1
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Vu DD, Bonucci A, Brenière M, Cisneros-Aguirre M, Pelupessy P, Wang Z, Carlier L, Bouvignies G, Cortes P, Aggarwal AK, Blackledge M, Gueroui Z, Belle V, Stark JM, Modesti M, Ferrage F. Multivalent interactions of the disordered regions of XLF and XRCC4 foster robust cellular NHEJ and drive the formation of ligation-boosting condensates in vitro. Nat Struct Mol Biol 2024:10.1038/s41594-024-01339-x. [PMID: 38898102 DOI: 10.1038/s41594-024-01339-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 05/28/2024] [Indexed: 06/21/2024]
Abstract
In mammalian cells, DNA double-strand breaks are predominantly repaired by non-homologous end joining (NHEJ). During repair, the Ku70-Ku80 heterodimer (Ku), X-ray repair cross complementing 4 (XRCC4) in complex with DNA ligase 4 (X4L4) and XRCC4-like factor (XLF) form a flexible scaffold that holds the broken DNA ends together. Insights into the architectural organization of the NHEJ scaffold and its regulation by the DNA-dependent protein kinase catalytic subunit (DNA-PKcs) were recently obtained by single-particle cryo-electron microscopy analysis. However, several regions, especially the C-terminal regions (CTRs) of the XRCC4 and XLF scaffolding proteins, have largely remained unresolved in experimental structures, which hampers the understanding of their functions. Here we used magnetic resonance techniques and biochemical assays to comprehensively characterize the interactions and dynamics of the XRCC4 and XLF CTRs at residue resolution. We show that the CTRs of XRCC4 and XLF are intrinsically disordered and form a network of multivalent heterotypic and homotypic interactions that promotes robust cellular NHEJ activity. Importantly, we demonstrate that the multivalent interactions of these CTRs lead to the formation of XLF and X4L4 condensates in vitro, which can recruit relevant effectors and critically stimulate DNA end ligation. Our work highlights the role of disordered regions in the mechanism and dynamics of NHEJ and lays the groundwork for the investigation of NHEJ protein disorder and its associated condensates inside cells with implications in cancer biology, immunology and the development of genome-editing strategies.
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Affiliation(s)
- Duc-Duy Vu
- Département de Chimie, LBM, CNRS UMR 7203, École Normale Supérieure, PSL University, Sorbonne University, Paris, France
| | - Alessio Bonucci
- Aix Marseille Univ, CNRS UMR 7281, BIP Bioénergétique et Ingénierie des Protéines, IMM, Marseille, France
| | - Manon Brenière
- Cancer Research Center of Marseille, Department of Genome Integrity, CNRS UMR7258, Inserm U1068, Institut Paoli-Calmettes, Aix-Marseille University, Marseille, France
| | - Metztli Cisneros-Aguirre
- Department of Cancer Genetics and Epigenetics, Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, Duarte, CA, USA
| | - Philippe Pelupessy
- Département de Chimie, LBM, CNRS UMR 7203, École Normale Supérieure, PSL University, Sorbonne University, Paris, France
| | - Ziqing Wang
- Département de Chimie, LBM, CNRS UMR 7203, École Normale Supérieure, PSL University, Sorbonne University, Paris, France
| | - Ludovic Carlier
- Département de Chimie, LBM, CNRS UMR 7203, École Normale Supérieure, PSL University, Sorbonne University, Paris, France
| | - Guillaume Bouvignies
- Département de Chimie, LBM, CNRS UMR 7203, École Normale Supérieure, PSL University, Sorbonne University, Paris, France
| | - Patricia Cortes
- Department of Molecular, Cellular and Biomedical Sciences, CUNY School of Medicine at City College of New York, New York, NY, USA
| | - Aneel K Aggarwal
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Martin Blackledge
- Institut de Biologie Structurale (IBS), Grenoble Alpes University, CNRS, CEA, Grenoble, France
| | - Zoher Gueroui
- PASTEUR, Département de Chimie, École Normale Supérieure, PSL University, Sorbonne University, CNRS, Paris, France
| | - Valérie Belle
- Aix Marseille Univ, CNRS UMR 7281, BIP Bioénergétique et Ingénierie des Protéines, IMM, Marseille, France
| | - Jeremy M Stark
- Department of Cancer Genetics and Epigenetics, Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, Duarte, CA, USA
| | - Mauro Modesti
- Cancer Research Center of Marseille, Department of Genome Integrity, CNRS UMR7258, Inserm U1068, Institut Paoli-Calmettes, Aix-Marseille University, Marseille, France.
| | - Fabien Ferrage
- Département de Chimie, LBM, CNRS UMR 7203, École Normale Supérieure, PSL University, Sorbonne University, Paris, France.
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2
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Stinson BM, Carney SM, Walter JC, Loparo JJ. Structural role for DNA Ligase IV in promoting the fidelity of non-homologous end joining. Nat Commun 2024; 15:1250. [PMID: 38341432 PMCID: PMC10858965 DOI: 10.1038/s41467-024-45553-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 01/25/2024] [Indexed: 02/12/2024] Open
Abstract
Nonhomologous end joining (NHEJ), the primary pathway of vertebrate DNA double-strand-break (DSB) repair, directly re-ligates broken DNA ends. Damaged DSB ends that cannot be immediately re-ligated are modified by NHEJ processing enzymes, including error-prone polymerases and nucleases, to enable ligation. However, DSB ends that are initially compatible for re-ligation are typically joined without end processing. As both ligation and end processing occur in the short-range (SR) synaptic complex that closely aligns DNA ends, it remains unclear how ligation of compatible ends is prioritized over end processing. In this study, we identify structural interactions of the NHEJ-specific DNA Ligase IV (Lig4) within the SR complex that prioritize ligation and promote NHEJ fidelity. Mutational analysis demonstrates that Lig4 must bind DNA ends to form the SR complex. Furthermore, single-molecule experiments show that a single Lig4 binds both DNA ends at the instant of SR synapsis. Thus, Lig4 is poised to ligate compatible ends upon initial formation of the SR complex before error-prone processing. Our results provide a molecular basis for the fidelity of NHEJ.
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Affiliation(s)
- Benjamin M Stinson
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA, 02115, USA
- Howard Hughes Medical Institute, Boston, MA, 02115, USA
| | - Sean M Carney
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA, 02115, USA
| | - Johannes C Walter
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA, 02115, USA.
- Howard Hughes Medical Institute, Boston, MA, 02115, USA.
| | - Joseph J Loparo
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA, 02115, USA.
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3
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De Bragança S, Dillingham MS, Moreno-Herrero F. Recent insights into eukaryotic double-strand DNA break repair unveiled by single-molecule methods. Trends Genet 2023; 39:924-940. [PMID: 37806853 DOI: 10.1016/j.tig.2023.09.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 09/04/2023] [Accepted: 09/07/2023] [Indexed: 10/10/2023]
Abstract
Genome integrity and maintenance are essential for the viability of all organisms. A wide variety of DNA damage types have been described, but double-strand breaks (DSBs) stand out as one of the most toxic DNA lesions. Two major pathways account for the repair of DSBs: homologous recombination (HR) and non-homologous end joining (NHEJ). Both pathways involve complex DNA transactions catalyzed by proteins that sequentially or cooperatively work to repair the damage. Single-molecule methods allow visualization of these complex transactions and characterization of the protein:DNA intermediates of DNA repair, ultimately allowing a comprehensive breakdown of the mechanisms underlying each pathway. We review current understanding of the HR and NHEJ responses to DSBs in eukaryotic cells, with a particular emphasis on recent advances through the use of single-molecule techniques.
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Affiliation(s)
- Sara De Bragança
- Department of Macromolecular Structures, Centro Nacional de Biotecnología (CNB), CSIC, Madrid, Spain
| | - Mark S Dillingham
- DNA:Protein Interactions Unit, School of Biochemistry, University of Bristol, Bristol BS8 1TD, UK
| | - Fernando Moreno-Herrero
- Department of Macromolecular Structures, Centro Nacional de Biotecnología (CNB), CSIC, Madrid, Spain.
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4
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Vogt A, He Y. Structure and mechanism in non-homologous end joining. DNA Repair (Amst) 2023; 130:103547. [PMID: 37556875 PMCID: PMC10528545 DOI: 10.1016/j.dnarep.2023.103547] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 07/26/2023] [Accepted: 07/27/2023] [Indexed: 08/11/2023]
Abstract
DNA double-stranded breaks (DSBs) are a particularly challenging form of DNA damage to repair because the damaged DNA must not only undergo the chemical reactions responsible for returning it to its original state, but, additionally, the two free ends can become physically separated in the nucleus and must be bridged prior to repair. In nonhomologous end joining (NHEJ), one of the major pathways of DSB repair, repair is carried out by a number of repair factors capable of binding to and directly joining DNA ends. It has been unclear how these processes are carried out at a molecular level, owing in part to the lack of structural evidence describing the coordination of the NHEJ factors with each other and a DNA substrate. Advances in cryo-Electron Microscopy (cryo-EM), allowing for the structural characterization of large protein complexes that would be intractable using other techniques, have led to the visualization several key steps of the NHEJ process, which support a model of sequential assembly of repair factors at the DSB, followed by end-bridging mediated by protein-protein complexes and transition to full synapsis. Here we examine the structural evidence for these models, devoting particular attention to recent work identifying a new NHEJ intermediate state and incorporating new NHEJ factors into the general mechanism. We also discuss the evolving understanding of end-bridging mechanisms in NHEJ and DNA-PKcs's role in mediating DSB repair.
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Affiliation(s)
- Alex Vogt
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA; Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, USA
| | - Yuan He
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA; Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, USA; Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, USA; Robert H. Lurie Comprehensive Cancer Center of Northwestern University, Northwestern University, Chicago, USA.
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5
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Loparo JJ. Holding it together: DNA end synapsis during non-homologous end joining. DNA Repair (Amst) 2023; 130:103553. [PMID: 37572577 PMCID: PMC10530278 DOI: 10.1016/j.dnarep.2023.103553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 08/04/2023] [Accepted: 08/06/2023] [Indexed: 08/14/2023]
Abstract
DNA double strand breaks (DSBs) are common lesions whose misrepair are drivers of oncogenic transformations. The non-homologous end joining (NHEJ) pathway repairs the majority of these breaks in vertebrates by directly ligating DNA ends back together. Upon formation of a DSB, a multiprotein complex is assembled on DNA ends which tethers them together within a synaptic complex. Synapsis is a critical step of the NHEJ pathway as loss of synapsis can result in mispairing of DNA ends and chromosome translocations. As DNA ends are commonly incompatible for ligation, the NHEJ machinery must also process ends to enable rejoining. This review describes how recent progress in single-molecule approaches and cryo-EM have advanced our molecular understanding of DNA end synapsis during NHEJ and how synapsis is coordinated with end processing to determine the fidelity of repair.
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Affiliation(s)
- Joseph J Loparo
- Dept. of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA.
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6
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Vu DD, Bonucci A, Brenière M, Cisneros-Aguirre M, Pelupessy P, Wang Z, Carlier L, Bouvignies G, Cortes P, Aggarwal AK, Blackledge M, Gueroui Z, Belle V, Stark JM, Modesti M, Ferrage F. Multivalent interactions of the disordered regions of XLF and XRCC4 foster robust cellular NHEJ and drive the formation of ligation-boosting condensates in vitro. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.12.548668. [PMID: 37503201 PMCID: PMC10369993 DOI: 10.1101/2023.07.12.548668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
In mammalian cells, DNA double-strand breaks are predominantly repaired by non-homologous end joining (NHEJ). During repair, the Ku70/80 heterodimer (Ku), XRCC4 in complex with DNA Ligase 4 (X4L4), and XLF form a flexible scaffold that holds the broken DNA ends together. Insights into the architectural organization of the NHEJ scaffold and its regulation by the DNA-dependent protein kinase catalytic subunit (DNA-PKcs) have recently been obtained by single-particle cryo-electron microscopy analysis. However, several regions, especially the C-terminal regions (CTRs) of the XRCC4 and XLF scaffolding proteins, have largely remained unresolved in experimental structures, which hampers the understanding of their functions. Here, we used magnetic resonance techniques and biochemical assays to comprehensively characterize the interactions and dynamics of the XRCC4 and XLF CTRs at atomic resolution. We show that the CTRs of XRCC4 and XLF are intrinsically disordered and form a network of multivalent heterotypic and homotypic interactions that promotes robust cellular NHEJ activity. Importantly, we demonstrate that the multivalent interactions of these CTRs led to the formation of XLF and X4L4 condensates in vitro which can recruit relevant effectors and critically stimulate DNA end ligation. Our work highlights the role of disordered regions in the mechanism and dynamics of NHEJ and lays the groundwork for the investigation of NHEJ protein disorder and its associated condensates inside cells with implications in cancer biology, immunology and the development of genome editing strategies.
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Affiliation(s)
- Duc-Duy Vu
- Département de Chimie, LBM, CNRS UMR 7203, École Normale Supérieure, PSL University, Sorbonne University, Paris, France
| | - Alessio Bonucci
- Aix Marseille Univ, CNRS UMR 7281, BIP Bioénergétique et Ingénierie des Protéines, IMM, Marseille, France
| | - Manon Brenière
- Cancer Research Center of Marseille, Department of Genome Integrity, CNRS UMR7258, Inserm U1068, Institut Paoli-Calmettes, Aix Marseille Univ, Marseille, France
| | - Metztli Cisneros-Aguirre
- Department of Cancer Genetics and Epigenetics, Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, 1500 E Duarte Rd., Duarte, CA 91010 USA
| | - Philippe Pelupessy
- Département de Chimie, LBM, CNRS UMR 7203, École Normale Supérieure, PSL University, Sorbonne University, Paris, France
| | - Ziqing Wang
- Département de Chimie, LBM, CNRS UMR 7203, École Normale Supérieure, PSL University, Sorbonne University, Paris, France
| | - Ludovic Carlier
- Département de Chimie, LBM, CNRS UMR 7203, École Normale Supérieure, PSL University, Sorbonne University, Paris, France
| | - Guillaume Bouvignies
- Département de Chimie, LBM, CNRS UMR 7203, École Normale Supérieure, PSL University, Sorbonne University, Paris, France
| | - Patricia Cortes
- Department of Molecular, Cellular and Biomedical Sciences, CUNY School of Medicine at City College of New York, 160 Convent Avenue, New York, NY 10029, USA
| | - Aneel K Aggarwal
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, New York, NY 10029, USA
| | - Martin Blackledge
- University Grenoble Alpes, CNRS, CEA, Institut de Biologie Structurale (IBS), Grenoble, France
| | - Zoher Gueroui
- PASTEUR, Département de Chimie, École Normale Supérieure, PSL University, Sorbonne Université, CNRS, Paris, France
| | - Valérie Belle
- Aix Marseille Univ, CNRS UMR 7281, BIP Bioénergétique et Ingénierie des Protéines, IMM, Marseille, France
| | - Jeremy M Stark
- Department of Cancer Genetics and Epigenetics, Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, 1500 E Duarte Rd., Duarte, CA 91010 USA
| | - Mauro Modesti
- Cancer Research Center of Marseille, Department of Genome Integrity, CNRS UMR7258, Inserm U1068, Institut Paoli-Calmettes, Aix Marseille Univ, Marseille, France
| | - Fabien Ferrage
- Département de Chimie, LBM, CNRS UMR 7203, École Normale Supérieure, PSL University, Sorbonne University, Paris, France
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7
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Buehl CJ, Goff NJ, Hardwick SW, Gellert M, Blundell TL, Yang W, Chaplin AK, Meek K. Two distinct long-range synaptic complexes promote different aspects of end processing prior to repair of DNA breaks by non-homologous end joining. Mol Cell 2023; 83:698-714.e4. [PMID: 36724784 PMCID: PMC9992237 DOI: 10.1016/j.molcel.2023.01.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 11/29/2022] [Accepted: 01/06/2023] [Indexed: 02/03/2023]
Abstract
Non-homologous end joining is the major double-strand break repair (DSBR) pathway in mammals. DNA-PK is the hub and organizer of multiple steps in non-homologous end joining (NHEJ). Recent high-resolution structures show how two distinct NHEJ complexes "synapse" two DNA ends. One complex includes a DNA-PK dimer mediated by XLF, whereas a distinct DNA-PK dimer forms via a domain-swap mechanism where the C terminus of Ku80 from one DNA-PK protomer interacts with another DNA-PK protomer in trans. Remarkably, the distance between the two synapsed DNA ends in both dimers is the same (∼115 Å), which matches the distance observed in the initial description of an NHEJ long-range synaptic complex. Here, a mutational strategy is used to demonstrate distinct cellular function(s) of the two dimers: one promoting fill-in end processing, while the other promotes DNA end resection. Thus, the specific DNA-PK dimer formed (which may be impacted by DNA end structure) dictates the mechanism by which ends will be made ligatable.
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Affiliation(s)
- Christopher J Buehl
- College of Veterinary Medicine, Department of Microbiology & Molecular Genetics, Department of Pathobiology & Diagnostic Investigation, Michigan State University, East Lansing, MI 48824, USA
| | - Noah J Goff
- College of Veterinary Medicine, Department of Microbiology & Molecular Genetics, Department of Pathobiology & Diagnostic Investigation, Michigan State University, East Lansing, MI 48824, USA
| | - Steven W Hardwick
- CryoEM Facility, Department of Biochemistry, University of Cambridge, Sanger Building, Tennis Court Road, Cambridge CB2 1GA, UK
| | - Martin Gellert
- Laboratory of Molecular Biology, NIDDK, National Institutes of Health, Bethesda, MD 20892, USA
| | - Tom L Blundell
- Department of Biochemistry, University of Cambridge, Sanger Building, Tennis Court Road, Cambridge CB2 1GA, UK
| | - Wei Yang
- Laboratory of Molecular Biology, NIDDK, National Institutes of Health, Bethesda, MD 20892, USA
| | - Amanda K Chaplin
- Department of Biochemistry, University of Cambridge, Sanger Building, Tennis Court Road, Cambridge CB2 1GA, UK; Leicester Institute for Structural and Chemical Biology, Department of Molecular and Cell Biology, University of Leicester, Leicester, UK.
| | - Katheryn Meek
- College of Veterinary Medicine, Department of Microbiology & Molecular Genetics, Department of Pathobiology & Diagnostic Investigation, Michigan State University, East Lansing, MI 48824, USA.
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8
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De Bragança S, Aicart-Ramos C, Arribas-Bosacoma R, Rivera-Calzada A, Unfried JP, Prats-Mari L, Marin-Baquero M, Fortes P, Llorca O, Moreno-Herrero F. APLF and long non-coding RNA NIHCOLE promote stable DNA synapsis in non-homologous end joining. Cell Rep 2023; 42:111917. [PMID: 36640344 DOI: 10.1016/j.celrep.2022.111917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 10/26/2022] [Accepted: 12/13/2022] [Indexed: 01/01/2023] Open
Abstract
The synapsis of DNA ends is a critical step for the repair of double-strand breaks by non-homologous end joining (NHEJ). This is performed by a multicomponent protein complex assembled around Ku70-Ku80 heterodimers and regulated by accessory factors, including long non-coding RNAs, through poorly understood mechanisms. Here, we use magnetic tweezers to investigate the contributions of core NHEJ proteins and APLF and lncRNA NIHCOLE to DNA synapsis. APLF stabilizes DNA end bridging and, together with Ku70-Ku80, establishes a minimal complex that supports DNA synapsis for several minutes under piconewton forces. We find the C-terminal acidic region of APLF to be critical for bridging. NIHCOLE increases the dwell time of the synapses by Ku70-Ku80 and APLF. This effect is further enhanced by a small and structured RNA domain within NIHCOLE. We propose a model where Ku70-Ku80 can simultaneously bind DNA, APLF, and structured RNAs to promote the stable joining of DNA ends.
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Affiliation(s)
- Sara De Bragança
- Department of Macromolecular Structures, Centro Nacional de Biotecnología (CNB), CSIC, Madrid, Spain
| | - Clara Aicart-Ramos
- Department of Macromolecular Structures, Centro Nacional de Biotecnología (CNB), CSIC, Madrid, Spain
| | - Raquel Arribas-Bosacoma
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton, UK
| | - Angel Rivera-Calzada
- Structural Biology Programme, Spanish National Cancer Research Center (CNIO), Madrid, Spain
| | - Juan Pablo Unfried
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel; Department of Gene Therapy and Regulation of Gene Expression, Center for Applied Medical Research (CIMA), University of Navarra (UNAV), Pamplona, Spain
| | - Laura Prats-Mari
- Department of Gene Therapy and Regulation of Gene Expression, Center for Applied Medical Research (CIMA), University of Navarra (UNAV), Pamplona, Spain
| | - Mikel Marin-Baquero
- Department of Macromolecular Structures, Centro Nacional de Biotecnología (CNB), CSIC, Madrid, Spain
| | - Puri Fortes
- Department of Gene Therapy and Regulation of Gene Expression, Center for Applied Medical Research (CIMA), University of Navarra (UNAV), Pamplona, Spain; Navarra Institute for Health Research (IdiSNA), Pamplona, Spain; Liver and Digestive Diseases Networking Biomedical Research Centre (CIBERehd), Spanish Network for Advanced Therapies (TERAV ISCIII), Madrid, Spain
| | - Oscar Llorca
- Structural Biology Programme, Spanish National Cancer Research Center (CNIO), Madrid, Spain.
| | - Fernando Moreno-Herrero
- Department of Macromolecular Structures, Centro Nacional de Biotecnología (CNB), CSIC, Madrid, Spain.
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9
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Cisneros-Aguirre M, Lopezcolorado FW, Tsai LJ, Bhargava R, Stark JM. The importance of DNAPKcs for blunt DNA end joining is magnified when XLF is weakened. Nat Commun 2022; 13:3662. [PMID: 35760797 PMCID: PMC9237100 DOI: 10.1038/s41467-022-31365-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 06/10/2022] [Indexed: 12/13/2022] Open
Abstract
Canonical non-homologous end joining (C-NHEJ) factors can assemble into a long-range (LR) complex with DNA ends relatively far apart that contains DNAPKcs, XLF, XRCC4, LIG4, and the KU heterodimer and a short-range (SR) complex lacking DNAPKcs that has the ends positioned for ligation. Since the SR complex can form de novo, the role of the LR complex (i.e., DNAPKcs) for chromosomal EJ is unclear. We have examined EJ of chromosomal blunt DNA double-strand breaks (DSBs), and found that DNAPKcs is significantly less important than XLF for such EJ. However, weakening XLF via disrupting interaction interfaces causes a marked requirement for DNAPKcs, its kinase activity, and its ABCDE-cluster autophosphorylation sites for blunt DSB EJ. In contrast, other aspects of genome maintenance are sensitive to DNAPKcs kinase inhibition in a manner that is not further enhanced by XLF loss (i.e., suppression of homology-directed repair and structural variants, and IR-resistance). We suggest that DNAPKcs is required to position a weakened XLF in an LR complex that can transition into a functional SR complex for blunt DSB EJ, but also has distinct functions for other aspects of genome maintenance. DNAPKcs and its kinase activity are required for blunt DNA break end joining when the bridging factor XLF is weakened, but for homologous recombination and radiation resistance, the influence of DNAPKcs is not further enhanced with loss of XLF.
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Affiliation(s)
- Metztli Cisneros-Aguirre
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute of the City of Hope, 1500 E Duarte Rd, Duarte, CA 91010, USA.,Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, 1500 E Duarte Rd, Duarte, CA 91010, USA
| | - Felicia Wednesday Lopezcolorado
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute of the City of Hope, 1500 E Duarte Rd, Duarte, CA 91010, USA
| | - Linda Jillianne Tsai
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute of the City of Hope, 1500 E Duarte Rd, Duarte, CA 91010, USA.,Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, 1500 E Duarte Rd, Duarte, CA 91010, USA
| | - Ragini Bhargava
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute of the City of Hope, 1500 E Duarte Rd, Duarte, CA 91010, USA.,Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, 1500 E Duarte Rd, Duarte, CA 91010, USA.,Department of Pharmacology and Chemical Biology, UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jeremy M Stark
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute of the City of Hope, 1500 E Duarte Rd, Duarte, CA 91010, USA. .,Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, 1500 E Duarte Rd, Duarte, CA 91010, USA.
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10
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Tang J, Li Z, Wu Q, Irfan M, Li W, Liu X. Role of Paralogue of XRCC4 and XLF in DNA Damage Repair and Cancer Development. Front Immunol 2022; 13:852453. [PMID: 35309348 PMCID: PMC8926060 DOI: 10.3389/fimmu.2022.852453] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 02/07/2022] [Indexed: 01/01/2023] Open
Abstract
Non-homologous end joining (cNHEJ) is a major pathway to repair double-strand breaks (DSBs) in DNA. Several core cNHEJ are involved in the progress of the repair such as KU70 and 80, DNA-dependent protein kinase catalytic subunit (DNA-PKcs), Artemis, X-ray repair cross-complementing protein 4 (XRCC4), DNA ligase IV, and XRCC4-like factor (XLF). Recent studies have added a number of new proteins during cNHEJ. One of the newly identified proteins is Paralogue of XRCC4 and XLF (PAXX), which acts as a scaffold that is required to stabilize the KU70/80 heterodimer at DSBs sites and promotes the assembly and/or stability of the cNHEJ machinery. PAXX plays an essential role in lymphocyte development in XLF-deficient background, while XLF/PAXX double-deficient mouse embryo died before birth. Emerging evidence also shows a connection between the expression levels of PAXX and cancer development in human patients, indicating a prognosis role of the protein. This review will summarize and discuss the function of PAXX in DSBs repair and its potential role in cancer development.
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Affiliation(s)
- Jialin Tang
- Guangdong Key Laboratory of Genome Instability and Human Disease Prevention, Department of Biochemistry and Molecular Biology, Shenzhen University School of Medicine, Shenzhen, China
| | - Zhongxia Li
- Guangdong Key Laboratory of Genome Instability and Human Disease Prevention, Department of Biochemistry and Molecular Biology, Shenzhen University School of Medicine, Shenzhen, China
| | - Qiong Wu
- Guangdong Key Laboratory of Genome Instability and Human Disease Prevention, Department of Biochemistry and Molecular Biology, Shenzhen University School of Medicine, Shenzhen, China
| | - Muhammad Irfan
- Guangdong Key Laboratory of Genome Instability and Human Disease Prevention, Department of Biochemistry and Molecular Biology, Shenzhen University School of Medicine, Shenzhen, China
| | - Weili Li
- Guangdong Key Laboratory of Genome Instability and Human Disease Prevention, Department of Biochemistry and Molecular Biology, Shenzhen University School of Medicine, Shenzhen, China
| | - Xiangyu Liu
- Guangdong Key Laboratory of Genome Instability and Human Disease Prevention, Department of Biochemistry and Molecular Biology, Shenzhen University School of Medicine, Shenzhen, China.,Department of Hematology, The Second People's Hospital of Shenzhen, Shenzhen, China
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11
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Ali A, Xiao W, Babar ME, Bi Y. Double-Stranded Break Repair in Mammalian Cells and Precise Genome Editing. Genes (Basel) 2022; 13:genes13050737. [PMID: 35627122 PMCID: PMC9142082 DOI: 10.3390/genes13050737] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 04/19/2022] [Accepted: 04/20/2022] [Indexed: 12/16/2022] Open
Abstract
In mammalian cells, double-strand breaks (DSBs) are repaired predominantly by error-prone non-homologous end joining (NHEJ), but less prevalently by error-free template-dependent homologous recombination (HR). DSB repair pathway selection is the bedrock for genome editing. NHEJ results in random mutations when repairing DSB, while HR induces high-fidelity sequence-specific variations, but with an undesirable low efficiency. In this review, we first discuss the latest insights into the action mode of NHEJ and HR in a panoramic view. We then propose the future direction of genome editing by virtue of these advancements. We suggest that by switching NHEJ to HR, full fidelity genome editing and robust gene knock-in could be enabled. We also envision that RNA molecules could be repurposed by RNA-templated DSB repair to mediate precise genetic editing.
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Affiliation(s)
- Akhtar Ali
- Key Laboratory of Animal Embryo and Molecular Breeding of Hubei Province, Institute of Animal Science and Veterinary Medicine, Hubei Academy of Agricultural Sciences, Wuhan 430064, China; (A.A.); (W.X.)
- Department of Biotechnology, Virtual University of Pakistan, Lahore 54000, Pakistan
| | - Wei Xiao
- Key Laboratory of Animal Embryo and Molecular Breeding of Hubei Province, Institute of Animal Science and Veterinary Medicine, Hubei Academy of Agricultural Sciences, Wuhan 430064, China; (A.A.); (W.X.)
| | - Masroor Ellahi Babar
- The University of Agriculture Dera Ismail Khan, Dera Ismail Khan 29220, Pakistan;
| | - Yanzhen Bi
- Key Laboratory of Animal Embryo and Molecular Breeding of Hubei Province, Institute of Animal Science and Veterinary Medicine, Hubei Academy of Agricultural Sciences, Wuhan 430064, China; (A.A.); (W.X.)
- Correspondence: ; Tel.: +86-151-0714-8708
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12
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Libri A, Marton T, Deriano L. The (Lack of) DNA Double-Strand Break Repair Pathway Choice During V(D)J Recombination. Front Genet 2022; 12:823943. [PMID: 35082840 PMCID: PMC8785701 DOI: 10.3389/fgene.2021.823943] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Accepted: 12/13/2021] [Indexed: 01/08/2023] Open
Abstract
DNA double-strand breaks (DSBs) are highly toxic lesions that can be mended via several DNA repair pathways. Multiple factors can influence the choice and the restrictiveness of repair towards a given pathway in order to warrant the maintenance of genome integrity. During V(D)J recombination, RAG-induced DSBs are (almost) exclusively repaired by the non-homologous end-joining (NHEJ) pathway for the benefit of antigen receptor gene diversity. Here, we review the various parameters that constrain repair of RAG-generated DSBs to NHEJ, including the peculiarity of DNA DSB ends generated by the RAG nuclease, the establishment and maintenance of a post-cleavage synaptic complex, and the protection of DNA ends against resection and (micro)homology-directed repair. In this physiological context, we highlight that certain DSBs have limited DNA repair pathway choice options.
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Affiliation(s)
- Alice Libri
- Genome Integrity, Immunity and Cancer Unit, Institut Pasteur, Université de Paris, INSERM U1223, Equipe Labellisée Ligue Contre Le Cancer, Paris, France
| | - Timea Marton
- Genome Integrity, Immunity and Cancer Unit, Institut Pasteur, Université de Paris, INSERM U1223, Equipe Labellisée Ligue Contre Le Cancer, Paris, France
| | - Ludovic Deriano
- Genome Integrity, Immunity and Cancer Unit, Institut Pasteur, Université de Paris, INSERM U1223, Equipe Labellisée Ligue Contre Le Cancer, Paris, France
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13
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Chen BR, Wang Y, Shen ZJ, Bennett A, Hindi I, Tyler JK, Sleckman BP. The RNF8 and RNF168 Ubiquitin Ligases Regulate Pro- and Anti-Resection Activities at Broken DNA Ends During Non-Homologous End Joining. DNA Repair (Amst) 2021; 108:103217. [PMID: 34481157 PMCID: PMC9586520 DOI: 10.1016/j.dnarep.2021.103217] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Revised: 08/24/2021] [Accepted: 08/25/2021] [Indexed: 12/30/2022]
Abstract
The RING-type E3 ubiquitin ligases RNF8 and RNF168 recruit DNA damage response (DDR) factors to chromatin flanking DNA double strand breaks (DSBs) including 53BP1, which protects DNA ends from resection during DNA DSB repair by non-homologous end joining (NHEJ). Deficiency of RNF8 or RNF168 does not lead to demonstrable NHEJ defects, but like deficiency of 53BP1, the combined deficiency of XLF and RNF8 or RNF168 leads to diminished NHEJ in lymphocytes arrested in G0/G1 phase. The function of RNF8 in NHEJ depends on its E3 ubiquitin ligase activity. Loss of RNF8 or RNF168 in G0/G1-phase lymphocytes leads to the resection of broken DNA ends, demonstrating that RNF8 and RNF168 function to protect DNA ends from nucleases, pos sibly through the recruitment of 53BP1. However, the loss of 53BP1 leads to more severe resection than the loss of RNF8 or RNF168. Moreover, in 53BP1-deficient cells, the loss of RNF8 or RNF168 leads to diminished DNA end resection. We conclude that RNF8 and RNF168 regulate pathways that both prevent and promote DNA end resection in cells arrested in G0/G1 phase.
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Affiliation(s)
- Bo-Ruei Chen
- Division of Hematology and Oncology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, 35233, United States; O'Neal Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, 35233, United States
| | - Yinan Wang
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY, 10065, United States
| | - Zih-Jie Shen
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY, 10065, United States
| | - Amelia Bennett
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY, 10065, United States
| | - Issa Hindi
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY, 10065, United States
| | - Jessica K Tyler
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY, 10065, United States
| | - Barry P Sleckman
- Division of Hematology and Oncology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, 35233, United States; O'Neal Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, 35233, United States.
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14
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Xue C, Greene EC. DNA Repair Pathway Choices in CRISPR-Cas9-Mediated Genome Editing. Trends Genet 2021; 37:639-656. [PMID: 33896583 PMCID: PMC8187289 DOI: 10.1016/j.tig.2021.02.008] [Citation(s) in RCA: 128] [Impact Index Per Article: 42.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 02/25/2021] [Accepted: 02/26/2021] [Indexed: 12/14/2022]
Abstract
Many clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (Cas9)-based genome editing technologies take advantage of Cas nucleases to induce DNA double-strand breaks (DSBs) at desired locations within a genome. Further processing of the DSBs by the cellular DSB repair machinery is then necessary to introduce desired mutations, sequence insertions, or gene deletions. Thus, the accuracy and efficiency of genome editing are influenced by the cellular DSB repair pathways. DSBs are themselves highly genotoxic lesions and as such cells have evolved multiple mechanisms for their repair. These repair pathways include homologous recombination (HR), classical nonhomologous end joining (cNHEJ), microhomology-mediated end joining (MMEJ) and single-strand annealing (SSA). In this review, we briefly highlight CRISPR-Cas9 and then describe the mechanisms of DSB repair. Finally, we summarize recent findings of factors that can influence the choice of DNA repair pathway in response to Cas9-induced DSBs.
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Affiliation(s)
- Chaoyou Xue
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Eric C Greene
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA.
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15
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Hammel M, Tainer JA. X-ray scattering reveals disordered linkers and dynamic interfaces in complexes and mechanisms for DNA double-strand break repair impacting cell and cancer biology. Protein Sci 2021; 30:1735-1756. [PMID: 34056803 PMCID: PMC8376411 DOI: 10.1002/pro.4133] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Revised: 05/23/2021] [Accepted: 05/25/2021] [Indexed: 12/17/2022]
Abstract
Evolutionary selection ensures specificity and efficiency in dynamic metastable macromolecular machines that repair DNA damage without releasing toxic and mutagenic intermediates. Here we examine non‐homologous end joining (NHEJ) as the primary conserved DNA double‐strand break (DSB) repair process in human cells. NHEJ has exemplary key roles in networks determining the development, outcome of cancer treatments by DSB‐inducing agents, generation of antibody and T‐cell receptor diversity, and innate immune response for RNA viruses. We determine mechanistic insights into NHEJ structural biochemistry focusing upon advanced small angle X‐ray scattering (SAXS) results combined with X‐ray crystallography (MX) and cryo‐electron microscopy (cryo‐EM). SAXS coupled to atomic structures enables integrated structural biology for objective quantitative assessment of conformational ensembles and assemblies in solution, intra‐molecular distances, structural similarity, functional disorder, conformational switching, and flexibility. Importantly, NHEJ complexes in solution undergo larger allosteric transitions than seen in their cryo‐EM or MX structures. In the long‐range synaptic complex, X‐ray repair cross‐complementing 4 (XRCC4) plus XRCC4‐like‐factor (XLF) form a flexible bridge and linchpin for DNA ends bound to KU heterodimer (Ku70/80) and DNA‐PKcs (DNA‐dependent protein kinase catalytic subunit). Upon binding two DNA ends, auto‐phosphorylation opens DNA‐PKcs dimer licensing NHEJ via concerted conformational transformations of XLF‐XRCC4, XLF–Ku80, and LigIVBRCT–Ku70 interfaces. Integrated structures reveal multifunctional roles for disordered linkers and modular dynamic interfaces promoting DSB end processing and alignment into the short‐range complex for ligation by LigIV. Integrated findings define dynamic assemblies fundamental to designing separation‐of‐function mutants and allosteric inhibitors targeting conformational transitions in multifunctional complexes.
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Affiliation(s)
- Michal Hammel
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - John A Tainer
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, California, USA.,Department of Cancer Biology, University of Texas MD Anderson Cancer Center, Houston, Texas, USA.,Department of Molecular and Cellular Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
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16
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Chen S, Lee L, Naila T, Fishbain S, Wang A, Tomkinson AE, Lees-Miller SP, He Y. Structural basis of long-range to short-range synaptic transition in NHEJ. Nature 2021; 593:294-298. [PMID: 33854234 PMCID: PMC8122075 DOI: 10.1038/s41586-021-03458-7] [Citation(s) in RCA: 90] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 03/15/2021] [Indexed: 02/07/2023]
Abstract
DNA double-strand breaks (DSBs) are a highly cytotoxic form of DNA damage and the incorrect repair of DSBs is linked to carcinogenesis1,2. The conserved error-prone non-homologous end joining (NHEJ) pathway has a key role in determining the effects of DSB-inducing agents that are used to treat cancer as well as the generation of the diversity in antibodies and T cell receptors2,3. Here we applied single-particle cryo-electron microscopy to visualize two key DNA-protein complexes that are formed by human NHEJ factors. The Ku70/80 heterodimer (Ku), the catalytic subunit of the DNA-dependent protein kinase (DNA-PKcs), DNA ligase IV (LigIV), XRCC4 and XLF form a long-range synaptic complex, in which the DNA ends are held approximately 115 Å apart. Two DNA end-bound subcomplexes comprising Ku and DNA-PKcs are linked by interactions between the DNA-PKcs subunits and a scaffold comprising LigIV, XRCC4, XLF, XRCC4 and LigIV. The relative orientation of the DNA-PKcs molecules suggests a mechanism for autophosphorylation in trans, which leads to the dissociation of DNA-PKcs and the transition into the short-range synaptic complex. Within this complex, the Ku-bound DNA ends are aligned for processing and ligation by the XLF-anchored scaffold, and a single catalytic domain of LigIV is stably associated with a nick between the two Ku molecules, which suggests that the joining of both strands of a DSB involves both LigIV molecules.
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Affiliation(s)
- Siyu Chen
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, IL, USA
| | - Linda Lee
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta, Canada
- Robson DNA Science Centre, Charbonneau Cancer Institute, University of Calgary, Calgary, Alberta, Canada
| | - Tasmin Naila
- Department of Internal Medicine, University of New Mexico, Albuquerque, NM, USA
- Department of Molecular Genetics & Microbiology, University of New Mexico, Albuquerque, NM, USA
- University of New Mexico Comprehensive Cancer Center, University of New Mexico, Albuquerque, NM, USA
| | - Susan Fishbain
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
| | - Annie Wang
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
| | - Alan E Tomkinson
- Department of Internal Medicine, University of New Mexico, Albuquerque, NM, USA
- Department of Molecular Genetics & Microbiology, University of New Mexico, Albuquerque, NM, USA
- University of New Mexico Comprehensive Cancer Center, University of New Mexico, Albuquerque, NM, USA
| | - Susan P Lees-Miller
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta, Canada
- Robson DNA Science Centre, Charbonneau Cancer Institute, University of Calgary, Calgary, Alberta, Canada
| | - Yuan He
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA.
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, IL, USA.
- Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, USA.
- Robert H. Lurie Comprehensive Cancer Center of Northwestern University, Northwestern University, Chicago, IL, USA.
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17
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Stinson BM, Loparo JJ. Repair of DNA Double-Strand Breaks by the Nonhomologous End Joining Pathway. Annu Rev Biochem 2021; 90:137-164. [PMID: 33556282 DOI: 10.1146/annurev-biochem-080320-110356] [Citation(s) in RCA: 85] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
DNA double-strand breaks pose a serious threat to genome stability. In vertebrates, these breaks are predominantly repaired by nonhomologous end joining (NHEJ), which pairs DNA ends in a multiprotein synaptic complex to promote their direct ligation. NHEJ is a highly versatile pathway that uses an array of processing enzymes to modify damaged DNA ends and enable their ligation. The mechanisms of end synapsis and end processing have important implications for genome stability. Rapid and stable synapsis is necessary to limit chromosome translocations that result from the mispairing of DNA ends. Furthermore, end processing must be tightly regulated to minimize mutations at the break site. Here, we review our current mechanistic understanding of vertebrate NHEJ, with a particular focus on end synapsis and processing.
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Affiliation(s)
- Benjamin M Stinson
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts 02115, USA; ,
| | - Joseph J Loparo
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts 02115, USA; ,
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18
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Carney SM, Moreno AT, Piatt SC, Cisneros-Aguirre M, Lopezcolorado FW, Stark JM, Loparo JJ. XLF acts as a flexible connector during non-homologous end joining. eLife 2020; 9:e61920. [PMID: 33289484 PMCID: PMC7744095 DOI: 10.7554/elife.61920] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Accepted: 12/07/2020] [Indexed: 01/01/2023] Open
Abstract
Non-homologous end joining (NHEJ) is the predominant pathway that repairs DNA double-strand breaks in vertebrates. During NHEJ DNA ends are held together by a multi-protein synaptic complex until they are ligated. Here, we use Xenopus laevis egg extract to investigate the role of the intrinsically disordered C-terminal tail of the XRCC4-like factor (XLF), a critical factor in end synapsis. We demonstrate that the XLF tail along with the Ku-binding motif (KBM) at the extreme C-terminus are required for end joining. Although the underlying sequence of the tail can be varied, a minimal tail length is required for NHEJ. Single-molecule FRET experiments that observe end synapsis in real-time show that this defect is due to a failure to closely align DNA ends. Our data supports a model in which a single C-terminal tail tethers XLF to Ku, while allowing XLF to form interactions with XRCC4 that enable synaptic complex formation.
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Affiliation(s)
- Sean M Carney
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical SchoolBostonUnited States
| | - Andrew T Moreno
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical SchoolBostonUnited States
| | - Sadie C Piatt
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical SchoolBostonUnited States
- Harvard Graduate Program in Biophysics, Harvard Medical SchoolBostonUnited States
| | - Metztli Cisneros-Aguirre
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute of the City of HopeDuarteUnited States
- Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of HopeDuarteUnited States
| | | | - Jeremy M Stark
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute of the City of HopeDuarteUnited States
- Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of HopeDuarteUnited States
| | - Joseph J Loparo
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical SchoolBostonUnited States
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19
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Szymonowicz K, Krysztofiak A, van der Linden J, Kern A, Deycmar S, Oeck S, Squire A, Koska B, Hlouschek J, Vüllings M, Neander C, Siveke JT, Matschke J, Pruschy M, Timmermann B, Jendrossek V. Proton Irradiation Increases the Necessity for Homologous Recombination Repair Along with the Indispensability of Non-Homologous End Joining. Cells 2020; 9:E889. [PMID: 32260562 PMCID: PMC7226794 DOI: 10.3390/cells9040889] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Revised: 03/29/2020] [Accepted: 03/30/2020] [Indexed: 12/16/2022] Open
Abstract
Technical improvements in clinical radiotherapy for maximizing cytotoxicity to the tumor while limiting negative impact on co-irradiated healthy tissues include the increasing use of particle therapy (e.g., proton therapy) worldwide. Yet potential differences in the biology of DNA damage induction and repair between irradiation with X-ray photons and protons remain elusive. We compared the differences in DNA double strand break (DSB) repair and survival of cells compromised in non-homologous end joining (NHEJ), homologous recombination repair (HRR) or both, after irradiation with an equal dose of X-ray photons, entrance plateau (EP) protons, and mid spread-out Bragg peak (SOBP) protons. We used super-resolution microscopy to investigate potential differences in spatial distribution of DNA damage foci upon irradiation. While DNA damage foci were equally distributed throughout the nucleus after X-ray photon irradiation, we observed more clustered DNA damage foci upon proton irradiation. Furthermore, deficiency in essential NHEJ proteins delayed DNA repair kinetics and sensitized cells to both, X-ray photon and proton irradiation, whereas deficiency in HRR proteins sensitized cells only to proton irradiation. We assume that NHEJ is indispensable for processing DNA DSB independent of the irradiation source, whereas the importance of HRR rises with increasing energy of applied irradiation.
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Affiliation(s)
- Klaudia Szymonowicz
- Institute of Cell Biology (Cancer Research), University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany; (K.S.); (A.K.); (J.v.d.L.); (S.O.); (J.H.); (J.M.)
| | - Adam Krysztofiak
- Institute of Cell Biology (Cancer Research), University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany; (K.S.); (A.K.); (J.v.d.L.); (S.O.); (J.H.); (J.M.)
| | - Jansje van der Linden
- Institute of Cell Biology (Cancer Research), University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany; (K.S.); (A.K.); (J.v.d.L.); (S.O.); (J.H.); (J.M.)
| | - Ajvar Kern
- West German Proton Therapy Centre Essen (WPE), West German Cancer Center (WTZ), University Hospital Essen, 45147 Essen, Germany; (A.K.); (B.K.); (M.V.); (B.T.)
| | - Simon Deycmar
- Department of Radiation Oncology, Laboratory for Applied Radiobiology, University Hospital Zurich, Zurich, Switzerland; (S.D.); (M.P.)
| | - Sebastian Oeck
- Institute of Cell Biology (Cancer Research), University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany; (K.S.); (A.K.); (J.v.d.L.); (S.O.); (J.H.); (J.M.)
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Anthony Squire
- Institute of Experimental Immunology and Imaging, Imaging Center Essen, University Hospital Essen, 45122 Essen, Germany;
| | - Benjamin Koska
- West German Proton Therapy Centre Essen (WPE), West German Cancer Center (WTZ), University Hospital Essen, 45147 Essen, Germany; (A.K.); (B.K.); (M.V.); (B.T.)
| | - Julian Hlouschek
- Institute of Cell Biology (Cancer Research), University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany; (K.S.); (A.K.); (J.v.d.L.); (S.O.); (J.H.); (J.M.)
| | - Melanie Vüllings
- West German Proton Therapy Centre Essen (WPE), West German Cancer Center (WTZ), University Hospital Essen, 45147 Essen, Germany; (A.K.); (B.K.); (M.V.); (B.T.)
| | - Christian Neander
- Institute of Developmental Cancer Therapeutics, West German Cancer Center, University Hospital Essen, Essen, Germany; (C.N.); (J.T.S.)
- Division of Solid Tumor Translational Oncology, German Cancer Consortium (DKTK, partner site Essen) and German Cancer Research Center, DKFZ, 69120 Heidelberg, Germany
| | - Jens T. Siveke
- Institute of Developmental Cancer Therapeutics, West German Cancer Center, University Hospital Essen, Essen, Germany; (C.N.); (J.T.S.)
- Division of Solid Tumor Translational Oncology, German Cancer Consortium (DKTK, partner site Essen) and German Cancer Research Center, DKFZ, 69120 Heidelberg, Germany
| | - Johann Matschke
- Institute of Cell Biology (Cancer Research), University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany; (K.S.); (A.K.); (J.v.d.L.); (S.O.); (J.H.); (J.M.)
| | - Martin Pruschy
- Department of Radiation Oncology, Laboratory for Applied Radiobiology, University Hospital Zurich, Zurich, Switzerland; (S.D.); (M.P.)
| | - Beate Timmermann
- West German Proton Therapy Centre Essen (WPE), West German Cancer Center (WTZ), University Hospital Essen, 45147 Essen, Germany; (A.K.); (B.K.); (M.V.); (B.T.)
- Division of Solid Tumor Translational Oncology, German Cancer Consortium (DKTK, partner site Essen) and German Cancer Research Center, DKFZ, 69120 Heidelberg, Germany
- Department of Particle Therapy, West German Proton Therapy Center Essen (WPE), West German Cancer Center (WTZ), University Hospital Essen, 45147 Essen, Germany
| | - Verena Jendrossek
- Institute of Cell Biology (Cancer Research), University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany; (K.S.); (A.K.); (J.v.d.L.); (S.O.); (J.H.); (J.M.)
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20
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Structural biology of multicomponent assemblies in DNA double-strand-break repair through non-homologous end joining. Curr Opin Struct Biol 2020; 61:9-16. [DOI: 10.1016/j.sbi.2019.09.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 09/30/2019] [Indexed: 01/19/2023]
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21
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Structural mechanism of DNA-end synapsis in the non-homologous end joining pathway for repairing double-strand breaks: bridge over troubled ends. Biochem Soc Trans 2020; 47:1609-1619. [PMID: 31829407 DOI: 10.1042/bst20180518] [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: 10/22/2019] [Revised: 11/25/2019] [Accepted: 11/27/2019] [Indexed: 12/18/2022]
Abstract
Non-homologous end joining (NHEJ) is a major repair pathway for DNA double-strand breaks (DSBs), which is the most toxic DNA damage in cells. Unrepaired DSBs can cause genome instability, tumorigenesis or cell death. DNA end synapsis is the first and probably the most important step of the NHEJ pathway, aiming to bring two broken DNA ends close together and provide structural stability for end processing and ligation. This process is mediated through a group of NHEJ proteins forming higher-order complexes, to recognise and bridge two DNA ends. Spatial and temporal understanding of the structural mechanism of DNA-end synapsis has been largely advanced through recent structural and single-molecule studies of NHEJ proteins. This review focuses on core NHEJ proteins that mediate DNA end synapsis through their unique structures and interaction properties, as well as how they play roles as anchor and linker proteins during the process of 'bridge over troubled ends'.
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Ruis B, Molan A, Takasugi T, Hendrickson EA. Absence of XRCC4 and its paralogs in human cells reveal differences in outcomes for DNA repair and V(D)J recombination. DNA Repair (Amst) 2019; 85:102738. [PMID: 31731258 DOI: 10.1016/j.dnarep.2019.102738] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 10/15/2019] [Accepted: 10/16/2019] [Indexed: 02/06/2023]
Abstract
The repair of DNA double-stranded breaks (DSBs) is an essential function performed by the Classical Non-Homologous End-Joining (C-NHEJ) pathway in higher eukaryotes. C-NHEJ, in fact, does double duty as it is also required for the repair of the intermediates formed during lymphoid B- and T-cell recombination. Consequently, the failure to properly repair DSBs leads to both genomic instability and immunodeficiency. A critical DSB protein required for C-NHEJ is the DNA Ligase IV (LIGIV) accessory factor, X-Ray Cross Complementing 4 (XRCC4). XRCC4 is believed to stabilize LIGIV, participate in LIGIV activation, and to help tether the broken DSB ends together. XRCC4's role in these processes has been muddied by the identification of two additional XRCC4 paralogs, XRCC4-Like Factor (XLF), and Paralog of XRCC4 and XLF (PAXX). The roles that these paralogs play in C-NHEJ is partially understood, but, in turn, has itself been obscured by species-specific differences observed in the absence of one or the other paralogs. In order to investigate the role(s) that XRCC4 may play, with or without XLF and/or PAXX, in lymphoid variable(diversity)joining [V(D)J] recombination as well as in DNA DSB repair in human somatic cells, we utilized gene targeting to inactivate the XRCC4 gene in both parental and XLF- HCT116 cells and then inactivated PAXX in those same cell lines. The loss of XRCC4 expression by itself led, as anticipated, to increased sensitivity to DNA damaging agents as well as an increased dependence on microhomology-mediated DNA repair whether in the context of DSB repair or during V(D)J recombination. The additional loss of XLF in these cell lines sensitized the cells even more whereas the presence or absence of PAXX was scarcely negligible. These studies demonstrate that, of the three LIG4 accessory factor paralogs, the absence of XRCC4 influences DNA repair and recombination the most in human cells.
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Affiliation(s)
- Brian Ruis
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Medical School, Minneapolis, MN, 55455, United States
| | - Amy Molan
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Medical School, Minneapolis, MN, 55455, United States
| | - Taylor Takasugi
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Medical School, Minneapolis, MN, 55455, United States
| | - Eric A Hendrickson
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Medical School, Minneapolis, MN, 55455, United States.
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Liu Z, Yu M, Fei B, Sun J, Wang D. Identification Of Natural Compound Derivative For Inhibition Of XLF And Overcoming Chemoresistance In Colorectal Cancer Cells. DRUG DESIGN DEVELOPMENT AND THERAPY 2019; 13:3823-3834. [PMID: 31806933 PMCID: PMC6847993 DOI: 10.2147/dddt.s215967] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 09/27/2019] [Indexed: 12/14/2022]
Abstract
Purpose A previous study has identified that XRCC4-like factor (XLF) is a potential target to overcome resistance to 5-fluorouracil (5-Fu) and oxaliplatin (OXA) in colorectal cancer (CRC). The purpose of this study is to develop potent XLF inhibitors to chemoresistance in CRC. Methods Virtual screening was adopted to identify novel XLF-binding compounds by initially testing 6800 molecules in Chemical Entities of Biological Interest library. Hit compounds were further validated by Western blot assay. Cell sensitivity to 5-Fu and OXA was measured using sulforhodamine B assay. The effect of XLF inhibitor on DNA repair efficiency was evaluated by comet assay, fluorescent-based nonhomologous end joining (NHEJ) and homologous recombination (HR) reporter assays. DNA-binding activity of NHEJ key factors was examined by chromatin fractionation assay. Results We identified G3, a novel and potent XLF inhibitor (IC50 0.47±0.02 µM). G3 induced XLF protein degradation in CRC cells. Significantly, G3 improved cell sensitivity to 5-Fu and OXA in chemoresistant CRC cell lines. Mechanistically, G3 depleted XLF expression, severely compromised NHEJ efficiency by up to 65% and inhibited NHEJ key factor assembly on DNA. G3 also inhibited HR efficiency in a time-dependent manner. Conclusion These results suggest that G3 overcomes 5-Fu and OXA resistance in CRC cells by inhibiting XLF expression. Thus, XLF is a promising target and its inhibitor G3 is a potential candidate for treatment of chemoresistant CRC patients.
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Affiliation(s)
- Zhuo Liu
- Department of Gastrointestinal Colorectal and Anal Surgery, China-Japan Union Hospital of Jilin University, Changchun, Jilin, People's Republic of China
| | - Miao Yu
- Department of Gastrointestinal Colorectal and Anal Surgery, China-Japan Union Hospital of Jilin University, Changchun, Jilin, People's Republic of China
| | - Bingyuan Fei
- Department of Gastrointestinal Colorectal and Anal Surgery, China-Japan Union Hospital of Jilin University, Changchun, Jilin, People's Republic of China
| | - Jing Sun
- Department of Biochemistry and Molecular Medicine, The George Washington University, Washington, DC, USA
| | - Dongxin Wang
- Department of Anesthesiology, Jilin Cancer Hospital, Jilin, People's Republic of China
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Wu Q, Liang S, Ochi T, Chirgadze DY, Huiskonen JT, Blundell TL. Understanding the structure and role of DNA-PK in NHEJ: How X-ray diffraction and cryo-EM contribute in complementary ways. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2019; 147:26-32. [DOI: 10.1016/j.pbiomolbio.2019.03.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 03/12/2019] [Accepted: 03/26/2019] [Indexed: 12/13/2022]
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The essential elements for the noncovalent association of two DNA ends during NHEJ synapsis. Nat Commun 2019; 10:3588. [PMID: 31399561 PMCID: PMC6688983 DOI: 10.1038/s41467-019-11507-z] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 07/17/2019] [Indexed: 01/13/2023] Open
Abstract
One of the most central questions about the repair of a double-strand DNA break (DSB) concerns how the two free DNA ends are brought together - a step called synapsis. Using single-molecule FRET (smFRET), we show here that both Ku plus XRCC4:DNA ligase IV are necessary and sufficient to achieve a flexible synapsis of blunt DNA ends, whereas either alone is not. Addition of XLF causes a transition to a close synaptic state, and maximum efficiency of close synapsis is achieved within 20 min. The promotion of close synapsis by XLF indicates a role that is independent of a filament structure, with action focused at the very ends of each duplex. DNA-PKcs is not required for the formation of either the flexible or close synaptic states. This model explains in biochemical terms the evolutionarily central synaptic role of Ku, X4L4, and XLF in NHEJ for all eukaryotes.
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Chen BR, Quinet A, Byrum AK, Jackson J, Berti M, Thangavel S, Bredemeyer AL, Hindi I, Mosammaparast N, Tyler JK, Vindigni A, Sleckman BP. XLF and H2AX function in series to promote replication fork stability. J Cell Biol 2019; 218:2113-2123. [PMID: 31123184 PMCID: PMC6605786 DOI: 10.1083/jcb.201808134] [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: 08/22/2018] [Revised: 04/03/2019] [Accepted: 05/03/2019] [Indexed: 12/21/2022] Open
Abstract
Chen et al. show that XLF functions to limit fork reversal during DNA replication. H2AX prevents MRE11-dependent replication stress in XLF-deficient cells, suggesting that H2AX prevents the resection of regressed arms at reversed forks. XRCC4-like factor (XLF) is a non-homologous end joining (NHEJ) DNA double strand break repair protein. However, XLF deficiency leads to phenotypes in mice and humans that are not necessarily consistent with an isolated defect in NHEJ. Here we show that XLF functions during DNA replication. XLF undergoes cell division cycle 7–dependent phosphorylation; associates with the replication factor C complex, a critical component of the replisome; and is found at replication forks. XLF deficiency leads to defects in replication fork progression and an increase in fork reversal. The additional loss of H2AX, which protects DNA ends from resection, leads to a requirement for ATR to prevent an MRE11-dependent loss of newly synthesized DNA and activation of DNA damage response. Moreover, H2ax−/−:Xlf−/− cells exhibit a marked dependence on the ATR kinase for survival. We propose that XLF and H2AX function in series to prevent replication stress induced by the MRE11-dependent resection of regressed arms at reversed replication forks.
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Affiliation(s)
- Bo-Ruei Chen
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY
| | - Annabel Quinet
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO
| | - Andrea K Byrum
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO
| | - Jessica Jackson
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO
| | - Matteo Berti
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO
| | - Saravanabhavan Thangavel
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO
| | - Andrea L Bredemeyer
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO
| | - Issa Hindi
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY
| | - Nima Mosammaparast
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO
| | - Jessica K Tyler
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY
| | - Alessandro Vindigni
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO
| | - Barry P Sleckman
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY
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Plugged into the Ku-DNA hub: The NHEJ network. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2019; 147:62-76. [PMID: 30851288 DOI: 10.1016/j.pbiomolbio.2019.03.001] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 02/26/2019] [Accepted: 03/01/2019] [Indexed: 12/16/2022]
Abstract
In vertebrates, double-strand breaks in DNA are primarily repaired by Non-Homologous End-Joining (NHEJ). The ring-shaped Ku heterodimer rapidly senses and threads onto broken DNA ends forming a recruiting hub. Through protein-protein contacts eventually reinforced by protein-DNA interactions, the Ku-DNA hub attracts a series of specialized proteins with scaffolding and/or enzymatic properties. To shed light on these dynamic interplays, we review here current knowledge on proteins directly interacting with Ku and on the contact points involved, with a particular accent on the different classes of Ku-binding motifs identified in several Ku partners. An integrated structural model of the core NHEJ network at the synapsis step is proposed.
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Yeap LS, Meng FL. Cis- and trans-factors affecting AID targeting and mutagenic outcomes in antibody diversification. Adv Immunol 2019; 141:51-103. [PMID: 30904133 DOI: 10.1016/bs.ai.2019.01.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Antigen receptor diversification is a hallmark of adaptive immunity which allows specificity of the receptor to particular antigen. B cell receptor (BCR) or its secreted form, antibody, is diversified through antigen-independent and antigen-dependent mechanisms. During B cell development in bone marrow, BCR is diversified via V(D)J recombination mediated by RAG endonuclease. Upon stimulation by antigen, B cell undergo somatic hypermutation (SHM) to allow affinity maturation and class switch recombination (CSR) to change the effector function of the antibody. Both SHM and CSR are initiated by activation-induced cytidine deaminase (AID). Repair of AID-initiated lesions through different DNA repair pathways results in diverse mutagenic outcomes. Here, we focus on discussing cis- and trans-factors that target AID to its substrates and factors that affect different outcomes of AID-initiated lesions. The knowledge of mechanisms that govern AID targeting and outcomes could be harnessed to elicit rare functional antibodies and develop ex vivo antibody diversification approaches with diversifying base editors.
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Affiliation(s)
- Leng-Siew Yeap
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Fei-Long Meng
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China.
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30
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Nemoz C, Ropars V, Frit P, Gontier A, Drevet P, Yu J, Guerois R, Pitois A, Comte A, Delteil C, Barboule N, Legrand P, Baconnais S, Yin Y, Tadi S, Barbet-Massin E, Berger I, Le Cam E, Modesti M, Rothenberg E, Calsou P, Charbonnier JB. XLF and APLF bind Ku80 at two remote sites to ensure DNA repair by non-homologous end joining. Nat Struct Mol Biol 2018; 25:971-980. [PMID: 30291363 PMCID: PMC6234012 DOI: 10.1038/s41594-018-0133-6] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 08/21/2018] [Indexed: 12/20/2022]
Abstract
The Ku70-Ku80 (Ku) heterodimer binds rapidly and tightly to the ends of DNA double-strand breaks and recruits factors of the non-homologous end-joining (NHEJ) repair pathway through molecular interactions that remain unclear. We have determined crystal structures of the Ku-binding motifs (KBM) of the NHEJ proteins APLF (A-KBM) and XLF (X-KBM) bound to a Ku-DNA complex. The two KBM motifs bind remote sites of the Ku80 α/β domain. The X-KBM occupies an internal pocket formed by an unprecedented large outward rotation of the Ku80 α/β domain. We observe independent recruitment of the APLF-interacting protein XRCC4 and of XLF to laser-irradiated sites via binding of A- and X-KBMs, respectively, to Ku80. Finally, we show that mutation of the X-KBM and A-KBM binding sites in Ku80 compromises both the efficiency and accuracy of end joining and cellular radiosensitivity. A- and X-KBMs may represent two initial anchor points to build the intricate interaction network required for NHEJ.
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Affiliation(s)
- Clement Nemoz
- Institute for Integrative Biology of the Cell, Institute Joliot, CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Virginie Ropars
- Institute for Integrative Biology of the Cell, Institute Joliot, CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Philippe Frit
- Institut de Pharmacologie et Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
- Equipe Labellisée Ligue Contre le Cancer 2018, Toulouse, France
| | - Amandine Gontier
- Institute for Integrative Biology of the Cell, Institute Joliot, CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Pascal Drevet
- Institute for Integrative Biology of the Cell, Institute Joliot, CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Jinchao Yu
- Institute for Integrative Biology of the Cell, Institute Joliot, CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Raphaël Guerois
- Institute for Integrative Biology of the Cell, Institute Joliot, CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Aurelien Pitois
- Institute for Integrative Biology of the Cell, Institute Joliot, CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Audrey Comte
- Institute for Integrative Biology of the Cell, Institute Joliot, CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Christine Delteil
- Institut de Pharmacologie et Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
- Equipe Labellisée Ligue Contre le Cancer 2018, Toulouse, France
| | - Nadia Barboule
- Institut de Pharmacologie et Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
- Equipe Labellisée Ligue Contre le Cancer 2018, Toulouse, France
| | - Pierre Legrand
- Synchrotron Soleil, L'Orme des Merisiers, Saint-Aubin, Gif-sur-Yvette, France
| | - Sonia Baconnais
- Signalisations, Noyaux et Innovations en Cancérologie, UMR 8126, CNRS, Université Paris-Sud, Gustave Roussy, Université Paris-Saclay, Villejuif, France
| | - Yandong Yin
- New York University School of Medicine, Perlmutter Cancer Center, New York, USA
| | - Satish Tadi
- Cancer Research Center of Marseille, CNRS UMR 7258, Inserm U1068, Institut Paoli-Calmettes, Aix-Marseille Université UM105, Marseille, France
| | | | - Imre Berger
- BrisSynBio Centre, School of Biochemistry, Faculty of Biomedical Sciences, University of Bristol, Bristol, UK
| | - Eric Le Cam
- Signalisations, Noyaux et Innovations en Cancérologie, UMR 8126, CNRS, Université Paris-Sud, Gustave Roussy, Université Paris-Saclay, Villejuif, France
| | - Mauro Modesti
- Cancer Research Center of Marseille, CNRS UMR 7258, Inserm U1068, Institut Paoli-Calmettes, Aix-Marseille Université UM105, Marseille, France
| | - Eli Rothenberg
- New York University School of Medicine, Perlmutter Cancer Center, New York, USA
| | - Patrick Calsou
- Institut de Pharmacologie et Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France.
- Equipe Labellisée Ligue Contre le Cancer 2018, Toulouse, France.
| | - Jean Baptiste Charbonnier
- Institute for Integrative Biology of the Cell, Institute Joliot, CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France.
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A single XLF dimer bridges DNA ends during nonhomologous end joining. Nat Struct Mol Biol 2018; 25:877-884. [PMID: 30177755 PMCID: PMC6128732 DOI: 10.1038/s41594-018-0120-y] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 07/05/2018] [Indexed: 01/09/2023]
Abstract
Non-homologous end joining (NHEJ) is the primary pathway of DNA double-strand break repair in vertebrate cells, yet it remains unclear how NHEJ factors assemble a synaptic complex that bridges DNA ends. To address the role of XRCC4-like factor (XLF) in synaptic complex assembly, we employed single-molecule fluorescence imaging in Xenopus laevis egg extract, a system that efficiently joins DNA ends. We find that a single XLF dimer binds to DNA substrates just prior to formation of a ligation-competent synaptic complex between DNA ends. The interaction of both globular head domains of the XLF dimer with XRCC4 is required for efficient formation of this synaptic complex. In contrast to a model in which filaments of XLF and XRCC4 bridge DNA ends, our results indicate that binding of a single XLF dimer facilitates the assembly of a stoichiometrically well-defined synaptic complex.
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32
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Hung PJ, Johnson B, Chen BR, Byrum AK, Bredemeyer AL, Yewdell WT, Johnson TE, Lee BJ, Deivasigamani S, Hindi I, Amatya P, Gross ML, Paull TT, Pisapia DJ, Chaudhuri J, Petrini JJH, Mosammaparast N, Amarasinghe GK, Zha S, Tyler JK, Sleckman BP. MRI Is a DNA Damage Response Adaptor during Classical Non-homologous End Joining. Mol Cell 2018; 71:332-342.e8. [PMID: 30017584 PMCID: PMC6083883 DOI: 10.1016/j.molcel.2018.06.018] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 05/20/2018] [Accepted: 06/07/2018] [Indexed: 11/15/2022]
Abstract
The modulator of retrovirus infection (MRI or CYREN) is a 30-kDa protein with a conserved N-terminal Ku-binding motif (KBM) and a C-terminal XLF-like motif (XLM). We show that MRI is intrinsically disordered and interacts with many DNA damage response (DDR) proteins, including the kinases ataxia telangiectasia mutated (ATM) and DNA-PKcs and the classical non-homologous end joining (cNHEJ) factors Ku70, Ku80, XRCC4, XLF, PAXX, and XRCC4. MRI forms large multimeric complexes that depend on its N and C termini and localizes to DNA double-strand breaks (DSBs), where it promotes the retention of DDR factors. Mice deficient in MRI and XLF exhibit embryonic lethality at a stage similar to those deficient in the core cNHEJ factors XRCC4 or DNA ligase IV. Moreover, MRI is required for cNHEJ-mediated DSB repair in XLF-deficient lymphocytes. We propose that MRI is an adaptor that, through multivalent interactions, increases the avidity of DDR factors to DSB-associated chromatin to promote cNHEJ.
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Affiliation(s)
- Putzer J Hung
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY 10065, USA; Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Britney Johnson
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Bo-Ruei Chen
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY 10065, USA
| | - Andrea K Byrum
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Andrea L Bredemeyer
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - William T Yewdell
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Tanya E Johnson
- The Department of Molecular Biosciences and the Howard Hughes Medical Institute, The University of Texas at Austin, Austin, TX 78712, USA
| | - Brian J Lee
- Institute for Cancer Genetics, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
| | - Shruthi Deivasigamani
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY 10065, USA
| | - Issa Hindi
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY 10065, USA
| | - Parmeshwar Amatya
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Michael L Gross
- Department of Chemistry, Washington University, One Brookings Drive, St. Louis, MO 63130, USA
| | - Tanya T Paull
- The Department of Molecular Biosciences and the Howard Hughes Medical Institute, The University of Texas at Austin, Austin, TX 78712, USA
| | - David J Pisapia
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY 10065, USA
| | - Jayanta Chaudhuri
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - John J H Petrini
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Nima Mosammaparast
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Gaya K Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Shan Zha
- Institute for Cancer Genetics, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
| | - Jessica K Tyler
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY 10065, USA
| | - Barry P Sleckman
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY 10065, USA.
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Bhargava R, Sandhu M, Muk S, Lee G, Vaidehi N, Stark JM. C-NHEJ without indels is robust and requires synergistic function of distinct XLF domains. Nat Commun 2018; 9:2484. [PMID: 29950655 PMCID: PMC6021437 DOI: 10.1038/s41467-018-04867-5] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 05/25/2018] [Indexed: 01/17/2023] Open
Abstract
To investigate the fidelity of canonical non-homologous end joining (C-NHEJ), we developed an assay to detect EJ between distal ends of two Cas9-induced chromosomal breaks that are joined without causing insertion/deletion mutations (indels). Here we find that such EJ requires several core C-NHEJ factors, including XLF. Using variants of this assay, we find that C-NHEJ is required for EJ events that use 1-2, but not ≥3, nucleotides of terminal microhomology. We also investigated XLF residues required for EJ without indels, finding that one of two binding domains is essential (L115 or C-terminal lysines that bind XRCC4 and KU/DNA, respectively), and that disruption of one of these domains sensitizes XLF to mutations that affect its dimer interface, which we examined with molecular dynamic simulations. Thus, C-NHEJ, including synergistic function of distinct XLF domains, is required for EJ of chromosomal breaks without indels.
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Affiliation(s)
- Ragini Bhargava
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute of the City of Hope, 1500 E Duarte Rd., Duarte, CA, 91010, USA
- Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, 1500 E Duarte Rd., Duarte, CA, 91010, USA
| | - Manbir Sandhu
- Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, 1500 E Duarte Rd., Duarte, CA, 91010, USA
- Department of Molecular Immunology, Beckman Research Institute of the City of Hope, 1500 E Duarte Rd., Duarte, CA, 91010, USA
| | - Sanychen Muk
- Department of Molecular Immunology, Beckman Research Institute of the City of Hope, 1500 E Duarte Rd., Duarte, CA, 91010, USA
| | - Gabriella Lee
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute of the City of Hope, 1500 E Duarte Rd., Duarte, CA, 91010, USA
| | - Nagarajan Vaidehi
- Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, 1500 E Duarte Rd., Duarte, CA, 91010, USA
- Department of Molecular Immunology, Beckman Research Institute of the City of Hope, 1500 E Duarte Rd., Duarte, CA, 91010, USA
| | - Jeremy M Stark
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute of the City of Hope, 1500 E Duarte Rd., Duarte, CA, 91010, USA.
- Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, 1500 E Duarte Rd., Duarte, CA, 91010, USA.
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Conlin MP, Reid DA, Small GW, Chang HH, Watanabe G, Lieber MR, Ramsden DA, Rothenberg E. DNA Ligase IV Guides End-Processing Choice during Nonhomologous End Joining. Cell Rep 2018; 20:2810-2819. [PMID: 28930678 DOI: 10.1016/j.celrep.2017.08.091] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 08/22/2017] [Accepted: 08/25/2017] [Indexed: 12/15/2022] Open
Abstract
Nonhomologous end joining (NHEJ) must adapt to diverse end structures during repair of chromosome breaks. Here, we investigate the mechanistic basis for this flexibility. DNA ends are aligned in a paired-end complex (PEC) by Ku, XLF, XRCC4, and DNA ligase IV (LIG4); we show by single-molecule analysis how terminal mispairs lead to mobilization of ends within PECs and consequent sampling of more end-alignment configurations. This remodeling is essential for direct ligation of damaged and mispaired ends during cellular NHEJ, since remodeling and ligation of such ends both require a LIG4-specific structural motif, insert1. Insert1 is also required for PEC remodeling that enables nucleolytic processing when end structures block direct ligation. Accordingly, cells expressing LIG4 lacking insert1 are sensitive to ionizing radiation. Cellular NHEJ of diverse ends thus identifies the steps necessary for repair through LIG4-mediated sensing of differences in end structure and consequent dynamic remodeling of aligned ends.
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Affiliation(s)
- Michael P Conlin
- Lineberger Comprehensive Cancer Center, Curriculum in Genetics and Molecular Biology, and Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Dylan A Reid
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016, USA
| | - George W Small
- Lineberger Comprehensive Cancer Center, Curriculum in Genetics and Molecular Biology, and Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Howard H Chang
- University of Southern California Keck School of Medicine, Norris Comprehensive Cancer Center, Los Angeles, CA 90033, USA
| | - Go Watanabe
- University of Southern California Keck School of Medicine, Norris Comprehensive Cancer Center, Los Angeles, CA 90033, USA
| | - Michael R Lieber
- University of Southern California Keck School of Medicine, Norris Comprehensive Cancer Center, Los Angeles, CA 90033, USA
| | - Dale A Ramsden
- Lineberger Comprehensive Cancer Center, Curriculum in Genetics and Molecular Biology, and Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, USA.
| | - Eli Rothenberg
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016, USA.
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35
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Pannunzio NR, Watanabe G, Lieber MR. Nonhomologous DNA end-joining for repair of DNA double-strand breaks. J Biol Chem 2017; 293:10512-10523. [PMID: 29247009 DOI: 10.1074/jbc.tm117.000374] [Citation(s) in RCA: 335] [Impact Index Per Article: 47.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Nonhomologous DNA end-joining (NHEJ) is the predominant double-strand break (DSB) repair pathway throughout the cell cycle and accounts for nearly all DSB repair outside of the S and G2 phases. NHEJ relies on Ku to thread onto DNA termini and thereby improve the affinity of the NHEJ enzymatic components consisting of polymerases (Pol μ and Pol λ), a nuclease (the Artemis·DNA-PKcs complex), and a ligase (XLF·XRCC4·Lig4 complex). Each of the enzymatic components is distinctive for its versatility in acting on diverse incompatible DNA end configurations coupled with a flexibility in loading order, resulting in many possible junctional outcomes from one DSB. DNA ends can either be directly ligated or, if the ends are incompatible, processed until a ligatable configuration is achieved that is often stabilized by up to 4 bp of terminal microhomology. Processing of DNA ends results in nucleotide loss or addition, explaining why DSBs repaired by NHEJ are rarely restored to their original DNA sequence. Thus, NHEJ is a single pathway with multiple enzymes at its disposal to repair DSBs, resulting in a diversity of repair outcomes.
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Affiliation(s)
- Nicholas R Pannunzio
- From the Departments of Pathology, Biochemistry and Molecular Biology, and Molecular Microbiology and Immunology, Section of Molecular and Computational Biology, Department of Biological Sciences, Norris Comprehensive Cancer Center, University of Southern California Keck School of Medicine, Los Angeles, California 90033
| | - Go Watanabe
- From the Departments of Pathology, Biochemistry and Molecular Biology, and Molecular Microbiology and Immunology, Section of Molecular and Computational Biology, Department of Biological Sciences, Norris Comprehensive Cancer Center, University of Southern California Keck School of Medicine, Los Angeles, California 90033
| | - Michael R Lieber
- From the Departments of Pathology, Biochemistry and Molecular Biology, and Molecular Microbiology and Immunology, Section of Molecular and Computational Biology, Department of Biological Sciences, Norris Comprehensive Cancer Center, University of Southern California Keck School of Medicine, Los Angeles, California 90033
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36
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Tadi SK, Tellier-Lebègue C, Nemoz C, Drevet P, Audebert S, Roy S, Meek K, Charbonnier JB, Modesti M. PAXX Is an Accessory c-NHEJ Factor that Associates with Ku70 and Has Overlapping Functions with XLF. Cell Rep 2017; 17:541-555. [PMID: 27705800 DOI: 10.1016/j.celrep.2016.09.026] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 08/31/2016] [Accepted: 09/09/2016] [Indexed: 01/19/2023] Open
Abstract
In mammalian cells, classical non-homologous end joining (c-NHEJ) is critical for DNA double-strand break repair induced by ionizing radiation and during V(D)J recombination in developing B and T lymphocytes. Recently, PAXX was identified as a c-NHEJ core component. We report here that PAXX-deficient cells exhibit a cellular phenotype uncharacteristic of a deficiency in c-NHEJ core components. PAXX-deficient cells display normal sensitivity to radiomimetic drugs, are proficient in transient V(D)J recombination assays, and do not shift toward higher micro-homology usage in plasmid repair assays. Although PAXX-deficient cells lack c-NHEJ phenotypes, PAXX forms a stable ternary complex with Ku bound to DNA. Formation of this complex involves an interaction with Ku70 and requires a bare DNA extension for stability. Moreover, the relatively weak Ku-dependent stimulation of LIG4/XRCC4 activity by PAXX is unmasked by XLF ablation. Thus, PAXX plays an accessory role during c-NHEJ that is largely overlapped by XLF's function.
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Affiliation(s)
- Satish K Tadi
- Cancer Research Center of Marseille, CNRS UMR7258, INSERM U1068, Institut Paoli-Calmettes, Aix-Marseille Université UM105, 13273 Marseille, France
| | - Carine Tellier-Lebègue
- Institute for Integrative Biology of the Cell (I2BC), IBITECS, CEA, CNRS, University Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette cedex, France
| | - Clément Nemoz
- Institute for Integrative Biology of the Cell (I2BC), IBITECS, CEA, CNRS, University Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette cedex, France
| | - Pascal Drevet
- Institute for Integrative Biology of the Cell (I2BC), IBITECS, CEA, CNRS, University Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette cedex, France
| | - Stéphane Audebert
- Cancer Research Center of Marseille, CNRS UMR7258, INSERM U1068, Institut Paoli-Calmettes, Aix-Marseille Université UM105, 13273 Marseille, France
| | - Sunetra Roy
- Department of Microbiology & Molecular Genetics, and Department of Pathobiology & Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA
| | - Katheryn Meek
- Department of Microbiology & Molecular Genetics, and Department of Pathobiology & Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA
| | - Jean-Baptiste Charbonnier
- Institute for Integrative Biology of the Cell (I2BC), IBITECS, CEA, CNRS, University Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette cedex, France
| | - Mauro Modesti
- Cancer Research Center of Marseille, CNRS UMR7258, INSERM U1068, Institut Paoli-Calmettes, Aix-Marseille Université UM105, 13273 Marseille, France.
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37
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Jaafar L, Li Z, Li S, Dynan WS. SFPQ•NONO and XLF function separately and together to promote DNA double-strand break repair via canonical nonhomologous end joining. Nucleic Acids Res 2017; 45:1848-1859. [PMID: 27924002 PMCID: PMC5605232 DOI: 10.1093/nar/gkw1209] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 11/28/2016] [Indexed: 01/10/2023] Open
Abstract
A complex of two related mammalian proteins, SFPQ and NONO, promotes DNA double-strand break repair via the canonical nonhomologous end joining (c-NHEJ) pathway. However, its mechanism of action is not fully understood. Here we describe an improved SFPQ•NONO-dependent in vitro end joining assay. We use this system to demonstrate that the SFPQ•NONO complex substitutes in vitro for the core c-NHEJ factor, XLF. Results are consistent with a model where SFPQ•NONO promotes sequence-independent pairing of DNA substrates, albeit in a way that differs in detail from XLF. Although SFPQ•NONO and XLF function redundantly in vitro, shRNA-mediated knockdown experiments indicate that NONO and XLF are both required for efficient end joining and radioresistance in cell-based assays. In addition, knockdown of NONO sensitizes cells to the interstrand crosslinking agent, cisplatin, whereas knockdown of XLF does not, and indeed suppresses the effect of NONO deficiency. These findings suggest that each protein has one or more unique activities, in addition to the DNA pairing revealed in vitro, that contribute to DNA repair in the more complex cellular milieu. The SFPQ•NONO complex contains an RNA binding domain, and prior work has demonstrated diverse roles in RNA metabolism. It is thus plausible that the additional repair function of NONO, revealed in cell-based assays, could involve RNA interaction.
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Affiliation(s)
- Lahcen Jaafar
- Departments of Radiation Oncology and Biochemistry, Emory University, Atlanta, GA 30322, USA
| | - Zhentian Li
- Departments of Radiation Oncology and Biochemistry, Emory University, Atlanta, GA 30322, USA
| | - Shuyi Li
- Departments of Radiation Oncology and Biochemistry, Emory University, Atlanta, GA 30322, USA
| | - William S Dynan
- Departments of Radiation Oncology and Biochemistry, Emory University, Atlanta, GA 30322, USA
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38
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Menon V, Povirk LF. XLF/Cernunnos: An important but puzzling participant in the nonhomologous end joining DNA repair pathway. DNA Repair (Amst) 2017; 58:29-37. [PMID: 28846869 DOI: 10.1016/j.dnarep.2017.08.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Revised: 07/24/2017] [Accepted: 08/07/2017] [Indexed: 01/15/2023]
Abstract
DNA double strand breaks (DSBs) are one of the most deleterious DNA lesions that promote cell death, genomic instability and carcinogenesis. The two major cellular mechanisms that repair DSBs are Nonhomologous End-Joining (NHEJ) and Homologous Recombination Repair (HRR). NHEJ is the predominant pathway, in which XLF (also called Cernunnos) is a key player. Patients with XLF mutation exhibit microcephaly, lymphopenia, and growth retardation, and are immunodeficient and radiosensitive. During NHEJ, XLF interacts with XRCC4-Ligase IV, stimulates its ligase activity, and forms DNA-binding filaments of alternating XLF and XRCC4 dimers that may serve to align broken DNA and promote ligation of noncomplementary ends. Despite its central role in NHEJ, the effects of XLF deficiency are surprisingly variable in different biological contexts, and different individual cell lines. This review summarizes the role of XLF in NHEJ, and the unexpected complexity of its interplay with other repair factors in supporting radiosurvival and V(D)J recombination.
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Affiliation(s)
- Vijay Menon
- Goodwin Research Laboratory, Massey Cancer Center, Virginia Commonwealth University, VA, USA
| | - Lawrence F Povirk
- Goodwin Research Laboratory, Massey Cancer Center, Virginia Commonwealth University, VA, USA; Department of Pharmacology and Toxicology, Virginia Commonwealth University, VA, USA.
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39
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Brosey CA, Ahmed Z, Lees-Miller SP, Tainer JA. What Combined Measurements From Structures and Imaging Tell Us About DNA Damage Responses. Methods Enzymol 2017; 592:417-455. [PMID: 28668129 DOI: 10.1016/bs.mie.2017.04.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
DNA damage outcomes depend upon the efficiency and fidelity of DNA damage responses (DDRs) for different cells and damage. As such, DDRs represent tightly regulated prototypical systems for linking nanoscale biomolecular structure and assembly to the biology of genomic regulation and cell signaling. However, the dynamic and multifunctional nature of DDR assemblies can render elusive the correlation between the structures of DDR factors and specific biological disruptions to the DDR when these structures are altered. In this chapter, we discuss concepts and strategies for combining structural, biophysical, and imaging techniques to investigate DDR recognition and regulation, and thus bridge sequence-level structural biochemistry to quantitative biological outcomes visualized in cells. We focus on representative DDR responses from PARP/PARG/AIF damage signaling in DNA single-strand break repair and nonhomologous end joining complexes in double-strand break repair. Methods with exemplary experimental results are considered with a focus on strategies for probing flexibility, conformational changes, and assembly processes that shape a predictive understanding of DDR mechanisms in a cellular context. Integration of structural and imaging measurements promises to provide foundational knowledge to rationally control and optimize DNA damage outcomes for synthetic lethality and for immune activation with resulting insights for biology and cancer interventions.
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Affiliation(s)
- Chris A Brosey
- The University of Texas, M.D. Anderson Cancer Center, Houston, TX, United States
| | - Zamal Ahmed
- The University of Texas, M.D. Anderson Cancer Center, Houston, TX, United States
| | - Susan P Lees-Miller
- Robson DNA Science Centre, Arnie Charbonneau Cancer Institute, University of Calgary, Calgary, AB, Canada.
| | - John A Tainer
- The University of Texas, M.D. Anderson Cancer Center, Houston, TX, United States; Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA, United States.
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40
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Non-homologous DNA end joining and alternative pathways to double-strand break repair. Nat Rev Mol Cell Biol 2017; 18:495-506. [PMID: 28512351 DOI: 10.1038/nrm.2017.48] [Citation(s) in RCA: 1032] [Impact Index Per Article: 147.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
DNA double-strand breaks (DSBs) are the most dangerous type of DNA damage because they can result in the loss of large chromosomal regions. In all mammalian cells, DSBs that occur throughout the cell cycle are repaired predominantly by the non-homologous DNA end joining (NHEJ) pathway. Defects in NHEJ result in sensitivity to ionizing radiation and the ablation of lymphocytes. The NHEJ pathway utilizes proteins that recognize, resect, polymerize and ligate the DNA ends in a flexible manner. This flexibility permits NHEJ to function on a wide range of DNA-end configurations, with the resulting repaired DNA junctions often containing mutations. In this Review, we discuss the most recent findings regarding the relative involvement of the different NHEJ proteins in the repair of various DNA-end configurations. We also discuss the shunting of DNA-end repair to the auxiliary pathways of alternative end joining (a-EJ) or single-strand annealing (SSA) and the relevance of these different pathways to human disease.
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41
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Normanno D, Négrel A, de Melo AJ, Betzi S, Meek K, Modesti M. Mutational phospho-mimicry reveals a regulatory role for the XRCC4 and XLF C-terminal tails in modulating DNA bridging during classical non-homologous end joining. eLife 2017; 6. [PMID: 28500754 PMCID: PMC5468090 DOI: 10.7554/elife.22900] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 05/12/2017] [Indexed: 12/23/2022] Open
Abstract
XRCC4 and DNA Ligase 4 (LIG4) form a tight complex that provides DNA ligase activity for classical non-homologous end joining (the predominant DNA double-strand break repair pathway in higher eukaryotes) and is stimulated by XLF. Independently of LIG4, XLF also associates with XRCC4 to form filaments that bridge DNA. These XRCC4/XLF complexes rapidly load and connect broken DNA, thereby stimulating intermolecular ligation. XRCC4 and XLF both include disordered C-terminal tails that are functionally dispensable in isolation but are phosphorylated in response to DNA damage by DNA-PK and/or ATM. Here we concomitantly modify the tails of XRCC4 and XLF by substituting fourteen previously identified phosphorylation sites with either alanine or aspartate residues. These phospho-blocking and -mimicking mutations impact both the stability and DNA bridging capacity of XRCC4/XLF complexes, but without affecting their ability to stimulate LIG4 activity. Implicit in this finding is that phosphorylation may regulate DNA bridging by XRCC4/XLF filaments.
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Affiliation(s)
- Davide Normanno
- Cancer Research Center of Marseille, CNRS UMR7258, Inserm U1068, Institut Paoli-Calmettes, Aix-Marseille Université UM105, Marseille, France
| | - Aurélie Négrel
- Cancer Research Center of Marseille, CNRS UMR7258, Inserm U1068, Institut Paoli-Calmettes, Aix-Marseille Université UM105, Marseille, France
| | - Abinadabe J de Melo
- Cancer Research Center of Marseille, CNRS UMR7258, Inserm U1068, Institut Paoli-Calmettes, Aix-Marseille Université UM105, Marseille, France
| | - Stéphane Betzi
- Cancer Research Center of Marseille, CNRS UMR7258, Inserm U1068, Institut Paoli-Calmettes, Aix-Marseille Université UM105, Marseille, France
| | - Katheryn Meek
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, United States.,Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, United States
| | - Mauro Modesti
- Cancer Research Center of Marseille, CNRS UMR7258, Inserm U1068, Institut Paoli-Calmettes, Aix-Marseille Université UM105, Marseille, France
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42
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Rulten SL, Grundy GJ. Non-homologous end joining: Common interaction sites and exchange of multiple factors in the DNA repair process. Bioessays 2017; 39. [PMID: 28133776 DOI: 10.1002/bies.201600209] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Non-homologous end-joining (NHEJ) is the dominant means of repairing chromosomal DNA double strand breaks (DSBs), and is essential in human cells. Fifteen or more proteins can be involved in the detection, signalling, synapsis, end-processing and ligation events required to repair a DSB, and must be assembled in the confined space around the DNA ends. We review here a number of interaction points between the core NHEJ components (Ku70, Ku80, DNA-PKcs, XRCC4 and Ligase IV) and accessory factors such as kinases, phosphatases, polymerases and structural proteins. Conserved protein-protein interaction sites such as Ku-binding motifs (KBMs), XLF-like motifs (XLMs), FHA and BRCT domains illustrate that different proteins compete for the same binding sites on the core machinery, and must be spatially and temporally regulated. We discuss how post-translational modifications such as phosphorylation, ADP-ribosylation and ubiquitinylation may regulate sequential steps in the NHEJ pathway or control repair at different types of DNA breaks.
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Affiliation(s)
- Stuart L Rulten
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton, UK
| | - Gabrielle J Grundy
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton, UK
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43
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Liu X, Shao Z, Jiang W, Lee BJ, Zha S. PAXX promotes KU accumulation at DNA breaks and is essential for end-joining in XLF-deficient mice. Nat Commun 2017; 8:13816. [PMID: 28051062 PMCID: PMC5216128 DOI: 10.1038/ncomms13816] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 10/26/2016] [Indexed: 01/08/2023] Open
Abstract
Non-homologous end-joining (NHEJ) is the most prominent DNA double strand break (DSB) repair pathway in mammalian cells. PAXX is the newest NHEJ factor, which shares structural similarity with known NHEJ factors—XRCC4 and XLF. Here we report that PAXX is dispensable for physiological NHEJ in otherwise wild-type mice. Yet Paxx−/− mice require XLF and Xlf−/− mice require PAXX for end-ligation. As such, Xlf−/−Paxx−/− mice display severe genomic instability and neuronal apoptosis, which eventually lead to embryonic lethality. Despite their structural similarities, only Xlf−/− cells, but not Paxx−/− cells require ATM/DNA-PK kinase activity for end-ligation. Mechanistically, PAXX promotes the accumulation of KU at DSBs, while XLF enhances LIG4 recruitment without affecting KU dynamics at DNA breaks in vivo. Together these findings identify the molecular functions of PAXX in KU accumulation at DNA ends and reveal distinct, yet critically complementary functions of PAXX and XLF during NHEJ. Non-homologous end-joining is the key pathway for repairing double-stranded DNA breaks in mammalian cells. Here the authors show that PAXX promotes the accumulation of KU at DNA breaks and is essential for end-joining in cells lacking XLF.
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Affiliation(s)
- Xiangyu Liu
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, Institute for Cancer Genetics, Columbia University, 1130 Saint Nicholas Avenue, Room 501, New York City, New York 10032, USA
| | - Zhengping Shao
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, Institute for Cancer Genetics, Columbia University, 1130 Saint Nicholas Avenue, Room 501, New York City, New York 10032, USA
| | - Wenxia Jiang
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, Institute for Cancer Genetics, Columbia University, 1130 Saint Nicholas Avenue, Room 501, New York City, New York 10032, USA
| | - Brian J Lee
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, Institute for Cancer Genetics, Columbia University, 1130 Saint Nicholas Avenue, Room 501, New York City, New York 10032, USA
| | - Shan Zha
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, Institute for Cancer Genetics, Columbia University, 1130 Saint Nicholas Avenue, Room 501, New York City, New York 10032, USA.,Division of Pediatric Oncology, Hematology and Stem Cell Transplantation, Department of Pediatrics, College of Physicians &Surgeons, Columbia University, 1130 Saint Nicholas Avenue, Room 501, New York City, New York 10032, USA
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44
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Lescale C, Deriano L. The RAG recombinase: Beyond breaking. Mech Ageing Dev 2016; 165:3-9. [PMID: 27863852 DOI: 10.1016/j.mad.2016.11.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 11/04/2016] [Accepted: 11/11/2016] [Indexed: 11/17/2022]
Abstract
DNA double-strand breaks (DSBs) are commonly seen as lesions that threaten genome integrity and contribute to cancer and aging processes. However, in the context of antigen receptor gene assembly, known as V(D)J recombination, DSBs are obligatory intermediates that allow the establishment of genetic diversity and adaptive immunity. V(D)J recombination is initiated when the lymphoid-restricted recombination-activating genes RAG1 and RAG2 are expressed and form a site-specific endonuclease (the RAG nuclease or RAG recombinase). Here, we discuss the ability of the RAG nuclease to minimize the risks of genome disruption by coupling the breakage and repair steps of the V(D)J reaction. This implies that the RAG genes, derived from an ancient transposon, have undergone strong selective pressure to prohibit transposition in favor of promoting controlled DNA end joining in cis by the ubiquitous DNA damage response and DNA repair machineries. We also discuss the idea that, in addition to being essential for the rearrangement of antigen receptor genes, RAG-mediated DSBs could impact cellular processes and outcomes by affecting genetic and epigenetic programs.
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Affiliation(s)
- Chloé Lescale
- Department of Immunology and Department of Genomes and Genetics, Institut Pasteur, 75015 Paris, France
| | - Ludovic Deriano
- Department of Immunology and Department of Genomes and Genetics, Institut Pasteur, 75015 Paris, France.
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45
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Hung PJ, Chen BR, George R, Liberman C, Morales AJ, Colon-Ortiz P, Tyler JK, Sleckman BP, Bredemeyer AL. Deficiency of XLF and PAXX prevents DNA double-strand break repair by non-homologous end joining in lymphocytes. Cell Cycle 2016; 16:286-295. [PMID: 27830975 DOI: 10.1080/15384101.2016.1253640] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Non-homologous end joining (NHEJ) is a major DNA double-strand break (DSB) repair pathway that functions in all phases of the cell cycle. NHEJ repairs genotoxic and physiological DSBs, such as those generated by ionizing radiation and during V(D)J recombination at antigen receptor loci, respectively. DNA end joining by NHEJ relies on the core factors Ku70, Ku80, XRCC4, and DNA Ligase IV. Additional proteins also play important roles in NHEJ. The XRCC4-like factor (XLF) participates in NHEJ through its interaction with XRCC4, and XLF deficiency in humans leads to immunodeficiency and increased sensitivity to ionizing radiation. However, XLF is dispensable for NHEJ-mediated DSB repair during V(D)J recombination in murine lymphocytes, where it may have redundant functions with other DSB repair factors. Paralog of XRCC4 and XLF (PAXX) is a recently identified NHEJ factor that has structural similarity to XRCC4 and XLF. Here we show that PAXX is also dispensable for NHEJ during V(D)J recombination and during the repair of genotoxic DSBs in lymphocytes. However, a combined deficiency of PAXX and XLF blocks NHEJ with a severity comparable to that observed in DNA Ligase IV-deficient cells. Similar to XLF, PAXX interacts with Ku through its C-terminal region, and mutations that disrupt Ku binding prevent PAXX from promoting NHEJ in XLF-deficient lymphocytes. Our findings suggest that the PAXX and XLF proteins may have redundant functions during NHEJ.
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Affiliation(s)
- Putzer J Hung
- a Department of Pathology and Laboratory Medicine , Weill Cornell Medical College , New York , NY , USA.,b Department of Pathology and Immunology , Washington University School of Medicine , St. Louis , MO , USA
| | - Bo-Ruei Chen
- a Department of Pathology and Laboratory Medicine , Weill Cornell Medical College , New York , NY , USA.,b Department of Pathology and Immunology , Washington University School of Medicine , St. Louis , MO , USA
| | - Rosmy George
- b Department of Pathology and Immunology , Washington University School of Medicine , St. Louis , MO , USA
| | - Caleb Liberman
- b Department of Pathology and Immunology , Washington University School of Medicine , St. Louis , MO , USA
| | - Abigail J Morales
- a Department of Pathology and Laboratory Medicine , Weill Cornell Medical College , New York , NY , USA.,b Department of Pathology and Immunology , Washington University School of Medicine , St. Louis , MO , USA
| | - Pedro Colon-Ortiz
- a Department of Pathology and Laboratory Medicine , Weill Cornell Medical College , New York , NY , USA
| | - Jessica K Tyler
- a Department of Pathology and Laboratory Medicine , Weill Cornell Medical College , New York , NY , USA
| | - Barry P Sleckman
- a Department of Pathology and Laboratory Medicine , Weill Cornell Medical College , New York , NY , USA.,b Department of Pathology and Immunology , Washington University School of Medicine , St. Louis , MO , USA
| | - Andrea L Bredemeyer
- b Department of Pathology and Immunology , Washington University School of Medicine , St. Louis , MO , USA
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Liang S, Esswein SR, Ochi T, Wu Q, Ascher DB, Chirgadze D, Sibanda BL, Blundell TL. Achieving selectivity in space and time with DNA double-strand-break response and repair: molecular stages and scaffolds come with strings attached. Struct Chem 2016. [DOI: 10.1007/s11224-016-0841-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Lescale C, Lenden Hasse H, Blackford AN, Balmus G, Bianchi JJ, Yu W, Bacoccina L, Jarade A, Clouin C, Sivapalan R, Reina-San-Martin B, Jackson SP, Deriano L. Specific Roles of XRCC4 Paralogs PAXX and XLF during V(D)J Recombination. Cell Rep 2016; 16:2967-2979. [PMID: 27601299 PMCID: PMC5033762 DOI: 10.1016/j.celrep.2016.08.069] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 08/02/2016] [Accepted: 08/23/2016] [Indexed: 11/04/2022] Open
Abstract
Paralog of XRCC4 and XLF (PAXX) is a member of the XRCC4 superfamily and plays a role in nonhomologous end-joining (NHEJ), a DNA repair pathway critical for lymphocyte antigen receptor gene assembly. Here, we find that the functions of PAXX and XLF in V(D)J recombination are masked by redundant joining activities. Thus, combined PAXX and XLF deficiency leads to an inability to join RAG-cleaved DNA ends. Additionally, we demonstrate that PAXX function in V(D)J recombination depends on its interaction with Ku. Importantly, we show that, unlike XLF, the role of PAXX during the repair of DNA breaks does not overlap with ATM and the RAG complex. Our findings illuminate the role of PAXX in V(D)J recombination and support a model in which PAXX and XLF function during NHEJ repair of DNA breaks, whereas XLF, the RAG complex, and the ATM-dependent DNA damage response promote end joining by stabilizing DNA ends.
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Affiliation(s)
- Chloé Lescale
- Departments of Immunology and Genomes and Genetics, Institut Pasteur, 75015 Paris, France
| | - Hélène Lenden Hasse
- Departments of Immunology and Genomes and Genetics, Institut Pasteur, 75015 Paris, France
| | - Andrew N Blackford
- Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK; CRUK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford OX3 7DQ, UK; The Wellcome Trust and Cancer Research UK Gurdon Institute, University of Cambridge, Cambridge CB2 1QN, UK
| | - Gabriel Balmus
- The Wellcome Trust and Cancer Research UK Gurdon Institute, University of Cambridge, Cambridge CB2 1QN, UK; Maintenance of Genome Stability, Genome Campus, Wellcome Trust Sanger Institute, Cambridge CB10 1SA, UK
| | - Joy J Bianchi
- Departments of Immunology and Genomes and Genetics, Institut Pasteur, 75015 Paris, France; Cellule Pasteur, University of Paris René Descartes, Sorbonne Paris Cité, Paris 75015, France
| | - Wei Yu
- Departments of Immunology and Genomes and Genetics, Institut Pasteur, 75015 Paris, France
| | - Léa Bacoccina
- Departments of Immunology and Genomes and Genetics, Institut Pasteur, 75015 Paris, France
| | - Angélique Jarade
- Departments of Immunology and Genomes and Genetics, Institut Pasteur, 75015 Paris, France
| | - Christophe Clouin
- Departments of Immunology and Genomes and Genetics, Institut Pasteur, 75015 Paris, France
| | - Rohan Sivapalan
- The Wellcome Trust and Cancer Research UK Gurdon Institute, University of Cambridge, Cambridge CB2 1QN, UK
| | - Bernardo Reina-San-Martin
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, INSERM-U964, CNRS-UMR7104, University of Strasbourg, 67400 Illkirch, France
| | - Stephen P Jackson
- The Wellcome Trust and Cancer Research UK Gurdon Institute, University of Cambridge, Cambridge CB2 1QN, UK; Maintenance of Genome Stability, Genome Campus, Wellcome Trust Sanger Institute, Cambridge CB10 1SA, UK
| | - Ludovic Deriano
- Departments of Immunology and Genomes and Genetics, Institut Pasteur, 75015 Paris, France.
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48
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Sliding sleeves of XRCC4-XLF bridge DNA and connect fragments of broken DNA. Nature 2016; 535:566-9. [PMID: 27437582 DOI: 10.1038/nature18643] [Citation(s) in RCA: 113] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 06/13/2016] [Indexed: 12/11/2022]
Abstract
Non-homologous end joining (NHEJ) is the primary pathway for repairing DNA double-strand breaks (DSBs) in mammalian cells. Such breaks are formed, for example, during gene-segment rearrangements in the adaptive immune system or by cancer therapeutic agents. Although the core components of the NHEJ machinery are known, it has remained difficult to assess the specific roles of these components and the dynamics of bringing and holding the fragments of broken DNA together. The structurally similar XRCC4 and XLF proteins are proposed to assemble as highly dynamic filaments at (or near) DSBs. Here we show, using dual- and quadruple-trap optical tweezers combined with fluorescence microscopy, how human XRCC4, XLF and XRCC4-XLF complexes interact with DNA in real time. We find that XLF stimulates the binding of XRCC4 to DNA, forming heteromeric complexes that diffuse swiftly along the DNA. Moreover, we find that XRCC4-XLF complexes robustly bridge two independent DNA molecules and that these bridges are able to slide along the DNA. These observations suggest that XRCC4-XLF complexes form mobile sleeve-like structures around DNA that can reconnect the broken ends very rapidly and hold them together. Understanding the dynamics and regulation of this mechanism will lead to clarification of how NHEJ proteins are involved in generating chromosomal translocations.
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49
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Structure-Based Virtual Ligand Screening on the XRCC4/DNA Ligase IV Interface. Sci Rep 2016; 6:22878. [PMID: 26964677 PMCID: PMC4786802 DOI: 10.1038/srep22878] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 02/23/2016] [Indexed: 12/15/2022] Open
Abstract
The association of DNA Ligase IV (Lig4) with XRCC4 is essential for repair of DNA double-strand breaks (DSBs) by Non-homologous end-joining (NHEJ) in humans. DSBs cytotoxicity is largely exploited in anticancer therapy. Thus, NHEJ is an attractive target for strategies aimed at increasing the sensitivity of tumors to clastogenic anticancer treatments. However the high affinity of the XRCC4/Lig4 interaction and the extended protein-protein interface make drug screening on this target particularly challenging. Here, we conducted a pioneering study aimed at interfering with XRCC4/Lig4 assembly. By Molecular Dynamics simulation using the crystal structure of the complex, we first delineated the Lig4 clamp domain as a limited suitable target. Then, we performed in silico screening of ~95,000 filtered molecules on this Lig4 subdomain. Hits were evaluated by Differential Scanning Fluorimetry, Saturation Transfer Difference-NMR spectroscopy and interaction assays with purified recombinant proteins. In this way we identified the first molecule able to prevent Lig4 binding to XRCC4 in vitro. This compound has a unique tripartite interaction with the Lig4 clamp domain that suggests a starting chemotype for rational design of analogous molecules with improved affinity.
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50
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Lescale C, Abramowski V, Bedora-Faure M, Murigneux V, Vera G, Roth DB, Revy P, de Villartay JP, Deriano L. RAG2 and XLF/Cernunnos interplay reveals a novel role for the RAG complex in DNA repair. Nat Commun 2016; 7:10529. [PMID: 26833222 PMCID: PMC4740868 DOI: 10.1038/ncomms10529] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 12/22/2015] [Indexed: 12/22/2022] Open
Abstract
XRCC4-like factor (XLF) functions in classical non-homologous end-joining (cNHEJ) but is dispensable for the repair of DNA double-strand breaks (DSBs) generated during V(D)J recombination. A long-standing hypothesis proposes that, in addition to its canonical nuclease activity, the RAG1/2 proteins participate in the DNA repair phase of V(D)J recombination. Here we show that in the context of RAG2 lacking the C-terminus domain (Rag2c/c mice), XLF deficiency leads to a profound lymphopenia associated with a severe defect in V(D)J recombination and, in the absence of p53, increased genomic instability at V(D)J sites. In addition, Rag2c/cXLF−/−p53−/− mice develop aggressive pro-B cell lymphomas bearing complex chromosomal translocations and gene amplifications involving Igh and c-myc/pvt1 loci. Our results reveal an unanticipated functional interplay between the RAG complex and XLF in repairing RAG-induced DSBs and maintaining genome integrity during antigen receptor gene assembly. Antigen receptor diversity relies on careful DNA cleavage and repair. Here the authors identify a functional interplay between RAG2 and XLF during V(D)J recombination, revealing an important role for the RAG complex in repairing induced DNA double-strand breaks and maintaining genome integrity.
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Affiliation(s)
- Chloé Lescale
- Departments of Immunology and Genomes and Genetics, Institut Pasteur, CNRS-URA 1961, Paris 75015, France
| | - Vincent Abramowski
- Laboratory of Genome Dynamics in the Immune System, INSERM UMR1163, Université Paris Descartes Sorbonne Paris Cité, Institut Imagine, Paris 75015, France
| | - Marie Bedora-Faure
- Departments of Immunology and Genomes and Genetics, Institut Pasteur, CNRS-URA 1961, Paris 75015, France
| | - Valentine Murigneux
- Departments of Immunology and Genomes and Genetics, Institut Pasteur, CNRS-URA 1961, Paris 75015, France
| | - Gabriella Vera
- Laboratory of Genome Dynamics in the Immune System, INSERM UMR1163, Université Paris Descartes Sorbonne Paris Cité, Institut Imagine, Paris 75015, France
| | - David B Roth
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Patrick Revy
- Laboratory of Genome Dynamics in the Immune System, INSERM UMR1163, Université Paris Descartes Sorbonne Paris Cité, Institut Imagine, Paris 75015, France
| | - Jean-Pierre de Villartay
- Laboratory of Genome Dynamics in the Immune System, INSERM UMR1163, Université Paris Descartes Sorbonne Paris Cité, Institut Imagine, Paris 75015, France
| | - Ludovic Deriano
- Departments of Immunology and Genomes and Genetics, Institut Pasteur, CNRS-URA 1961, Paris 75015, France
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