1
|
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] [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.
Collapse
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.
| |
Collapse
|
2
|
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.
Collapse
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.
| |
Collapse
|
3
|
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.
Collapse
Affiliation(s)
- Joseph J Loparo
- Dept. of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA.
| |
Collapse
|
4
|
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.
Collapse
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
| |
Collapse
|
5
|
Nishikubo K, Hasegawa M, Izumi Y, Fujii K, Matsuo K, Matsumoto Y, Yokoya A. Structural study of wild-type and phospho-mimic XRCC4 dimer and multimer proteins using circular dichroism spectroscopy. Int J Radiat Biol 2023; 99:1684-1691. [PMID: 37171809 DOI: 10.1080/09553002.2023.2214210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 05/05/2023] [Indexed: 05/13/2023]
Abstract
PURPOSE To investigate the structural features of wild-type and phospho-mimicking mutated XRCC4 protein, a protein involved in DNA double-strand break repair. MATERIALS AND METHODS XRCC4 with a HisTag were expressed by E. coli harboring plasmid DNA and purified. Phospho-mimicking mutants in which one phosphorylation site was replaced with aspartic acid were also prepared in order to reproduce the negative charge resulting from phosphorylation. The proteins were separated into dimers and multimers by gel filtration chromatography. Circular dichroism (CD) spectroscopy was performed in the region from ultraviolet to vacuum-ultraviolet. The CD spectra were analyzed with two analysis programs to evaluate the secondary structures of the wild-type and phospho-mimicked dimers and multimers. RESULT AND DISCUSSION The proportion of β-strand in the wild-type dimers was very low, particularly in their C-terminal region, including the five phosphorylation sites. The secondary structure of the phospho-mimic hardly changed in the dimeric form. In contrast, the β-strand content increased and the α-helix content decreased upon multimerization of the wild-type protein. The structural change of multimers slightly depended on the phospho-mimic site. These results suggest that the β-strand structure stabilizes the multimerization of XRCC4 and it is regulated by phosphorylation at the C-terminal site in living cells. CONCLUSION An increase in the β-strand content in XRCC4 is essential for stabilization of the multimeric form through C-terminal phosphorylation, allowing the formation of the large double-strand break repair machinery.
Collapse
Affiliation(s)
- Kai Nishikubo
- Graduate School of Science and Engineering, Ibaraki University, Mito, Ibaraki, Japan
- Institute for Quantum Life Science, Quantum Life and Medical Science Directorate, National Institutes of Quantum Sciences and Technology (QST), Tokai, Ibaraki, Japan
| | - Maho Hasegawa
- Graduate School of Science and Engineering, Ibaraki University, Mito, Ibaraki, Japan
- Institute for Quantum Life Science, Quantum Life and Medical Science Directorate, National Institutes of Quantum Sciences and Technology (QST), Tokai, Ibaraki, Japan
| | - Yudai Izumi
- Institute for Quantum Life Science, Quantum Life and Medical Science Directorate, National Institutes of Quantum Sciences and Technology (QST), Tokai, Ibaraki, Japan
| | - Kentaro Fujii
- Institute for Quantum Life Science, Quantum Life and Medical Science Directorate, National Institutes of Quantum Sciences and Technology (QST), Tokai, Ibaraki, Japan
| | - Koichi Matsuo
- Hiroshima Synchrotron Radiation Center, Hiroshima University, Higashi-Hiroshima, Hiroshima, Japan
| | - Yoshihisa Matsumoto
- Laboratory for Zero-Carbon Energy, Institute of Innovative Research, Tokyo Institute of Technology, Meguro-ku, Tokyo, Japan
| | - Akinari Yokoya
- Graduate School of Science and Engineering, Ibaraki University, Mito, Ibaraki, Japan
- Institute for Quantum Life Science, Quantum Life and Medical Science Directorate, National Institutes of Quantum Sciences and Technology (QST), Tokai, Ibaraki, Japan
| |
Collapse
|
6
|
Watanabe G, Lieber MR. The flexible and iterative steps within the NHEJ pathway. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2023; 180-181:105-119. [PMID: 37150451 DOI: 10.1016/j.pbiomolbio.2023.05.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 04/28/2023] [Accepted: 05/04/2023] [Indexed: 05/09/2023]
Abstract
Cellular and biochemical studies of nonhomologous DNA end joining (NHEJ) have long established that nuclease and polymerase action are necessary for the repair of a very large fraction of naturally-arising double-strand breaks (DSBs). This conclusion is derived from NHEJ studies ranging from yeast to humans and all genetically-tractable model organisms. Biochemical models derived from recent real-time and structural studies have yet to incorporate physical space or timing for DNA end processing. In real-time single molecule FRET (smFRET) studies, our lab analyzed NHEJ synapsis of DNA ends in a defined biochemical system. We described a Flexible Synapsis (FS) state in which the DNA ends were in proximity via only Ku and XRCC4:DNA ligase 4 (X4L4), and in an orientation that would not yet permit ligation until base pairing between one or more nucleotides of microhomology (MH) occurred, thereby allowing an in-line Close Synapsis (CS) state. If no MH was achievable, then XLF was critical for ligation. Neither FS or CS required DNA-PKcs, unless Artemis activation was necessary to permit local resection and subsequent base pairing between the two DNA ends being joined. Here we conjecture on possible 3D configurations for this FS state, which would spatially accommodate the nuclease and polymerase processing steps in an iterative manner. The FS model permits repeated attempts at ligation of at least one strand at the DSB after each round of nuclease or polymerase action. In addition to activation of Artemis, other possible roles for DNA-PKcs are discussed.
Collapse
Affiliation(s)
- Go Watanabe
- Departments of Pathology, Biochemistry, Molecular Microbiology & Immunology, and Section of Molecular & Computational Biology (Department of Biological Sciences), University of Southern California, Los Angeles, CA, 90089-9176, USA
| | - Michael R Lieber
- Departments of Pathology, Biochemistry, Molecular Microbiology & Immunology, and Section of Molecular & Computational Biology (Department of Biological Sciences), University of Southern California, Los Angeles, CA, 90089-9176, USA.
| |
Collapse
|
7
|
Goff NJ, Brenière M, Buehl CJ, de Melo AJ, Huskova H, Ochi T, Blundell TL, Mao W, Yu K, Modesti M, Meek K. Catalytically inactive DNA ligase IV promotes DNA repair in living cells. Nucleic Acids Res 2022; 50:11058-11071. [PMID: 36263813 PMCID: PMC9638927 DOI: 10.1093/nar/gkac913] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 10/18/2022] [Indexed: 11/17/2022] Open
Abstract
DNA double strand breaks (DSBs) are induced by external genotoxic agents (ionizing radiation or genotoxins) or by internal processes (recombination intermediates in lymphocytes or by replication errors). The DNA ends induced by these genotoxic processes are often not ligatable, requiring potentially mutagenic end-processing to render ends compatible for ligation by non-homologous end-joining (NHEJ). Using single molecule approaches, Loparo et al. propose that NHEJ fidelity can be maintained by restricting end-processing to a ligation competent short-range NHEJ complex that 'maximizes the fidelity of DNA repair'. These in vitro studies show that although this short-range NHEJ complex requires DNA ligase IV (Lig4), its catalytic activity is dispensable. Here using cellular models, we show that inactive Lig4 robustly promotes DNA repair in living cells. Compared to repair products from wild-type cells, those isolated from cells with inactive Lig4 show a somewhat increased fraction that utilize micro-homology (MH) at the joining site consistent with alternative end-joining (a-EJ). But unlike a-EJ in the absence of NHEJ, a large percentage of joints isolated from cells with inactive Lig4 occur with no MH - thus, clearly distinct from a-EJ. Finally, biochemical assays demonstrate that the inactive Lig4 complex promotes the activity of DNA ligase III (Lig3).
Collapse
Affiliation(s)
- Noah J Goff
- College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA,Department of Microbiology & Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA,Department of Pathobiology & Diagnostic Investigation, Michigan State University, East Lansing, MI 48824, USA
| | - Manon Brenière
- Centre de Recherche en Cancérologie de Marseille, CNRS UMR7258, Inserm U1068, Institut Paoli-Calmettes, Aix-Marseille Universiteé, Marseille, France
| | - Christopher J Buehl
- College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA,Department of Microbiology & Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA,Department of Pathobiology & Diagnostic Investigation, Michigan State University, East Lansing, MI 48824, USA
| | - Abinadabe J de Melo
- Centre de Recherche en Cancérologie de Marseille, CNRS UMR7258, Inserm U1068, Institut Paoli-Calmettes, Aix-Marseille Universiteé, Marseille, France
| | - Hana Huskova
- Centre de Recherche en Cancérologie de Marseille, CNRS UMR7258, Inserm U1068, Institut Paoli-Calmettes, Aix-Marseille Universiteé, Marseille, France
| | - Takashi Ochi
- The Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9TJ, UK
| | - Tom L Blundell
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, UK
| | - Weifeng Mao
- College of Human Medicine, Michigan State University, East Lansing, MI 48824, USA,Department of Microbiology & Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA
| | - Kefei Yu
- College of Human Medicine, Michigan State University, East Lansing, MI 48824, USA,Department of Microbiology & Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA
| | - Mauro Modesti
- Correspondence may also be addressed to Mauro Modesti.
| | | |
Collapse
|
8
|
Watanabe G, Lieber MR, Williams DR. Structural analysis of the basal state of the Artemis:DNA-PKcs complex. Nucleic Acids Res 2022; 50:7697-7720. [PMID: 35801871 PMCID: PMC9303282 DOI: 10.1093/nar/gkac564] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 06/05/2022] [Accepted: 06/17/2022] [Indexed: 01/17/2023] Open
Abstract
Artemis nuclease and DNA-dependent protein kinase catalytic subunit (DNA-PKcs) are key components in nonhomologous DNA end joining (NHEJ), the major repair mechanism for double-strand DNA breaks. Artemis activation by DNA-PKcs resolves hairpin DNA ends formed during V(D)J recombination. Artemis deficiency disrupts development of adaptive immunity and leads to radiosensitive T- B- severe combined immunodeficiency (RS-SCID). An activated state of Artemis in complex with DNA-PK was solved by cryo-EM recently, which showed Artemis bound to the DNA. Here, we report that the pre-activated form (basal state) of the Artemis:DNA-PKcs complex is stable on an agarose-acrylamide gel system, and suitable for cryo-EM structural analysis. Structures show that the Artemis catalytic domain is dynamically positioned externally to DNA-PKcs prior to ABCDE autophosphorylation and show how both the catalytic and regulatory domains of Artemis interact with the N-HEAT and FAT domains of DNA-PKcs. We define a mutually exclusive binding site for Artemis and XRCC4 on DNA-PKcs and show that an XRCC4 peptide disrupts the Artemis:DNA-PKcs complex. All of the findings are useful in explaining how a hypomorphic L3062R missense mutation of DNA-PKcs could lead to insufficient Artemis activation, hence RS-SCID. Our results provide various target site candidates to design disruptors for Artemis:DNA-PKcs complex formation.
Collapse
Affiliation(s)
- Go Watanabe
- Department of Pathology, Department of Biochemistry & Molecular Biology, Department of Molecular Microbiology & Immunology, and Section of Computational & Molecular Biology, USC Norris Comprehensive Cancer Center, University of Southern California Keck School of Medicine, 1441 Eastlake Ave, Rm. 5428, Los Angeles, CA 90089, USA
| | - Michael R Lieber
- Department of Pathology, Department of Biochemistry & Molecular Biology, Department of Molecular Microbiology & Immunology, and Section of Computational & Molecular Biology, USC Norris Comprehensive Cancer Center, University of Southern California Keck School of Medicine, 1441 Eastlake Ave, Rm. 5428, Los Angeles, CA 90089, USA
| | - Dewight R Williams
- Eyring Materials Center, John Cowley Center for High Resolution Electron Microscopy, Arizona State University, Tempe, AZ 85281, USA
| |
Collapse
|
9
|
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.
Collapse
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.
| |
Collapse
|
10
|
Cabello-Lobato MJ, Jenner M, Cisneros-Aguirre M, Brüninghoff K, Sandy Z, da Costa I, Jowitt T, Loch C, Jackson S, Wu Q, Mootz H, Stark J, Cliff M, Schmidt C. Microarray screening reveals two non-conventional SUMO-binding modules linked to DNA repair by non-homologous end-joining. Nucleic Acids Res 2022; 50:4732-4754. [PMID: 35420136 PMCID: PMC9071424 DOI: 10.1093/nar/gkac237] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 03/03/2022] [Accepted: 03/25/2022] [Indexed: 11/25/2022] Open
Abstract
SUMOylation is critical for numerous cellular signalling pathways, including the maintenance of genome integrity via the repair of DNA double-strand breaks (DSBs). If misrepaired, DSBs can lead to cancer, neurodegeneration, immunodeficiency and premature ageing. Using systematic human proteome microarray screening combined with widely applicable carbene footprinting, genetic code expansion and high-resolution structural profiling, we define two non-conventional and topology-selective SUMO2-binding regions on XRCC4, a DNA repair protein important for DSB repair by non-homologous end-joining (NHEJ). Mechanistically, the interaction of SUMO2 and XRCC4 is incompatible with XRCC4 binding to three other proteins important for NHEJ-mediated DSB repair. These findings are consistent with SUMO2 forming a redundant NHEJ layer with the potential to regulate different NHEJ complexes at distinct levels including, but not limited to, XRCC4 interactions with XLF, LIG4 and IFFO1. Regulation of NHEJ is not only relevant for carcinogenesis, but also for the design of precision anti-cancer medicines and the optimisation of CRISPR/Cas9-based gene editing. In addition to providing molecular insights into NHEJ, this work uncovers a conserved SUMO-binding module and provides a rich resource on direct SUMO binders exploitable towards uncovering SUMOylation pathways in a wide array of cellular processes.
Collapse
Affiliation(s)
- Maria Jose Cabello-Lobato
- Manchester Cancer Research Centre (MCRC), Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, 555 Wilmslow Road, Manchester M20 4GJ, UK
| | - Matthew Jenner
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK
- Warwick Integrative Synthetic Biology (WISB) Centre, University of Warwick, Coventry CV4 7AL, UK
| | - 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
| | - Kira Brüninghoff
- Institute of Biochemistry, University of Muenster, Corrensstraße 36, 48149 Muenster, Germany
| | - Zac Sandy
- Manchester Cancer Research Centre (MCRC), Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, 555 Wilmslow Road, Manchester M20 4GJ, UK
| | - Isabelle C da Costa
- Manchester Cancer Research Centre (MCRC), Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, 555 Wilmslow Road, Manchester M20 4GJ, UK
| | - Thomas A Jowitt
- Wellcome Trust Centre for Cell-Matrix Research, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester M13 9PT, UK
| | | | - Stephen P Jackson
- Wellcome/Cancer Research UK Gurdon Institute and Department of Biochemistry, University of Cambridge, Cambridge CB2 1QN, UK
| | - Qian Wu
- Astbury Centre for Structural Molecular Biology, School of Molecular & Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Henning D Mootz
- Institute of Biochemistry, University of Muenster, Corrensstraße 36, 48149 Muenster, Germany
| | - 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
| | - Matthew J Cliff
- Manchester Institute of Biotechnology (MIB) and School of Chemistry, University of Manchester, Manchester M1 7DN, UK
| | - Christine K Schmidt
- Manchester Cancer Research Centre (MCRC), Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, 555 Wilmslow Road, Manchester M20 4GJ, UK
| |
Collapse
|
11
|
Hu C, Bugbee T, Dacus D, Palinski R, Wallace N. Beta human papillomavirus 8 E6 allows colocalization of non-homologous end joining and homologous recombination repair factors. PLoS Pathog 2022; 18:e1010275. [PMID: 35148356 PMCID: PMC8836322 DOI: 10.1371/journal.ppat.1010275] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 01/12/2022] [Indexed: 12/30/2022] Open
Abstract
Beta human papillomavirus (β-HPV) are hypothesized to make DNA damage more mutagenic and potentially more carcinogenic. Double strand breaks (DSBs) are the most deleterious DNA lesion. They are typically repaired by homologous recombination (HR) or non-homologous end joining (NHEJ). HR occurs after DNA replication while NHEJ can occur at any point in the cell cycle. HR and NHEJ are not thought to occur in the same cell at the same time. HR is restricted to cells in phases of the cell cycle where homologous templates are available, while NHEJ occurs primarily during G1. β-HPV type 8 protein E6 (8E6) attenuates both repair pathways. We use a series of immunofluorescence microscopy and flow cytometry experiments to better define the impact of this attenuation. We found that 8E6 causes colocalization of HR factors (RPA70 and RAD51) with an NHEJ factor (activated DNA-PKcs or pDNA-PKcs) at persistent DSBs. 8E6 also causes RAD51 foci to form during G1. The initiation of NHEJ and HR at the same lesion could lead to antagonistic DNA end processing. Further, HR cannot be readily completed in an error-free manner during G1. Both aberrant repair events would cause deletions. To determine if these mutations were occurring, we used next generation sequencing of the 200kb surrounding a CAS9-induced DSB. 8E6 caused a 21-fold increase in deletions. Chemical and genetic inhibition of p300 as well as an 8E6 mutant that is incapable of destabilizing p300 demonstrates that 8E6 is acting via p300 destabilization. More specific chemical inhibitors of DNA repair provided mechanistic insight by mimicking 8E6-induced dysregulation of DNA repair in a virus-free system. Specifically, inhibition of NHEJ causes RAD51 foci to form in G1 and colocalization of RAD51 with pDNA-PKcs. Our previous work shows that a master transcription regulator, p300, facilitates two major DNA double strand break (DSB) repair pathways: non-homologous end joining (NHEJ) and homologous recombination (HR). By degrading p300, beta genus human papillomavirus 8 protein E6 (8E6) hinders pDNA-PKcs resolution, an essential step during NHEJ. NHEJ and HR are known to compete, with only one pathway initiating repair of a DSB. NHEJ tends to be used in G1 and HR occurs in S/G2. Here, we show that 8E6 allows NHEJ and HR to initiate at the same break site. We show that 8E6 allows HR to initiate in G1, suggesting that NHEJ starts but fails before HR is initiated at the same DSB. Next generation sequencing of the region surrounding a CAS9-induced DSB supports our hypothesis that this dysregulation of DSB repair is mutagenic as 8E6 caused a 15- to 20-fold increase in mutations associated with a CAS9-induced DSB. These studies support the putative role of HPV8 infections in non-melanoma skin cancer development.
Collapse
Affiliation(s)
- Changkun Hu
- Division of Biology, Kansas State University, Manhattan, Kansas, United States of America
| | - Taylor Bugbee
- Division of Biology, Kansas State University, Manhattan, Kansas, United States of America
| | - Dalton Dacus
- Division of Biology, Kansas State University, Manhattan, Kansas, United States of America
| | - Rachel Palinski
- Kansas State Veterinary Diagnostic Laboratory, Kansas State University, Manhattan, Kansas, United States of America
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, Kansas, United States of America
| | - Nicholas Wallace
- Division of Biology, Kansas State University, Manhattan, Kansas, United States of America
- * E-mail:
| |
Collapse
|
12
|
Koike M, Yutoku Y, Koike A. Feline XRCC4 undergoes rapid Ku-dependent recruitment to DNA damage sites. FEBS Open Bio 2022; 12:798-810. [PMID: 35000298 PMCID: PMC8972062 DOI: 10.1002/2211-5463.13363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 11/30/2021] [Accepted: 01/07/2022] [Indexed: 11/16/2022] Open
Abstract
Radiation and chemotherapy resistance remain some of the greatest challenges in human and veterinary cancer therapies. XRCC4, an essential molecule for nonhomologous end joining repair, is a promising target for radiosensitizers. Genetic variants and mutations of XRCC4 contribute to cancer susceptibility, and XRCC4 is also the causative gene of microcephalic primordial dwarfism (MPD) in humans. The development of clinically effective molecular‐targeted drugs requires accurate understanding of the functions and regulatory mechanisms of XRCC4. In this study, we cloned and sequenced the cDNA of feline XRCC4. Comparative analysis indicated that sequences and post‐translational modification sites that are predicted to be involved in regulating the localization of human XRCC4, including the nuclear localization signal, are mostly conserved in feline XRCC4. All examined target amino acids responsible for human MPD are completely conserved in feline XRCC4. Furthermore, we found that the localization of feline XRCC4 dynamically changes during the cell cycle. Soon after irradiation, feline XRCC4 accumulated at laser‐induced DNA double‐strand break (DSB) sites in both the interphase and mitotic phase, and this accumulation was dependent on the presence of Ku. Additionally, XRCC4 superfamily proteins XLF and PAXX accumulated at the DSB sites. Collectively, these findings suggest that mechanisms regulating the spatiotemporal localization of XRCC4 are crucial for XRCC4 function in humans and cats. Our findings contribute to elucidating the functions of XRCC4 and the role of abnormal XRCC4 in diseases, including cancers and MPD, and may help in developing XRCC4‐targeted drugs, such as radiosensitizers, for humans and cats.
Collapse
Affiliation(s)
- Manabu Koike
- Institute for Quantum Medical Science, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan.,Department of Regulatory Biology, Faculty of Science, Saitama University, Saitama, Saitama, 338-8570, Japan
| | - Yasutomo Yutoku
- Institute for Quantum Medical Science, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan
| | - Aki Koike
- Institute for Quantum Medical Science, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan
| |
Collapse
|
13
|
Frock RL, Sadeghi C, Meng J, Wang JL. DNA End Joining: G0-ing to the Core. Biomolecules 2021; 11:biom11101487. [PMID: 34680120 PMCID: PMC8533500 DOI: 10.3390/biom11101487] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 10/05/2021] [Accepted: 10/06/2021] [Indexed: 12/28/2022] Open
Abstract
Humans have evolved a series of DNA double-strand break (DSB) repair pathways to efficiently and accurately rejoin nascently formed pairs of double-stranded DNA ends (DSEs). In G0/G1-phase cells, non-homologous end joining (NHEJ) and alternative end joining (A-EJ) operate to support covalent rejoining of DSEs. While NHEJ is predominantly utilized and collaborates extensively with the DNA damage response (DDR) to support pairing of DSEs, much less is known about A-EJ collaboration with DDR factors when NHEJ is absent. Non-cycling lymphocyte progenitor cells use NHEJ to complete V(D)J recombination of antigen receptor genes, initiated by the RAG1/2 endonuclease which holds its pair of targeted DSBs in a synapse until each specified pair of DSEs is handed off to the NHEJ DSB sensor complex, Ku. Similar to designer endonuclease DSBs, the absence of Ku allows for A-EJ to access RAG1/2 DSEs but with random pairing to complete their repair. Here, we describe recent insights into the major phases of DSB end joining, with an emphasis on synapsis and tethering mechanisms, and bring together new and old concepts of NHEJ vs. A-EJ and on RAG2-mediated repair pathway choice.
Collapse
|
14
|
Cabello-Lobato MJ, Schmidt CK, Cliff MJ. 1H, 13C, 15N backbone resonance assignment for the 1-164 construct of human XRCC4. BIOMOLECULAR NMR ASSIGNMENTS 2021; 15:389-395. [PMID: 34173222 PMCID: PMC8481219 DOI: 10.1007/s12104-021-10035-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 06/14/2021] [Indexed: 06/13/2023]
Abstract
DNA double-strand breaks (DSBs) represent the most cytotoxic DNA lesions, as-if mis- or unrepaired-they can cause cell death or lead to genome instability, which in turn can cause cancer. DSBs are repaired by two major pathways termed homologous recombination and non-homologous end-joining (NHEJ). NHEJ is responsible for repairing the vast majority of DSBs arising in human cells. Defects in NHEJ factors are also associated with microcephaly, primordial dwarfism and immune deficiencies. One of the key proteins important for mediating NHEJ is XRCC4. XRCC4 is a dimer, with the dimer interface mediated by an extended coiled-coil. The N-terminal head domain forms a mixed alpha-beta globular structure. Numerous factors interact with the C-terminus of the coiled-coil domain, which is also associated with significant self-association between XRCC4 dimers. A range of construct lengths of human XRCC4 were expressed and purified, and the 1-164 variant had the best NMR properties, as judged by consistent linewidths, and chemical shift dispersion. In this work we report the 1H, 15 N and 13C backbone resonance assignments of human XRCC4 in the solution form of the 1-164 construct. Assignments were obtained by heteronuclear multidimensional NMR spectroscopy. In total, 156 of 161 assignable residues of XRCC4 were assigned to resonances in the TROSY spectrum, with an additional 11 resonances assigned to His-Tag residues. Prediction of solution secondary structure from a chemical shift analysis using the TALOS + webserver is in good agreement with the published X-ray crystal structures of this protein.
Collapse
Affiliation(s)
- Maria Jose Cabello-Lobato
- Manchester Cancer Research Centre, Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, 555 Wilmslow Road, Manchester, M20 4GJ, UK
| | - Christine K Schmidt
- Manchester Cancer Research Centre, Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, 555 Wilmslow Road, Manchester, M20 4GJ, UK.
| | - Matthew J Cliff
- Manchester Institute of Biotechnology (MIB), University of Manchester, 131 Princess St, Manchester, M1 7DN, UK.
| |
Collapse
|
15
|
Liang S, Chaplin AK, Stavridi AK, Appleby R, Hnizda A, Blundell TL. Stages, scaffolds and strings in the spatial organisation of non-homologous end joining: Insights from X-ray diffraction and Cryo-EM. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2021; 163:60-73. [PMID: 33285184 PMCID: PMC8224183 DOI: 10.1016/j.pbiomolbio.2020.11.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 11/26/2020] [Indexed: 01/10/2023]
Abstract
Non-homologous end joining (NHEJ) is the preferred pathway for the repair of DNA double-strand breaks in humans. Here we describe three structural aspects of the repair pathway: stages, scaffolds and strings. We discuss the orchestration of DNA repair to guarantee robust and efficient NHEJ. We focus on structural studies over the past two decades, not only using X-ray diffraction, but also increasingly exploiting cryo-EM to investigate the macromolecular assemblies.
Collapse
Affiliation(s)
- Shikang Liang
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1GA, Cambridgeshire, UK
| | - Amanda K Chaplin
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1GA, Cambridgeshire, UK
| | - Antonia Kefala Stavridi
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1GA, Cambridgeshire, UK
| | - Robert Appleby
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1GA, Cambridgeshire, UK
| | - Ales Hnizda
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1GA, Cambridgeshire, UK
| | - Tom L Blundell
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1GA, Cambridgeshire, UK.
| |
Collapse
|
16
|
Matsumoto Y, Asa ADDC, Modak C, Shimada M. DNA-Dependent Protein Kinase Catalytic Subunit: The Sensor for DNA Double-Strand Breaks Structurally and Functionally Related to Ataxia Telangiectasia Mutated. Genes (Basel) 2021; 12:genes12081143. [PMID: 34440313 PMCID: PMC8394720 DOI: 10.3390/genes12081143] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Revised: 07/19/2021] [Accepted: 07/22/2021] [Indexed: 11/16/2022] Open
Abstract
The DNA-dependent protein kinase (DNA-PK) is composed of a DNA-dependent protein kinase catalytic subunit (DNA-PKcs) and Ku70/Ku80 heterodimer. DNA-PK is thought to act as the “sensor” for DNA double-stranded breaks (DSB), which are considered the most deleterious type of DNA damage. In particular, DNA-PKcs and Ku are shown to be essential for DSB repair through nonhomologous end joining (NHEJ). The phenotypes of animals and human individuals with defective DNA-PKcs or Ku functions indicate their essential roles in these developments, especially in neuronal and immune systems. DNA-PKcs are structurally related to Ataxia–telangiectasia mutated (ATM), which is also implicated in the cellular responses to DSBs. DNA-PKcs and ATM constitute the phosphatidylinositol 3-kinase-like kinases (PIKKs) family with several other molecules. Here, we review the accumulated knowledge on the functions of DNA-PKcs, mainly based on the phenotypes of DNA-PKcs-deficient cells in animals and human individuals, and also discuss its relationship with ATM in the maintenance of genomic stability.
Collapse
|
17
|
Wilde JJ, Aida T, Del Rosario RCH, Kaiser T, Qi P, Wienisch M, Zhang Q, Colvin S, Feng G. Efficient embryonic homozygous gene conversion via RAD51-enhanced interhomolog repair. Cell 2021; 184:3267-3280.e18. [PMID: 34043941 PMCID: PMC8240950 DOI: 10.1016/j.cell.2021.04.035] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 03/03/2021] [Accepted: 04/19/2021] [Indexed: 12/20/2022]
Abstract
Searching for factors to improve knockin efficiency for therapeutic applications, biotechnology, and generation of non-human primate models of disease, we found that the strand exchange protein RAD51 can significantly increase Cas9-mediated homozygous knockin in mouse embryos through an interhomolog repair (IHR) mechanism. IHR is a hallmark of meiosis but only occurs at low frequencies in somatic cells, and its occurrence in zygotes is controversial. Using multiple approaches, we provide evidence for an endogenous IHR mechanism in the early embryo that can be enhanced by RAD51. This process can be harnessed to generate homozygotes from wild-type zygotes using exogenous donors and to convert heterozygous alleles into homozygous alleles without exogenous templates. Furthermore, we identify additional IHR-promoting factors and describe features of IHR events. Together, our findings show conclusive evidence for IHR in mouse embryos and describe an efficient method for enhanced gene conversion.
Collapse
Affiliation(s)
- Jonathan J Wilde
- Department of Brain & Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA.
| | - Tomomi Aida
- Department of Brain & Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA
| | - Ricardo C H Del Rosario
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Tobias Kaiser
- Department of Brain & Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA
| | - Peimin Qi
- Department of Brain & Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA
| | - Martin Wienisch
- Department of Brain & Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA
| | - Qiangge Zhang
- Department of Brain & Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA
| | - Steven Colvin
- Department of Brain & Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA
| | - Guoping Feng
- Department of Brain & Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
| |
Collapse
|
18
|
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: 17] [Impact Index Per Article: 5.7] [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.
Collapse
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
| |
Collapse
|
19
|
Asa ADDC, Wanotayan R, Sharma MK, Tsukada K, Shimada M, Matsumoto Y. Functional analysis of XRCC4 mutations in reported microcephaly and growth defect patients in terms of radiosensitivity. JOURNAL OF RADIATION RESEARCH 2021; 62:380-389. [PMID: 33842963 PMCID: PMC8127669 DOI: 10.1093/jrr/rrab016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Revised: 02/01/2021] [Indexed: 05/08/2023]
Abstract
Non-homologous end joining is one of the main pathways for DNA double-strand break (DSB) repair and is also implicated in V(D)J recombination in immune system. Therefore, mutations in non-homologous end-joining (NHEJ) proteins were found to be associated with immunodeficiency in human as well as in model animals. Several human patients with mutations in XRCC4 were reported to exhibit microcephaly and growth defects, but unexpectedly showed normal immune function. Here, to evaluate the functionality of these disease-associated mutations of XRCC4 in terms of radiosensitivity, we generated stable transfectants expressing these mutants in XRCC4-deficient murine M10 cells and measured their radiosensitivity by colony formation assay. V83_S105del, R225X and D254Mfs*68 were expressed at a similar level to wild-type XRCC4, while W43R, R161Q and R275X were expressed at even higher level than wild-type XRCC4. The expression levels of DNA ligase IV in the transfectants with these mutants were comparable to that in the wild-type XRCC4 transfectant. The V83S_S105del transfectant and, to a lesser extent, D254Mfs*68 transfectant, showed substantially increased radiosensitivity compared to the wild-type XRCC4 transfectant. The W43R, R161Q, R225X and R275X transfectants showed a slight but statistically significant increase in radiosensitivity compared to the wild-type XRCC4 transfectant. When expressed as fusion proteins with Green fluorescent protein (GFP), R225X, R275X and D254Mfs*68 localized to the cytoplasm, whereas other mutants localized to the nucleus. These results collectively indicated that the defects of XRCC4 in patients might be mainly due to insufficiency in protein quantity and impaired functionality, underscoring the importance of XRCC4's DSB repair function in normal development.
Collapse
Affiliation(s)
- Anie Day D C Asa
- Laboratory for Advanced Nuclear Energy, Institute of Innovative Research, Tokyo Institute of Technology, Tokyo 152-8550, Japan
| | - Rujira Wanotayan
- Laboratory for Advanced Nuclear Energy, Institute of Innovative Research, Tokyo Institute of Technology, Tokyo 152-8550, Japan
- Department of Radiological Technology, Mahidol University, Nakhon Pathom 73170, Thailand
| | - Mukesh Kumar Sharma
- Laboratory for Advanced Nuclear Energy, Institute of Innovative Research, Tokyo Institute of Technology, Tokyo 152-8550, Japan
- Department of Zoology, SPC Government College, Ajmer-305001, Rajasthan, India
| | - Kaima Tsukada
- Laboratory for Advanced Nuclear Energy, Institute of Innovative Research, Tokyo Institute of Technology, Tokyo 152-8550, Japan
| | - Mikio Shimada
- Laboratory for Advanced Nuclear Energy, Institute of Innovative Research, Tokyo Institute of Technology, Tokyo 152-8550, Japan
| | - Yoshihisa Matsumoto
- Corresponding author. Yoshihisa Matsumoto, Laboratory for Advanced Nuclear Energy, Institute of Innovative Research, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550 Japan. E-mail: ; FAX: +81-3-5734-3703
| |
Collapse
|
20
|
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: 74] [Impact Index Per Article: 24.7] [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.
Collapse
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.
| |
Collapse
|
21
|
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: 71] [Impact Index Per Article: 23.7] [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.
Collapse
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; ,
| |
Collapse
|
22
|
Zell J, Rota Sperti F, Britton S, Monchaud D. DNA folds threaten genetic stability and can be leveraged for chemotherapy. RSC Chem Biol 2021; 2:47-76. [PMID: 35340894 PMCID: PMC8885165 DOI: 10.1039/d0cb00151a] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 09/20/2020] [Indexed: 12/22/2022] Open
Abstract
Damaging DNA is a current and efficient strategy to fight against cancer cell proliferation. Numerous mechanisms exist to counteract DNA damage, collectively referred to as the DNA damage response (DDR) and which are commonly dysregulated in cancer cells. Precise knowledge of these mechanisms is necessary to optimise chemotherapeutic DNA targeting. New research on DDR has uncovered a series of promising therapeutic targets, proteins and nucleic acids, with application notably via an approach referred to as combination therapy or combinatorial synthetic lethality. In this review, we summarise the cornerstone discoveries which gave way to the DNA being considered as an anticancer target, and the manipulation of DDR pathways as a valuable anticancer strategy. We describe in detail the DDR signalling and repair pathways activated in response to DNA damage. We then summarise the current understanding of non-B DNA folds, such as G-quadruplexes and DNA junctions, when they are formed and why they can offer a more specific therapeutic target compared to that of canonical B-DNA. Finally, we merge these subjects to depict the new and highly promising chemotherapeutic strategy which combines enhanced-specificity DNA damaging and DDR targeting agents. This review thus highlights how chemical biology has given rise to significant scientific advances thanks to resolutely multidisciplinary research efforts combining molecular and cell biology, chemistry and biophysics. We aim to provide the non-specialist reader a gateway into this exciting field and the specialist reader with a new perspective on the latest results achieved and strategies devised.
Collapse
Affiliation(s)
- Joanna Zell
- Institut de Chimie Moléculaire de l'Université de Bourgogne, ICMUB CNRS UMR 6302, UBFC Dijon France
| | - Francesco Rota Sperti
- Institut de Chimie Moléculaire de l'Université de Bourgogne, ICMUB CNRS UMR 6302, UBFC Dijon France
| | - Sébastien Britton
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS Toulouse France
- Équipe Labellisée la Ligue Contre le Cancer 2018 Toulouse France
| | - David Monchaud
- Institut de Chimie Moléculaire de l'Université de Bourgogne, ICMUB CNRS UMR 6302, UBFC Dijon France
| |
Collapse
|
23
|
González-Prieto R, Eifler-Olivi K, Claessens LA, Willemstein E, Xiao Z, Talavera Ormeno CMP, Ovaa H, Ulrich HD, Vertegaal ACO. Global non-covalent SUMO interaction networks reveal SUMO-dependent stabilization of the non-homologous end joining complex. Cell Rep 2021; 34:108691. [PMID: 33503430 DOI: 10.1016/j.celrep.2021.108691] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 12/11/2020] [Accepted: 01/05/2021] [Indexed: 12/17/2022] Open
Abstract
In contrast to our extensive knowledge on covalent small ubiquitin-like modifier (SUMO) target proteins, we are limited in our understanding of non-covalent SUMO-binding proteins. We identify interactors of different SUMO isoforms-monomeric SUMO1, monomeric SUMO2, or linear trimeric SUMO2 chains-using a mass spectrometry-based proteomics approach. We identify 379 proteins that bind to different SUMO isoforms, mainly in a preferential manner. Interestingly, XRCC4 is the only DNA repair protein in our screen with a preference for SUMO2 trimers over mono-SUMO2, as well as the only protein in our screen that belongs to the non-homologous end joining (NHEJ) DNA double-strand break repair pathway. A SUMO interaction motif (SIM) in XRCC4 regulates its recruitment to sites of DNA damage and phosphorylation of S320 by DNA-PKcs. Our data highlight the importance of non-covalent and covalent sumoylation for DNA double-strand break repair via the NHEJ pathway and provide a resource of SUMO isoform interactors.
Collapse
Affiliation(s)
- Román González-Prieto
- Department of Cell and Chemical Biology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, the Netherlands.
| | - Karolin Eifler-Olivi
- Department of Cell and Chemical Biology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, the Netherlands; Institute of Molecular Biology (IMB), Ackermannweg 4, 55128 Mainz, Germany
| | - Laura A Claessens
- Department of Cell and Chemical Biology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, the Netherlands
| | - Edwin Willemstein
- Department of Cell and Chemical Biology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, the Netherlands
| | - Zhenyu Xiao
- Department of Cell and Chemical Biology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, the Netherlands
| | - Cami M P Talavera Ormeno
- Department of Cell and Chemical Biology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, the Netherlands; Oncode Institute, Einthovenweg 20, 2333 ZC Leiden, the Netherlands
| | - Huib Ovaa
- Department of Cell and Chemical Biology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, the Netherlands; Oncode Institute, Einthovenweg 20, 2333 ZC Leiden, the Netherlands
| | - Helle D Ulrich
- Institute of Molecular Biology (IMB), Ackermannweg 4, 55128 Mainz, Germany
| | - Alfred C O Vertegaal
- Department of Cell and Chemical Biology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, the Netherlands.
| |
Collapse
|
24
|
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: 19] [Impact Index Per Article: 4.8] [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.
Collapse
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
| |
Collapse
|
25
|
Britton S, Chanut P, Delteil C, Barboule N, Frit P, Calsou P. ATM antagonizes NHEJ proteins assembly and DNA-ends synapsis at single-ended DNA double strand breaks. Nucleic Acids Res 2020; 48:9710-9723. [PMID: 32890395 PMCID: PMC7515714 DOI: 10.1093/nar/gkaa723] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 07/29/2020] [Accepted: 08/21/2020] [Indexed: 12/15/2022] Open
Abstract
Two DNA repair pathways operate at DNA double strand breaks (DSBs): non-homologous end-joining (NHEJ), that requires two adjacent DNA ends for ligation, and homologous recombination (HR), that resects one DNA strand for invasion of a homologous duplex. Faithful repair of replicative single-ended DSBs (seDSBs) is mediated by HR, due to the lack of a second DNA end for end-joining. ATM stimulates resection at such breaks through multiple mechanisms including CtIP phosphorylation, which also promotes removal of the DNA-ends sensor and NHEJ protein Ku. Here, using a new method for imaging the recruitment of the Ku partner DNA-PKcs at DSBs, we uncover an unanticipated role of ATM in removing DNA-PKcs from seDSBs in human cells. Phosphorylation of DNA-PKcs on the ABCDE cluster is necessary not only for DNA-PKcs clearance but also for the subsequent MRE11/CtIP-dependent release of Ku from these breaks. We propose that at seDSBs, ATM activity is necessary for the release of both Ku and DNA-PKcs components of the NHEJ apparatus, and thereby prevents subsequent aberrant interactions between seDSBs accompanied by DNA-PKcs autophosphorylation and detrimental commitment to Lig4-dependent end-joining.
Collapse
Affiliation(s)
- Sébastien Britton
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
- Equipe Labellisée Ligue contre le Cancer 2018, Toulouse, France
| | - Pauline Chanut
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
- Equipe Labellisée Ligue contre le Cancer 2018, Toulouse, France
| | - Christine Delteil
- Institut de Pharmacologie et de 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 de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
- Equipe Labellisée Ligue contre le Cancer 2018, Toulouse, France
| | - Philippe Frit
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
- Equipe Labellisée Ligue contre le Cancer 2018, Toulouse, France
| | - Patrick Calsou
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
- Equipe Labellisée Ligue contre le Cancer 2018, Toulouse, France
| |
Collapse
|
26
|
Hu C, Bugbee T, Gamez M, Wallace NA. Beta Human Papillomavirus 8E6 Attenuates Non-Homologous End Joining by Hindering DNA-PKcs Activity. Cancers (Basel) 2020; 12:cancers12092356. [PMID: 32825402 PMCID: PMC7564021 DOI: 10.3390/cancers12092356] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 08/15/2020] [Accepted: 08/18/2020] [Indexed: 12/20/2022] Open
Abstract
Cutaneous viral infections occur in a background of near continual exposure to environmental genotoxins, like UV radiation in sunlight. Failure to repair damaged DNA is an established driver of tumorigenesis and substantial cellular resources are devoted to repairing DNA lesions. Beta-human papillomaviruses (β-HPVs) attenuate DNA repair signaling. However, their role in human disease is unclear. Some have proposed that β-HPV promotes tumorigenesis, while others suggest that β-HPV protects against skin cancer. Most of the molecular evidence that β-HPV impairs DNA repair has been gained via characterization of the E6 protein from β-HPV 8 (β-HPV 8E6). Moreover, β-HPV 8E6 hinders DNA repair by binding and destabilizing p300, a transcription factor for multiple DNA repair genes. By reducing p300 availability, β-HPV 8E6 attenuates a major double strand DNA break (DSB) repair pathway, homologous recombination. Here, β-HPV 8E6 impairs another DSB repair pathway, non-homologous end joining (NHEJ). Specifically, β-HPV 8E6 acts by attenuating DNA-dependent protein kinase (DNA-PK) activity, a critical NHEJ kinase. This includes DNA-PK activation and the downstream of steps in the pathway associated with DNA-PK activity. Notably, β-HPV 8E6 inhibits NHEJ through p300 dependent and independent means. Together, these data expand the known genome destabilizing capabilities of β-HPV 8E6.
Collapse
Affiliation(s)
- Changkun Hu
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA; (C.H.); (T.B.)
| | - Taylor Bugbee
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA; (C.H.); (T.B.)
| | - Monica Gamez
- Bristol Medical School, Translational Health Sciences, University of Bristol, Bristol BS1 3NY, UK;
| | - Nicholas A. Wallace
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA; (C.H.); (T.B.)
- Correspondence:
| |
Collapse
|
27
|
Bhargava R, Lopezcolorado FW, Tsai LJ, Stark JM. The canonical non-homologous end joining factor XLF promotes chromosomal deletion rearrangements in human cells. J Biol Chem 2020; 295:125-137. [PMID: 31753920 PMCID: PMC6952595 DOI: 10.1074/jbc.ra119.010421] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 11/20/2019] [Indexed: 02/05/2023] Open
Abstract
Clastogen exposure can result in chromosomal rearrangements, including large deletions and inversions that are associated with cancer development. To examine such rearrangements in human cells, here we developed a reporter assay based on endogenous genes on chromosome 12. Using the RNA-guided nuclease Cas9, we induced two DNA double-strand breaks, one each in the GAPDH and CD4 genes, that caused a deletion rearrangement leading to CD4 expression from the GAPDH promoter. We observed that this GAPDH-CD4 deletion rearrangement activates CD4+ cells that can be readily detected by flow cytometry. Similarly, double-strand breaks in the LPCAT3 and CD4 genes induced an LPCAT3-CD4 inversion rearrangement resulting in CD4 expression. Studying the GAPDH-CD4 deletion rearrangement in multiple cell lines, we found that the canonical non-homologous end joining (C-NHEJ) factor XLF promotes these rearrangements. Junction analysis uncovered that the relative contribution of C-NHEJ appears lower in U2OS than in HEK293 and A549 cells. Furthermore, an ATM kinase inhibitor increased C-NHEJ-mediated rearrangements only in U2OS cells. We also found that an XLF residue that is critical for an interaction with the C-NHEJ factor X-ray repair cross-complementing 4 (XRCC4), and XRCC4 itself are each important for promoting both this deletion rearrangement and end joining without insertion/deletion mutations. In summary, a reporter assay based on endogenous genes on chromosome 12 reveals that XLF-dependent C-NHEJ promotes deletion rearrangements in human cells and that cell type-specific differences in the contribution of C-NHEJ and ATM kinase inhibition influence these rearrangements.
Collapse
Affiliation(s)
- Ragini Bhargava
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute of the City of Hope, Duarte, California 91010; Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, Duarte, California 91010
| | | | - L Jillianne Tsai
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute of the City of Hope, Duarte, California 91010; Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, Duarte, California 91010
| | - Jeremy M Stark
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute of the City of Hope, Duarte, California 91010; Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, Duarte, California 91010.
| |
Collapse
|
28
|
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.
Collapse
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.
| |
Collapse
|
29
|
Gonzalez-Rodriguez Y, Bunting SF. XLF extends its range from DNA repair to replication. J Cell Biol 2019; 218:2075-2076. [PMID: 31189608 PMCID: PMC6605802 DOI: 10.1083/jcb.201905221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Gonzalez-Rodriguez and Bunting preview work from the Sleckman laboratory describing a new function for the repair protein XLF in the protection of DNA replication fork stability. The close interplay between DNA replication and repair is underscored by a report from Chen et al. (2019. J. Cell Biol.https://doi.org/10.1083/jcb.201808134) in this issue. The authors demonstrate that the non-homologous end-joining factor XLF promotes the stability of replication forks.
Collapse
Affiliation(s)
- Yanira Gonzalez-Rodriguez
- Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, NJ
| | - Samuel F Bunting
- Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, NJ
| |
Collapse
|
30
|
Koike M, Yutoku Y, Koike A. Feline XLF accumulates at DNA damage sites in a Ku-dependent manner. FEBS Open Bio 2019; 9:1052-1062. [PMID: 31115163 PMCID: PMC6551493 DOI: 10.1002/2211-5463.12589] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 12/14/2018] [Accepted: 01/02/2019] [Indexed: 11/05/2022] Open
Abstract
Resistance to radiotherapy and chemotherapy is a common problem in the treatment of cancer in humans and companion animals, including cats. There is thus an urgent need to develop new treatments. Molecularly targeted therapies hold the promise of high specificity and significant cancer‐killing effects. Accumulating evidence shows that DNA double‐strand break (DSB) repair proteins, which function in Ku‐dependent non‐homologous DNA‐end joining (NHEJ), are potential target molecules for next‐generation cancer therapies. Although cancer radioresistance in cats has been previously described, there are no reports on feline Ku‐dependent NHEJ. Here, we cloned and sequenced feline XLFcDNA and characterized X‐ray repair cross‐complementing protein 4‐like factor (XLF), which is one of the core NHEJ proteins. We demonstrated that feline XLF localizes to the nuclei of feline cells and that feline XLF immediately accumulates at laser‐induced DSB sites in a Ku‐dependent manner. Amino acid sequence alignment analysis showed that feline XLF has only 80.9% identity with human XLF protein, while the predicted nuclear localization signal and putative 14‐3‐3‐binding motif are perfectly conserved among human, cat, dog, chimpanzee, and mouse. These findings are consistent with the hypothesis that regulation of subcellular localization is important for the function of XLF. Furthermore, these findings may be useful in clarifying the mechanisms underlying feline Ku‐dependent DSB repair and feline cell radioresistance, and possibly facilitate the development of new molecularly targeted therapies that target common proteins in human and feline cancers.
Collapse
Affiliation(s)
- Manabu Koike
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Yasutomo Yutoku
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Aki Koike
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| |
Collapse
|
31
|
Zhang Q, Xiao K, Paredes JM, Mamonova T, Sneddon WB, Liu H, Wang D, Li S, McGarvey JC, Uehling D, Al-Awar R, Joseph B, Jean-Alphonse F, Orte A, Friedman PA. Parathyroid hormone initiates dynamic NHERF1 phosphorylation cycling and conformational changes that regulate NPT2A-dependent phosphate transport. J Biol Chem 2019; 294:4546-4571. [PMID: 30696771 PMCID: PMC6433080 DOI: 10.1074/jbc.ra119.007421] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 01/25/2019] [Indexed: 12/30/2022] Open
Abstract
Na+-H+ exchanger regulatory factor-1 (NHERF1) is a PDZ protein that scaffolds membrane proteins, including sodium-phosphate co-transport protein 2A (NPT2A) at the plasma membrane. NHERF1 is a phosphoprotein with 40 Ser and Thr residues. Here, using tandem MS analysis, we characterized the sites of parathyroid hormone (PTH)-induced NHERF1 phosphorylation and identified 10 high-confidence phosphorylation sites. Ala replacement at Ser46, Ser162, Ser181, Ser269, Ser280, Ser291, Thr293, Ser299, and Ser302 did not affect phosphate uptake, but S290A substitution abolished PTH-dependent phosphate transport. Unexpectedly, Ser290 was rapidly dephosphorylated and rephosphorylated after PTH stimulation, and we found that protein phosphatase 1α (PP1α), which binds NHERF1 through a conserved VxF/W PP1 motif, dephosphorylates Ser290 Mutating 257VPF259 eliminated PP1 binding and blunted dephosphorylation. Tautomycetin blocked PP1 activity and abrogated PTH-sensitive phosphate transport. Using fluorescence lifetime imaging (FLIM), we observed that PTH paradoxically and transiently elevates intracellular phosphate. Added phosphate blocked PP1α-mediated Ser290 dephosphorylation of recombinant NHERF1. Hydrogen-deuterium exchange MS revealed that β-sheets in NHERF1's PDZ2 domain display lower deuterium uptake than those in the structurally similar PDZ1, implying that PDZ1 is more cloistered. Dephosphorylated NHERF1 exhibited faster exchange at C-terminal residues suggesting that NHERF1 dephosphorylation precedes Ser290 rephosphorylation. Our results show that PP1α and NHERF1 form a holoenzyme and that a multiprotein kinase cascade involving G protein-coupled receptor kinase 6A controls the Ser290 phosphorylation status of NHERF1 and regulates PTH-sensitive, NPT2A-mediated phosphate uptake. These findings reveal how reversible phosphorylation modifies protein conformation and function and the biochemical mechanisms underlying PTH control of phosphate transport.
Collapse
Affiliation(s)
- Qiangmin Zhang
- From the Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology
| | - Kunhong Xiao
- From the Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology.,Vascular Medicine Institute, and.,Biomedical Mass Spectrometry Center, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261
| | - José M Paredes
- the Department of Physical Chemistry, Faculty of Pharmacy, University of Granada, 18071-Granada, Spain
| | - Tatyana Mamonova
- From the Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology
| | - W Bruce Sneddon
- From the Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology
| | - Hongda Liu
- From the Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology
| | - Dawei Wang
- From the Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology
| | - Sheng Li
- the Department of Medicine, University of California San Diego, La Jolla, California 92093, and
| | - Jennifer C McGarvey
- From the Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology
| | - David Uehling
- the Department of Drug Discovery, Ontario Institute for Cancer Research, Toronto, Ontario M5G 0A3, Canada
| | - Rima Al-Awar
- the Department of Drug Discovery, Ontario Institute for Cancer Research, Toronto, Ontario M5G 0A3, Canada
| | - Babu Joseph
- the Department of Drug Discovery, Ontario Institute for Cancer Research, Toronto, Ontario M5G 0A3, Canada
| | | | - Angel Orte
- the Department of Physical Chemistry, Faculty of Pharmacy, University of Granada, 18071-Granada, Spain
| | - Peter A Friedman
- From the Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, .,Department of Structural Biology
| |
Collapse
|
32
|
Amiri Moghani AR, Sharma MK, Matsumoto Y. In cellulo phosphorylation of DNA double-strand break repair protein XRCC4 on Ser260 by DNA-PK. JOURNAL OF RADIATION RESEARCH 2018; 59:700-708. [PMID: 30247612 PMCID: PMC6251426 DOI: 10.1093/jrr/rry072] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Indexed: 05/16/2023]
Abstract
XRCC4 is one of the core factors for DNA double-strand break (DSB) repair through non-homologous end joining (NHEJ). XRCC4 is phosphorylated by DNA-dependent protein kinase (DNA-PK), with Ser260 and Ser320 (Ser318 in the alternatively spliced form) being the major phosphorylation sites in vitro. It was recently reported that Ser320 is phosphorylated by DNA-PK in response to DNA damage; however, it is currently unclear whether Ser260 is phosphorylated in cellulo in response to DNA damage. Herein, we generated an antibody against XRCC4 phosphorylated on Ser260 and examined its phosphorylation status via Western blotting. XRCC4 Ser260 phosphorylation increased after irradiation with 30-300 Gy of γ-rays and was suppressed by DNA-PK inhibitor but not by ATM inhibitor. Moreover, XRCC4 Ser260 phosphorylation decreased in DNA-PKcs-deficient cells. These observations indicate that XRCC4 Ser260 is phosphorylated by DNA-PK in cellulo. The XRCC4S260A mutant reversed the high radiosensitivity of XRCC4-deficient M10 cells to a similar level to that of wild-type XRCC4. However, the clonogenic survival of cells expressing the XRCC4S260A mutant was slightly but significantly lower than that of those expressing wild-type XRCC4. In addition, XRCC4S260A-expressing cells displayed a significantly greater number of γ-H2AX foci than XRCC4WT-expressing cells 4 h after 1 Gy irradiation and without irradiation. The present results suggest a potential role of XRCC4 Ser260 phosphorylation by DNA-PK in DSB repair.
Collapse
Affiliation(s)
- Ali Reza Amiri Moghani
- Laboratory for Advanced Nuclear Energy, Institute of Innovative Research, Tokyo Institute of Technology, 2-12-1-N1–30, Ookayama, Meguro-ku, Tokyo, Japan
| | - Mukesh Kumar Sharma
- Laboratory for Advanced Nuclear Energy, Institute of Innovative Research, Tokyo Institute of Technology, 2-12-1-N1–30, Ookayama, Meguro-ku, Tokyo, Japan
- Department of Zoology, SPC Government College, Ajmer, Rajasthan, India
| | - Yoshihisa Matsumoto
- Laboratory for Advanced Nuclear Energy, Institute of Innovative Research, Tokyo Institute of Technology, 2-12-1-N1–30, Ookayama, Meguro-ku, Tokyo, Japan
- Corresponding author. Laboratory for Advanced Nuclear Energy, Institute of Innovative Research, Tokyo Institute of Technology, 2-12-1-N1–30, Ookayama, Meguro-ku, Tokyo 152-8550, Japan. Tel/Fax: +81-0-3-5734-3703;
| |
Collapse
|
33
|
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: 39] [Impact Index Per Article: 6.5] [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.
Collapse
|