201
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Dhar S, Datta A, Brosh RM. DNA helicases and their roles in cancer. DNA Repair (Amst) 2020; 96:102994. [PMID: 33137625 DOI: 10.1016/j.dnarep.2020.102994] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 09/28/2020] [Indexed: 12/15/2022]
Abstract
DNA helicases, known for their fundamentally important roles in genomic stability, are high profile players in cancer. Not only are there monogenic helicase disorders with a strong disposition to cancer, it is well appreciated that helicase variants are associated with specific cancers (e.g., breast cancer). Flipping the coin, DNA helicases are frequently overexpressed in cancerous tissues and reduction in helicase gene expression results in reduced proliferation and growth capacity, as well as DNA damage induction and apoptosis of cancer cells. The seminal roles of helicases in the DNA damage and replication stress responses, as well as DNA repair pathways, validate their vital importance in cancer biology and suggest their potential values as targets in anti-cancer therapy. In recent years, many laboratories have characterized the specialized roles of helicase to resolve transcription-replication conflicts, maintain telomeres, mediate cell cycle checkpoints, remodel stalled replication forks, and regulate transcription. In vivo models, particularly mice, have been used to interrogate helicase function and serve as a bridge for preclinical studies that may lead to novel therapeutic approaches. In this review, we will summarize our current knowledge of DNA helicases and their roles in cancer, emphasizing the latest developments.
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Affiliation(s)
- Srijita Dhar
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Arindam Datta
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Robert M Brosh
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA.
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202
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Abstract
Physiological and pathological roles for R-loop structures continue to be discovered, and studies suggest that R-loops could contribute to human disease. R-loops are nucleic acid structures characterized by a DNA:RNA hybrid and displaced single-stranded DNA that occur in connection with transcription. R-loops form naturally and have been shown to be important for a number of physiological processes such as mitochondrial replication initiation, class switch recombination, DNA repair, modulating DNA topology, and regulation of gene expression. However, subsets of R-loops or persistent R-loops lead to DNA breaks, chromosome rearrangement, and genome instability. In addition, R-loops have been linked to human diseases, specifically neurological disorders and cancer. Of the large amount of research produced recently on R-loops, this review covers evidence for R-loop involvement in normal cellular physiology and pathophysiology, as well as describing factors that contribute to R-loop regulation.
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Affiliation(s)
- Ryan Patrick Mackay
- Department of Molecular and Cellular Physiology and Louisiana State University Health Sciences Center - Shreveport, Shreveport, Louisiana, USA
| | - Qinqin Xu
- Department of Otolaryngology - Head & Neck Surgery, Louisiana State University Health Sciences Center - Shreveport, Shreveport, Louisiana, USA
| | - Paul M Weinberger
- Department of Molecular and Cellular Physiology and Louisiana State University Health Sciences Center - Shreveport, Shreveport, Louisiana, USA.,Department of Otolaryngology - Head & Neck Surgery, Louisiana State University Health Sciences Center - Shreveport, Shreveport, Louisiana, USA
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203
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Nastasi C, Mannarino L, D’Incalci M. DNA Damage Response and Immune Defense. Int J Mol Sci 2020; 21:E7504. [PMID: 33053746 PMCID: PMC7588887 DOI: 10.3390/ijms21207504] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 10/08/2020] [Accepted: 10/10/2020] [Indexed: 02/07/2023] Open
Abstract
DNA damage is the cause of numerous human pathologies including cancer, premature aging, and chronic inflammatory conditions. The DNA damage response (DDR), in turn, coordinates DNA damage checkpoint activation and promotes the removal of DNA lesions. In recent years, several studies have shown how the DDR and the immune system are tightly connected, revealing an important crosstalk between the two of them. This interesting interplay has opened up new perspectives in clinical studies for immunological diseases as well as for cancer treatment. In this review, we provide an overview, from cellular to molecular pathways, on how DDR and the immune system communicate and share the crucial commitment of maintaining the genomic fitness.
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Affiliation(s)
- Claudia Nastasi
- Department of Oncology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156 Milan, Italy;
| | | | - Maurizio D’Incalci
- Department of Oncology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156 Milan, Italy;
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204
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The ALPK1/TIFA/NF-κB axis links a bacterial carcinogen to R-loop-induced replication stress. Nat Commun 2020; 11:5117. [PMID: 33037203 PMCID: PMC7547021 DOI: 10.1038/s41467-020-18857-z] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 09/16/2020] [Indexed: 02/07/2023] Open
Abstract
Exposure of gastric epithelial cells to the bacterial carcinogen Helicobacter pylori causes DNA double strand breaks. Here, we show that H. pylori-induced DNA damage occurs co-transcriptionally in S-phase cells that activate NF-κB signaling upon innate immune recognition of the lipopolysaccharide biosynthetic intermediate β-ADP-heptose by the ALPK1/TIFA signaling pathway. DNA damage depends on the bi-functional RfaE enzyme and the Cag pathogenicity island of H. pylori, is accompanied by replication fork stalling and can be observed also in primary cells derived from gastric organoids. Importantly, H. pylori-induced replication stress and DNA damage depend on the presence of co-transcriptional RNA/DNA hybrids (R-loops) that form in infected cells during S-phase as a consequence of β-ADP-heptose/ ALPK1/TIFA/NF-κB signaling. H. pylori resides in close proximity to S-phase cells in the gastric mucosa of gastritis patients. Taken together, our results link bacterial infection and NF-κB-driven innate immune responses to R-loop-dependent replication stress and DNA damage. The bacterial pathogen Helicobacter pylori is known for its ability to induce DNA double-strand breaks in the genome of its target cells. Here, we show that H. pylori-induced DNA damage and replication stress occurs in S-phase cells as a result of R-loop-mediated transcription/replication conflicts that are triggered by activation of the ALPK1/TIFA/NF-κB signaling axis.
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205
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Yu Z, Mersaoui SY, Guitton-Sert L, Coulombe Y, Song J, Masson JY, Richard S. DDX5 resolves R-loops at DNA double-strand breaks to promote DNA repair and avoid chromosomal deletions. NAR Cancer 2020; 2:zcaa028. [PMID: 33015627 PMCID: PMC7520851 DOI: 10.1093/narcan/zcaa028] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 08/25/2020] [Accepted: 09/10/2020] [Indexed: 02/07/2023] Open
Abstract
R-loops are three-stranded structures consisting of a DNA/RNA hybrid and a displaced DNA strand. The regulatory factors required to process this fundamental genetic structure near double-strand DNA breaks (DSBs) are not well understood. We previously reported that cellular depletion of the ATP-dependent DEAD box RNA helicase DDX5 increases R-loops genome-wide causing genomic instability. In this study, we define a pivotal role for DDX5 in clearing R-loops at or near DSBs enabling proper DNA repair to avoid aberrations such as chromosomal deletions. Remarkably, using the non-homologous end joining reporter gene (EJ5-GFP), we show that DDX5-deficient U2OS cells exhibited asymmetric end deletions on the side of the DSBs where there is overlap with a transcribed gene. Cross-linking and immunoprecipitation showed that DDX5 bound RNA transcripts near DSBs and required its helicase domain and the presence of DDX5 near DSBs was also shown by chromatin immunoprecipitation. DDX5 was excluded from DSBs in a transcription- and ATM activation-dependent manner. Using DNA/RNA immunoprecipitation, we show DDX5-deficient cells had increased R-loops near DSBs. Finally, DDX5 deficiency led to delayed exonuclease 1 and replication protein A recruitment to laser irradiation-induced DNA damage sites, resulting in homologous recombination repair defects. Our findings define a role for DDX5 in facilitating the clearance of RNA transcripts overlapping DSBs to ensure proper DNA repair.
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Affiliation(s)
- Zhenbao Yu
- Segal Cancer Center, Lady Davis Institute for Medical Research and Gerald Bronfman Department of Oncology and Departments of Biochemistry, Human Genetics and Medicine, McGill University, Montréal, Québec H3T 1E2, Canada
| | - Sofiane Y Mersaoui
- Segal Cancer Center, Lady Davis Institute for Medical Research and Gerald Bronfman Department of Oncology and Departments of Biochemistry, Human Genetics and Medicine, McGill University, Montréal, Québec H3T 1E2, Canada
| | - Laure Guitton-Sert
- Genome Stability Laboratory, CHU de Québec Research Center, Oncology Axis, Department of Molecular Biology, Medical Biochemistry and Pathology, Laval University Cancer Research Center, 9 McMahon, Québec City, Québec G1R 3S3, Canada
| | - Yan Coulombe
- Genome Stability Laboratory, CHU de Québec Research Center, Oncology Axis, Department of Molecular Biology, Medical Biochemistry and Pathology, Laval University Cancer Research Center, 9 McMahon, Québec City, Québec G1R 3S3, Canada
| | - Jingwen Song
- Segal Cancer Center, Lady Davis Institute for Medical Research and Gerald Bronfman Department of Oncology and Departments of Biochemistry, Human Genetics and Medicine, McGill University, Montréal, Québec H3T 1E2, Canada
| | - Jean-Yves Masson
- Genome Stability Laboratory, CHU de Québec Research Center, Oncology Axis, Department of Molecular Biology, Medical Biochemistry and Pathology, Laval University Cancer Research Center, 9 McMahon, Québec City, Québec G1R 3S3, Canada
| | - Stéphane Richard
- Segal Cancer Center, Lady Davis Institute for Medical Research and Gerald Bronfman Department of Oncology and Departments of Biochemistry, Human Genetics and Medicine, McGill University, Montréal, Québec H3T 1E2, Canada
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Cristini A, Ricci G, Britton S, Salimbeni S, Huang SYN, Marinello J, Calsou P, Pommier Y, Favre G, Capranico G, Gromak N, Sordet O. Dual Processing of R-Loops and Topoisomerase I Induces Transcription-Dependent DNA Double-Strand Breaks. Cell Rep 2020; 28:3167-3181.e6. [PMID: 31533039 DOI: 10.1016/j.celrep.2019.08.041] [Citation(s) in RCA: 95] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 07/08/2019] [Accepted: 08/12/2019] [Indexed: 12/25/2022] Open
Abstract
Although accumulation of DNA damage and genomic instability in resting cells can cause neurodegenerative disorders, our understanding of how transcription produces DNA double-strand breaks (DSBs) is limited. Transcription-blocking topoisomerase I cleavage complexes (TOP1ccs) are frequent events that prime DSB production in non-replicating cells. Here, we report a mechanism of their formation by showing that they arise from two nearby single-strand breaks (SSBs) on opposing DNA strands: one SSB from the removal of transcription-blocking TOP1ccs by the TDP1 pathway and the other from the cleavage of R-loops by endonucleases, including XPF, XPG, and FEN1. Genetic defects in TOP1cc removal (TDP1, PNKP, and XRCC1) or in the resolution of R-loops (SETX) enhance DSB formation and prevent their repair. Such deficiencies cause neurological disorders. Owing to the high frequency of TOP1cc trapping and the widespread distribution of R-loops, these persistent transcriptional DSBs could accumulate over time in neuronal cells, contributing to the neurodegenerative diseases.
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Affiliation(s)
- Agnese Cristini
- Cancer Research Center of Toulouse, INSERM, Université de Toulouse, Université Toulouse III Paul Sabatier, CNRS, 31037 Toulouse, France; Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Giulia Ricci
- Cancer Research Center of Toulouse, INSERM, Université de Toulouse, Université Toulouse III Paul Sabatier, CNRS, 31037 Toulouse, France; Department of Pharmacy and Biotechnology, University of Bologna, 40126 Bologna, Italy
| | - Sébastien Britton
- Institut de Pharmacologie et Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Equipe Labellisée Ligue contre le Cancer 2018, 31077 Toulouse, France
| | - Simona Salimbeni
- Cancer Research Center of Toulouse, INSERM, Université de Toulouse, Université Toulouse III Paul Sabatier, CNRS, 31037 Toulouse, France; Department of Pharmacy and Biotechnology, University of Bologna, 40126 Bologna, Italy
| | - Shar-Yin Naomi Huang
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD, USA
| | - Jessica Marinello
- Department of Pharmacy and Biotechnology, University of Bologna, 40126 Bologna, Italy
| | - Patrick Calsou
- Institut de Pharmacologie et Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Equipe Labellisée Ligue contre le Cancer 2018, 31077 Toulouse, France
| | - Yves Pommier
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD, USA
| | - Gilles Favre
- Cancer Research Center of Toulouse, INSERM, Université de Toulouse, Université Toulouse III Paul Sabatier, CNRS, 31037 Toulouse, France
| | - Giovanni Capranico
- Department of Pharmacy and Biotechnology, University of Bologna, 40126 Bologna, Italy
| | - Natalia Gromak
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK.
| | - Olivier Sordet
- Cancer Research Center of Toulouse, INSERM, Université de Toulouse, Université Toulouse III Paul Sabatier, CNRS, 31037 Toulouse, France.
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207
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Meers C, Keskin H, Banyai G, Mazina O, Yang T, Gombolay AL, Mukherjee K, Kaparos EI, Newnam G, Mazin A, Storici F. Genetic Characterization of Three Distinct Mechanisms Supporting RNA-Driven DNA Repair and Modification Reveals Major Role of DNA Polymerase ζ. Mol Cell 2020; 79:1037-1050.e5. [PMID: 32882183 DOI: 10.1016/j.molcel.2020.08.011] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 06/30/2020] [Accepted: 08/12/2020] [Indexed: 01/08/2023]
Abstract
DNA double-stranded breaks (DSBs) are dangerous lesions threatening genomic stability. Fidelity of DSB repair is best achieved by recombination with a homologous template sequence. In yeast, transcript RNA was shown to template DSB repair of DNA. However, molecular pathways of RNA-driven repair processes remain obscure. Utilizing assays of RNA-DNA recombination with and without an induced DSB in yeast DNA, we characterize three forms of RNA-mediated genomic modifications: RNA- and cDNA-templated DSB repair (R-TDR and c-TDR) using an RNA transcript or a DNA copy of the RNA transcript for DSB repair, respectively, and a new mechanism of RNA-templated DNA modification (R-TDM) induced by spontaneous or mutagen-induced breaks. While c-TDR requires reverse transcriptase, translesion DNA polymerase ζ (Pol ζ) plays a major role in R-TDR, and it is essential for R-TDM. This study characterizes mechanisms of RNA-DNA recombination, uncovering a role of Pol ζ in transferring genetic information from transcript RNA to DNA.
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Affiliation(s)
- Chance Meers
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Havva Keskin
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Gabor Banyai
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Olga Mazina
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102, USA
| | - Taehwan Yang
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Alli L Gombolay
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Kuntal Mukherjee
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Efiyenia I Kaparos
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Gary Newnam
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Alexander Mazin
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102, USA
| | - Francesca Storici
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA.
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208
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Lam FC, Kong YW, Huang Q, Vu Han TL, Maffa AD, Kasper EM, Yaffe MB. BRD4 prevents the accumulation of R-loops and protects against transcription-replication collision events and DNA damage. Nat Commun 2020; 11:4083. [PMID: 32796829 PMCID: PMC7428008 DOI: 10.1038/s41467-020-17503-y] [Citation(s) in RCA: 78] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 06/17/2020] [Indexed: 12/20/2022] Open
Abstract
Proper chromatin function and maintenance of genomic stability depends on spatiotemporal coordination between the transcription and replication machinery. Loss of this coordination can lead to DNA damage from increased transcription-replication collision events. We report that deregulated transcription following BRD4 loss in cancer cells leads to the accumulation of RNA:DNA hybrids (R-loops) and collisions with the replication machinery causing replication stress and DNA damage. Whole genome BRD4 and γH2AX ChIP-Seq with R-loop IP qPCR reveals that BRD4 inhibition leads to accumulation of R-loops and DNA damage at a subset of known BDR4, JMJD6, and CHD4 co-regulated genes. Interference with BRD4 function causes transcriptional downregulation of the DNA damage response protein TopBP1, resulting in failure to activate the ATR-Chk1 pathway despite increased replication stress, leading to apoptotic cell death in S-phase and mitotic catastrophe. These findings demonstrate that inhibition of BRD4 induces transcription-replication conflicts, DNA damage, and cell death in oncogenic cells.
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Affiliation(s)
- Fred C Lam
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 500 Main Street, Cambridge, MA, 02139, USA.
- Center for Precision Cancer Medicine, Massachusetts Institute of Technology, 500 Main Street, Cambridge, MA, 02139, USA.
- Faculty of Health Sciences, Division of Neurosurgery, Hamilton General Hospital, McMaster University, 237 Barton St E, Hamilton, ON, L8L 2X2, Canada.
| | - Yi Wen Kong
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 500 Main Street, Cambridge, MA, 02139, USA
- Center for Precision Cancer Medicine, Massachusetts Institute of Technology, 500 Main Street, Cambridge, MA, 02139, USA
| | - Qiuying Huang
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 500 Main Street, Cambridge, MA, 02139, USA
| | - Tu-Lan Vu Han
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 500 Main Street, Cambridge, MA, 02139, USA
| | - Amanda D Maffa
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 500 Main Street, Cambridge, MA, 02139, USA
| | - Ekkehard M Kasper
- Faculty of Health Sciences, Division of Neurosurgery, Hamilton General Hospital, McMaster University, 237 Barton St E, Hamilton, ON, L8L 2X2, Canada
| | - Michael B Yaffe
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 500 Main Street, Cambridge, MA, 02139, USA.
- Center for Precision Cancer Medicine, Massachusetts Institute of Technology, 500 Main Street, Cambridge, MA, 02139, USA.
- Departments of Biology and Bioengineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
- Beth Israel Deaconess Medical Center, Department of Surgery, Harvard Medical School, Boston, MA, 02215, USA.
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209
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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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210
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211
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Villarreal OD, Mersaoui SY, Yu Z, Masson JY, Richard S. Genome-wide R-loop analysis defines unique roles for DDX5, XRN2, and PRMT5 in DNA/RNA hybrid resolution. Life Sci Alliance 2020; 3:3/10/e202000762. [PMID: 32747416 PMCID: PMC7409538 DOI: 10.26508/lsa.202000762] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 07/23/2020] [Accepted: 07/24/2020] [Indexed: 01/22/2023] Open
Abstract
Genome-wide analysis of R-loop alterations in U2OS cells deficient of DDX5, XRN2, and PRMT5 identify >50,650 DRIP-seq peaks spanning ∼4.5% of the genomic sequence. R-loops near TSS generated intergenic antisense transcription. DDX5, XRN2, and PRMT5 have been shown to resolve DNA/RNA hybrids (R-loops) at RNA polymerase II transcription termination sites at few genomic loci. Herein, we perform genome-wide R-loop mapping using classical DNA/RNA immunoprecipitation and high-throughput sequencing (DRIP-seq) of loci regulated by DDX5, XRN2, and PRMT5. We observed hundreds to thousands of R-loop gains and losses at transcribed loci in DDX5-, XRN2-, and PRMT5-deficient U2OS cells. R-loop gains were characteristic of highly transcribed genes located at gene-rich regions, whereas R-loop losses were observed in low-density gene areas. DDX5, XRN2, and PRMT5 shared many R-loop gain loci at transcription termination sites, consistent with their coordinated role in RNA polymerase II transcription termination. DDX5-depleted cells had unique R-loop gain peaks near the transcription start site that did not overlap with those of siXRN2 and siPRMT5 cells, suggesting a role for DDX5 in transcription initiation independent of XRN2 and PRMT5. Moreover, we observed that the accumulated R-loops at certain loci in siDDX5, siXRN2, and siPRMT5 cells near the transcription start site of genes led to antisense intergenic transcription. Our findings define unique and shared roles of DDX5, XRN2, and PRMT5 in DNA/RNA hybrid regulation.
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Affiliation(s)
- Oscar D Villarreal
- Segal Cancer Center, Lady Davis Institute for Medical Research and Gerald Bronfman Department of Oncology and Departments of Biochemistry, Human Genetics and Medicine, McGill University, Montréal, Canada
| | - Sofiane Y Mersaoui
- Segal Cancer Center, Lady Davis Institute for Medical Research and Gerald Bronfman Department of Oncology and Departments of Biochemistry, Human Genetics and Medicine, McGill University, Montréal, Canada.,Genome Stability Laboratory, Centre Hospitalier Universitaire de Québec Research Center, Oncology Axis; Department of Molecular Biology, Medical Biochemistry and Pathology; Laval University Cancer Research Center, Québec City, Canada
| | - Zhenbao Yu
- Segal Cancer Center, Lady Davis Institute for Medical Research and Gerald Bronfman Department of Oncology and Departments of Biochemistry, Human Genetics and Medicine, McGill University, Montréal, Canada
| | - Jean-Yves Masson
- Genome Stability Laboratory, Centre Hospitalier Universitaire de Québec Research Center, Oncology Axis; Department of Molecular Biology, Medical Biochemistry and Pathology; Laval University Cancer Research Center, Québec City, Canada
| | - Stéphane Richard
- Segal Cancer Center, Lady Davis Institute for Medical Research and Gerald Bronfman Department of Oncology and Departments of Biochemistry, Human Genetics and Medicine, McGill University, Montréal, Canada
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212
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Mystery of Expansion: DNA Metabolism and Unstable Repeats. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1241:101-124. [PMID: 32383118 DOI: 10.1007/978-3-030-41283-8_7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
The mammalian genome mostly contains repeated sequences. Some of these repeats are in the regulatory elements of genes, and their instability, particularly the propensity to change the repeat unit number, is responsible for 36 well-known neurodegenerative human disorders. The mechanism of repeat expansion has been an unsolved question for more than 20 years. There are a few hypotheses describing models of mutation development. Every hypothesis is based on assumptions about unusual secondary structures that violate DNA metabolism processes in the cell. Some models are based on replication errors, and other models are based on mismatch repair or base excision repair errors. Additionally, it has been shown that epigenetic regulation of gene expression can influence the probability and frequency of expansion. In this review, we consider the molecular bases of repeat expansion disorders and discuss possible mechanisms of repeat expansion during cell metabolism.
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213
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Blokhina YP, Buchwalter A. Moving fast and breaking things: Incidence and repair of DNA damage within ribosomal DNA repeats. Mutat Res 2020; 821:111715. [PMID: 32717383 DOI: 10.1016/j.mrfmmm.2020.111715] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 06/25/2020] [Accepted: 07/13/2020] [Indexed: 12/31/2022]
Abstract
The genes that code for ribosomal RNA are present in hundreds of tandemly arrayed copies in the human genome. Ribosomal DNA repeats transcribe vast amounts of ribosomal RNA in order to meet the cell's relentless demand for ribosome production. Intrinsic features of ribosomal DNA repeats render them uniquely vulnerable to DNA damage. Sensing and repairing damage to ribosomal DNA involves dramatic spatial reorganization of the nucleolus, the phase-separated nuclear subdomain where ribosomes are made. We highlight recent advances in detecting the incidence of DNA damage and defining the mechanisms of DNA repair on these essential genes.
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Affiliation(s)
- Yana P Blokhina
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, United States
| | - Abigail Buchwalter
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, United States; Department of Physiology, University of California, San Francisco, San Francisco, CA, United States; Chan Zuckerberg Biohub, San Francisco, CA, United States.
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214
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Zhang C, Chen L, Peng D, Jiang A, He Y, Zeng Y, Xie C, Zhou H, Luo X, Liu H, Chen L, Ren J, Wang W, Zhao Y. METTL3 and N6-Methyladenosine Promote Homologous Recombination-Mediated Repair of DSBs by Modulating DNA-RNA Hybrid Accumulation. Mol Cell 2020; 79:425-442.e7. [PMID: 32615088 DOI: 10.1016/j.molcel.2020.06.017] [Citation(s) in RCA: 167] [Impact Index Per Article: 41.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 04/15/2020] [Accepted: 06/09/2020] [Indexed: 12/20/2022]
Abstract
Double-strand breaks (DSBs) are the most deleterious DNA lesions, which, if left unrepaired, may lead to genome instability or cell death. Here, we report that, in response to DSBs, the RNA methyltransferase METTL3 is activated by ATM-mediated phosphorylation at S43. Phosphorylated METTL3 is then localized to DNA damage sites, where it methylates the N6 position of adenosine (m6A) in DNA damage-associated RNAs, which recruits the m6A reader protein YTHDC1 for protection. In this way, the METTL3-m6A-YTHDC1 axis modulates accumulation of DNA-RNA hybrids at DSBs sites, which then recruit RAD51 and BRCA1 for homologous recombination (HR)-mediated repair. METTL3-deficient cells display defective HR, accumulation of unrepaired DSBs, and genome instability. Accordingly, depletion of METTL3 significantly enhances the sensitivity of cancer cells and murine xenografts to DNA damage-based therapy. These findings uncover the function of METTL3 and YTHDC1 in HR-mediated DSB repair, which may have implications for cancer therapy.
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Affiliation(s)
- Canfeng Zhang
- MOE Key Laboratory of Gene Function and Regulation, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Liping Chen
- MOE Key Laboratory of Gene Function and Regulation, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Di Peng
- MOE Key Laboratory of Gene Function and Regulation, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China; State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou 510006, China
| | - Ao Jiang
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Yunru He
- MOE Key Laboratory of Gene Function and Regulation, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Yanru Zeng
- MOE Key Laboratory of Gene Function and Regulation, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China; State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou 510006, China
| | - Chen Xie
- MOE Key Laboratory of Gene Function and Regulation, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Haoxian Zhou
- MOE Key Laboratory of Gene Function and Regulation, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Xiaotong Luo
- MOE Key Laboratory of Gene Function and Regulation, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China; State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou 510006, China
| | - Haiying Liu
- MOE Key Laboratory of Gene Function and Regulation, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Liang Chen
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Jian Ren
- MOE Key Laboratory of Gene Function and Regulation, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China; State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou 510006, China
| | - Wengong Wang
- Department of Biochemistry and Molecular Biology, Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, School of Basic Medical Sciences, Peking University Health Science Center, 38 Xueyuan Road, Beijing 100191, China
| | - Yong Zhao
- MOE Key Laboratory of Gene Function and Regulation, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, China; State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou 510006, China.
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215
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Pérez-Calero C, Bayona-Feliu A, Xue X, Barroso SI, Muñoz S, González-Basallote VM, Sung P, Aguilera A. UAP56/DDX39B is a major cotranscriptional RNA-DNA helicase that unwinds harmful R loops genome-wide. Genes Dev 2020; 34:898-912. [PMID: 32439635 PMCID: PMC7328515 DOI: 10.1101/gad.336024.119] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 04/20/2020] [Indexed: 01/10/2023]
Abstract
Nonscheduled R loops represent a major source of DNA damage and replication stress. Cells have different ways to prevent R-loop accumulation. One mechanism relies on the conserved THO complex in association with cotranscriptional RNA processing factors including the RNA-dependent ATPase UAP56/DDX39B and histone modifiers such as the SIN3 deacetylase in humans. We investigated the function of UAP56/DDX39B in R-loop removal. We show that UAP56 depletion causes R-loop accumulation, R-loop-mediated genome instability, and replication fork stalling. We demonstrate an RNA-DNA helicase activity in UAP56 and show that its overexpression suppresses R loops and genome instability induced by depleting five different unrelated factors. UAP56/DDX39B localizes to active chromatin and prevents the accumulation of RNA-DNA hybrids over the entire genome. We propose that, in addition to its RNA processing role, UAP56/DDX39B is a key helicase required to eliminate harmful cotranscriptional RNA structures that otherwise would block transcription and replication.
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Affiliation(s)
- Carmen Pérez-Calero
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER) Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Sevilla 41092, Spain
| | - Aleix Bayona-Feliu
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER) Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Sevilla 41092, Spain
| | - Xiaoyu Xue
- Molecular Biophysics and Biochemistry, School of Medicine, University of Yale, New Haven, Connecticut 06510, USA
- Department of Chemistry and Biochemistry, Texas State University, San Marcos, Texas 78666, USA
| | - Sonia I Barroso
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER) Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Sevilla 41092, Spain
| | - Sergio Muñoz
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER) Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Sevilla 41092, Spain
| | - Víctor M González-Basallote
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER) Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Sevilla 41092, Spain
| | - Patrick Sung
- Molecular Biophysics and Biochemistry, School of Medicine, University of Yale, New Haven, Connecticut 06510, USA
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229, USA
| | - Andrés Aguilera
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER) Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Sevilla 41092, Spain
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216
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Involvement of POLA2 in Double Strand Break Repair and Genotoxic Stress. Int J Mol Sci 2020; 21:ijms21124245. [PMID: 32549188 PMCID: PMC7352189 DOI: 10.3390/ijms21124245] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 06/09/2020] [Accepted: 06/10/2020] [Indexed: 02/04/2023] Open
Abstract
Cellular survival is dependent on the efficient replication and transmission of genomic information. DNA damage can be introduced into the genome by several different methods, one being the act of DNA replication. Replication is a potent source of DNA damage and genomic instability, especially through the formation of DNA double strand breaks (DSBs). DNA polymerase alpha is responsible for replication initiation. One subunit of the DNA polymerase alpha replication machinery is POLA2. Given the connection between replication and genomic instability, we decided to examine the role of POLA2 in DSB repair, as little is known about this topic. We found that loss of POLA2 leads to an increase in spontaneous DSB formation. Loss of POLA2 also slows DSB repair kinetics after treatment with etoposide and inhibits both of the major double strand break repair pathways: non-homologous end-joining and homologous recombination. In addition, loss of POLA2 leads to increased sensitivity to ionizing radiation and PARP1 inhibition. Lastly, POLA2 expression is elevated in glioblastoma multiforme tumors and correlates with poor overall patient survival. These data demonstrate a role for POLA2 in DSB repair and resistance to genotoxic stress.
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217
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Cofsky JC, Karandur D, Huang CJ, Witte IP, Kuriyan J, Doudna JA. CRISPR-Cas12a exploits R-loop asymmetry to form double-strand breaks. eLife 2020; 9:e55143. [PMID: 32519675 PMCID: PMC7286691 DOI: 10.7554/elife.55143] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 04/08/2020] [Indexed: 12/17/2022] Open
Abstract
Type V CRISPR-Cas interference proteins use a single RuvC active site to make RNA-guided breaks in double-stranded DNA substrates, an activity essential for both bacterial immunity and genome editing. The best-studied of these enzymes, Cas12a, initiates DNA cutting by forming a 20-nucleotide R-loop in which the guide RNA displaces one strand of a double-helical DNA substrate, positioning the DNase active site for first-strand cleavage. However, crystal structures and biochemical data have not explained how the second strand is cut to complete the double-strand break. Here, we detect intrinsic instability in DNA flanking the RNA-3' side of R-loops, which Cas12a can exploit to expose second-strand DNA for cutting. Interestingly, DNA flanking the RNA-5' side of R-loops is not intrinsically unstable. This asymmetry in R-loop structure may explain the uniformity of guide RNA architecture and the single-active-site cleavage mechanism that are fundamental features of all type V CRISPR-Cas systems.
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Affiliation(s)
- Joshua C Cofsky
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Deepti Karandur
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
- California Institute for Quantitative Biosciences (QB3), University of California, BerkeleyBerkeleyUnited States
- Howard Hughes Medical Institute, University of California, BerkeleyBerkeleyUnited States
| | - Carolyn J Huang
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Isaac P Witte
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - John Kuriyan
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
- California Institute for Quantitative Biosciences (QB3), University of California, BerkeleyBerkeleyUnited States
- Howard Hughes Medical Institute, University of California, BerkeleyBerkeleyUnited States
- Department of Chemistry, University of California, BerkeleyBerkeleyUnited States
- MBIB Division, Lawrence Berkeley National LaboratoryBerkeleyUnited States
| | - Jennifer A Doudna
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
- California Institute for Quantitative Biosciences (QB3), University of California, BerkeleyBerkeleyUnited States
- Howard Hughes Medical Institute, University of California, BerkeleyBerkeleyUnited States
- Department of Chemistry, University of California, BerkeleyBerkeleyUnited States
- MBIB Division, Lawrence Berkeley National LaboratoryBerkeleyUnited States
- Innovative Genomics Institute, University of California, BerkeleyBerkeleyUnited States
- Gladstone Institutes, University of California, San FranciscoSan FranciscoUnited States
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218
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Human XPG nuclease structure, assembly, and activities with insights for neurodegeneration and cancer from pathogenic mutations. Proc Natl Acad Sci U S A 2020; 117:14127-14138. [PMID: 32522879 PMCID: PMC7321962 DOI: 10.1073/pnas.1921311117] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
DNA repair is essential to life and to avoidance of genome instability and cancer. Xeroderma pigmentosum group G (XPG) protein acts in multiple DNA repair pathways, both as an active enzyme and as a scaffold for coordinating with other repair proteins. We present here the structure of the catalytic domain responsible for its DNA binding and nuclease activity. Our analysis provides structure-based hypotheses for how XPG recognizes its bubble DNA substrate and predictions of the structural impacts of XPG disease mutations associated with two phenotypically distinct diseases: xeroderma pigmentosum (XP, skin cancer prone) or Cockayne syndrome (XP/CS, severe progressive developmental defects). Xeroderma pigmentosum group G (XPG) protein is both a functional partner in multiple DNA damage responses (DDR) and a pathway coordinator and structure-specific endonuclease in nucleotide excision repair (NER). Different mutations in the XPG gene ERCC5 lead to either of two distinct human diseases: Cancer-prone xeroderma pigmentosum (XP-G) or the fatal neurodevelopmental disorder Cockayne syndrome (XP-G/CS). To address the enigmatic structural mechanism for these differing disease phenotypes and for XPG’s role in multiple DDRs, here we determined the crystal structure of human XPG catalytic domain (XPGcat), revealing XPG-specific features for its activities and regulation. Furthermore, XPG DNA binding elements conserved with FEN1 superfamily members enable insights on DNA interactions. Notably, all but one of the known pathogenic point mutations map to XPGcat, and both XP-G and XP-G/CS mutations destabilize XPG and reduce its cellular protein levels. Mapping the distinct mutation classes provides structure-based predictions for disease phenotypes: Residues mutated in XP-G are positioned to reduce local stability and NER activity, whereas residues mutated in XP-G/CS have implied long-range structural defects that would likely disrupt stability of the whole protein, and thus interfere with its functional interactions. Combined data from crystallography, biochemistry, small angle X-ray scattering, and electron microscopy unveil an XPG homodimer that binds, unstacks, and sculpts duplex DNA at internal unpaired regions (bubbles) into strongly bent structures, and suggest how XPG complexes may bind both NER bubble junctions and replication forks. Collective results support XPG scaffolding and DNA sculpting functions in multiple DDR processes to maintain genome stability.
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219
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Kuciński J, Chamera S, Kmera A, Rowley MJ, Fujii S, Khurana P, Nowotny M, Wierzbicki AT. Evolutionary History and Activity of RNase H1-Like Proteins in Arabidopsis thaliana. PLANT & CELL PHYSIOLOGY 2020; 61:1107-1119. [PMID: 32191307 PMCID: PMC7295395 DOI: 10.1093/pcp/pcaa040] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 03/14/2020] [Indexed: 06/01/2023]
Abstract
RNase H1 is an endonuclease specific toward the RNA strand of RNA:DNA hybrids. Members of this protein family are present in most living organisms and are essential for removing RNA that base pairs with DNA. It prevents detrimental effects of RNA:DNA hybrids and is involved in several biological processes. Arabidopsis thaliana has been previously shown to contain three genes encoding RNase H1 proteins that localize to three distinct cellular compartments. We show that these genes originate from two gene duplication events. One occurred in the common ancestor of dicots and produced nuclear and organellar RNase H1 paralogs. Second duplication occurred in the common ancestor of Brassicaceae and produced mitochondrial- and plastid-localized proteins. These proteins have the canonical RNase H1 activity, which requires at least four ribonucleotides for endonucleolytic digestion. Analysis of mutants in the RNase H1 genes revealed that the nuclear RNH1A and mitochondrial RNH1B are dispensable for development under normal growth conditions. However, the presence of at least one organellar RNase H1 (RNH1B or RNH1C) is required for embryonic development. The plastid-localized RNH1C affects plastid DNA copy number and sensitivity to replicative stress. Our results present the evolutionary history of RNH1 proteins in A. thaliana, demonstrate their canonical RNase H1 activity and indicate their role in early embryonic development.
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Affiliation(s)
- Jan Kuciński
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Sebastian Chamera
- Laboratory of Protein Structure, International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Aleksandra Kmera
- Laboratory of Protein Structure, International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - M Jordan Rowley
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE, USA
| | - Sho Fujii
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Pragya Khurana
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Marcin Nowotny
- Laboratory of Protein Structure, International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Andrzej T Wierzbicki
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
- Laboratory of Protein Structure, International Institute of Molecular and Cell Biology, Warsaw, Poland
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220
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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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221
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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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222
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Liang F, Miller AS, Tang C, Maranon D, Williamson EA, Hromas R, Wiese C, Zhao W, Sung P, Kupfer GM. The DNA-binding activity of USP1-associated factor 1 is required for efficient RAD51-mediated homologous DNA pairing and homology-directed DNA repair. J Biol Chem 2020; 295:8186-8194. [PMID: 32350107 DOI: 10.1074/jbc.ra120.013714] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 04/27/2020] [Indexed: 11/06/2022] Open
Abstract
USP1-associated factor 1 (UAF1) is an integral component of the RAD51-associated protein 1 (RAD51AP1)-UAF1-ubiquitin-specific peptidase 1 (USP1) trimeric deubiquitinase complex. This complex acts on DNA-bound, monoubiquitinated Fanconi anemia complementation group D2 (FANCD2) protein in the Fanconi anemia pathway of the DNA damage response. Moreover, RAD51AP1 and UAF1 cooperate to enhance homologous DNA pairing mediated by the recombinase RAD51 in DNA repair via the homologous recombination (HR) pathway. However, whereas the DNA-binding activity of RAD51AP1 has been shown to be important for RAD51-mediated homologous DNA pairing and HR-mediated DNA repair, the role of DNA binding by UAF1 in these processes is unclear. We have isolated mutant UAF1 variants that are impaired in DNA binding and tested them together with RAD51AP1 in RAD51-mediated HR. This biochemical analysis revealed that the DNA-binding activity of UAF1 is indispensable for enhanced RAD51 recombinase activity within the context of the UAF1-RAD51AP1 complex. In cells, DNA-binding deficiency of UAF1 increased DNA damage sensitivity and impaired HR efficiency, suggesting that UAF1 and RAD51AP1 have coordinated roles in DNA binding during HR and DNA damage repair. Our findings show that even though UAF1's DNA-binding activity is redundant with that of RAD51AP1 in FANCD2 deubiquitination, it is required for efficient HR-mediated chromosome damage repair.
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Affiliation(s)
- Fengshan Liang
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, Connecticut, USA.,Department of Pediatrics, Section of Hematology-Oncology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Adam S Miller
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Caroline Tang
- Department of Pediatrics, Section of Hematology-Oncology, Yale University School of Medicine, New Haven, Connecticut, USA.,Department of Pathology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - David Maranon
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, Colorado, USA
| | - Elizabeth A Williamson
- Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Robert Hromas
- Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Claudia Wiese
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, Colorado, USA
| | - Weixing Zhao
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Patrick Sung
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Gary M Kupfer
- Department of Pediatrics, Section of Hematology-Oncology, Yale University School of Medicine, New Haven, Connecticut, USA .,Department of Pathology, Yale University School of Medicine, New Haven, Connecticut, USA
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223
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Ragu S, Matos-Rodrigues G, Lopez BS. Replication Stress, DNA Damage, Inflammatory Cytokines and Innate Immune Response. Genes (Basel) 2020; 11:E409. [PMID: 32283785 PMCID: PMC7230342 DOI: 10.3390/genes11040409] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 04/03/2020] [Accepted: 04/06/2020] [Indexed: 12/21/2022] Open
Abstract
Complete and accurate DNA replication is essential to genome stability maintenance during cellular division. However, cells are routinely challenged by endogenous as well as exogenous agents that threaten DNA stability. DNA breaks and the activation of the DNA damage response (DDR) arising from endogenous replication stress have been observed at pre- or early stages of oncogenesis and senescence. Proper detection and signalling of DNA damage are essential for the autonomous cellular response in which the DDR regulates cell cycle progression and controls the repair machinery. In addition to this autonomous cellular response, replicative stress changes the cellular microenvironment, activating the innate immune response that enables the organism to protect itself against the proliferation of damaged cells. Thereby, the recent descriptions of the mechanisms of the pro-inflammatory response activation after replication stress, DNA damage and DDR defects constitute important conceptual novelties. Here, we review the links of replication, DNA damage and DDR defects to innate immunity activation by pro-inflammatory paracrine effects, highlighting the implications for human syndromes and immunotherapies.
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Affiliation(s)
| | | | - Bernard S. Lopez
- Institut Cochin, INSERM U1016, UMR 8104 CNRS, Université de Paris, Equipe Labellisée Ligue Contre le Cancer, 24 rue du Faubourg St Jacques, 75014 Paris, France; (S.R.); (G.M.-R.)
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224
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Liang Z, Liang F, Teng Y, Chen X, Liu J, Longerich S, Rao T, Green AM, Collins NB, Xiong Y, Lan L, Sung P, Kupfer GM. Binding of FANCI-FANCD2 Complex to RNA and R-Loops Stimulates Robust FANCD2 Monoubiquitination. Cell Rep 2020; 26:564-572.e5. [PMID: 30650351 PMCID: PMC6350941 DOI: 10.1016/j.celrep.2018.12.084] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 11/15/2018] [Accepted: 12/18/2018] [Indexed: 11/04/2022] Open
Abstract
Fanconi anemia (FA) is characterized by developmental abnormalities, bone marrow failure, and cancer predisposition. FA cells are hypersensitive to DNA replicative stress and accumulate co-transcriptional R-loops. Here, we use the Damage At RNA Transcription assay to reveal colocalization of FANCD2 with R-loops in a highly transcribed genomic locus upon DNA damage. We further demonstrate that highly purified human FANCI-FANCD2 (ID2) complex binds synthetic single-stranded RNA (ssRNA) and R-loop substrates with high affinity, preferring guanine-rich sequences. Importantly, we elucidate that human ID2 binds an R-loop structure via recognition of the displaced ssDNA and ssRNA but not the RNA:DNA hybrids. Finally, a series of RNA and R-loop substrates are found to strongly stimulate ID2 monoubiquitination, with activity corresponding to their binding affinity. In summary, our results support a mechanism whereby the ID2 complex suppresses the formation of pathogenic R-loops by binding ssRNA and ssDNA species, thereby activating the FA pathway. Fanconi anemia pathway has a well-known role in the repair of DNA crosslinks, but its recently identified role in suppression of co-transcriptional R-loops remains elusive. Here, Liang et al. show that FANCI-FANCD2 has intrinsic RNA and R-loop binding activity and provide mechanistic insights into FA pathway activation upon transcription stress.
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Affiliation(s)
- Zhuobin Liang
- Department of Pediatrics, Yale Medical School, New Haven, CT 06520, USA; Department of Molecular Biology and Biophysics, Yale Medical School, New Haven, CT 06520, USA
| | - Fengshan Liang
- Department of Pediatrics, Yale Medical School, New Haven, CT 06520, USA; Department of Molecular Biology and Biophysics, Yale Medical School, New Haven, CT 06520, USA
| | - Yaqun Teng
- School of Medicine, Tsinghua University, No.1 Tsinghua Yuan, Haidian District, Beijing 100084, China; Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Xiaoyong Chen
- Department of Pediatrics, Yale Medical School, New Haven, CT 06520, USA
| | - Jingchun Liu
- Department of Pediatrics, Yale Medical School, New Haven, CT 06520, USA
| | - Simonne Longerich
- Department of Molecular Biology and Biophysics, Yale Medical School, New Haven, CT 06520, USA
| | - Timsi Rao
- Department of Molecular Biology and Biophysics, Yale Medical School, New Haven, CT 06520, USA
| | - Allison M Green
- Department of Pediatrics, Yale Medical School, New Haven, CT 06520, USA; Department of Pathology, Yale Medical School, New Haven, CT 06520, USA
| | - Natalie B Collins
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Yong Xiong
- Department of Molecular Biology and Biophysics, Yale Medical School, New Haven, CT 06520, USA
| | - Li Lan
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA; Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, MA 02129, USA; Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02129, USA
| | - Patrick Sung
- Department of Molecular Biology and Biophysics, Yale Medical School, New Haven, CT 06520, USA; Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA.
| | - Gary M Kupfer
- Department of Pediatrics, Yale Medical School, New Haven, CT 06520, USA; Department of Pathology, Yale Medical School, New Haven, CT 06520, USA.
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225
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Abstract
RNA polymerase II (Pol II) transcribes all protein-coding genes and many noncoding RNAs in eukaryotic genomes. Although Pol II is a complex, 12-subunit enzyme, it lacks the ability to initiate transcription and cannot consistently transcribe through long DNA sequences. To execute these essential functions, an array of proteins and protein complexes interact with Pol II to regulate its activity. In this review, we detail the structure and mechanism of over a dozen factors that govern Pol II initiation (e.g., TFIID, TFIIH, and Mediator), pausing, and elongation (e.g., DSIF, NELF, PAF, and P-TEFb). The structural basis for Pol II transcription regulation has advanced rapidly in the past decade, largely due to technological innovations in cryoelectron microscopy. Here, we summarize a wealth of structural and functional data that have enabled a deeper understanding of Pol II transcription mechanisms; we also highlight mechanistic questions that remain unanswered or controversial.
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Affiliation(s)
- Allison C Schier
- Department of Biochemistry, University of Colorado, Boulder, Colorado 80303, USA
| | - Dylan J Taatjes
- Department of Biochemistry, University of Colorado, Boulder, Colorado 80303, USA
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226
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Kazadi D, Lim J, Rothschild G, Grinstein V, Laffleur B, Becherel O, Lavin MJ, Basu U. Effects of senataxin and RNA exosome on B-cell chromosomal integrity. Heliyon 2020; 6:e03442. [PMID: 32195383 PMCID: PMC7075999 DOI: 10.1016/j.heliyon.2020.e03442] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 01/07/2020] [Accepted: 02/13/2020] [Indexed: 11/10/2022] Open
Abstract
Loss of function of senataxin (SETX), a bona-fide RNA/DNA helicase, is associated with neuronal degeneration leading to Ataxia and Ocular Apraxia (AOA) in human patients. SETX is proposed to promote transcription termination, DNA replication, DNA repair, and to unwind deleterious RNA:DNA hybrids in the genome. In all the above-mentioned mechanisms, SETX unwinds transcription complex-associated nascent RNA which is then degraded by the RNA exosome complex. Here we have used B cells isolated from a SETX mutant mouse model and compared genomic instability and immunoglobulin heavy chain locus (IgH) class switch recombination (CSR) to evaluate aberrant and programmed genomic rearrangements, respectively. Similar to RNA exosome mutant primary B cells, SETX mutant primary B cells display genomic instability but a modest decrease in efficiency of CSR. Furthermore, knockdown of Setx mRNAs from CH12–F3 B-cell lines leads to a defect in IgA CSR and accumulation of aberrant patterns of mutations in IgH switch sequences. Given that SETX mutant mice do not recapitulate the AOA neurodegenerative phenotype, it is possible that some aspects of SETX biology are rescued by redundant helicases in mice. Overall, our study provides new insights into the role of the SETX/RNA exosome axis in suppressing genomic instability so that programmed DNA breaks are properly orchestrated.
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Affiliation(s)
- David Kazadi
- Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Junghyun Lim
- Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Gerson Rothschild
- Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Veronika Grinstein
- Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Brice Laffleur
- Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Olivier Becherel
- Centre for Clinical Research, University of Queensland, Brisbane, Qld, Australia
| | - Martin J Lavin
- Centre for Clinical Research, University of Queensland, Brisbane, Qld, Australia
| | - Uttiya Basu
- Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
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227
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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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228
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Amparo C, Clark J, Bedell V, Murata-Collins JL, Martella M, Pichiorri F, Warner EF, Abdelhamid MAS, Waller ZAE, Smith SS. Duplex DNA from Sites of Helicase-Polymerase Uncoupling Links Non-B DNA Structure Formation to Replicative Stress. Cancer Genomics Proteomics 2020; 17:101-115. [PMID: 32108033 DOI: 10.21873/cgp.20171] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 01/25/2020] [Accepted: 01/27/2020] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Replication impediments can produce helicase-polymerase uncoupling allowing lagging strand synthesis to continue for as much as 6 kb from the site of the impediment. MATERIALS AND METHODS We developed a cloning procedure designed to recover fragments from lagging strand near the helicase halt site. RESULTS A total of 62% of clones from a p53-deficient tumor cell line (PC3) and 33% of the clones from a primary cell line (HPS-19I) were within 5 kb of a G-quadruplex forming sequence. Analyses of a RACK7 gene sequence, that was cloned multiple times from the PC3 line, revealed multiple deletions in region about 1 kb from the cloned region that was present in a non-B conformation. Sequences from the region formed G-quadruplex and i-motif structures under physiological conditions. CONCLUSION Defects in components of non-B structure suppression systems (e.g. p53 helicase targeting) promote replication-linked damage selectively targeted to sequences prone to G-quadruplex and i-motif formation.
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Affiliation(s)
- Camille Amparo
- Division of Urology, City of Hope National Medical Center, Duarte, CA, U.S.A.,Beckman Research Institute, City of Hope, Duarte, CA, U.S.A
| | - Jarrod Clark
- Division of Urology, City of Hope National Medical Center, Duarte, CA, U.S.A.,Beckman Research Institute, City of Hope, Duarte, CA, U.S.A
| | - Victoria Bedell
- Division of Cytogenetics, City of Hope National Medical Center, Duarte, CA, U.S.A
| | | | - Marianna Martella
- Judy and Bernard Briskin Center for Multiple Myeloma Research, City of Hope National Medical Center, Duarte, CA, U.S.A.,Hematological Malignancies and Translational Science, City of Hope National Medical Center, Duarte, CA, U.S.A
| | - Flavia Pichiorri
- Judy and Bernard Briskin Center for Multiple Myeloma Research, City of Hope National Medical Center, Duarte, CA, U.S.A.,Hematological Malignancies and Translational Science, City of Hope National Medical Center, Duarte, CA, U.S.A
| | - Emily F Warner
- School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich, U.K
| | | | - Zoë A E Waller
- School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich, U.K
| | - Steven S Smith
- Beckman Research Institute, City of Hope, Duarte, CA, U.S.A. .,Hematological Malignancies and Translational Science, City of Hope National Medical Center, Duarte, CA, U.S.A
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229
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Andrade NS, Ramic M, Esanov R, Liu W, Rybin MJ, Gaidosh G, Abdallah A, Del’Olio S, Huff TC, Chee NT, Anatha S, Gendron TF, Wahlestedt C, Zhang Y, Benatar M, Mueller C, Zeier Z. Dipeptide repeat proteins inhibit homology-directed DNA double strand break repair in C9ORF72 ALS/FTD. Mol Neurodegener 2020; 15:13. [PMID: 32093728 PMCID: PMC7041170 DOI: 10.1186/s13024-020-00365-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 02/13/2020] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND The C9ORF72 hexanucleotide repeat expansion is the most common known genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), two fatal age-related neurodegenerative diseases. The C9ORF72 expansion encodes five dipeptide repeat proteins (DPRs) that are produced through a non-canonical translation mechanism. Among the DPRs, proline-arginine (PR), glycine-arginine (GR), and glycine-alanine (GA) are the most neurotoxic and increase the frequency of DNA double strand breaks (DSBs). While the accumulation of these genotoxic lesions is increasingly recognized as a feature of disease, the mechanism(s) of DPR-mediated DNA damage are ill-defined and the effect of DPRs on the efficiency of each DNA DSB repair pathways has not been previously evaluated. METHODS AND RESULTS Using DNA DSB repair assays, we evaluated the efficiency of specific repair pathways, and found that PR, GR and GA decrease the efficiency of non-homologous end joining (NHEJ), single strand annealing (SSA), and microhomology-mediated end joining (MMEJ), but not homologous recombination (HR). We found that PR inhibits DNA DSB repair, in part, by binding to the nucleolar protein nucleophosmin (NPM1). Depletion of NPM1 inhibited NHEJ and SSA, suggesting that NPM1 loss-of-function in PR expressing cells leads to impediments of both non-homologous and homology-directed DNA DSB repair pathways. By deleting NPM1 sub-cellular localization signals, we found that PR binds NPM1 regardless of the cellular compartment to which NPM1 was directed. Deletion of the NPM1 acidic loop motif, known to engage other arginine-rich proteins, abrogated PR and NPM1 binding. Using confocal and super-resolution immunofluorescence microscopy, we found that levels of RAD52, a component of the SSA repair machinery, were significantly increased iPSC neurons relative to isogenic controls in which the C9ORF72 expansion had been deleted using CRISPR/Cas9 genome editing. Western analysis of post-mortem brain tissues confirmed that RAD52 immunoreactivity is significantly increased in C9ALS/FTD samples as compared to controls. CONCLUSIONS Collectively, we characterized the inhibitory effects of DPRs on key DNA DSB repair pathways, identified NPM1 as a facilitator of DNA repair that is inhibited by PR, and revealed deficits in homology-directed DNA DSB repair pathways as a novel feature of C9ORF72-related disease.
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Affiliation(s)
- Nadja S. Andrade
- Department of Psychiatry & Behavioral Sciences, Center for Therapeutic Innovation, University of Miami Miller School of Medicine, 1501 NW 10th Ave, Biomedical Research Building Room 413, Florida, Miami 33136 USA
| | - Melina Ramic
- Department of Psychiatry & Behavioral Sciences, Center for Therapeutic Innovation, University of Miami Miller School of Medicine, 1501 NW 10th Ave, Biomedical Research Building Room 413, Florida, Miami 33136 USA
| | - Rustam Esanov
- Department of Psychiatry & Behavioral Sciences, Center for Therapeutic Innovation, University of Miami Miller School of Medicine, 1501 NW 10th Ave, Biomedical Research Building Room 413, Florida, Miami 33136 USA
| | - Wenjun Liu
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, 1600 NW 10th Ave, Miami, FL 33136 USA
| | - Mathew J. Rybin
- Department of Psychiatry & Behavioral Sciences, Center for Therapeutic Innovation, University of Miami Miller School of Medicine, 1501 NW 10th Ave, Biomedical Research Building Room 413, Florida, Miami 33136 USA
| | - Gabriel Gaidosh
- John P Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, 1501 NW 10th Ave, Miami, FL 33136 USA
- Sylvester Comprehensive Cancer Center, Biomedical Research Building, 1501 NW 10th Avenue, Miami, FL 33136 USA
| | - Abbas Abdallah
- Department of Neurology, University of Massachusetts Medical School, Worchester, MA USA
| | - Samuel Del’Olio
- Department of Psychiatry & Behavioral Sciences, Center for Therapeutic Innovation, University of Miami Miller School of Medicine, 1501 NW 10th Ave, Biomedical Research Building Room 413, Florida, Miami 33136 USA
| | - Tyler C. Huff
- John P Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, 1501 NW 10th Ave, Miami, FL 33136 USA
- Dr. John T Macdonald Foundation Department of Human Genetics, University of Miami Miller School of Medicine, 1601 NW 12th Ave, Miami, FL. 33136 USA
| | - Nancy T. Chee
- Department of Psychiatry & Behavioral Sciences, Center for Therapeutic Innovation, University of Miami Miller School of Medicine, 1501 NW 10th Ave, Biomedical Research Building Room 413, Florida, Miami 33136 USA
| | - Sadhana Anatha
- Department of Psychiatry & Behavioral Sciences, Center for Therapeutic Innovation, University of Miami Miller School of Medicine, 1501 NW 10th Ave, Biomedical Research Building Room 413, Florida, Miami 33136 USA
| | - Tania F. Gendron
- Department of Neuroscience, Mayo Clinic, 4500 San Pablo Rd, Jacksonville, FL 32224 USA
| | - Claes Wahlestedt
- Department of Psychiatry & Behavioral Sciences, Center for Therapeutic Innovation, University of Miami Miller School of Medicine, 1501 NW 10th Ave, Biomedical Research Building Room 413, Florida, Miami 33136 USA
| | - Yanbin Zhang
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, 1600 NW 10th Ave, Miami, FL 33136 USA
| | - Michael Benatar
- Department of Neurology, University of Miami Miller School of Medicine, 115 NW 14th St.,, Miami, FL 33136 USA
| | - Christian Mueller
- Department of Neurology, University of Massachusetts Medical School, Worchester, MA USA
- Department of Pediatrics and Horae Gene Therapy Center, University of Massachusetts Medical School, Worcester, MA USA
| | - Zane Zeier
- Department of Psychiatry & Behavioral Sciences, Center for Therapeutic Innovation, University of Miami Miller School of Medicine, 1501 NW 10th Ave, Biomedical Research Building Room 413, Florida, Miami 33136 USA
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230
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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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231
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Gómez-González B, Barroso S, Herrera-Moyano E, Aguilera A. Spontaneous DNA-RNA hybrids: differential impacts throughout the cell cycle. Cell Cycle 2020; 19:525-531. [PMID: 32065022 DOI: 10.1080/15384101.2020.1728015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
A large body of research supports that transcription plays a major role among the many sources of replicative stress contributing to genome instability. It is therefore not surprising that the DNA damage response has a role in the prevention of transcription-induced threatening events such as the formation of DNA-RNA hybrids, as we have recently found through an siRNA screening. Three major DDR pathways were defined to participate in the protection against DNA-RNA hybrids: ATM/CHK2, ATR/CHK1 and Postreplication Repair (PRR). Based on these observations, we envision different scenarios of DNA-RNA hybridization and their consequent DNA damage.
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Affiliation(s)
- Belén Gómez-González
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Seville, Spain
| | - Sonia Barroso
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Seville, Spain
| | - Emilia Herrera-Moyano
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Seville, Spain
| | - Andrés Aguilera
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Seville, Spain
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232
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Tan J, Wang X, Phoon L, Yang H, Lan L. Resolution of ROS‐induced G‐quadruplexes and R‐loops at transcriptionally active sites is dependent on BLM helicase. FEBS Lett 2020; 594:1359-1367. [DOI: 10.1002/1873-3468.13738] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 12/23/2019] [Accepted: 01/15/2020] [Indexed: 12/21/2022]
Affiliation(s)
- Jun Tan
- Massachusetts General Hospital Cancer Center Harvard Medical School Charlestown MA USA
- Department of Radiation Oncology Harvard Medical School Massachusetts General Hospital Boston MA USA
| | - Xiangyu Wang
- Massachusetts General Hospital Cancer Center Harvard Medical School Charlestown MA USA
- Department of Radiation Oncology Harvard Medical School Massachusetts General Hospital Boston MA USA
| | - Laiyee Phoon
- Massachusetts General Hospital Cancer Center Harvard Medical School Charlestown MA USA
- Department of Radiation Oncology Harvard Medical School Massachusetts General Hospital Boston MA USA
| | - Haibo Yang
- Massachusetts General Hospital Cancer Center Harvard Medical School Charlestown MA USA
- Department of Radiation Oncology Harvard Medical School Massachusetts General Hospital Boston MA USA
| | - Li Lan
- Massachusetts General Hospital Cancer Center Harvard Medical School Charlestown MA USA
- Department of Radiation Oncology Harvard Medical School Massachusetts General Hospital Boston MA USA
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233
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Marabitti V, Lillo G, Malacaria E, Palermo V, Pichierri P, Franchitto A. Checkpoint Defects Elicit a WRNIP1-Mediated Response to Counteract R-Loop-Associated Genomic Instability. Cancers (Basel) 2020; 12:cancers12020389. [PMID: 32046194 PMCID: PMC7072626 DOI: 10.3390/cancers12020389] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 02/03/2020] [Accepted: 02/05/2020] [Indexed: 12/04/2022] Open
Abstract
Conflicts between replication and transcription are a common source of genomic instability, a characteristic of almost all human cancers. Aberrant R-loops can cause a block to replication fork progression. A growing number of factors are involved in the resolution of these harmful structures and many perhaps are still unknown. Here, we reveal that the Werner interacting protein 1 (WRNIP1)-mediated response is implicated in counteracting aberrant R-loop accumulation. Using human cellular models with compromised Ataxia-Telangiectasia and Rad3-Related (ATR)-dependent checkpoint activation, we show that WRNIP1 is stabilized in chromatin and is needed for maintaining genome integrity by mediating the Ataxia Telangiectasia Mutated (ATM)-dependent phosphorylation of Checkpoint kinase 1 (CHK1). Furthermore, we demonstrated that loss of Werner Syndrome protein (WRN) or ATR signaling leads to formation of R-loop-dependent parental ssDNA upon mild replication stress, which is covered by Radiorestistance protein 51 (RAD51). We prove that Werner helicase-interacting protein 1 (WRNIP1) chromatin retention is also required to stabilize the association of RAD51 with ssDNA in proximity of R-loops. Therefore, in these pathological contexts, ATM inhibition or WRNIP1 abrogation is accompanied by increased levels of genomic instability. Overall, our findings suggest a novel function for WRNIP1 in preventing R-loop-driven genome instability, providing new clues to understand the way replication–transcription conflicts are handled.
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234
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Regulation of long non-coding RNAs and genome dynamics by the RNA surveillance machinery. Nat Rev Mol Cell Biol 2020; 21:123-136. [PMID: 32020081 DOI: 10.1038/s41580-019-0209-0] [Citation(s) in RCA: 131] [Impact Index Per Article: 32.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/19/2019] [Indexed: 02/07/2023]
Abstract
Much of the mammalian genome is transcribed, generating long non-coding RNAs (lncRNAs) that can undergo post-transcriptional surveillance whereby only a subset of the non-coding transcripts is allowed to attain sufficient stability to persist in the cellular milieu and control various cellular functions. Paralleling protein turnover by the proteasome complex, lncRNAs are also likely to exist in a dynamic equilibrium that is maintained through constant monitoring by the RNA surveillance machinery. In this Review, we describe the RNA surveillance factors and discuss the vital role of lncRNA surveillance in orchestrating various biological processes, including the protection of genome integrity, maintenance of pluripotency of embryonic stem cells, antibody-gene diversification, coordination of immune cell activation and regulation of heterochromatin formation. We also discuss examples of human diseases and developmental defects associated with the failure of RNA surveillance mechanisms, further highlighting the importance of lncRNA surveillance in maintaining cell and organism functions and health.
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235
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Cristini A, Gromak N, Sordet O. Transcription-dependent DNA double-strand breaks and human disease. Mol Cell Oncol 2020; 7:1691905. [PMID: 32158914 PMCID: PMC7051148 DOI: 10.1080/23723556.2019.1691905] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 11/08/2019] [Accepted: 11/08/2019] [Indexed: 12/13/2022]
Abstract
Accumulation of DNA damage in resting cells is an emerging cause of human disease. We identified a mechanism of DNA double-strand break (DSB) formation in non-replicating cells, which strictly depends on transcription. These transcriptional DSBs arise from the twinned processing of R-loops and topoisomerase I and may underlie neurological disorders and cancers.
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Affiliation(s)
- Agnese Cristini
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Natalia Gromak
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Olivier Sordet
- Cancer Research Center of Toulouse, INSERM, Université de Toulouse, Université Toulouse III Paul Sabatier, CNRS, Toulouse, France
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236
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Carrasco-Salas Y, Malapert A, Sulthana S, Molcrette B, Chazot-Franguiadakis L, Bernard P, Chédin F, Faivre-Moskalenko C, Vanoosthuyse V. The extruded non-template strand determines the architecture of R-loops. Nucleic Acids Res 2020; 47:6783-6795. [PMID: 31066439 PMCID: PMC6648340 DOI: 10.1093/nar/gkz341] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Revised: 04/16/2019] [Accepted: 04/26/2019] [Indexed: 01/05/2023] Open
Abstract
Three-stranded R-loop structures have been associated with genomic instability phenotypes. What underlies their wide-ranging effects on genome stability remains poorly understood. Here we combined biochemical and atomic force microscopy approaches with single molecule R-loop footprinting to demonstrate that R-loops formed at the model Airn locus in vitro adopt a defined set of three-dimensional conformations characterized by distinct shapes and volumes, which we call R-loop objects. Interestingly, we show that these R-loop objects impose specific physical constraints on the DNA, as revealed by the presence of stereotypical angles in the surrounding DNA. Biochemical probing and mutagenesis experiments revealed that the formation of R-loop objects at Airn is dictated by the extruded non-template strand, suggesting that R-loops possess intrinsic sequence-driven properties. Consistent with this, we show that R-loops formed at the fission yeast gene sum3 do not form detectable R-loop objects. Our results reveal that R-loops differ by their architectures and that the organization of the non-template strand is a fundamental characteristic of R-loops, which could explain that only a subset of R-loops is associated with replication-dependent DNA breaks.
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Affiliation(s)
- Yeraldinne Carrasco-Salas
- Université de Lyon, ENSL, UCBL, CNRS, Laboratoire de Physique, 46 Allée d'Italie, 69007 Lyon, France
| | - Amélie Malapert
- Université de Lyon, ENSL, UCBL, CNRS, Laboratory of Biology and Modelling of the Cell (LBMC), 46 Allée d'Italie, 69007 Lyon, France
| | - Shaheen Sulthana
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA
| | - Bastien Molcrette
- Université de Lyon, ENSL, UCBL, CNRS, Laboratoire de Physique, 46 Allée d'Italie, 69007 Lyon, France
| | - Léa Chazot-Franguiadakis
- Université de Lyon, ENSL, UCBL, CNRS, Laboratoire de Physique, 46 Allée d'Italie, 69007 Lyon, France
| | - Pascal Bernard
- Université de Lyon, ENSL, UCBL, CNRS, Laboratory of Biology and Modelling of the Cell (LBMC), 46 Allée d'Italie, 69007 Lyon, France
| | - Frédéric Chédin
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA
| | | | - Vincent Vanoosthuyse
- Université de Lyon, ENSL, UCBL, CNRS, Laboratory of Biology and Modelling of the Cell (LBMC), 46 Allée d'Italie, 69007 Lyon, France
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237
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Kawaguchi T, Rollins MG, Moinpour M, Morera AA, Ebmeier CC, Old WM, Schwartz JC. Changes to the TDP-43 and FUS Interactomes Induced by DNA Damage. J Proteome Res 2020; 19:360-370. [PMID: 31693373 PMCID: PMC6947635 DOI: 10.1021/acs.jproteome.9b00575] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Indexed: 12/13/2022]
Abstract
The RNA-binding proteins TDP-43 and FUS are tied as the third leading known genetic cause for amyotrophic lateral sclerosis (ALS), and TDP-43 proteopathies are found in nearly all ALS patients. Both the natural function and contribution to pathology for TDP-43 remain unclear. The intersection of functions between TDP-43 and FUS can focus attention for those natural functions mostly likely to be relevant to disease. Here, we compare the role played by TDP-43 and FUS, maintaining chromatin stability for dividing HEK293T cells. We also determine and compare the interactomes of TDP-43 and FUS, quantitating changes in those before and after DNA damage. Finally, selected interactions with known importance to DNA damage repair were validated by co-immunoprecipitation assays. This study uncovered TDP-43 and FUS binding to several factors important to DNA repair mechanisms that can be replication-dependent, -independent, or both. These results provide further evidence that TDP-43 has an important role in DNA stability and provide new ways that TDP-43 can bind to the machinery that guards DNA integrity in cells.
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Affiliation(s)
- Tetsuya Kawaguchi
- Department
of Chemistry and Biochemistry and Department of Molecular and Cellular
Biology, University of Arizona, Tucson, Arizona 85721, United States
| | - Matthew G. Rollins
- Department
of Chemistry and Biochemistry and Department of Molecular and Cellular
Biology, University of Arizona, Tucson, Arizona 85721, United States
| | - Mahta Moinpour
- Department
of Chemistry and Biochemistry and Department of Molecular and Cellular
Biology, University of Arizona, Tucson, Arizona 85721, United States
| | - Andres A. Morera
- Department
of Chemistry and Biochemistry and Department of Molecular and Cellular
Biology, University of Arizona, Tucson, Arizona 85721, United States
| | - Christopher C. Ebmeier
- Department
of Molecular and Cellular Biology, University
of Colorado, Boulder, Colorado 80309, United States
| | - William M. Old
- Department
of Molecular and Cellular Biology, University
of Colorado, Boulder, Colorado 80309, United States
| | - Jacob C. Schwartz
- Department
of Chemistry and Biochemistry and Department of Molecular and Cellular
Biology, University of Arizona, Tucson, Arizona 85721, United States
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238
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Majhi PD, Sharma A, Roberts AL, Daniele E, Majewski AR, Chuong LM, Black AL, Vandenberg LN, Schneider SS, Dunphy KA, Jerry DJ. Effects of Benzophenone-3 and Propylparaben on Estrogen Receptor-Dependent R-Loops and DNA Damage in Breast Epithelial Cells and Mice. ENVIRONMENTAL HEALTH PERSPECTIVES 2020; 128:17002. [PMID: 31939680 PMCID: PMC7015622 DOI: 10.1289/ehp5221] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
BACKGROUND Endocrine-disrupting chemicals have been shown to have broad effects on development, but their mutagenic actions that can lead to cancer have been less clearly demonstrated. Physiological levels of estrogen have been shown to stimulate DNA damage in breast epithelial cells through mechanisms mediated by estrogen-receptor alpha (ERα). Benzophenone-3 (BP-3) and propylparaben (PP) are xenoestrogens found in the urine of >96% of U.S. OBJECTIVES We investigated the effect of BP-3 and PP on estrogen receptor-dependent transactivation and DNA damage at concentrations relevant to exposures in humans. METHODS In human breast epithelial cells, DNA damage following treatment with 17β-estradiol (E2), BP-3, and PP was determined by immunostaining with antibodies against γ-H2AX and 53BP1. Estrogenic responses were determined using luciferase reporter assays and gene expression. Formation of R-loops was determined with DNA: RNA hybrid-specific S9.6 antibody. Short-term exposure to the chemicals was also studied in ovariectomized mice. Immunostaining of mouse mammary epithelium was performed to quantify R-loops and DNA damage in vivo. RESULTS Concentrations of 1μM and 5μM BP-3 or PP increased DNA damage similar to that of E2 treatment in a ERα-dependent manner. However, BP-3 and PP had limited transactivation of target genes at 1μM and 5μM concentrations. BP-3 and PP exposure caused R-loop formation in a normal human breast epithelial cell line when ERα was introduced. R-loops and DNA damage were also detected in mammary epithelial cells of mice treated with BP-3 and PP. CONCLUSIONS Acute exposure to xenoestrogens (PP and BP-3) in mice induce DNA damage mediated by formation of ERα-dependent R-loops at concentrations 10-fold lower than those required for transactivation. Exposure to these xenoestrogens may cause deleterious estrogenic responses, such as DNA damage, in susceptible individuals. https://doi.org/10.1289/EHP5221.
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Affiliation(s)
- Prabin Dhangada Majhi
- Department of Veterinary & Animal Sciences, University of Massachusetts, Amherst, Massachusetts, USA
- Department of Botany, Ravenshaw University, Cuttack, Odisha, India
| | - Aman Sharma
- Department of Veterinary & Animal Sciences, University of Massachusetts, Amherst, Massachusetts, USA
| | - Amy L. Roberts
- Department of Veterinary & Animal Sciences, University of Massachusetts, Amherst, Massachusetts, USA
| | - Elizabeth Daniele
- Department of Veterinary & Animal Sciences, University of Massachusetts, Amherst, Massachusetts, USA
| | - Aliza R. Majewski
- Department of Veterinary & Animal Sciences, University of Massachusetts, Amherst, Massachusetts, USA
| | - Lynn M. Chuong
- Department of Veterinary & Animal Sciences, University of Massachusetts, Amherst, Massachusetts, USA
| | - Amye L. Black
- Department of Veterinary & Animal Sciences, University of Massachusetts, Amherst, Massachusetts, USA
| | - Laura N. Vandenberg
- Department of Environmental Health Sciences, University of Massachusetts, Amherst, Massachusetts, USA
| | - Sallie S. Schneider
- University of Massachusetts Medical School, Baystate Campus, Springfield, Massachusetts, USA
- Pioneer Valley Life Sciences Institute, Springfield, Massachusetts, USA
| | - Karen A. Dunphy
- Department of Veterinary & Animal Sciences, University of Massachusetts, Amherst, Massachusetts, USA
| | - D. Joseph Jerry
- Department of Veterinary & Animal Sciences, University of Massachusetts, Amherst, Massachusetts, USA
- Pioneer Valley Life Sciences Institute, Springfield, Massachusetts, USA
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239
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Heft IE, Mostovoy Y, Levy-Sakin M, Ma W, Stevens AJ, Pastor S, McCaffrey J, Boffelli D, Martin DI, Xiao M, Kennedy MA, Kwok PY, Sikela JM. The Driver of Extreme Human-Specific Olduvai Repeat Expansion Remains Highly Active in the Human Genome. Genetics 2020; 214:179-191. [PMID: 31754017 PMCID: PMC6944415 DOI: 10.1534/genetics.119.302782] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 11/05/2019] [Indexed: 11/18/2022] Open
Abstract
Sequences encoding Olduvai protein domains (formerly DUF1220) show the greatest human lineage-specific increase in copy number of any coding region in the genome and have been associated, in a dosage-dependent manner, with brain size, cognitive aptitude, autism, and schizophrenia. Tandem intragenic duplications of a three-domain block, termed the Olduvai triplet, in four NBPF genes in the chromosomal 1q21.1-0.2 region, are primarily responsible for the striking human-specific copy number increase. Interestingly, most of the Olduvai triplets are adjacent to, and transcriptionally coregulated with, three human-specific NOTCH2NL genes that have been shown to promote cortical neurogenesis. Until now, the underlying genomic events that drove the Olduvai hyperamplification in humans have remained unexplained. Here, we show that the presence or absence of an alternative first exon of the Olduvai triplet perfectly discriminates between amplified (58/58) and unamplified (0/12) triplets. We provide sequence and breakpoint analyses that suggest the alternative exon was produced by an nonallelic homologous recombination-based mechanism involving the duplicative transposition of an existing Olduvai exon found in the CON3 domain, which typically occurs at the C-terminal end of NBPF genes. We also provide suggestive in vitro evidence that the alternative exon may promote instability through a putative G-quadraplex (pG4)-based mechanism. Lastly, we use single-molecule optical mapping to characterize the intragenic structural variation observed in NBPF genes in 154 unrelated individuals and 52 related individuals from 16 families and show that the presence of pG4-containing Olduvai triplets is strongly correlated with high levels of Olduvai copy number variation. These results suggest that the same driver of genomic instability that allowed the evolutionarily recent, rapid, and extreme human-specific Olduvai expansion remains highly active in the human genome.
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Affiliation(s)
- Ilea E Heft
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, Colorado 80045
- Human Medical Genetics and Genomics Program, University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Yulia Mostovoy
- Cardiovascular Research Institute, University of California, San Francisco, California
| | - Michal Levy-Sakin
- Cardiovascular Research Institute, University of California, San Francisco, California
| | - Walfred Ma
- Cardiovascular Research Institute, University of California, San Francisco, California
| | - Aaron J Stevens
- Department of Pathology, University of Otago, Christchurch, New Zealand 8140
| | - Steven Pastor
- School of Biomedical Engineering, Drexel University, Philadelphia, Pennsylvania 19104
| | - Jennifer McCaffrey
- School of Biomedical Engineering, Drexel University, Philadelphia, Pennsylvania 19104
| | - Dario Boffelli
- Children's Hospital Oakland Research Institute, Oakland, California 94609
| | - David I Martin
- Children's Hospital Oakland Research Institute, Oakland, California 94609
| | - Ming Xiao
- School of Biomedical Engineering, Drexel University, Philadelphia, Pennsylvania 19104
| | - Martin A Kennedy
- Department of Pathology, University of Otago, Christchurch, New Zealand 8140
| | - Pui-Yan Kwok
- Cardiovascular Research Institute, University of California, San Francisco, California
- Department of Dermatology, University of California, San Francisco, California
- Institute for Human Genetics, University of California, San Francisco, California
| | - James M Sikela
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, Colorado 80045
- Human Medical Genetics and Genomics Program, University of Colorado School of Medicine, Aurora, Colorado 80045
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240
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Georges A, Gopaul D, Denby Wilkes C, Giordanengo Aiach N, Novikova E, Barrault MB, Alibert O, Soutourina J. Functional interplay between Mediator and RNA polymerase II in Rad2/XPG loading to the chromatin. Nucleic Acids Res 2019; 47:8988-9004. [PMID: 31299084 PMCID: PMC6753472 DOI: 10.1093/nar/gkz598] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 06/27/2019] [Accepted: 06/29/2019] [Indexed: 12/30/2022] Open
Abstract
Transcription and maintenance of genome integrity are fundamental cellular functions. Deregulation of transcription and defects in DNA repair lead to serious pathologies. The Mediator complex links RNA polymerase (Pol) II transcription and nucleotide excision repair via Rad2/XPG endonuclease. However, the functional interplay between Rad2/XPG, Mediator and Pol II remains to be determined. In this study, we investigated their functional dynamics using genomic and genetic approaches. In a mutant affected in Pol II phosphorylation leading to Mediator stabilization on core promoters, Rad2 genome-wide occupancy shifts towards core promoters following that of Mediator, but decreases on transcribed regions together with Pol II. Specific Mediator mutations increase UV sensitivity, reduce Rad2 recruitment to transcribed regions, lead to uncoupling of Rad2, Mediator and Pol II and to colethality with deletion of Rpb9 Pol II subunit involved in transcription-coupled repair. We provide new insights into the functional interplay between Rad2, Mediator and Pol II and propose that dynamic interactions with Mediator and Pol II are involved in Rad2 loading to the chromatin. Our work contributes to the understanding of the complex link between transcription and DNA repair machineries, dysfunction of which leads to severe diseases.
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Affiliation(s)
- Adrien Georges
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Diyavarshini Gopaul
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Cyril Denby Wilkes
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Nathalie Giordanengo Aiach
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Elizaveta Novikova
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Marie-Bénédicte Barrault
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | | | - Julie Soutourina
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
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241
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Apostolou Z, Chatzinikolaou G, Stratigi K, Garinis GA. Nucleotide Excision Repair and Transcription-Associated Genome Instability. Bioessays 2019; 41:e1800201. [PMID: 30919497 DOI: 10.1002/bies.201800201] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 12/10/2018] [Indexed: 12/12/2022]
Abstract
Transcription is a potential threat to genome integrity, and transcription-associated DNA damage must be repaired for proper messenger RNA (mRNA) synthesis and for cells to transmit their genome intact into progeny. For a wide range of structurally diverse DNA lesions, cells employ the highly conserved nucleotide excision repair (NER) pathway to restore their genome back to its native form. Recent evidence suggests that NER factors function, in addition to the canonical DNA repair mechanism, in processes that facilitate mRNA synthesis or shape the 3D chromatin architecture. Here, these findings are critically discussed and a working model that explains the puzzling clinical heterogeneity of NER syndromes highlighting the relevance of physiological, transcription-associated DNA damage to mammalian development and disease is proposed.
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Affiliation(s)
- Zivkos Apostolou
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Nikolaou Plastira 100, Heraklion 70013, Crete, Greece.,Department of Biology, University of Crete, Vassilika Vouton, Heraklion GR71409, Crete, Greece
| | - Georgia Chatzinikolaou
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Nikolaou Plastira 100, Heraklion 70013, Crete, Greece
| | - Kalliopi Stratigi
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Nikolaou Plastira 100, Heraklion 70013, Crete, Greece
| | - George A Garinis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Nikolaou Plastira 100, Heraklion 70013, Crete, Greece.,Department of Biology, University of Crete, Vassilika Vouton, Heraklion GR71409, Crete, Greece
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242
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Dong X, Chen R. Understanding aberrant RNA splicing to facilitate cancer diagnosis and therapy. Oncogene 2019; 39:2231-2242. [PMID: 31819165 DOI: 10.1038/s41388-019-1138-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 11/22/2019] [Accepted: 11/27/2019] [Indexed: 12/31/2022]
Abstract
Almost all genes in normal cells undergo alternative RNA splicing to generate a greater extent of diversification of gene products for normal cellular functions. RNA splicing is tightly regulated and closely interplays with genetic and epigenetic machinery. While DNA polymorphism and somatic mutations modulate alternative splicing patterns, RNA splicing also controls genomic stability, chromatin organization, and transcriptome. Tumor cells, in turn, often take advantage of aberrant RNA splicing to develop, grow and progress into therapy-resistant tumors. Understanding alternative RNA splicing in tumor cells would, therefore, provide us opportunities to gain further insights into tumor biology, identify diagnostic or prognosis biomarkers, as well as to design effective therapeutic means to control tumor progression. Here, we provide an overview of RNA splicing mechanisms and use prostate cancer as an example to review recent advancements in our understanding of RNA splicing in cancer progression and therapy resistance. We also discuss emerging diagnostic and therapeutic potentials of RNA splicing events or RNA splicing factors.
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Affiliation(s)
- Xuesen Dong
- Department of Urologic Sciences, Faculty of Medicine, The University of British Columbia, 2660 Oak Street, Vancouver, BC, V6H 3Z6, Canada. .,The Vancouver Prostate Centre, Vancouver General Hospital, 2660 Oak Street, Vancouver, BC, V6H 3Z6, Canada.
| | - Ruiqi Chen
- Faculty of Medicine, University of Toronto, 27 King's College Circle 8, Toronto, ON, M5S 1A1, Canada
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243
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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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244
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Drugging the R-loop interactome: RNA-DNA hybrid binding proteins as targets for cancer therapy. DNA Repair (Amst) 2019; 84:102642. [DOI: 10.1016/j.dnarep.2019.102642] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Revised: 05/16/2019] [Accepted: 07/02/2019] [Indexed: 02/07/2023]
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245
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Cerritelli SM, Crouch RJ. RNase H2-RED carpets the path to eukaryotic RNase H2 functions. DNA Repair (Amst) 2019; 84:102736. [PMID: 31761672 PMCID: PMC6936605 DOI: 10.1016/j.dnarep.2019.102736] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 10/15/2019] [Indexed: 11/24/2022]
Abstract
Eukaryotic RNases H2 have dual functions in initiating the removal of ribonucleoside monophosphates (rNMPs) incorporated by DNA polymerases during DNA synthesis and in cleaving the RNA moiety of RNA/DNA hybrids formed during transcription and retrotransposition. The other major cellular RNase H, RNase H1, shares the hybrid processing activity, but not all substrates. After RNase H2 incision at the rNMPs in DNA the Ribonucleotide Excision Repair (RER) pathway completes the removal, restoring dsDNA. The development of the RNase H2-RED (Ribonucleotide Excision Defective) mutant enzyme, which can process RNA/DNA hybrids but is unable to cleave rNMPs embedded in DNA has unlinked the two activities and illuminated the roles of RNase H2 in cellular metabolism. Studies mostly in Saccharomyces cerevisiae, have shown both activities of RNase H2 are necessary to maintain genome integrity and that RNase H1 and H2 have overlapping as well as distinct RNA/DNA hybrid substrates. In mouse RNase H2-RED confirmed that rNMPs in DNA during embryogenesis induce lethality in a p53-dependent DNA damage response. In mammalian cell cultures, RNase H2-RED helped identifying DNA lesions produced by Top1 cleavage at rNMPs and led to determine that RNase H2 participates in the retrotransposition of LINE-1 elements. In this review, we summarize the studies and conclusions reached by utilization of RNase H2-RED enzyme in different model systems.
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Affiliation(s)
- Susana M Cerritelli
- SFR, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Robert J Crouch
- SFR, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA.
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246
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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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247
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Chappidi N, Nascakova Z, Boleslavska B, Zellweger R, Isik E, Andrs M, Menon S, Dobrovolna J, Balbo Pogliano C, Matos J, Porro A, Lopes M, Janscak P. Fork Cleavage-Religation Cycle and Active Transcription Mediate Replication Restart after Fork Stalling at Co-transcriptional R-Loops. Mol Cell 2019; 77:528-541.e8. [PMID: 31759821 DOI: 10.1016/j.molcel.2019.10.026] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2018] [Revised: 07/03/2019] [Accepted: 10/16/2019] [Indexed: 01/08/2023]
Abstract
Formation of co-transcriptional R-loops underlies replication fork stalling upon head-on transcription-replication encounters. Here, we demonstrate that RAD51-dependent replication fork reversal induced by R-loops is followed by the restart of semiconservative DNA replication mediated by RECQ1 and RECQ5 helicases, MUS81/EME1 endonuclease, RAD52 strand-annealing factor, the DNA ligase IV (LIG4)/XRCC4 complex, and the non-catalytic subunit of DNA polymerase δ, POLD3. RECQ5 disrupts RAD51 filaments assembled on stalled forks after RECQ1-mediated reverse branch migration, preventing a new round of fork reversal and facilitating fork cleavage by MUS81/EME1. MUS81-dependent DNA breaks accumulate in cells lacking RAD52 or LIG4 upon induction of R-loop formation, suggesting that RAD52 acts in concert with LIG4/XRCC4 to catalyze fork religation, thereby mediating replication restart. The resumption of DNA synthesis after R-loop-associated fork stalling also requires active transcription, the restoration of which depends on MUS81, RAD52, LIG4, and the transcription elongation factor ELL. These findings provide mechanistic insights into transcription-replication conflict resolution.
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Affiliation(s)
- Nagaraja Chappidi
- Institute of Molecular Cancer Research, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Zuzana Nascakova
- Institute of Molecular Genetics of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague, Czech Republic
| | - Barbora Boleslavska
- Institute of Molecular Genetics of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague, Czech Republic
| | - Ralph Zellweger
- Institute of Molecular Cancer Research, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Esin Isik
- Institute of Molecular Cancer Research, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Martin Andrs
- Institute of Molecular Genetics of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague, Czech Republic
| | - Shruti Menon
- Institute of Molecular Cancer Research, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Jana Dobrovolna
- Institute of Molecular Genetics of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague, Czech Republic
| | | | - Joao Matos
- Institute of Biochemistry, ETH Zurich, Otto-Stern-Weg 3, 8093 Zurich, Switzerland
| | - Antonio Porro
- Institute of Molecular Cancer Research, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Massimo Lopes
- Institute of Molecular Cancer Research, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Pavel Janscak
- Institute of Molecular Cancer Research, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland; Institute of Molecular Genetics of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague, Czech Republic.
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248
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Matos DA, Zhang JM, Ouyang J, Nguyen HD, Genois MM, Zou L. ATR Protects the Genome against R Loops through a MUS81-Triggered Feedback Loop. Mol Cell 2019; 77:514-527.e4. [PMID: 31708417 DOI: 10.1016/j.molcel.2019.10.010] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 08/11/2019] [Accepted: 10/08/2019] [Indexed: 12/20/2022]
Abstract
R loops arising during transcription induce genomic instability, but how cells respond to the R loop-associated genomic stress is still poorly understood. Here, we show that cells harboring high levels of R loops rely on the ATR kinase for survival. In response to aberrant R loop accumulation, the ataxia telangiectasia and Rad3-related (ATR)-Chk1 pathway is activated by R loop-induced reversed replication forks. In contrast to the activation of ATR by replication inhibitors, R loop-induced ATR activation requires the MUS81 endonuclease. ATR protects the genome from R loops by suppressing transcription-replication collisions, promoting replication fork recovery, and enforcing a G2/M cell-cycle arrest. Furthermore, ATR prevents excessive cleavage of reversed forks by MUS81, revealing a MUS81-triggered and ATR-mediated feedback loop that fine-tunes MUS81 activity at replication forks. These results suggest that ATR is a key sensor and suppressor of R loop-induced genomic instability, uncovering a signaling circuitry that safeguards the genome against R loops.
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Affiliation(s)
- Dominick A Matos
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
| | - Jia-Min Zhang
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
| | - Jian Ouyang
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
| | - Hai Dang Nguyen
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
| | - Marie-Michelle Genois
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
| | - Lee Zou
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA; Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.
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249
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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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250
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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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