10.1007/s10577-020-09628-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 02/07/2020] [Accepted: 02/14/2020] [Indexed: 01/06/2023]
Abstract
Innovations in high-throughout sequencing approaches are being marshaled to both reveal the composition of the abundant and heterogeneous noncoding RNAs that populate cell nuclei and lend insight to the mechanisms by which noncoding RNAs influence chromosome biology and gene expression. This review focuses on some of the recent technological developments that have enabled the isolation of nascent transcripts and chromatin-associated and DNA-interacting RNAs. Coupled with emerging genome assembly and analytical approaches, the field is poised to achieve a comprehensive catalog of nuclear noncoding RNAs, including those derived from repetitive regions within eukaryotic genomes. Herein, particular attention is paid to the challenges and advances in the sequence analyses of repeat and transposable element-derived noncoding RNAs and in ascribing specific function(s) to such RNAs.
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Affiliation(s)
- Rachel J O'Neill
- Institute for Systems Genomics, University of Connecticut, Storrs, CT, 06269, USA.
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, 06269, USA.
- Department of Genetics and Genome Sciences, University of Connecticut Health Center, Farmington, CT, 06030, USA.
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117
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Brambati A, Zardoni L, Nardini E, Pellicioli A, Liberi G. The dark side of RNA:DNA hybrids. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2020; 784:108300. [PMID: 32430097 DOI: 10.1016/j.mrrev.2020.108300] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 02/07/2020] [Accepted: 02/23/2020] [Indexed: 12/15/2022]
Abstract
RNA:DNA hybrids form when nascent transcripts anneal to the DNA template strand or any homologous DNA region. Co-transcriptional RNA:DNA hybrids, organized in R-loop structures together with the displaced non-transcribed strand, assist gene expression, DNA repair and other physiological cellular functions. A dark side of the matter is that RNA:DNA hybrids are also a cause of DNA damage and human diseases. In this review, we summarize recent advances in the understanding of the mechanisms by which the impairment of hybrid turnover promotes DNA damage and genome instability via the interference with DNA replication and DNA double-strand break repair. We also discuss how hybrids could contribute to cancer, neurodegeneration and susceptibility to viral infections, focusing on dysfunctions associated with the anti-R-loop helicase Senataxin.
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Affiliation(s)
- Alessandra Brambati
- Istituto di Genetica Molecolare Luigi Luca Cavalli-Sforza, CNR, Via Abbiategrasso 207, 27100, Pavia, Italy.
| | - Luca Zardoni
- Istituto di Genetica Molecolare Luigi Luca Cavalli-Sforza, CNR, Via Abbiategrasso 207, 27100, Pavia, Italy; Scuola Universitaria Superiore, IUSS, 27100, Pavia, Italy
| | - Eleonora Nardini
- Istituto di Genetica Molecolare Luigi Luca Cavalli-Sforza, CNR, Via Abbiategrasso 207, 27100, Pavia, Italy
| | - Achille Pellicioli
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milan, Italy
| | - Giordano Liberi
- Istituto di Genetica Molecolare Luigi Luca Cavalli-Sforza, CNR, Via Abbiategrasso 207, 27100, Pavia, Italy; IFOM Foundation, Via Adamello 16, 20139, Milan, Italy.
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118
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From R-Loops to G-Quadruplexes: Emerging New Threats for the Replication Fork. Int J Mol Sci 2020; 21:ijms21041506. [PMID: 32098397 PMCID: PMC7073102 DOI: 10.3390/ijms21041506] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 02/14/2020] [Accepted: 02/20/2020] [Indexed: 12/12/2022] Open
Abstract
Replicating the entire genome is one of the most complex tasks for all organisms. Research carried out in the last few years has provided us with a clearer picture on how cells preserve genomic information from the numerous insults that may endanger its stability. Different DNA repair pathways, coping with exogenous or endogenous threat, have been dissected at the molecular level. More recently, there has been an increasing interest towards intrinsic obstacles to genome replication, paving the way to a novel view on genomic stability. Indeed, in some cases, the movement of the replication fork can be hindered by the presence of stable DNA: RNA hybrids (R-loops), the folding of G-rich sequences into G-quadruplex structures (G4s) or repetitive elements present at Common Fragile Sites (CFS). Although differing in their nature and in the way they affect the replication fork, all of these obstacles are a source of replication stress. Replication stress is one of the main hallmarks of cancer and its prevention is becoming increasingly important as a target for future chemotherapeutics. Here we will try to summarize how these three obstacles are generated and how the cells handle replication stress upon their encounter. Finally, we will consider their role in cancer and their exploitation in current chemotherapeutic approaches.
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119
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Abstract
The study by Tan-Wong et al. (2019) in this issue of Molecular Cell reveals a capacity of R-loops to promote antisense transcription expanding our view of the features that a DNA region may have to act as a promoter.
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Affiliation(s)
- Ana G Rondón
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Universidad de Sevilla- CSIC, Seville, Spain
| | - Andrés Aguilera
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Universidad de Sevilla- CSIC, Seville, Spain.
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120
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Appanah R, Lones EC, Aiello U, Libri D, De Piccoli G. Sen1 Is Recruited to Replication Forks via Ctf4 and Mrc1 and Promotes Genome Stability. Cell Rep 2020; 30:2094-2105.e9. [PMID: 32075754 PMCID: PMC7034062 DOI: 10.1016/j.celrep.2020.01.087] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 09/06/2019] [Accepted: 01/24/2020] [Indexed: 01/21/2023] Open
Abstract
DNA replication and RNA transcription compete for the same substrate during S phase. Cells have evolved several mechanisms to minimize such conflicts. Here, we identify the mechanism by which the transcription termination helicase Sen1 associates with replisomes. We show that the N terminus of Sen1 is both sufficient and necessary for replisome association and that it binds to the replisome via the components Ctf4 and Mrc1. We generated a separation of function mutant, sen1-3, which abolishes replisome binding without affecting transcription termination. We observe that the sen1-3 mutants show increased genome instability and recombination levels. Moreover, sen1-3 is synthetically defective with mutations in genes involved in RNA metabolism and the S phase checkpoint. RNH1 overexpression suppresses defects in the former, but not the latter. These findings illustrate how Sen1 plays a key function at replication forks during DNA replication to promote fork progression and chromosome stability.
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Affiliation(s)
- Rowin Appanah
- Warwick Medical School, University of Warwick, CV4 7AL Coventry, UK
| | | | - Umberto Aiello
- Institut Jacques Monod, CNRS, UMR7592, Université Paris Diderot, Paris Sorbonne Cité, Paris, France
| | - Domenico Libri
- Institut Jacques Monod, CNRS, UMR7592, Université Paris Diderot, Paris Sorbonne Cité, Paris, France
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121
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Gutbrod MJ, Martienssen RA. Conserved chromosomal functions of RNA interference. Nat Rev Genet 2020; 21:311-331. [PMID: 32051563 DOI: 10.1038/s41576-019-0203-6] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/26/2019] [Indexed: 12/21/2022]
Abstract
RNA interference (RNAi), a cellular process through which small RNAs target and regulate complementary RNA transcripts, has well-characterized roles in post-transcriptional gene regulation and transposon repression. Recent studies have revealed additional conserved roles for RNAi proteins, such as Argonaute and Dicer, in chromosome function. By guiding chromatin modification, RNAi components promote chromosome segregation during both mitosis and meiosis and regulate chromosomal and genomic dosage response. Small RNAs and the RNAi machinery also participate in the resolution of DNA damage. Interestingly, many of these lesser-studied functions seem to be more strongly conserved across eukaryotes than are well-characterized functions such as the processing of microRNAs. These findings have implications for the evolution of RNAi since the last eukaryotic common ancestor, and they provide a more complete view of the functions of RNAi.
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Affiliation(s)
- Michael J Gutbrod
- Watson School of Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Robert A Martienssen
- Watson School of Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA. .,Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA.
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Zhou H, Li L, Wang Q, Hu Y, Zhao W, Gautam M, Li L. H3K9 Demethylation-Induced R-Loop Accumulation Is Linked to Disorganized Nucleoli. Front Genet 2020; 11:43. [PMID: 32117455 PMCID: PMC7025566 DOI: 10.3389/fgene.2020.00043] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 01/15/2020] [Indexed: 11/24/2022] Open
Abstract
The nucleolar structure and integrity are important for a range of cellular functions of the nucleoli. It has been shown that cells lacking histone H3 Lysine 9 (H3K9) methylation form fragmented nucleoli. However, the molecular mechanism involved remains poorly understood. Here, we present evidence suggesting that loss of H3K9 dimethylation (H3K9me2) triggers R-loop accumulation at the rDNA locus, which further leads to the multilobed nucleoli. We reveal that suppression of H3K9 methyltransferase G9a by the inhibitor BIX 01294 causes R-loop accumulation at the rDNA region as well as inducing formation of multiple nucleoli. SiRNA-mediated knockdown of RNase H1 which can hydrolyze the RNA chain in R-loops causes an increase in R-loop formation, which in turn results in multiple nucleoli in one nucleus, whereas H3K9me2 levels are not affected by R-loop accumulation. Inhibition of RNA polymerase I transcription elongation by small molecule inhibitors induces a substantial decrease in H3K9me2 levels, accumulation of R-loops at rDNA sites, and nucleolus fragmentation. These results provide a mechanistic insight into the role of H3K9me2 in the structural integrity and organization of nucleoli via regulating R-loop accumulation.
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Affiliation(s)
- Hong Zhou
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
| | - Le Li
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
| | - Qing Wang
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
| | - Yan Hu
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
| | - Weiwei Zhao
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
| | - Mayank Gautam
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
| | - Lijia Li
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
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Regulatory R-loops as facilitators of gene expression and genome stability. Nat Rev Mol Cell Biol 2020; 21:167-178. [PMID: 32005969 DOI: 10.1038/s41580-019-0206-3] [Citation(s) in RCA: 269] [Impact Index Per Article: 67.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/17/2019] [Indexed: 12/23/2022]
Abstract
R-loops are three-stranded structures that harbour an RNA-DNA hybrid and frequently form during transcription. R-loop misregulation is associated with DNA damage, transcription elongation defects, hyper-recombination and genome instability. In contrast to such 'unscheduled' R-loops, evidence is mounting that cells harness the presence of RNA-DNA hybrids in scheduled, 'regulatory' R-loops to promote DNA transactions, including transcription termination and other steps of gene regulation, telomere stability and DNA repair. R-loops formed by cellular RNAs can regulate histone post-translational modification and may be recognized by dedicated reader proteins. The two-faced nature of R-loops implies that their formation, location and timely removal must be tightly regulated. In this Perspective, we discuss the cellular processes that regulatory R-loops modulate, the regulation of R-loops and the potential differences that may exist between regulatory R-loops and unscheduled R-loops.
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Chang WF, Xu J, Lin TY, Hsu J, Hsieh-Li HM, Hwu YM, Liu JL, Lu CH, Sung LY. Survival Motor Neuron Protein Participates in Mouse Germ Cell Development and Spermatogonium Maintenance. Int J Mol Sci 2020; 21:ijms21030794. [PMID: 31991812 PMCID: PMC7037566 DOI: 10.3390/ijms21030794] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 01/15/2020] [Accepted: 01/23/2020] [Indexed: 12/13/2022] Open
Abstract
The defective human survival motor neuron 1 (SMN1) gene leads to spinal muscular atrophy (SMA), the most common genetic cause of infant mortality. We previously reported that loss of SMN results in rapid differentiation of Drosophila germline stem cells and mouse embryonic stem cells (ESCs), indicating that SMN also plays important roles in germ cell development and stem cell biology. Here, we show that in healthy mice, SMN is highly expressed in the gonadal tissues, prepubertal spermatogonia, and adult spermatocytes, whereas low SMN expression is found in differentiated spermatid and sperm. In SMA-like mice, the growth of testis tissues is retarded, accompanied with gamete development abnormalities and loss of the spermatogonia-specific marker. Consistently, knockdown of Smn1 in spermatogonial stem cells (SSCs) leads to a compromised regeneration capacity in vitro and in vivo in transplantation experiments. In SMA-like mice, apoptosis and accumulation of the R-loop structure were significantly elevated, indicating that SMN plays a critical role in the survival of male germ cells. The present work demonstrates that SMN, in addition to its critical roles in neuronal development, participates in mouse germ cell and spermatogonium maintenance.
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Affiliation(s)
- Wei-Fang Chang
- Institute of Biotechnology, National Taiwan University, Taipei 106, Taiwan; (W.-F.C.); (T.-Y.L.); (J.H.)
| | - Jie Xu
- Center for Advanced Models for Translational Sciences and Therapeutics, University of Michigan Medical Center, Ann Arbor, MI 48109, USA;
| | - Tzu-Ying Lin
- Institute of Biotechnology, National Taiwan University, Taipei 106, Taiwan; (W.-F.C.); (T.-Y.L.); (J.H.)
| | - Jing Hsu
- Institute of Biotechnology, National Taiwan University, Taipei 106, Taiwan; (W.-F.C.); (T.-Y.L.); (J.H.)
| | - Hsiu-Mei Hsieh-Li
- Department of Life Science, National Taiwan Normal University, Taipei 116, Taiwan;
| | - Yuh-Ming Hwu
- Department of Obstetrics and Gynecology, Mackay Memorial Hospital, Taipei 10449, Taiwan;
- Department of Obstetrics and Gynecology, Mackay Medical College, New Taipei City 252, Taiwan
- Department of Obstetrics and Gynecology, Mackay Junior College of Medicine, Nursing, and Management, Taipei 11260, Taiwan
| | - Ji-Long Liu
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 2JD, UK;
- School of Life Science and Technology, Shanghai Tech University, Shanghai 201210, China
| | - Chung-Hao Lu
- Department of Obstetrics and Gynecology, Mackay Memorial Hospital, Taipei 10449, Taiwan;
- Correspondence: (C.-H.L.); (L.-Y.S.)
| | - Li-Ying Sung
- Institute of Biotechnology, National Taiwan University, Taipei 106, Taiwan; (W.-F.C.); (T.-Y.L.); (J.H.)
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei 115, Taiwan
- Animal Resource Center, National Taiwan University, Taipei 106, Taiwan
- Correspondence: (C.-H.L.); (L.-Y.S.)
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126
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Achar YJ, Adhil M, Choudhary R, Gilbert N, Foiani M. Negative supercoil at gene boundaries modulates gene topology. Nature 2020; 577:701-705. [PMID: 31969709 DOI: 10.1038/s41586-020-1934-4] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 11/25/2019] [Indexed: 11/08/2022]
Abstract
Transcription challenges the integrity of replicating chromosomes by generating topological stress and conflicts with forks1,2. The DNA topoisomerases Top1 and Top2 and the HMGB family protein Hmo1 assist DNA replication and transcription3-6. Here we describe the topological architecture of genes in Saccharomyces cerevisiae during the G1 and S phases of the cell cycle. We found under-wound DNA at gene boundaries and over-wound DNA within coding regions. This arrangement does not depend on Pol II or S phase. Top2 and Hmo1 preserve negative supercoil at gene boundaries, while Top1 acts at coding regions. Transcription generates RNA-DNA hybrids within coding regions, independently of fork orientation. During S phase, Hmo1 protects under-wound DNA from Top2, while Top2 confines Pol II and Top1 at coding units, counteracting transcription leakage and aberrant hybrids at gene boundaries. Negative supercoil at gene boundaries prevents supercoil diffusion and nucleosome repositioning at coding regions. DNA looping occurs at Top2 clusters. We propose that Hmo1 locks gene boundaries in a cruciform conformation and, with Top2, modulates the architecture of genes that retain the memory of the topological arrangements even when transcription is repressed.
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MESH Headings
- Chromatin Assembly and Disassembly
- DNA Replication
- DNA Topoisomerases, Type I/metabolism
- DNA Topoisomerases, Type II/genetics
- DNA Topoisomerases, Type II/metabolism
- DNA, Cruciform/chemistry
- DNA, Cruciform/genetics
- DNA, Cruciform/metabolism
- DNA, Fungal/chemistry
- DNA, Fungal/genetics
- DNA, Fungal/metabolism
- DNA, Superhelical/chemistry
- DNA, Superhelical/genetics
- DNA, Superhelical/metabolism
- G1 Phase
- Gene Expression Regulation, Fungal
- Genes, Fungal
- High Mobility Group Proteins/metabolism
- Mutation
- Nucleic Acid Hybridization
- Nucleosomes/chemistry
- Nucleosomes/genetics
- Nucleosomes/metabolism
- Open Reading Frames/genetics
- RNA Polymerase II/genetics
- RNA Polymerase II/metabolism
- RNA, Fungal/chemistry
- RNA, Fungal/genetics
- RNA, Fungal/metabolism
- S Phase
- Saccharomyces cerevisiae/cytology
- Saccharomyces cerevisiae/enzymology
- Saccharomyces cerevisiae/genetics
- Saccharomyces cerevisiae Proteins/metabolism
- Transcription, Genetic
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Affiliation(s)
| | - Mohamood Adhil
- IFOM (Fondazione Istituto FIRC di Oncologia Molecolare), Milan, Italy
| | - Ramveer Choudhary
- IFOM (Fondazione Istituto FIRC di Oncologia Molecolare), Milan, Italy
| | - Nick Gilbert
- Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Marco Foiani
- IFOM (Fondazione Istituto FIRC di Oncologia Molecolare), Milan, Italy.
- Università degli Studi di Milano, Milan, Italy.
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127
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Argaud D, Boulanger MC, Chignon A, Mkannez G, Mathieu P. Enhancer-mediated enrichment of interacting JMJD3-DDX21 to ENPP2 locus prevents R-loop formation and promotes transcription. Nucleic Acids Res 2019; 47:8424-8438. [PMID: 31251802 PMCID: PMC6895255 DOI: 10.1093/nar/gkz560] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 06/17/2019] [Accepted: 06/25/2019] [Indexed: 12/11/2022] Open
Abstract
ENPP2, which encodes for the enzyme autotaxin (ATX), is overexpressed during chronic inflammatory diseases and various cancers. However, the molecular mechanism involved in the ENPP2 transcription remains elusive. Here, in HEK 293T cells, we demonstrated that lipopolysaccharide (LPS) increased the transcription process at ENPP2 locus through a NF-кB pathway and a reduction of H3K27me3 level, a histone repressive mark, by the demethylase UTX. Simultaneously, the H3K27me3 demethylase JMJD3/KDM6B was recruited to the transcription start site (TSS), within the gene body and controlled the expression of ENPP2 in a non-enzymatic manner. Mass spectrometry data revealed a novel interaction for JMJD3 with DDX21, a RNA helicase that unwinds R-loops created by nascent transcript and DNA template. Upon LPS treatment, JMJD3 is necessary for DDX21 recruitment at ENPP2 locus allowing the resolution of aberrant R-loops. CRISPR-Cas9-mediated deletion of a distant-acting enhancer decreased the expression of ENPP2 and lowered the recruitment of JMJD3–DDX21 complex at TSS and its progression through the gene body. Taken together, these findings revealed that enhancer-mediated enrichment of novel JMJD3–DDX21 interaction at ENPP2 locus is necessary for nascent transcript synthesis via the resolution of aberrant R-loops formation in response to inflammatory stimulus.
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Affiliation(s)
- Deborah Argaud
- Laboratory of Cardiovascular Pathobiology, Quebec Heart and Lung Institute/Research Center, Department of Surgery, Laval University, Quebec G1V-4G5, Canada
| | - Marie-Chloé Boulanger
- Laboratory of Cardiovascular Pathobiology, Quebec Heart and Lung Institute/Research Center, Department of Surgery, Laval University, Quebec G1V-4G5, Canada
| | - Arnaud Chignon
- Laboratory of Cardiovascular Pathobiology, Quebec Heart and Lung Institute/Research Center, Department of Surgery, Laval University, Quebec G1V-4G5, Canada
| | - Ghada Mkannez
- Laboratory of Cardiovascular Pathobiology, Quebec Heart and Lung Institute/Research Center, Department of Surgery, Laval University, Quebec G1V-4G5, Canada
| | - Patrick Mathieu
- Laboratory of Cardiovascular Pathobiology, Quebec Heart and Lung Institute/Research Center, Department of Surgery, Laval University, Quebec G1V-4G5, Canada
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128
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Cristini A, Groh M, Kristiansen MS, Gromak N. RNA/DNA Hybrid Interactome Identifies DXH9 as a Molecular Player in Transcriptional Termination and R-Loop-Associated DNA Damage. Cell Rep 2019; 23:1891-1905. [PMID: 29742442 PMCID: PMC5976580 DOI: 10.1016/j.celrep.2018.04.025] [Citation(s) in RCA: 246] [Impact Index Per Article: 49.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 03/03/2018] [Accepted: 04/04/2018] [Indexed: 11/27/2022] Open
Abstract
R-loops comprise an RNA/DNA hybrid and displaced single-stranded DNA. They play important biological roles and are implicated in pathology. Even so, proteins recognizing these structures are largely undefined. Using affinity purification with the S9.6 antibody coupled to mass spectrometry, we defined the RNA/DNA hybrid interactome in HeLa cells. This consists of known R-loop-associated factors SRSF1, FACT, and Top1, and yet uncharacterized interactors, including helicases, RNA processing, DNA repair, and chromatin factors. We validate specific examples of these interactors and characterize their involvement in R-loop biology. A top candidate DHX9 helicase promotes R-loop suppression and transcriptional termination. DHX9 interacts with PARP1, and both proteins prevent R-loop-associated DNA damage. DHX9 and other interactome helicases are overexpressed in cancer, linking R-loop-mediated DNA damage and disease. Our RNA/DNA hybrid interactome provides a powerful resource to study R-loop biology in health and disease. Mass spectrometry identifies the RNA/DNA hybrid interactome in human cells Top RNA/DNA interactome candidate DHX9 promotes R-loop suppression DHX9 regulates transcriptional termination DHX9 interacts with PARP1 and prevents R-loop-associated DNA damage
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Affiliation(s)
- Agnese Cristini
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Matthias Groh
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Maiken S Kristiansen
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Natalia Gromak
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK.
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129
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Kinyamu HK, Bennett BD, Bushel PR, Archer TK. Proteasome inhibition creates a chromatin landscape favorable to RNA Pol II processivity. J Biol Chem 2019; 295:1271-1287. [PMID: 31806706 DOI: 10.1074/jbc.ra119.011174] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 12/02/2019] [Indexed: 11/06/2022] Open
Abstract
Proteasome activity is required for diverse cellular processes, including transcriptional and epigenetic regulation. However, inhibiting proteasome activity can lead to an increase in transcriptional output that is correlated with enriched levels of trimethyl H3K4 and phosphorylated forms of RNA polymerase (Pol) II at the promoter and gene body. Here, we perform gene expression analysis and ChIP followed by sequencing (ChIP-seq) in MCF-7 breast cancer cells treated with the proteasome inhibitor MG132, and we further explore genome-wide effects of proteasome inhibition on the chromatin state and RNA Pol II transcription. Analysis of gene expression programs and chromatin architecture reveals that chemically inhibiting proteasome activity creates a distinct chromatin state, defined by spreading of the H3K4me3 mark into the gene bodies of differentially-expressed genes. The distinct H3K4me3 chromatin profile and hyperacetylated nucleosomes at transcription start sites establish a chromatin landscape that facilitates recruitment of Ser-5- and Ser-2-phosphorylated RNA Pol II. Subsequent transcriptional events result in diverse gene expression changes. Alterations of H3K36me3 levels in the gene body reflect productive RNA Pol II elongation of transcripts of genes that are induced, underscoring the requirement for proteasome activity at multiple phases of the transcriptional cycle. Finally, by integrating genomics data and pathway analysis, we find that the differential effects of proteasome inhibition on the chromatin state modulate genes that are fundamental for cancer cell survival. Together, our results uncover underappreciated downstream effects of proteasome inhibitors that may underlie targeting of distinct chromatin states and key steps of RNA Pol II-mediated transcription in cancer cells.
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Affiliation(s)
- H Karimi Kinyamu
- Chromatin and Gene Expression Section, Epigenetics and Stem Cell Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, North Carolina 27709
| | - Brian D Bennett
- Chromatin and Gene Expression Section, Epigenetics and Stem Cell Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, North Carolina 27709.,Integrative Bioinformatics Support Group, Epigenetics and Stem Cell Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, North Carolina 27709
| | - Pierre R Bushel
- Biostatistics and Computational Biology Branch, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, North Carolina 27709
| | - Trevor K Archer
- Chromatin and Gene Expression Section, Epigenetics and Stem Cell Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, North Carolina 27709
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130
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Chiang HC, Zhang X, Li J, Zhao X, Chen J, Wang HTH, Jatoi I, Brenner A, Hu Y, Li R. BRCA1-associated R-loop affects transcription and differentiation in breast luminal epithelial cells. Nucleic Acids Res 2019; 47:5086-5099. [PMID: 30982901 PMCID: PMC6547407 DOI: 10.1093/nar/gkz262] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 03/06/2019] [Accepted: 04/01/2019] [Indexed: 12/17/2022] Open
Abstract
BRCA1-associated basal-like breast cancer originates from luminal progenitor cells. Breast epithelial cells from cancer-free BRCA1 mutation carriers are defective in luminal differentiation. However, how BRCA1 deficiency leads to lineage-specific differentiation defect is not clear. BRCA1 is implicated in resolving R-loops, DNA-RNA hybrid structures associated with genome instability and transcriptional regulation. We recently showed that R-loops are preferentially accumulated in breast luminal epithelial cells of BRCA1 mutation carriers. Here, we interrogate the impact of a BRCA1 mutation-associated R-loop located in a putative transcriptional enhancer upstream of the ERα-encoding ESR1 gene. Genetic ablation confirms the relevance of this R-loop-containing region to enhancer-promoter interactions and transcriptional activation of the corresponding neighboring genes, including ESR1, CCDC170 and RMND1. BRCA1 knockdown in ERα+ luminal breast cancer cells increases intensity of this R-loop and reduces transcription of its neighboring genes. The deleterious effect of BRCA1 depletion on transcription is mitigated by ectopic expression of R-loop-removing RNase H1. Furthermore, RNase H1 overexpression in primary breast cells from BRCA1 mutation carriers results in a shift from luminal progenitor cells to mature luminal cells. Our findings suggest that BRCA1-dependent R-loop mitigation contributes to luminal cell-specific transcription and differentiation, which could in turn suppress BRCA1-associated tumorigenesis.
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Affiliation(s)
- Huai-Chin Chiang
- Department of Biochemistry & Molecular Medicine, School of Medicine & Health Sciences, The George Washington University, Washington, DC 20037, USA
| | - Xiaowen Zhang
- Department of Biochemistry & Molecular Medicine, School of Medicine & Health Sciences, The George Washington University, Washington, DC 20037, USA
| | - Jingwei Li
- Department of Molecular Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Xiayan Zhao
- Department of Molecular Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Jerry Chen
- Department of Molecular Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Howard T-H Wang
- Department of Surgery, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Ismail Jatoi
- Department of Surgery, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Andrew Brenner
- Department of Medicine, The Mays Cancer Center, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Yanfen Hu
- Department of Anatomy & Cell Biology, School of Medicine & Health Sciences, The George Washington University, Washington, DC 20037, USA
| | - Rong Li
- Department of Biochemistry & Molecular Medicine, School of Medicine & Health Sciences, The George Washington University, Washington, DC 20037, USA
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131
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Kim JJ, Lee SY, Gong F, Battenhouse AM, Boutz DR, Bashyal A, Refvik ST, Chiang CM, Xhemalce B, Paull TT, Brodbelt JS, Marcotte EM, Miller KM. Systematic bromodomain protein screens identify homologous recombination and R-loop suppression pathways involved in genome integrity. Genes Dev 2019; 33:1751-1774. [PMID: 31753913 PMCID: PMC6942044 DOI: 10.1101/gad.331231.119] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Accepted: 10/28/2019] [Indexed: 01/01/2023]
Abstract
Bromodomain proteins (BRD) are key chromatin regulators of genome function and stability as well as therapeutic targets in cancer. Here, we systematically delineate the contribution of human BRD proteins for genome stability and DNA double-strand break (DSB) repair using several cell-based assays and proteomic interaction network analysis. Applying these approaches, we identify 24 of the 42 BRD proteins as promoters of DNA repair and/or genome integrity. We identified a BRD-reader function of PCAF that bound TIP60-mediated histone acetylations at DSBs to recruit a DUB complex to deubiquitylate histone H2BK120, to allowing direct acetylation by PCAF, and repair of DSBs by homologous recombination. We also discovered the bromo-and-extra-terminal (BET) BRD proteins, BRD2 and BRD4, as negative regulators of transcription-associated RNA-DNA hybrids (R-loops) as inhibition of BRD2 or BRD4 increased R-loop formation, which generated DSBs. These breaks were reliant on topoisomerase II, and BRD2 directly bound and activated topoisomerase I, a known restrainer of R-loops. Thus, comprehensive interactome and functional profiling of BRD proteins revealed new homologous recombination and genome stability pathways, providing a framework to understand genome maintenance by BRD proteins and the effects of their pharmacological inhibition.
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Affiliation(s)
- Jae Jin Kim
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712, USA.,Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Seo Yun Lee
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712, USA.,Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Fade Gong
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712, USA.,Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Anna M Battenhouse
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712, USA.,Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas 78712, USA.,Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Daniel R Boutz
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712, USA.,Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas 78712, USA.,Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Aarti Bashyal
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Samantha T Refvik
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712, USA.,Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas 78712, USA.,The Howard Hughes Medical Institute
| | - Cheng-Ming Chiang
- Simmons Comprehensive Cancer Center, Department of Biochemistry, Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Blerta Xhemalce
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712, USA.,Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas 78712, USA.,Livestrong Cancer Institutes, Dell Medical School, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Tanya T Paull
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712, USA.,Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas 78712, USA.,The Howard Hughes Medical Institute.,Livestrong Cancer Institutes, Dell Medical School, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Jennifer S Brodbelt
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, USA.,Livestrong Cancer Institutes, Dell Medical School, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Edward M Marcotte
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712, USA.,Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas 78712, USA.,Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Kyle M Miller
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712, USA.,Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas 78712, USA.,Livestrong Cancer Institutes, Dell Medical School, The University of Texas at Austin, Austin, Texas 78712, USA
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132
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Saha A, Nanavaty VP, Li B. Telomere and Subtelomere R-loops and Antigenic Variation in Trypanosomes. J Mol Biol 2019; 432:4167-4185. [PMID: 31682833 DOI: 10.1016/j.jmb.2019.10.025] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Revised: 10/02/2019] [Accepted: 10/21/2019] [Indexed: 12/12/2022]
Abstract
Trypanosoma brucei is a kinetoplastid parasite that causes African trypanosomiasis, which is fatal if left untreated. T. brucei regularly switches its major surface antigen, VSG, to evade the host immune responses. VSGs are exclusively expressed from subtelomeric expression sites (ESs) where VSG genes are flanked by upstream 70 bp repeats and downstream telomeric repeats. The telomere downstream of the active VSG is transcribed into a long-noncoding RNA (TERRA), which forms RNA:DNA hybrids (R-loops) with the telomeric DNA. At an elevated level, telomere R-loops cause more telomeric and subtelomeric double-strand breaks (DSBs) and increase VSG switching rate. In addition, stabilized R-loops are observed at the 70 bp repeats and immediately downstream of ES-linked VSGs in RNase H defective cells, which also have an increased amount of subtelomeric DSBs and more frequent VSG switching. Although subtelomere plasticity is expected to be beneficial to antigenic variation, severe defects in subtelomere integrity and stability increase cell lethality. Therefore, regulation of the telomere and 70 bp repeat R-loop levels is important for the balance between antigenic variation and cell fitness in T. brucei. In addition, the high level of the active ES transcription favors accumulation of R-loops at the telomere and 70 bp repeats, providing an intrinsic mechanism for local DSB formation, which is a strong inducer of VSG switching.
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Affiliation(s)
- Arpita Saha
- Center for Gene Regulation in Health and Disease, Department of Biological, Geological, and Environmental Sciences, College of Science and Health Professions, Cleveland State University, 2121 Euclid Avenue, Cleveland, OH 44115, USA
| | - Vishal P Nanavaty
- Center for Gene Regulation in Health and Disease, Department of Biological, Geological, and Environmental Sciences, College of Science and Health Professions, Cleveland State University, 2121 Euclid Avenue, Cleveland, OH 44115, USA
| | - Bibo Li
- Center for Gene Regulation in Health and Disease, Department of Biological, Geological, and Environmental Sciences, College of Science and Health Professions, Cleveland State University, 2121 Euclid Avenue, Cleveland, OH 44115, USA; Case Comprehensive Cancer Center, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA; Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA.
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133
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R-Loops Promote Antisense Transcription across the Mammalian Genome. Mol Cell 2019; 76:600-616.e6. [PMID: 31679819 PMCID: PMC6868509 DOI: 10.1016/j.molcel.2019.10.002] [Citation(s) in RCA: 95] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 08/14/2019] [Accepted: 09/30/2019] [Indexed: 11/25/2022]
Abstract
Widespread antisense long noncoding RNA (lncRNA) overlap with many protein-coding genes in mammals and emanate from gene promoter, enhancer, and termination regions. However, their origin and biological purpose remain unclear. We show that these antisense lncRNA can be generated by R-loops that form when nascent transcript invades the DNA duplex behind elongating RNA polymerase II (Pol II). Biochemically, R-loops act as intrinsic Pol II promoters to induce de novo RNA synthesis. Furthermore, their removal across the human genome by RNase H1 overexpression causes the selective reduction of antisense transcription. Consequently, we predict that R-loops act to facilitate the synthesis of many gene proximal antisense lncRNA. Not only are R-loops widely associated with DNA damage and repair, but we now show that they have the capacity to promote de novo transcript synthesis that may have aided the evolution of gene regulation. R-loops formed within plasmids promote antisense transcription in nuclear extracts TSS of lncRNA and eRNA are often near R-loop structures and sensitive to RNase H1 Preinitiation complexes associated with lncRNA synthesis are R-loop dependent Many mammalian lncRNA derive from R-loop promoter activity
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134
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R Loops: From Physiological to Pathological Roles. Cell 2019; 179:604-618. [PMID: 31607512 DOI: 10.1016/j.cell.2019.08.055] [Citation(s) in RCA: 353] [Impact Index Per Article: 70.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 08/19/2019] [Accepted: 08/28/2019] [Indexed: 12/13/2022]
Abstract
DNA-RNA hybrids play a physiological role in cellular processes, but often, they represent non-scheduled co-transcriptional structures with a negative impact on transcription, replication and DNA repair. Accumulating evidence suggests that they constitute a source of replication stress, DNA breaks and genome instability. Reciprocally, DNA breaks facilitate DNA-RNA hybrid formation by releasing the double helix torsional conformation. Cells avoid DNA-RNA accumulation by either preventing or removing hybrids directly or by DNA repair-coupled mechanisms. Given the R-loop impact on chromatin and genome organization and its potential relation with genetic diseases, we review R-loop homeostasis as well as their physiological and pathological roles.
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135
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Wells JP, White J, Stirling PC. R Loops and Their Composite Cancer Connections. Trends Cancer 2019; 5:619-631. [DOI: 10.1016/j.trecan.2019.08.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 08/29/2019] [Accepted: 08/30/2019] [Indexed: 12/19/2022]
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136
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Chen FX, Smith ER, Shilatifard A. Born to run: control of transcription elongation by RNA polymerase II. Nat Rev Mol Cell Biol 2019; 19:464-478. [PMID: 29740129 DOI: 10.1038/s41580-018-0010-5] [Citation(s) in RCA: 253] [Impact Index Per Article: 50.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The dynamic regulation of transcription elongation by RNA polymerase II (Pol II) is an integral part of the implementation of gene expression programmes during development. In most metazoans, the majority of transcribed genes exhibit transient pausing of Pol II at promoter-proximal regions, and the release of Pol II into gene bodies is controlled by many regulatory factors that respond to environmental and developmental cues. Misregulation of the elongation stage of transcription is implicated in cancer and other human diseases, suggesting that mechanistic understanding of transcription elongation control is therapeutically relevant. In this Review, we discuss the features, establishment and maintenance of Pol II pausing, the transition into productive elongation, the control of transcription elongation by enhancers and by factors of other cellular processes, such as topoisomerases and poly(ADP-ribose) polymerases (PARPs), and the potential of therapeutic targeting of the elongation stage of transcription by Pol II.
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Affiliation(s)
- Fei Xavier Chen
- Simpson Querrey Center for Epigenetics and the Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Edwin R Smith
- Simpson Querrey Center for Epigenetics and the Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Ali Shilatifard
- Simpson Querrey Center for Epigenetics and the Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
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137
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Caron P, van der Linden J, van Attikum H. Bon voyage: A transcriptional journey around DNA breaks. DNA Repair (Amst) 2019; 82:102686. [PMID: 31476573 DOI: 10.1016/j.dnarep.2019.102686] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 07/20/2019] [Accepted: 08/06/2019] [Indexed: 02/06/2023]
Abstract
DNA double-strand breaks (DSBs) affect chromatin integrity and impact DNA-dependent processes such as transcription. Several studies revealed that the transcription of genes located in close proximity to DSBs is transiently repressed. This is achieved through the establishment of either a transient repressive chromatin context or eviction of the RNA polymerase II complex from the damaged chromatin. While these mechanisms of transcription repression have been shown to affect the efficiency and accuracy of DSB repair, it became evident that the transcriptional state of chromatin before DSB formation also influences this process. Moreover, transcription can be initiated from DSB ends, generating long non-coding (lnc)RNAs that will be processed into sequence-specific double-stranded RNAs. These so-called DNA damage-induced (dd)RNAs dictate DSB repair by regulating the accumulation of DNA repair proteins at DSBs. Thus, a complex interplay between mechanisms of transcription activation and repression occurs at DSBs and affects their repair. Here we review our current understanding of the mechanisms that coordinate transcription and DSB repair to prevent genome instability arising from DNA breaks in transcribed regions.
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Affiliation(s)
- Pierre Caron
- Department of Human Genetics, Leiden University Medical Center, Einthovenweg 20, 2333ZC, Leiden, the Netherlands
| | - Janette van der Linden
- Department of Human Genetics, Leiden University Medical Center, Einthovenweg 20, 2333ZC, Leiden, the Netherlands
| | - Haico van Attikum
- Department of Human Genetics, Leiden University Medical Center, Einthovenweg 20, 2333ZC, Leiden, the Netherlands.
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138
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Burger K, Ketley RF, Gullerova M. Beyond the Trinity of ATM, ATR, and DNA-PK: Multiple Kinases Shape the DNA Damage Response in Concert With RNA Metabolism. Front Mol Biosci 2019; 6:61. [PMID: 31428617 PMCID: PMC6688092 DOI: 10.3389/fmolb.2019.00061] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 07/11/2019] [Indexed: 12/22/2022] Open
Abstract
Our genome is constantly exposed to endogenous and exogenous sources of DNA damage resulting in various alterations of the genetic code. DNA double-strand breaks (DSBs) are considered one of the most cytotoxic lesions. Several types of repair pathways act to repair DNA damage and maintain genome stability. In the canonical DNA damage response (DDR) DSBs are recognized by the sensing kinases Ataxia-telangiectasia mutated (ATM), Ataxia-telangiectasia and Rad3-related (ATR), and DNA-dependent protein kinase (DNA-PK), which initiate a cascade of kinase-dependent amplification steps known as DSB signaling. Recent evidence suggests that efficient recognition and repair of DSBs relies on the transcription and processing of non-coding (nc)RNA molecules by RNA polymerase II (RNAPII) and the RNA interference (RNAi) factors Drosha and Dicer. Multiple kinases influence the phosphorylation status of both the RNAPII carboxy-terminal domain (CTD) and Dicer in order to regulate RNA-dependent DSBs repair. The importance of kinase signaling and RNA processing in the DDR is highlighted by the regulation of p53-binding protein (53BP1), a key regulator of DSB repair pathway choice between homologous recombination (HR) and non-homologous end joining (NHEJ). Additionally, emerging evidence suggests that RNA metabolic enzymes also play a role in the repair of other types of DNA damage, including the DDR to ultraviolet radiation (UVR). RNAi factors are also substrates for mitogen-activated protein kinase (MAPK) signaling and mediate the turnover of ncRNA during nucleotide excision repair (NER) in response to UVR. Here, we review kinase-dependent phosphorylation events on RNAPII, Drosha and Dicer, and 53BP1 that modulate the key steps of the DDR to DSBs and UVR, suggesting an intimate link between the DDR and RNA metabolism.
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Affiliation(s)
| | | | - Monika Gullerova
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
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139
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Yu K, Lieber MR. Current insights into the mechanism of mammalian immunoglobulin class switch recombination. Crit Rev Biochem Mol Biol 2019; 54:333-351. [PMID: 31509023 PMCID: PMC6856442 DOI: 10.1080/10409238.2019.1659227] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 08/13/2019] [Accepted: 08/20/2019] [Indexed: 12/12/2022]
Abstract
Immunoglobulin (Ig) class switch recombination (CSR) is the gene rearrangement process by which B lymphocytes change the Ig heavy chain constant region to permit a switch of Ig isotype from IgM to IgG, IgA, or IgE. At the DNA level, CSR occurs via generation and joining of DNA double strand breaks (DSBs) at intronic switch regions located just upstream of each of the heavy chain constant regions. Activation-induced deaminase (AID), a B cell specific enzyme, catalyzes cytosine deaminations (converting cytosines to uracils) as the initial DNA lesions that eventually lead to DSBs and CSR. Progress on AID structure integrates very well with knowledge about Ig class switch region nucleic acid structures that are supported by functional studies. It is an ideal time to review what is known about the mechanism of Ig CSR and its relation to somatic hypermutation. There have been many comprehensive reviews on various aspects of the CSR reaction and regulation of AID expression and activity. This review is focused on the relation between AID and switch region nucleic acid structures, with a particular emphasis on R-loops.
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Affiliation(s)
- Kefei Yu
- Michigan State University, Department of Microbiology & Molecular Genetics, 5175 Biomedical Physical Sciences, East Lansing, MI 48824
| | - Michael R. Lieber
- USC Norris Comprehensive Cancer Ctr., Departments of Pathology, of Molecular Microbiology & Immunology, of Biochemistry & Molecular Biology, and of the Section of Molecular & Computational Biology within the Department of Biological Sciences, 1441 Eastlake Ave., NTT5428, Los Angeles, CA 90089-9176
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140
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Karl M, Sommer C, Gabriel CH, Hecklau K, Venzke M, Hennig AF, Radbruch A, Selbach M, Baumgrass R. Recruitment of Histone Methyltransferase Ehmt1 to Foxp3 TSDR Counteracts Differentiation of Induced Regulatory T Cells. J Mol Biol 2019; 431:3606-3625. [PMID: 31362003 DOI: 10.1016/j.jmb.2019.07.031] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 07/13/2019] [Accepted: 07/17/2019] [Indexed: 12/21/2022]
Abstract
Differentiation toward CD4+ regulatory T (Treg) cells is essentially dependent on an epigenetic program at Treg signature genes, which involves remodeling of the Treg-specific demethylated regions (TSDRs). In particular, the epigenetic status of the conserved non-coding sequence 2 of Foxp3 (Foxp3 TSDR) determines expression stability of the master transcription factor and thus Treg lineage identity. However, the molecular mechanisms controlling the epigenetic remodeling at TSDRs in Treg and conventional T cells are largely unknown. Using a combined approach of DNA pull-down and mass spectrometric analysis, we report a novel regulatory mechanism in which transcription factor Wiz recruits the histone methyltransferase Ehmt1 to Foxp3 TSDR. We show that both Wiz and Ehmt1 are crucial for shaping the region with the repressive histone modification H3K9me2 in conventional T cells. Consistently, knocking out either Ehmt1 or Wiz by CRISPR/Cas resulted in the loss of H3K9me2 and enhanced Foxp3 expression during iTreg differentiation. Moreover, the essential role of the Wiz-Ehmt1 interaction as observed at several TSDRs indicates a global function of Ehmt1 in the Treg differentiation program.
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Affiliation(s)
- Martin Karl
- Signal Transduction, German Rheumatism Research Center (DRFZ), A Leibniz Institute, Charitéplatz 1, 10117 Berlin, Germany
| | - Christian Sommer
- Proteome Dynamics, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Str. 10, 13125 Berlin, Germany
| | - Christian H Gabriel
- Signal Transduction, German Rheumatism Research Center (DRFZ), A Leibniz Institute, Charitéplatz 1, 10117 Berlin, Germany
| | - Katharina Hecklau
- Signal Transduction, German Rheumatism Research Center (DRFZ), A Leibniz Institute, Charitéplatz 1, 10117 Berlin, Germany
| | - Melanie Venzke
- Signal Transduction, German Rheumatism Research Center (DRFZ), A Leibniz Institute, Charitéplatz 1, 10117 Berlin, Germany
| | - Anna Floriane Hennig
- Signal Transduction, German Rheumatism Research Center (DRFZ), A Leibniz Institute, Charitéplatz 1, 10117 Berlin, Germany
| | - Andreas Radbruch
- Cell Biology, German Rheumatism Research Center (DRFZ), A Leibniz Institute, Charitéplatz 1, 10117 Berlin, Germany; Charité-University Medicine, Charitéplatz 1, 10117 Berlin, Germany
| | - Matthias Selbach
- Proteome Dynamics, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Str. 10, 13125 Berlin, Germany
| | - Ria Baumgrass
- Signal Transduction, German Rheumatism Research Center (DRFZ), A Leibniz Institute, Charitéplatz 1, 10117 Berlin, Germany.
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141
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Non-canonical DNA/RNA structures during Transcription-Coupled Double-Strand Break Repair: Roadblocks or Bona fide repair intermediates? DNA Repair (Amst) 2019; 81:102661. [PMID: 31331819 DOI: 10.1016/j.dnarep.2019.102661] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Although long overlooked, it is now well understood that DNA does not systematically assemble into a canonical double helix, known as B-DNA, throughout the entire genome but can also accommodate other structures including DNA hairpins, G-quadruplexes and RNA:DNA hybrids. Notably, these non-canonical DNA structures form preferentially at transcriptionally active loci. Acting as replication roadblocks and being targeted by multiple machineries, these structures weaken the genome and render it prone to damage, including DNA double-strand breaks (DSB). In addition, secondary structures also further accumulate upon DSB formation. Here we discuss the potential functions of pre-existing or de novo formed nucleic acid structures, as bona fide repair intermediates or repair roadblocks, especially during Transcription-Coupled DNA Double-Strand Break repair (TC-DSBR), and provide an update on the specialized protein complexes displaying the ability to remove these structures to safeguard genome integrity.
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142
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Abstract
Transcription is a source of genome instability that stimulates mutation and recombination. Part of the damage produced by transcription is mediated by R-loops, non-B DNA structures that normally form by the re-annealing of the nascent RNA with the template DNA outside the catalytic center of the RNA polymerase, displacing the non-template strand. Recent discoveries have revealed that R-loops might not be harmful by themselves. Instead, chromatin compaction triggered by these structures seems necessary, as deduced from the histone modifications frequently found associated with harmful R-loops. Remarkably, hybrids may also become harmful if stabilized by specific RNA binding proteins, one example of which is the yeast Yra1. We discuss here the possible mechanisms by which cells may stabilize R-loops and the consequences on transcription-replication conflicts and telomere homeostasis.
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Affiliation(s)
- Ana G Rondón
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, 41092, Seville, Spain
| | - Andrés Aguilera
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, 41092, Seville, Spain.
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143
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Xiao R, Chen JY, Liang Z, Luo D, Chen G, Lu ZJ, Chen Y, Zhou B, Li H, Du X, Yang Y, San M, Wei X, Liu W, Lécuyer E, Graveley BR, Yeo GW, Burge CB, Zhang MQ, Zhou Y, Fu XD. Pervasive Chromatin-RNA Binding Protein Interactions Enable RNA-Based Regulation of Transcription. Cell 2019; 178:107-121.e18. [PMID: 31251911 PMCID: PMC6760001 DOI: 10.1016/j.cell.2019.06.001] [Citation(s) in RCA: 202] [Impact Index Per Article: 40.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 03/21/2019] [Accepted: 05/31/2019] [Indexed: 01/03/2023]
Abstract
Increasing evidence suggests that transcriptional control and chromatin activities at large involve regulatory RNAs, which likely enlist specific RNA-binding proteins (RBPs). Although multiple RBPs have been implicated in transcription control, it has remained unclear how extensively RBPs directly act on chromatin. We embarked on a large-scale RBP ChIP-seq analysis, revealing widespread RBP presence in active chromatin regions in the human genome. Like transcription factors (TFs), RBPs also show strong preference for hotspots in the genome, particularly gene promoters, where their association is frequently linked to transcriptional output. Unsupervised clustering reveals extensive co-association between TFs and RBPs, as exemplified by YY1, a known RNA-dependent TF, and RBM25, an RBP involved in splicing regulation. Remarkably, RBM25 depletion attenuates all YY1-dependent activities, including chromatin binding, DNA looping, and transcription. We propose that various RBPs may enhance network interaction through harnessing regulatory RNAs to control transcription.
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Affiliation(s)
- Rui Xiao
- Department of Cellular and Molecular Medicine, Institute of Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Medical Research Institute, Wuhan University, Wuhan, Hubei 430071, China.
| | - Jia-Yu Chen
- Department of Cellular and Molecular Medicine, Institute of Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Zhengyu Liang
- Department of Cellular and Molecular Medicine, Institute of Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA; MOE Key Laboratory of Bioinformatics, Tsinghua University, Beijing 100084, China
| | - Daji Luo
- Department of Cellular and Molecular Medicine, Institute of Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA; School of Basic Medical Sciences, Wuhan University, Wuhan, Hubei 430071, China
| | - Geng Chen
- College of Life Sciences and Institute for Advanced Studies, Wuhan University, Wuhan, Hubei 430072, China
| | - Zhi John Lu
- MOE Key Laboratory of Bioinformatics, Tsinghua University, Beijing 100084, China
| | - Yang Chen
- MOE Key Laboratory of Bioinformatics, Tsinghua University, Beijing 100084, China
| | - Bing Zhou
- Department of Cellular and Molecular Medicine, Institute of Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Hairi Li
- Department of Cellular and Molecular Medicine, Institute of Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Xian Du
- College of Life Sciences and Institute for Advanced Studies, Wuhan University, Wuhan, Hubei 430072, China
| | - Yang Yang
- College of Life Sciences and Institute for Advanced Studies, Wuhan University, Wuhan, Hubei 430072, China
| | - Mingkui San
- Medical Research Institute, Wuhan University, Wuhan, Hubei 430071, China
| | - Xintao Wei
- Department of Genetics and Genome Sciences, Institute for Systems Genomics, UConn Health Science Center, Farmington, CT 06030, USA
| | - Wen Liu
- School of Pharmaceutical Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Eric Lécuyer
- Institut de Recherches Cliniques de Montréal, Département de Biochimie and Médecine Moléculaire, Université de Montréal, Montréal, QC H2W 1R7, Canada
| | - Brenton R Graveley
- Department of Genetics and Genome Sciences, Institute for Systems Genomics, UConn Health Science Center, Farmington, CT 06030, USA
| | - Gene W Yeo
- Department of Cellular and Molecular Medicine, Institute of Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Christopher B Burge
- Program in Computational and Systems Biology, Department of Biology, MIT, Cambridge, MA 02139, USA
| | - Michael Q Zhang
- MOE Key Laboratory of Bioinformatics, Tsinghua University, Beijing 100084, China; Department of Biological Sciences, Center for Systems Biology, University of Texas, Dallas, TX 75080, USA
| | - Yu Zhou
- College of Life Sciences and Institute for Advanced Studies, Wuhan University, Wuhan, Hubei 430072, China
| | - Xiang-Dong Fu
- Department of Cellular and Molecular Medicine, Institute of Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA.
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144
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Hegedüs É, Kókai E, Nánási P, Imre L, Halász L, Jossé R, Antunovics Z, Webb MR, El Hage A, Pommier Y, Székvölgyi L, Dombrádi V, Szabó G. Endogenous single-strand DNA breaks at RNA polymerase II promoters in Saccharomyces cerevisiae. Nucleic Acids Res 2019; 46:10649-10668. [PMID: 30445637 PMCID: PMC6237785 DOI: 10.1093/nar/gky743] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Accepted: 08/16/2018] [Indexed: 12/12/2022] Open
Abstract
Molecular combing and gel electrophoretic studies revealed endogenous nicks with free 3'OH ends at ∼100 kb intervals in the genomic DNA (gDNA) of unperturbed and G1-synchronized Saccharomyces cerevisiae cells. Analysis of the distribution of endogenous nicks by Nick ChIP-chip indicated that these breaks accumulated at active RNA polymerase II (RNAP II) promoters, reminiscent of the promoter-proximal transient DNA breaks of higher eukaryotes. Similar periodicity of endogenous nicks was found within the ribosomal rDNA cluster, involving every ∼10th of the tandemly repeated 9.1 kb units of identical sequence. Nicks were mapped by Southern blotting to a few narrow regions within the affected units. Three of them were overlapping the RNAP II promoters, while the ARS-containing IGS2 region was spared of nicks. By using a highly sensitive reverse-Southwestern blot method to map free DNA ends with 3'OH, nicks were shown to be distinct from other known rDNA breaks and linked to the regulation of rDNA silencing. Nicks in rDNA and the rest of the genome were typically found at the ends of combed DNA molecules, occasionally together with R-loops, comprising a major pool of vulnerable sites that are connected with transcriptional regulation.
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Affiliation(s)
- Éva Hegedüs
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Endre Kókai
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Péter Nánási
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - László Imre
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - László Halász
- MTA-DE Momentum Genome Architecture and Recombination Research Group, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Rozenn Jossé
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute (CCR-NCI), NIH, Bethesda, MD, USA
| | - Zsuzsa Antunovics
- Department of Genetics and Applied Microbiology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | | | - Aziz El Hage
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Yves Pommier
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute (CCR-NCI), NIH, Bethesda, MD, USA
| | - Lóránt Székvölgyi
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.,MTA-DE Momentum Genome Architecture and Recombination Research Group, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Viktor Dombrádi
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Gábor Szabó
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
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145
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Jasoliya M, Sacca F, Sahdeo S, Chedin F, Pane C, Brescia Morra V, Filla A, Pook M, Cortopassi G. Dimethyl fumarate dosing in humans increases frataxin expression: A potential therapy for Friedreich's Ataxia. PLoS One 2019; 14:e0217776. [PMID: 31158268 PMCID: PMC6546270 DOI: 10.1371/journal.pone.0217776] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 05/18/2019] [Indexed: 11/19/2022] Open
Abstract
Friedreich's Ataxia (FA) is an inherited neurodegenerative disorder resulting from decreased expression of the mitochondrial protein frataxin, for which there is no approved therapy. High throughput screening of clinically used drugs identified Dimethyl fumarate (DMF) as protective in FA patient cells. Here we demonstrate that DMF significantly increases frataxin gene (FXN) expression in FA cell model, FA mouse model and in DMF treated humans. DMF also rescues mitochondrial biogenesis deficiency in FA-patient derived cell model. We further examined the mechanism of DMF's frataxin induction in FA patient cells. It has been shown that transcription-inhibitory R-loops form at GAA expansion mutations, thus decreasing FXN expression. In FA patient cells, we demonstrate that DMF significantly increases transcription initiation. As a potential consequence, we observe significant reduction in both R-loop formation and transcriptional pausing thereby significantly increasing FXN expression. Lastly, DMF dosed Multiple Sclerosis (MS) patients showed significant increase in FXN expression by ~85%. Since inherited deficiency in FXN is the primary cause of FA, and DMF is demonstrated to increase FXN expression in humans, DMF could be considered for Friedreich's therapy.
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Affiliation(s)
- Mittal Jasoliya
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, California, United States of America
| | - Francesco Sacca
- Department of Neurosciences, Odontostomatological and Reproductive Sciences, University Federico II, Naples, Italy
| | - Sunil Sahdeo
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, California, United States of America
| | - Frederic Chedin
- Department of Molecular and Cellular Biology, University of California, Davis, California, United States of America
| | - Chiara Pane
- Department of Neurosciences, Odontostomatological and Reproductive Sciences, University Federico II, Naples, Italy
| | - Vincenzo Brescia Morra
- Department of Neurosciences, Odontostomatological and Reproductive Sciences, University Federico II, Naples, Italy
| | - Alessandro Filla
- Department of Neurosciences, Odontostomatological and Reproductive Sciences, University Federico II, Naples, Italy
| | - Mark Pook
- Department of Life Sciences, College of Health & Life Sciences, Brunel University London, Uxbridge, United Kingdom
| | - Gino Cortopassi
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, California, United States of America
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146
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Abstract
Genome replication involves dealing with obstacles that can result from DNA damage but also from chromatin alterations, topological stress, tightly bound proteins or non-B DNA structures such as R loops. Experimental evidence reveals that an engaged transcription machinery at the DNA can either enhance such obstacles or be an obstacle itself. Thus, transcription can become a potentially hazardous process promoting localized replication fork hindrance and stress, which would ultimately cause genome instability, a hallmark of cancer cells. Understanding the causes behind transcription-replication conflicts as well as how the cell resolves them to sustain genome integrity is the aim of this review.
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147
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Yuan W, Zhou J, Tong J, Zhuo W, Wang L, Li Y, Sun Q, Qian W. ALBA protein complex reads genic R-loops to maintain genome stability in Arabidopsis. SCIENCE ADVANCES 2019; 5:eaav9040. [PMID: 31106272 PMCID: PMC6520018 DOI: 10.1126/sciadv.aav9040] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 04/02/2019] [Indexed: 05/19/2023]
Abstract
The R-loop, composed of a DNA-RNA hybrid and the displaced single-stranded DNA, regulates diverse cellular processes. However, how cellular R-loops are recognized remains poorly understood. Here, we report the discovery of the evolutionally conserved ALBA proteins (AtALBA1 and AtALBA2) functioning as the genic R-loop readers in Arabidopsis. While AtALBA1 binds to the DNA-RNA hybrid, AtALBA2 associates with single-stranded DNA in the R-loops in vitro. In vivo, these two proteins interact and colocalize in the nucleus, where they preferentially bind to genic regions with active epigenetic marks in an R-loop-dependent manner. Depletion of AtALBA1 or AtALBA2 results in hypersensitivity of plants to DNA damaging agents. The formation of DNA breaks in alba mutants originates from unprotected R-loops. Our results reveal that the AtALBA1 and AtALBA2 protein complex is the genic R-loop reader crucial for genome stability in Arabidopsis.
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Affiliation(s)
- Wei Yuan
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
- Tsinghua-Peking Joint Center for Life Sciences and Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Jincong Zhou
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
| | - Jinjin Tong
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
- Tsinghua-Peking Joint Center for Life Sciences and Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Wanqing Zhuo
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Lishuan Wang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Yan Li
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
| | - Qianwen Sun
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
- Corresponding author. (Q.S.); (W.Q.)
| | - Weiqiang Qian
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
- Corresponding author. (Q.S.); (W.Q.)
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148
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Burger K, Schlackow M, Gullerova M. Tyrosine kinase c-Abl couples RNA polymerase II transcription to DNA double-strand breaks. Nucleic Acids Res 2019; 47:3467-3484. [PMID: 30668775 PMCID: PMC6468493 DOI: 10.1093/nar/gkz024] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 01/08/2019] [Accepted: 01/10/2019] [Indexed: 12/23/2022] Open
Abstract
DNA is constantly exposed to endogenous and exogenous damage. Various types of DNA repair counteract highly toxic DNA double-strand breaks (DSBs) to maintain genome stability. Recent findings suggest that the human DNA damage response (DDR) utilizes small RNA species, which are produced as long non-coding (nc)RNA precursors and promote recognition of DSBs. However, regulatory principles that control production of such transcripts remain largely elusive. Here we show that the Abelson tyrosine kinase c-Abl/ABL1 causes formation of RNA polymerase II (RNAPII) foci, predominantly phosphorylated at carboxy-terminal domain (CTD) residue Tyr1, at DSBs. CTD Tyr1-phosphorylated RNAPII (CTD Y1P) synthetizes strand-specific, damage-responsive transcripts (DARTs), which trigger formation of double-stranded (ds)RNA intermediates via DNA-RNA hybrid intermediates to promote recruitment of p53-binding protein 1 (53BP1) and Mediator of DNA damage checkpoint 1 (MDC1) to endogenous DSBs. Interference with transcription, c-Abl activity, DNA-RNA hybrid formation or dsRNA processing impairs CTD Y1P foci formation, attenuates DART synthesis and delays recruitment of DDR factors and DSB signalling. Collectively, our data provide novel insight in RNA-dependent DDR by coupling DSB-induced c-Abl activity on RNAPII to generate DARTs for consequent DSB recognition.
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Affiliation(s)
- Kaspar Burger
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Margarita Schlackow
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Monika Gullerova
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
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149
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The Emerging Roles of TERRA in Telomere Maintenance and Genome Stability. Cells 2019; 8:cells8030246. [PMID: 30875900 PMCID: PMC6468625 DOI: 10.3390/cells8030246] [Citation(s) in RCA: 96] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 03/08/2019] [Accepted: 03/12/2019] [Indexed: 12/20/2022] Open
Abstract
The finding that transcription occurs at chromosome ends has opened new fields of study on the roles of telomeric transcripts in chromosome end maintenance and genome stability. Indeed, the ends of chromosomes are required to be protected from activation of DNA damage response and DNA repair pathways. Chromosome end protection is achieved by the activity of specific proteins that associate with chromosome ends, forming telomeres. Telomeres need to be constantly maintained as they are in a heterochromatic state and fold into specific structures (T-loops), which may hamper DNA replication. In addition, in the absence of maintenance mechanisms, chromosome ends shorten at every cell division due to limitations in the DNA replication machinery, which is unable to fully replicate the extremities of chromosomes. Altered telomere structure or critically short chromosome ends generate dysfunctional telomeres, ultimately leading to replicative senescence or chromosome instability. Telomere biology is thus implicated in multiple human diseases, including cancer. Emerging evidence indicates that a class of long noncoding RNAs transcribed at telomeres, known as TERRA for “TElomeric Repeat-containing RNA,” actively participates in the mechanisms regulating telomere maintenance and chromosome end protection. However, the molecular details of TERRA activities remain to be elucidated. In this review, we discuss recent findings on the emerging roles of TERRA in telomere maintenance and genome stability and their implications in human diseases.
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150
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Peck SA, Hughes KD, Victorino JF, Mosley AL. Writing a wrong: Coupled RNA polymerase II transcription and RNA quality control. WILEY INTERDISCIPLINARY REVIEWS-RNA 2019; 10:e1529. [PMID: 30848101 PMCID: PMC6570551 DOI: 10.1002/wrna.1529] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 12/27/2018] [Accepted: 02/07/2019] [Indexed: 12/20/2022]
Abstract
Processing and maturation of precursor RNA species is coupled to RNA polymerase II transcription. Co-transcriptional RNA processing helps to ensure efficient and proper capping, splicing, and 3' end processing of different RNA species to help ensure quality control of the transcriptome. Many improperly processed transcripts are not exported from the nucleus, are restricted to the site of transcription, and are in some cases degraded, which helps to limit any possibility of aberrant RNA causing harm to cellular health. These critical quality control pathways are regulated by the highly dynamic protein-protein interaction network at the site of transcription. Recent work has further revealed the extent to which the processes of transcription and RNA processing and quality control are integrated, and how critically their coupling relies upon the dynamic protein interactions that take place co-transcriptionally. This review focuses specifically on the intricate balance between 3' end processing and RNA decay during transcription termination. This article is categorized under: RNA Turnover and Surveillance > Turnover/Surveillance Mechanisms RNA Processing > 3' End Processing RNA Processing > Splicing Mechanisms RNA Processing > Capping and 5' End Modifications.
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Affiliation(s)
- Sarah A Peck
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Katlyn D Hughes
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Jose F Victorino
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Amber L Mosley
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana
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