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Locke AJ, Abou Farraj R, Tran C, Zeinali E, Mashayekhi F, Ali JYH, Glover JNM, Ismail IH. The role of RNF138 in DNA end resection is regulated by ubiquitylation and CDK phosphorylation. J Biol Chem 2024; 300:105709. [PMID: 38309501 PMCID: PMC10910129 DOI: 10.1016/j.jbc.2024.105709] [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: 07/05/2023] [Revised: 01/02/2024] [Accepted: 01/18/2024] [Indexed: 02/05/2024] Open
Abstract
Double-strand breaks (DSBs) are DNA lesions that pose a significant threat to genomic stability. The repair of DSBs by the homologous recombination (HR) pathway is preceded by DNA end resection, the 5' to 3' nucleolytic degradation of DNA away from the DSB. We and others previously identified a role for RNF138, a really interesting new gene finger E3 ubiquitin ligase, in stimulating DNA end resection and HR. Yet, little is known about how RNF138's function is regulated in the context of DSB repair. Here, we show that RNF138 is phosphorylated at residue T27 by cyclin-dependent kinase (CDK) activity during the S and G2 phases of the cell cycle. We also observe that RNF138 is ubiquitylated constitutively, with ubiquitylation occurring in part on residue K158 and rising during the S/G2 phases. Interestingly, RNF138 ubiquitylation decreases upon genotoxic stress. By mutating RNF138 at residues T27, K158, and the previously identified S124 ataxia telangiectasia mutated phosphorylation site (Han et al., 2016, ref. 22), we find that post-translational modifications at all three positions mediate DSB repair. Cells expressing the T27A, K158R, and S124A variants of RNF138 are impaired in DNA end resection, HR activity, and are more sensitive to ionizing radiation compared to those expressing wildtype RNF138. Our findings shed more light on how RNF138 activity is controlled by the cell during HR.
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Affiliation(s)
- Andrew J Locke
- Division of Experimental Oncology, Department of Oncology, Faculty of Medicine & Dentistry, Cross Cancer Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Rabih Abou Farraj
- Department of Biochemistry, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Caroline Tran
- Division of Experimental Oncology, Department of Oncology, Faculty of Medicine & Dentistry, Cross Cancer Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Elham Zeinali
- Division of Experimental Oncology, Department of Oncology, Faculty of Medicine & Dentistry, Cross Cancer Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Fatemeh Mashayekhi
- Division of Experimental Oncology, Department of Oncology, Faculty of Medicine & Dentistry, Cross Cancer Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Jana Yasser Hafez Ali
- Division of Experimental Oncology, Department of Oncology, Faculty of Medicine & Dentistry, Cross Cancer Institute, University of Alberta, Edmonton, Alberta, Canada
| | - J N Mark Glover
- Department of Biochemistry, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Ismail Hassan Ismail
- Division of Experimental Oncology, Department of Oncology, Faculty of Medicine & Dentistry, Cross Cancer Institute, University of Alberta, Edmonton, Alberta, Canada; Biophysics Department, Faculty of Science, Cairo University, Giza, Egypt.
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2
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Sachsenweger J, Jansche R, Merk T, Heitmeir B, Deniz M, Faust U, Roggia C, Tzschach A, Schroeder C, Riess A, Pospiech H, Peltoketo H, Pylkäs K, Winqvist R, Wiesmüller L. ABRAXAS1 orchestrates BRCA1 activities to counter genome destabilizing repair pathways-lessons from breast cancer patients. Cell Death Dis 2023; 14:328. [PMID: 37198153 DOI: 10.1038/s41419-023-05845-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 04/27/2023] [Accepted: 05/02/2023] [Indexed: 05/19/2023]
Abstract
It has been well-established that mutations in BRCA1 and BRCA2, compromising functions in DNA double-strand break repair (DSBR), confer hereditary breast and ovarian cancer risk. Importantly, mutations in these genes explain only a minor fraction of the hereditary risk and of the subset of DSBR deficient tumors. Our screening efforts identified two truncating germline mutations in the gene encoding the BRCA1 complex partner ABRAXAS1 in German early-onset breast cancer patients. To unravel the molecular mechanisms triggering carcinogenesis in these carriers of heterozygous mutations, we examined DSBR functions in patient-derived lymphoblastoid cells (LCLs) and in genetically manipulated mammary epithelial cells. By use of these strategies we were able to demonstrate that these truncating ABRAXAS1 mutations exerted dominant effects on BRCA1 functions. Interestingly, we did not observe haploinsufficiency regarding homologous recombination (HR) proficiency (reporter assay, RAD51-foci, PARP-inhibitor sensitivity) in mutation carriers. However, the balance was shifted to use of mutagenic DSBR-pathways. The dominant effect of truncated ABRAXAS1 devoid of the C-terminal BRCA1 binding site can be explained by retention of the N-terminal interaction sites for other BRCA1-A complex partners like RAP80. In this case BRCA1 was channeled from the BRCA1-A to the BRCA1-C complex, which induced single-strand annealing (SSA). Further truncation, additionally deleting the coiled-coil region of ABRAXAS1, unleashed excessive DNA damage responses (DDRs) de-repressing multiple DSBR-pathways including SSA and non-homologous end-joining (NHEJ). Our data reveal de-repression of low-fidelity repair activities as a common feature of cells from patients with heterozygous mutations in genes encoding BRCA1 and its complex partners.
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Affiliation(s)
- Juliane Sachsenweger
- Department of Obstetrics and Gynecology, Ulm University, Ulm, Germany
- Laboratory of Cancer Genetics and Tumor Biology, Translational Medicine Research Unit, Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Rebecca Jansche
- Department of Obstetrics and Gynecology, Ulm University, Ulm, Germany
| | - Tatjana Merk
- Department of Obstetrics and Gynecology, Ulm University, Ulm, Germany
| | - Benedikt Heitmeir
- Department of Obstetrics and Gynecology, Ulm University, Ulm, Germany
| | - Miriam Deniz
- Department of Obstetrics and Gynecology, Ulm University, Ulm, Germany
| | - Ulrike Faust
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Cristiana Roggia
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Andreas Tzschach
- Institute of Human Genetics, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Christopher Schroeder
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Angelika Riess
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Helmut Pospiech
- Leibniz Institute on Aging - Fritz Lipmann Institute, Jena, Germany
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Hellevi Peltoketo
- Laboratory of Cancer Genetics and Tumor Biology, Translational Medicine Research Unit, Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Katri Pylkäs
- Laboratory of Cancer Genetics and Tumor Biology, Translational Medicine Research Unit, Biocenter Oulu, University of Oulu, Oulu, Finland
- Laboratory of Cancer Genetics and Tumor Biology, Northern Finland Laboratory Centre, Oulu, Finland
| | - Robert Winqvist
- Laboratory of Cancer Genetics and Tumor Biology, Translational Medicine Research Unit, Biocenter Oulu, University of Oulu, Oulu, Finland
- Laboratory of Cancer Genetics and Tumor Biology, Northern Finland Laboratory Centre, Oulu, Finland
| | - Lisa Wiesmüller
- Department of Obstetrics and Gynecology, Ulm University, Ulm, Germany.
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Mladenova V, Mladenov E, Chaudhary S, Stuschke M, Iliakis G. The high toxicity of DSB-clusters modelling high-LET-DNA damage derives from inhibition of c-NHEJ and promotion of alt-EJ and SSA despite increases in HR. Front Cell Dev Biol 2022; 10:1016951. [PMID: 36263011 PMCID: PMC9574094 DOI: 10.3389/fcell.2022.1016951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 09/14/2022] [Indexed: 11/13/2022] Open
Abstract
Heavy-ion radiotherapy utilizing high linear energy transfer (high-LET) ionizing radiation (IR) is a promising cancer treatment modality owing to advantageous physical properties of energy deposition and associated toxicity over X-rays. Therapies utilizing high-LET radiation will benefit from a better understanding of the molecular mechanisms underpinning their increased biological efficacy. Towards this goal, we investigate here the biological consequences of well-defined clusters of DNA double-strand breaks (DSBs), a form of DNA damage, which on theoretical counts, has often been considered central to the enhanced toxicity of high-LET IR. We test clonal cell lines harboring in their genomes constructs with appropriately engineered I-SceI recognition sites that convert upon I-SceI expression to individual DSBs, or DSB-clusters comprising known numbers of DSBs with defined DNA-ends. We find that, similarly to high-LET IR, DSB-clusters of increasing complexity, i.e. increasing numbers of DSBs, with compatible or incompatible ends, compromise classical non-homologous end-joining, favor DNA end-resection and promote resection-dependent DSB-processing. Analysis of RAD51 foci shows increased engagement of error-free homologous recombination on DSB-clusters. Multicolor fluorescence in situ hybridization analysis shows that complex DSB-clusters markedly increase the incidence of structural chromosomal abnormalities (SCAs). Since RAD51-knockdown further increases SCAs-incidence, we conclude that homologous recombination suppresses SCAs-formation. Strikingly, CtIP-depletion inhibits SCAs-formation, suggesting that it relies on alternative end-joining or single-strand annealing. Indeed, ablation of RAD52 causes a marked reduction in SCAs, as does also inhibition of PARP1. We conclude that increased DSB-cluster formation that accompanies LET-increases, enhances IR-effectiveness by promoting DNA end-resection, which suppresses c-NHEJ and enhances utilization of alt-EJ or SSA. Although increased resection also favors HR, on balance, error-prone processing dominates, causing the generally observed increased toxicity of high-LET radiation. These findings offer new mechanistic insights into high-LET IR-toxicity and have translational potential in the clinical setting that may be harnessed by combining high-LET IR with inhibitors of PARP1 or RAD52.
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Affiliation(s)
- Veronika Mladenova
- Department of Radiation Therapy, Division of Experimental Radiation Biology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
- Institute of Medical Radiation Biology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Emil Mladenov
- Department of Radiation Therapy, Division of Experimental Radiation Biology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
- Institute of Medical Radiation Biology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Shipra Chaudhary
- Institute of Medical Radiation Biology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
- Institute for Advanced Biosciences, Inserm U 1209 / CNRS UMR 5309 Joint Research Center, Grenoble Alpes University, Grenoble, France
| | - Martin Stuschke
- Department of Radiation Therapy, Division of Experimental Radiation Biology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
- German Cancer Consortium (DKTK), Partner Site University Hospital Essen, Essen, Germany
- German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - George Iliakis
- Department of Radiation Therapy, Division of Experimental Radiation Biology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
- Institute of Medical Radiation Biology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
- *Correspondence: George Iliakis,
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Averbeck NB, Barent C, Jakob B, Syzonenko T, Durante M, Taucher-Scholz G. The Ubiquitin Ligase RNF138 Cooperates with CtIP to Stimulate Resection of Complex DNA Double-Strand Breaks in Human G1-Phase Cells. Cells 2022; 11:cells11162561. [PMID: 36010636 PMCID: PMC9406464 DOI: 10.3390/cells11162561] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 08/04/2022] [Accepted: 08/05/2022] [Indexed: 11/30/2022] Open
Abstract
DNA double-strand breaks (DSBs) represent the molecular origin of ionizing-radiation inflicted biological effects. An increase in the ionization density causes more complex, clustered DSBs that can be processed by resection also in G1 phase, where repair of resected DSBs is considered erroneous and may contribute to the increased biological effectiveness of heavy ions in radiotherapy. To investigate the resection regulation of complex DSBs, we exposed G1 cells depleted for different candidate factors to heavy ions or α-particle radiation. Immunofluorescence microscopy was used to monitor the resection marker RPA, the DSB marker γH2AX and the cell-cycle markers CENP-F and geminin. The Fucci system allowed to select G1 cells, cell survival was measured by clonogenic assay. We show that in G1 phase the ubiquitin ligase RNF138 functions in resection regulation. RNF138 ubiquitinates the resection factor CtIP in a radiation-dependent manner to allow its DSB recruitment in G1 cells. At complex DSBs, RNF138′s participation becomes more relevant, consistent with the observation that also resection is more frequent at these DSBs. Furthermore, deficiency of RNF138 affects both DSB repair and cell survival upon induction of complex DSBs. We conclude that RNF138 is a regulator of resection that is influenced by DSB complexity and can affect the quality of DSB repair in G1 cells.
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Affiliation(s)
- Nicole B. Averbeck
- Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstr. 1, 64291 Darmstadt, Germany
- Correspondence:
| | - Carina Barent
- Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstr. 1, 64291 Darmstadt, Germany
| | - Burkhard Jakob
- Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstr. 1, 64291 Darmstadt, Germany
- Department of Biology, Technische Universität Darmstadt, Schnittspahnstr. 11, 64287 Darmstadt, Germany
| | - Tatyana Syzonenko
- Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstr. 1, 64291 Darmstadt, Germany
| | - Marco Durante
- Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstr. 1, 64291 Darmstadt, Germany
- Department of Condensed Matter Physics, Technische Universität Darmstadt, Hochschulstr. 6–8, 64289 Darmstadt, Germany
| | - Gisela Taucher-Scholz
- Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstr. 1, 64291 Darmstadt, Germany
- Department of Biology, Technische Universität Darmstadt, Schnittspahnstr. 11, 64287 Darmstadt, Germany
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5
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Danforth JM, Provencher L, Goodarzi AA. Chromatin and the Cellular Response to Particle Radiation-Induced Oxidative and Clustered DNA Damage. Front Cell Dev Biol 2022; 10:910440. [PMID: 35912116 PMCID: PMC9326100 DOI: 10.3389/fcell.2022.910440] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 06/21/2022] [Indexed: 12/03/2022] Open
Abstract
Exposure to environmental ionizing radiation is prevalent, with greatest lifetime doses typically from high Linear Energy Transfer (high-LET) alpha particles via the radioactive decay of radon gas in indoor air. Particle radiation is highly genotoxic, inducing DNA damage including oxidative base lesions and DNA double strand breaks. Due to the ionization density of high-LET radiation, the consequent damage is highly clustered wherein ≥2 distinct DNA lesions occur within 1–2 helical turns of one another. These multiply-damaged sites are difficult for eukaryotic cells to resolve either quickly or accurately, resulting in the persistence of DNA damage and/or the accumulation of mutations at a greater rate per absorbed dose, relative to lower LET radiation types. The proximity of the same and different types of DNA lesions to one another is challenging for DNA repair processes, with diverse pathways often confounding or interplaying with one another in complex ways. In this context, understanding the state of the higher order chromatin compaction and arrangements is essential, as it influences the density of damage produced by high-LET radiation and regulates the recruitment and activity of DNA repair factors. This review will summarize the latest research exploring the processes by which clustered DNA damage sites are induced, detected, and repaired in the context of chromatin.
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6
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Particle radiotherapy and molecular therapies: mechanisms and strategies towards clinical applications. Expert Rev Mol Med 2022; 24:e8. [PMID: 35101155 DOI: 10.1017/erm.2022.2] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Immunotherapy and targeted therapy are now commonly used in clinical trials in combination with radiotherapy for several cancers. While results are promising and encouraging, the molecular mechanisms of the interaction between the drugs and radiation remain largely unknown. This is especially important when switching from conventional photon therapy to particle therapy using protons or heavier ions. Different dose deposition patterns and molecular radiobiology can in fact modify the interaction with drugs and their effectiveness. We will show here that whilst the main molecular players are the same after low and high linear energy transfer radiation exposure, significant differences are observed in post-exposure signalling pathways that may lead to different effects of the drugs. We will also emphasise that the problem of the timing between drug administration and radiation and the fractionation regime are critical issues that need to be addressed urgently to achieve optimal results in combined treatments with particle therapy.
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7
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Rall-Scharpf M, Friedl TWP, Biechonski S, Denkinger M, Milyavsky M, Wiesmüller L. Sex-specific differences in DNA double-strand break repair of cycling human lymphocytes during aging. Aging (Albany NY) 2021; 13:21066-21089. [PMID: 34506302 PMCID: PMC8457596 DOI: 10.18632/aging.203519] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 08/10/2021] [Indexed: 12/15/2022]
Abstract
The gender gap in life expectancy and cancer incidence suggests differences in the aging process between the sexes. Genomic instability has been recognized as a key factor in aging, but little is known about sex-specific differences. Therefore, we analyzed DNA double-strand break (DSB) repair in cycling human peripheral blood lymphocytes (PBL) from male and female donors of different age. Reporter-based DSB repair analyses revealed differential regulation of pathway usage in PBL from male and female donors with age: Non-homologous end joining (NHEJ) was inversely regulated in men and women; the activity of pathways requiring end processing and strand annealing steps such as microhomology-mediated end joining (MMEJ) declined with age in women but not in men. Screening candidate proteins identified the NHEJ protein KU70 as well as the end resection regulatory factors ATM and BLM showing reduced expression during aging in women. Consistently, the regulatory factor BLM contributed to the MMEJ proficiency in young but not in old women as demonstrated by knockdown analysis. In conclusion, we show that DSB repair is subject to changes upon aging and age-related changes in DSB repair are distinct in men and women.
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Affiliation(s)
| | - Thomas W P Friedl
- Department of Obstetrics and Gynecology, Ulm University, Ulm, Germany
| | - Shahar Biechonski
- Department of Pathology, Sackler Faculty of Medicine, Tel Aviv University, Tel-Aviv, Israel
| | - Michael Denkinger
- Institute for Geriatric Research Unit, Agaplesion Bethesda Hospital, Ulm University, Ulm, Germany
| | - Michael Milyavsky
- Department of Pathology, Sackler Faculty of Medicine, Tel Aviv University, Tel-Aviv, Israel
| | - Lisa Wiesmüller
- Department of Obstetrics and Gynecology, Ulm University, Ulm, Germany
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8
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Mancini M, Magnani E, Macchi F, Bonapace IM. The multi-functionality of UHRF1: epigenome maintenance and preservation of genome integrity. Nucleic Acids Res 2021; 49:6053-6068. [PMID: 33939809 PMCID: PMC8216287 DOI: 10.1093/nar/gkab293] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 04/02/2021] [Accepted: 04/12/2021] [Indexed: 12/23/2022] Open
Abstract
During S phase, the cooperation between the macromolecular complexes regulating DNA synthesis, epigenetic information maintenance and DNA repair is advantageous for cells, as they can rapidly detect DNA damage and initiate the DNA damage response (DDR). UHRF1 is a fundamental epigenetic regulator; its ability to coordinate DNA methylation and histone code is unique across proteomes of different species. Recently, UHRF1’s role in DNA damage repair has been explored and recognized to be as important as its role in maintaining the epigenome. UHRF1 is a sensor for interstrand crosslinks and a determinant for the switch towards homologous recombination in the repair of double-strand breaks; its loss results in enhanced sensitivity to DNA damage. These functions are finely regulated by specific post-translational modifications and are mediated by the SRA domain, which binds to damaged DNA, and the RING domain. Here, we review recent studies on the role of UHRF1 in DDR focusing on how it recognizes DNA damage and cooperates with other proteins in its repair. We then discuss how UHRF1’s epigenetic abilities in reading and writing histone modifications, or its interactions with ncRNAs, could interlace with its role in DDR.
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Affiliation(s)
- Monica Mancini
- Department of Biotechnology and Life Sciences, University of Insubria, Busto Arsizio, VA 21052, Italy
| | - Elena Magnani
- Program in Biology, New York University Abu Dhabi, Abu Dhabi, PO Box 129188, United Arab Emirates
| | - Filippo Macchi
- Program in Biology, New York University Abu Dhabi, Abu Dhabi, PO Box 129188, United Arab Emirates
| | - Ian Marc Bonapace
- Department of Biotechnology and Life Sciences, University of Insubria, Busto Arsizio, VA 21052, Italy
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9
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Osborne HC, Irving E, Forment JV, Schmidt CK. E2 enzymes in genome stability: pulling the strings behind the scenes. Trends Cell Biol 2021; 31:628-643. [PMID: 33685796 DOI: 10.1016/j.tcb.2021.01.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 01/27/2021] [Accepted: 01/29/2021] [Indexed: 02/06/2023]
Abstract
Ubiquitin and ubiquitin-like proteins (UBLs) function as critical post-translational modifiers in the maintenance of genome stability. Ubiquitin/UBL-conjugating enzymes (E2s) are responsible, as part of a wider enzymatic cascade, for transferring single moieties or polychains of ubiquitin/UBLs to one or multiple residues on substrate proteins. Recent advances in structural and mechanistic understanding of how ubiquitin/UBL substrate attachment is orchestrated indicate that E2s can exert control over chain topology, substrate-site specificity, and downstream physiological effects to help maintain genome stability. Drug discovery efforts have typically focussed on modulating other members of the ubiquitin/UBL cascades or the ubiquitin-proteasome system. Here, we review the current standing of E2s in genome stability and revisit their potential as pharmacological targets for developing novel anti-cancer therapies.
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Affiliation(s)
- Hugh C Osborne
- 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
| | - Elsa Irving
- Bioscience, Oncology R&D, AstraZeneca, Cambridge CB4 0WG, UK
| | - Josep V Forment
- Bioscience, Oncology R&D, AstraZeneca, Cambridge CB4 0WG, 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.
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10
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Soni A, Mladenov E, Iliakis G. Proficiency in homologous recombination repair is prerequisite for activation of G 2-checkpoint at low radiation doses. DNA Repair (Amst) 2021; 101:103076. [PMID: 33640756 DOI: 10.1016/j.dnarep.2021.103076] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 11/30/2020] [Accepted: 02/13/2021] [Indexed: 10/22/2022]
Abstract
Pathways of repair of DNA double strand breaks (DSBs) cooperate with DNA damage cell cycle checkpoints to safeguard genomic stability when cells are exposed to ionizing radiation (IR). It is widely accepted that checkpoints facilitate the function of DSB repair pathways. Whether DSB repair proficiency feeds back into checkpoint activation is less well investigated. Here, we study activation of the G2-checkpoint in cells deficient in homologous recombination repair (HRR) after exposure to low IR doses (∼1 Gy) in the G2-phase. We report that in the absence of functional HRR, activation of the G2-checkpoint is severely impaired. This response is specific for HRR, as cells deficient in classical non-homologous end joining (c-NHEJ) develop a similar or stronger G2-checkpoint than wild-type (WT) cells. Inhibition of ATM or ATR leaves largely unaffected residual G2-checkpoint in HRR-deficient cells, suggesting that the G2-checkpoint engagement of ATM/ATR is coupled to HRR. HRR-deficient cells show in G2-phase reduced DSB-end-resection, as compared to WT-cells or c-NHEJ mutants, confirming the reported link between resection and G2-checkpoint activation. Strikingly, at higher IR doses (≥4 Gy) HRR-deficient cells irradiated in G2-phase activate a weak but readily detectable ATM/ATR-dependent G2-checkpoint, whereas HRR-deficient cells irradiated in S-phase develop a stronger G2-checkpoint than WT-cells. We conclude that HRR and the ATM/ATR-dependent G2-checkpoint are closely intertwined in cells exposed to low IR-doses in G2-phase, where HRR dominates; they uncouple as HRR becomes suppressed at higher IR doses. Notably, this coupling is specific for cells irradiated in G2-phase, and cells irradiated in S-phase utilize a different mechanistic setup.
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Affiliation(s)
- Aashish Soni
- Institute of Medical Radiation Biology, University of Duisburg-Essen Medical School, 45122, Essen, Germany
| | - Emil Mladenov
- Institute of Medical Radiation Biology, University of Duisburg-Essen Medical School, 45122, Essen, Germany
| | - George Iliakis
- Institute of Medical Radiation Biology, University of Duisburg-Essen Medical School, 45122, Essen, Germany.
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11
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Yang H, Ren S, Yu S, Pan H, Li T, Ge S, Zhang J, Xia N. Methods Favoring Homology-Directed Repair Choice in Response to CRISPR/Cas9 Induced-Double Strand Breaks. Int J Mol Sci 2020; 21:E6461. [PMID: 32899704 PMCID: PMC7555059 DOI: 10.3390/ijms21186461] [Citation(s) in RCA: 78] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 08/20/2020] [Accepted: 09/01/2020] [Indexed: 12/15/2022] Open
Abstract
Precise gene editing is-or will soon be-in clinical use for several diseases, and more applications are under development. The programmable nuclease Cas9, directed by a single-guide RNA (sgRNA), can introduce double-strand breaks (DSBs) in target sites of genomic DNA, which constitutes the initial step of gene editing using this novel technology. In mammals, two pathways dominate the repair of the DSBs-nonhomologous end joining (NHEJ) and homology-directed repair (HDR)-and the outcome of gene editing mainly depends on the choice between these two repair pathways. Although HDR is attractive for its high fidelity, the choice of repair pathway is biased in a biological context. Mammalian cells preferentially employ NHEJ over HDR through several mechanisms: NHEJ is active throughout the cell cycle, whereas HDR is restricted to S/G2 phases; NHEJ is faster than HDR; and NHEJ suppresses the HDR process. This suggests that definitive control of outcome of the programmed DNA lesioning could be achieved through manipulating the choice of cellular repair pathway. In this review, we summarize the DSB repair pathways, the mechanisms involved in choice selection based on DNA resection, and make progress in the research investigating strategies that favor Cas9-mediated HDR based on the manipulation of repair pathway choice to increase the frequency of HDR in mammalian cells. The remaining problems in improving HDR efficiency are also discussed. This review should facilitate the development of CRISPR/Cas9 technology to achieve more precise gene editing.
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Affiliation(s)
| | | | | | | | - Tingdong Li
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, National Institute of Diagnostics and Vaccine Development in Infectious Disease, Collaborative Innovation Centers of Biological Products, School of Public Health, Xiamen University, Xiamen 361102, China; (H.Y.); (S.R.); (S.Y.); (H.P.); (J.Z.); (N.X.)
| | - Shengxiang Ge
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, National Institute of Diagnostics and Vaccine Development in Infectious Disease, Collaborative Innovation Centers of Biological Products, School of Public Health, Xiamen University, Xiamen 361102, China; (H.Y.); (S.R.); (S.Y.); (H.P.); (J.Z.); (N.X.)
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12
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Vpu modulates DNA repair to suppress innate sensing and hyper-integration of HIV-1. Nat Microbiol 2020; 5:1247-1261. [PMID: 32690953 DOI: 10.1038/s41564-020-0753-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 06/11/2020] [Indexed: 12/19/2022]
Abstract
To avoid innate sensing and immune control, human immunodeficiency virus type 1 (HIV-1) has to prevent the accumulation of viral complementary DNA species. Here, we show that the late HIV-1 accessory protein Vpu hijacks DNA repair mechanisms to promote degradation of nuclear viral cDNA in cells that are already productively infected. Vpu achieves this by interacting with RanBP2-RanGAP1*SUMO1-Ubc9 SUMO E3-ligase complexes at the nuclear pore to reprogramme promyelocytic leukaemia protein nuclear bodies and reduce SUMOylation of Bloom syndrome protein, unleashing end degradation of viral cDNA. Concomitantly, Vpu inhibits RAD52-mediated homologous repair of viral cDNA, preventing the generation of dead-end circular forms of single copies of the long terminal repeat and permitting sustained nucleolytic attack. Our results identify Vpu as a key modulator of the DNA repair machinery. We show that Bloom syndrome protein eliminates nuclear HIV-1 cDNA and thereby suppresses immune sensing and proviral hyper-integration. Therapeutic targeting of DNA repair may facilitate the induction of antiviral immunity and suppress proviral integration replenishing latent HIV reservoirs.
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13
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Li F, Mladenov E, Mortoga S, Iliakis G. SCF SKP2 regulates APC/C CDH1-mediated degradation of CTIP to adjust DNA-end resection in G 2-phase. Cell Death Dis 2020; 11:548. [PMID: 32683422 PMCID: PMC7368859 DOI: 10.1038/s41419-020-02755-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 06/22/2020] [Accepted: 06/25/2020] [Indexed: 11/20/2022]
Abstract
The cell cycle-dependent engagement of DNA-end resection at DSBs is regulated by phosphorylation of CTIP by CDKs, the central regulators of cell cycle transitions. Cell cycle transitions are also intimately regulated by protein degradation via two E3 ubiquitin ligases: SCFSKP2 and APC/CCDH1 complex. Although APC/CCDH1 regulates CTIP in G1– and G2-phase, contributions by SCFSKP2 have not been reported. We demonstrate that SCFSKP2 is a strong positive regulator of resection. Knockdown of SKP2, fully suppresses resection in several cell lines. Notably, this suppression is G2-phase specific and is not observed in S-phase or G1–phase cells. Knockdown of SKP2 inactivates SCFSKP2 causing APC/CCDH1 activation, which degrades CTIP. The stabilizing function of SCFSKP2 on CTIP promotes resection and supports gene conversion (GC), alternative end joining (alt-EJ) and cell survival. We propose that CDKs and SCFSKP2-APC/CCDH1 cooperate to regulate resection and repair pathway choice at DSBs in G2-phase.
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Affiliation(s)
- Fanghua Li
- Institute of Medical Radiation Biology, University of Duisburg-Essen Medical School, 45122, Essen, Germany
| | - Emil Mladenov
- Institute of Medical Radiation Biology, University of Duisburg-Essen Medical School, 45122, Essen, Germany
| | - Sharif Mortoga
- Institute of Medical Radiation Biology, University of Duisburg-Essen Medical School, 45122, Essen, Germany
| | - George Iliakis
- Institute of Medical Radiation Biology, University of Duisburg-Essen Medical School, 45122, Essen, Germany.
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14
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Garvin AJ. Beyond reversal: ubiquitin and ubiquitin-like proteases and the orchestration of the DNA double strand break repair response. Biochem Soc Trans 2019; 47:1881-1893. [PMID: 31769469 PMCID: PMC6925521 DOI: 10.1042/bst20190534] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 11/05/2019] [Accepted: 11/06/2019] [Indexed: 12/14/2022]
Abstract
The cellular response to genotoxic DNA double strand breaks (DSBs) uses a multitude of post-translational modifications to localise, modulate and ultimately clear DNA repair factors in a timely and accurate manner. Ubiquitination is well established as vital to the DSB response, with a carefully co-ordinated pathway of histone ubiquitination events being a central component of DSB signalling. Other ubiquitin-like modifiers (Ubl) including SUMO and NEDD8 have since been identified as playing important roles in DSB repair. In the last five years ∼20 additional Ub/Ubl proteases have been implicated in the DSB response. The number of proteases identified highlights the complexity of the Ub/Ubl signal present at DSBs. Ub/Ubl proteases regulate turnover, activity and protein-protein interactions of DSB repair factors both catalytically and non-catalytically. This not only ensures efficient repair of breaks but has a role in channelling repair into the correct DSB repair sub-pathways. Ultimately Ub/Ubl proteases have essential roles in maintaining genomic stability. Given that deficiencies in many Ub/Ubl proteases promotes sensitivity to DNA damaging chemotherapies, they could be attractive targets for cancer treatment.
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Affiliation(s)
- Alexander J. Garvin
- Institute of Cancer and Genomic Sciences, University of Birmingham, Edgbaston, Birmingham, U.K
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15
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Burdova K, Storchova R, Palek M, Macurek L. WIP1 Promotes Homologous Recombination and Modulates Sensitivity to PARP Inhibitors. Cells 2019; 8:cells8101258. [PMID: 31619012 PMCID: PMC6830099 DOI: 10.3390/cells8101258] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 09/30/2019] [Accepted: 10/10/2019] [Indexed: 12/23/2022] Open
Abstract
Genotoxic stress triggers a combined action of DNA repair and cell cycle checkpoint pathways. Protein phosphatase 2C delta (referred to as WIP1) is involved in timely inactivation of DNA damage response by suppressing function of p53 and other targets at chromatin. Here we show that WIP1 promotes DNA repair through homologous recombination. Loss or inhibition of WIP1 delayed disappearance of the ionizing radiation-induced 53BP1 foci in S/G2 cells and promoted cell death. We identify breast cancer associated protein 1 (BRCA1) as interactor and substrate of WIP1 and demonstrate that WIP1 activity is needed for correct dynamics of BRCA1 recruitment to chromatin flanking the DNA lesion. In addition, WIP1 dephosphorylates 53BP1 at Threonine 543 that was previously implicated in mediating interaction with RIF1. Finally, we report that inhibition of WIP1 allowed accumulation of DNA damage in S/G2 cells and increased sensitivity of cancer cells to a poly-(ADP-ribose) polymerase inhibitor olaparib. We propose that inhibition of WIP1 may increase sensitivity of BRCA1-proficient cancer cells to olaparib.
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Affiliation(s)
- Kamila Burdova
- Cancer Cell Biology, Institute of Molecular Genetics of the Czech Academy of Sciences, CZ14220 Prague, Czech Republic.
| | - Radka Storchova
- Cancer Cell Biology, Institute of Molecular Genetics of the Czech Academy of Sciences, CZ14220 Prague, Czech Republic.
| | - Matous Palek
- Cancer Cell Biology, Institute of Molecular Genetics of the Czech Academy of Sciences, CZ14220 Prague, Czech Republic.
| | - Libor Macurek
- Cancer Cell Biology, Institute of Molecular Genetics of the Czech Academy of Sciences, CZ14220 Prague, Czech Republic.
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16
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Zhang M, Jiang D, Xie X, He Y, Lv M, Jiang X. miR-129-3p inhibits NHEJ pathway by targeting SAE1 and represses gastric cancer progression. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2019; 12:1539-1547. [PMID: 31933971 PMCID: PMC6947116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Accepted: 01/25/2019] [Indexed: 06/10/2023]
Abstract
Gastric cancer (GC) is one of the leading malignancies worldwide and is also a leading cause of cancer-related mortality. Micro RNA (miRNA) is a group of short non-coding RNAs modulating gene expression through targeting the 3'UTR of genes. Peripheral blood exosome miRNAs are relatively stable and might be used as biomarkers for clinical diagnosis. In this study, we found a reduced level of miR-129-3p in GC tumor when compared with adjacent non-tumor tissues, and the peripheral blood exosome miR-129-3p level was also reduced when compared with healthy controls. Subsequently, we identified that miR-129-3p repressed the expression of SUMO-activating enzyme subunit 1 (SAE1) directly through targeting 3'UTR. miR-129-3p also inhibited the sumoylation modification of XRCC4 which disturbed the nuclear localization of XRCC4 and induced more DNA damage in GC cells. Furthermore, overexpression of miR-129-3p induced more cell apoptosis and inhibited GC cell proliferation, migration and invasion, indicating miR-129-3p is a powerful anti-tumor miRNA and has potential for GC treatment.
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Affiliation(s)
- Mingming Zhang
- Department of Gastroenterology, Qingdao University Affiliated Qingdao Municipal Hospital Jiaozhou Road 1#, Qingdao 266071, PR China
| | - Dalei Jiang
- Department of Gastroenterology, Qingdao University Affiliated Qingdao Municipal Hospital Jiaozhou Road 1#, Qingdao 266071, PR China
| | - Xiangjun Xie
- Department of Gastroenterology, Qingdao University Affiliated Qingdao Municipal Hospital Jiaozhou Road 1#, Qingdao 266071, PR China
| | - Yuanlong He
- Department of Gastroenterology, Qingdao University Affiliated Qingdao Municipal Hospital Jiaozhou Road 1#, Qingdao 266071, PR China
| | - Mei Lv
- Department of Gastroenterology, Qingdao University Affiliated Qingdao Municipal Hospital Jiaozhou Road 1#, Qingdao 266071, PR China
| | - Xiangjun Jiang
- Department of Gastroenterology, Qingdao University Affiliated Qingdao Municipal Hospital Jiaozhou Road 1#, Qingdao 266071, PR China
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17
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Jiang B, Fan X, Zhang D, Liu H, Fan C. Identifying UBA2 as a proliferation and cell cycle regulator in lung cancer A549 cells. J Cell Biochem 2019; 120:12752-12761. [PMID: 30848500 DOI: 10.1002/jcb.28543] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2018] [Revised: 11/26/2018] [Accepted: 12/06/2018] [Indexed: 11/07/2022]
Abstract
Ubiquitin activating enzyme 2 (UBA2) is a basic component of E1-activating enzyme in the SUMOylation system. Expression and function of UBA2 in human cancers are largely unknown. In this study we investigate UBA2 expression the function in human non-small-cell lung cancer. Immunochemistry study showed that UBA2 was overexpressed in cancer tissues (53.3%, 40 of 75) compared with normal lung tissues (14.3%, 4 of 28) (P < 0.05). Immunostaining of UBA2 was mainly detected in nucleus. Overexpression of UBA2 in cancer tissues was significantly associated with poor differentiation, large tumor size ( > 5.0 cm), higher T stages (T3 + 4), lymph node metastasis and advanced TNM stages (III + IV). In vitro study showed that UBA2 was expressed in A549, 95D, H1975, and H1299 cells. Knockdown of UBA2 in A549 cells significantly inhibited cancer cell proliferation and upregulated cancer cell apoptosis (P < 0.05). Cell cycle analysis showed that knockdown of UBA2 in A549 cell significantly increased the G1 and G2/M phase cells and reduced the S phase cells (P < 0.05). Gene expression profile after knockdown of UBA2 in A549 cells showed that the most related function was cell cycle, cell death and survival, and cellular growth and proliferation. Western blot analysis study showed that knockdown of UBA2 significantly inhibited expression of poly(ADP-ribose) polymerase 1, mini-chromosome maintenance 7 (MCM7), MCM2, MCM3 and MCM7. These results indicated that UBA2 was a critical cell cycle and proliferation regulator and may be a novel cancer marker in this malignant tumor.
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Affiliation(s)
- Biying Jiang
- Department of Pathology, First Affiliated Hospital and College of Basic Medical Sciences of China Medical University, Shenyang, Liaoning, China
| | - Xiaoxi Fan
- Department of Thoracic Surgery, First Affiliated Hospital of China Medical University, Shenyang, Liaoning, China
| | - Di Zhang
- Department of Pathology, First Affiliated Hospital and College of Basic Medical Sciences of China Medical University, Shenyang, Liaoning, China
| | - Haifeng Liu
- Department of Pathology, First Affiliated Hospital and College of Basic Medical Sciences of China Medical University, Shenyang, Liaoning, China
| | - Chuifeng Fan
- Department of Pathology, First Affiliated Hospital and College of Basic Medical Sciences of China Medical University, Shenyang, Liaoning, China
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18
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Torrecilla I, Oehler J, Ramadan K. The role of ubiquitin-dependent segregase p97 (VCP or Cdc48) in chromatin dynamics after DNA double strand breaks. Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0282. [PMID: 28847819 PMCID: PMC5577460 DOI: 10.1098/rstb.2016.0282] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/24/2017] [Indexed: 12/27/2022] Open
Abstract
DNA double strand breaks (DSBs) are the most cytotoxic DNA lesions and, if not repaired, lead to chromosomal rearrangement, genomic instability and cell death. Cells have evolved a complex network of DNA repair and signalling molecules which promptly detect and repair DSBs, commonly known as the DNA damage response (DDR). The DDR is orchestrated by various post-translational modifications such as phosphorylation, methylation, ubiquitination or SUMOylation. As DSBs are located in complex chromatin structures, the repair of DSBs is engineered at two levels: (i) at sites of broken DNA and (ii) at chromatin structures that surround DNA lesions. Thus, DNA repair and chromatin remodelling machineries must work together to efficiently repair DSBs. Here, we summarize the current knowledge of the ubiquitin-dependent molecular unfoldase/segregase p97 (VCP in vertebrates and Cdc48 in worms and lower eukaryotes) in DSB repair. We identify p97 as an essential factor that regulates DSB repair. p97-dependent extraction of ubiquitinated substrates mediates spatio-temporal protein turnover at and around the sites of DSBs, thus orchestrating chromatin remodelling and DSB repair. As p97 is a druggable target, p97 inhibition in the context of DDR has great potential for cancer therapy, as shown for other DDR components such as PARP, ATR and CHK1.This article is part of the themed issue 'Chromatin modifiers and remodellers in DNA repair and signalling'.
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Affiliation(s)
- Ignacio Torrecilla
- Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
| | - Judith Oehler
- Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
| | - Kristijan Ramadan
- Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
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19
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SAMHD1 Sheds Moonlight on DNA Double-Strand Break Repair. Trends Genet 2017; 33:895-897. [PMID: 28969870 DOI: 10.1016/j.tig.2017.09.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 09/19/2017] [Indexed: 12/31/2022]
Abstract
SAMHD1 (sterile α motif and histidine (H) aspartate (D) domain-containing protein 1) is known for its antiviral activity of hydrolysing deoxynucleotides required for virus replication. Daddacha et al. identify a hydrolase-independent, moonlighting function of SAMHD1 that facilitates homologous recombination of DNA double-strand breaks (DSBs) by promoting recruitment of C-terminal binding protein interacting protein (CTIP), a DNA-end resection factor, to damaged DNA. These findings could benefit anticancer treatment.
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