1
|
Hao Q, Li J, Yeap LS. Molecular mechanisms of DNA lesion and repair during antibody somatic hypermutation. SCIENCE CHINA. LIFE SCIENCES 2024:10.1007/s11427-024-2615-1. [PMID: 39048716 DOI: 10.1007/s11427-024-2615-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Accepted: 05/08/2024] [Indexed: 07/27/2024]
Abstract
Antibody diversification is essential for an effective immune response, with somatic hypermutation (SHM) serving as a key molecular process in this adaptation. Activation-induced cytidine deaminase (AID) initiates SHM by inducing DNA lesions, which are ultimately resolved into point mutations, as well as small insertions and deletions (indels). These mutational outcomes contribute to antibody affinity maturation. The mechanisms responsible for generating point mutations and indels involve the base excision repair (BER) and mismatch repair (MMR) pathways, which are well coordinated to maintain genomic integrity while allowing for beneficial mutations to occur. In this regard, translesion synthesis (TLS) polymerases contribute to the diversity of mutational outcomes in antibody genes by enabling the bypass of DNA lesions. This review summarizes our current understanding of the distinct molecular mechanisms that generate point mutations and indels during SHM. Understanding these mechanisms is critical for elucidating the development of broadly neutralizing antibodies (bnAbs) and autoantibodies, and has implications for vaccine design and therapeutics.
Collapse
Affiliation(s)
- Qian Hao
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Department of Endocrinology and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Jinfeng Li
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Department of Endocrinology and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Leng-Siew Yeap
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Department of Endocrinology and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
| |
Collapse
|
2
|
Chauhan AS, Jhujh SS, Stewart GS. E3 ligases: a ubiquitous link between DNA repair, DNA replication and human disease. Biochem J 2024; 481:923-944. [PMID: 38985307 DOI: 10.1042/bcj20240124] [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: 03/20/2024] [Revised: 05/20/2024] [Accepted: 05/24/2024] [Indexed: 07/11/2024]
Abstract
Maintenance of genome stability is of paramount importance for the survival of an organism. However, genomic integrity is constantly being challenged by various endogenous and exogenous processes that damage DNA. Therefore, cells are heavily reliant on DNA repair pathways that have evolved to deal with every type of genotoxic insult that threatens to compromise genome stability. Notably, inherited mutations in genes encoding proteins involved in these protective pathways trigger the onset of disease that is driven by chromosome instability e.g. neurodevelopmental abnormalities, neurodegeneration, premature ageing, immunodeficiency and cancer development. The ability of cells to regulate the recruitment of specific DNA repair proteins to sites of DNA damage is extremely complex but is primarily mediated by protein post-translational modifications (PTMs). Ubiquitylation is one such PTM, which controls genome stability by regulating protein localisation, protein turnover, protein-protein interactions and intra-cellular signalling. Over the past two decades, numerous ubiquitin (Ub) E3 ligases have been identified to play a crucial role not only in the initiation of DNA replication and DNA damage repair but also in the efficient termination of these processes. In this review, we discuss our current understanding of how different Ub E3 ligases (RNF168, TRAIP, HUWE1, TRIP12, FANCL, BRCA1, RFWD3) function to regulate DNA repair and replication and the pathological consequences arising from inheriting deleterious mutations that compromise the Ub-dependent DNA damage response.
Collapse
Affiliation(s)
- Anoop S Chauhan
- Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, U.K
| | - Satpal S Jhujh
- Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, U.K
| | - Grant S Stewart
- Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, U.K
| |
Collapse
|
3
|
Zhao B, Xia Z, Yang B, Guo Y, Zhou R, Gu M, Liu M, Li Q, Bai W, Huang J, Zhang X, Zhu C, Leung KT, Chen C, Dong J. USP7 promotes IgA class switching through stabilizing RUNX3 for germline transcription activation. Cell Rep 2024; 43:114194. [PMID: 38735043 DOI: 10.1016/j.celrep.2024.114194] [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: 09/05/2023] [Revised: 03/04/2024] [Accepted: 04/18/2024] [Indexed: 05/14/2024] Open
Abstract
Class switch recombination (CSR) diversifies the effector functions of antibodies and involves complex regulation of transcription and DNA damage repair. Here, we show that the deubiquitinase USP7 promotes CSR to immunoglobulin A (IgA) and suppresses unscheduled IgG switching in mature B cells independent of its role in DNA damage repair, but through modulating switch region germline transcription. USP7 depletion impairs Sα transcription, leading to abnormal activation of Sγ germline transcription and increased interaction with the CSR center via loop extrusion for unscheduled IgG switching. Rescue of Sα transcription by transforming growth factor β (TGF-β) in USP7-deleted cells suppresses Sγ germline transcription and prevents loop extrusion toward IgG CSR. Mechanistically, USP7 protects transcription factor RUNX3 from ubiquitination-mediated degradation to promote Sα germline transcription. Our study provides evidence for active transcription serving as an anchor to impede loop extrusion and reveals a functional interplay between USP7 and TGF-β signaling in promoting RUNX3 expression for efficient IgA CSR.
Collapse
Affiliation(s)
- Bo Zhao
- Department of Immunology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Department of Pediatrics, the Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, Guangdong 518107, China; Key Laboratory of Tropical Disease Control, Ministry of Education, Sun Yat-Sen University, Guangzhou 510080, China
| | - Zhigang Xia
- Department of Pediatrics, the Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, Guangdong 518107, China
| | - Beibei Yang
- Department of Immunology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Key Laboratory of Tropical Disease Control, Ministry of Education, Sun Yat-Sen University, Guangzhou 510080, China
| | - Yao Guo
- Department of Immunology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Key Laboratory of Tropical Disease Control, Ministry of Education, Sun Yat-Sen University, Guangzhou 510080, China
| | - Ruizhi Zhou
- Department of Pediatrics, the Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, Guangdong 518107, China
| | - Mingyu Gu
- Department of Immunology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Key Laboratory of Tropical Disease Control, Ministry of Education, Sun Yat-Sen University, Guangzhou 510080, China
| | - Meiling Liu
- Department of Immunology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Key Laboratory of Tropical Disease Control, Ministry of Education, Sun Yat-Sen University, Guangzhou 510080, China
| | - Qingcheng Li
- Department of Pediatrics, the Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, Guangdong 518107, China
| | - Wanyu Bai
- Department of Immunology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Department of Pediatrics, the Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, Guangdong 518107, China; Key Laboratory of Tropical Disease Control, Ministry of Education, Sun Yat-Sen University, Guangzhou 510080, China
| | - Junbin Huang
- Department of Pediatrics, the Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, Guangdong 518107, China
| | - Xuefei Zhang
- Biomedical Pioneering Innovation Center, Innovation Center for Genomics, Peking University, Beijing 100871, China
| | - Chengming Zhu
- Center for Scientific Research, the Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, Guangdong 518107, China
| | - Kam Tong Leung
- Department of Paediatrics, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Chun Chen
- Department of Pediatrics, the Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, Guangdong 518107, China.
| | - Junchao Dong
- Department of Immunology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Department of Pediatrics, the Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, Guangdong 518107, China; Key Laboratory of Tropical Disease Control, Ministry of Education, Sun Yat-Sen University, Guangzhou 510080, China.
| |
Collapse
|
4
|
Al Jamal I, Parquet M, Guiyedi K, Aoufouchi S, Le Guillou M, Rizzo D, Pollet J, Dupont M, Boulin M, Faumont N, Boutouil H, Jardin F, Ruminy P, El Hamel C, Lerat J, Al Hamaoui S, Makdissy N, Feuillard J, Gachard N, Peron S. IGH 3'RR recombination uncovers a non-germinal center imprint and c-MYC-dependent IGH rearrangement in unmutated chronic lymphocytic leukemia. Haematologica 2024; 109:466-478. [PMID: 37496419 PMCID: PMC10828775 DOI: 10.3324/haematol.2023.282897] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 07/20/2023] [Indexed: 07/28/2023] Open
Abstract
Chronic lymphocytic leukemia (CLL) is an incurable indolent non-Hodgkin lymphoma characterized by tumor B cells that weakly express a B-cell receptor. The mutational status of the variable region (IGHV) within the immunoglobulin heavy chain (IGH) locus is an important prognosis indicator and raises the question of the CLL cell of origin. Mutated IGHV gene CLL are genetically imprinted by activation-induced cytidine deaminase (AID). AID is also required for IGH rearrangements: class switch recombination and recombination between switch Mu (Sμ) and the 3' regulatory region (3'RR) (Sμ-3'RRrec). The great majority of CLL B cells being unswitched led us to examine IGH rearrangement blockade in CLL. Our results separated CLL into two groups on the basis of Sμ-3'RRrec counts per sample: Sμ-3'RRrecHigh cases (mostly unmutated CLL) and Sμ-3'RRrecLow cases (mostly mutated CLL), but not based on the class switch recombination junction counts. Sμ-3'RRrec appeared to be ongoing in Sμ-3'RRrecHigh CLL cells and comparison of Sμ-3'RRrec junction structural features pointed to different B-cell origins for both groups. In accordance with IGHV mutational status and PIM1 mutation rate, Sμ-3'RRrecHigh CLL harbor a non-germinal center experienced B-cell imprint while Sμ-3'RRrecLow CLL are from AID-experienced B cells from a secondary lymphoid organ. In addition to the proposals already made concerning the CLL cell of origin, our study highlights that analysis of IGH recombinatory activity can identify CLL cases from different origins. Finally, on-going Sμ-3'RRrec in Sμ-3'RRrecHigh cells appeared to presumably be the consequence of high c-MYC expression, as c-MYC overexpression potentiated IGH rearrangements and Sμ-3'RRrec, even in the absence of AID for the latter.
Collapse
Affiliation(s)
- Israa Al Jamal
- Centre National de la Recherche Scientifique (CNRS) Unite Mixte de Recherche (UMR) 7276/INSERM U1262, Universite de Limoges, Limoges, France; Faculty of Sciences, GSBT Genomic Surveillance and Biotherapy Team, Mont Michel Campus, Lebanese University, Tripoli
| | - Milene Parquet
- Centre National de la Recherche Scientifique (CNRS) Unite Mixte de Recherche (UMR) 7276/INSERM U1262, Universite de Limoges, Limoges
| | - Kenza Guiyedi
- Centre National de la Recherche Scientifique (CNRS) Unite Mixte de Recherche (UMR) 7276/INSERM U1262, Universite de Limoges, Limoges
| | - Said Aoufouchi
- CNRS UMR9019, Gustave Roussy, B-cell and Genome Plasticity Team, Villejuif, France and Universite Paris-Saclay, Orsay
| | - Morwenna Le Guillou
- CNRS UMR9019, Gustave Roussy, B-cell and Genome Plasticity Team, Villejuif, France and Universite Paris-Saclay, Orsay
| | - David Rizzo
- Centre National de la Recherche Scientifique (CNRS) Unite Mixte de Recherche (UMR) 7276/INSERM U1262, Universite de Limoges, Limoges, France; Laboratoire d'Hematologie Biologique, Centre Hospitalier Universitaire de Limoges, Limoges
| | - Justine Pollet
- Centre National de la Recherche Scientifique (CNRS) Unite Mixte de Recherche (UMR) 7276/INSERM U1262, Universite de Limoges, Limoges
| | - Marine Dupont
- Centre National de la Recherche Scientifique (CNRS) Unite Mixte de Recherche (UMR) 7276/INSERM U1262, Universite de Limoges, Limoges, France; Laboratoire d'Hematologie Biologique, Centre Hospitalier Universitaire de Limoges, Limoges
| | - Melanie Boulin
- Centre National de la Recherche Scientifique (CNRS) Unite Mixte de Recherche (UMR) 7276/INSERM U1262, Universite de Limoges, Limoges, France; Laboratoire d'Hematologie Biologique, Centre Hospitalier Universitaire de Limoges, Limoges
| | - Nathalie Faumont
- Centre National de la Recherche Scientifique (CNRS) Unite Mixte de Recherche (UMR) 7276/INSERM U1262, Universite de Limoges, Limoges
| | - Hend Boutouil
- Centre National de la Recherche Scientifique (CNRS) Unite Mixte de Recherche (UMR) 7276/INSERM U1262, Universite de Limoges, Limoges
| | - Fabrice Jardin
- Inserm U1245 and Department of Henri-Becquerel Hematology Center and Normandie Univ UNIROUEN, Rouen
| | - Philippe Ruminy
- Inserm U1245 and Department of Henri-Becquerel Hematology Center and Normandie Univ UNIROUEN, Rouen
| | - Chahrazed El Hamel
- Collection Biologique Hopital de la Mere et de l'Enfant (CB-HME), Department of Pediatrics, Limoges University Hospital, Limoges
| | - Justine Lerat
- Department of Otorinolaryngology, Limoges University Hospital, Limoges
| | - Samar Al Hamaoui
- Faculty of Sciences, GSBT Genomic Surveillance and Biotherapy Team, Mont Michel Campus, Lebanese University, Tripoli
| | - Nehman Makdissy
- Faculty of Sciences, GSBT Genomic Surveillance and Biotherapy Team, Mont Michel Campus, Lebanese University, Tripoli
| | - Jean Feuillard
- Centre National de la Recherche Scientifique (CNRS) Unite Mixte de Recherche (UMR) 7276/INSERM U1262, Universite de Limoges, Limoges, France; Laboratoire d'Hematologie Biologique, Centre Hospitalier Universitaire de Limoges, Limoges
| | - Nathalie Gachard
- Centre National de la Recherche Scientifique (CNRS) Unite Mixte de Recherche (UMR) 7276/INSERM U1262, Universite de Limoges, Limoges, France; Laboratoire d'Hematologie Biologique, Centre Hospitalier Universitaire de Limoges, Limoges
| | - Sophie Peron
- Centre National de la Recherche Scientifique (CNRS) Unite Mixte de Recherche (UMR) 7276/INSERM U1262, Universite de Limoges, Limoges.
| |
Collapse
|
5
|
Kabrani E, Saha T, Di Virgilio M. DNA repair and antibody diversification: the 53BP1 paradigm. Trends Immunol 2023; 44:782-791. [PMID: 37640588 DOI: 10.1016/j.it.2023.08.004] [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: 06/30/2023] [Revised: 08/01/2023] [Accepted: 08/03/2023] [Indexed: 08/31/2023]
Abstract
The DNA double-strand break (DSB) repair factor 53BP1 has long been implicated in V(D)J and class switch recombination (CSR) of mammalian lymphocyte receptors. However, the dissection of the underlying molecular activities is hampered by a paucity of studies [V(D)J] and plurality of phenotypes (CSR) associated with 53BP1 deficiency. Here, we revisit the currently accepted roles of 53BP1 in antibody diversification in view of the recent identification of its downstream effectors in DSB protection and latest advances in genome architecture. We propose that, in addition to end protection, 53BP1-mediated end-tethering stabilization is essential for CSR. Furthermore, we support a pre-DSB role during V(D)J recombination. Our perspective underscores the importance of evaluating repair of DSBs in relation to their dynamic architectural contexts.
Collapse
Affiliation(s)
- Eleni Kabrani
- Laboratory of Genome Diversification and Integrity, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin 13125, Germany.
| | - Tannishtha Saha
- Laboratory of Genome Diversification and Integrity, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin 13125, Germany; Freie Universität Berlin, Berlin 14195, Germany
| | - Michela Di Virgilio
- Laboratory of Genome Diversification and Integrity, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin 13125, Germany; Charité-Universitätsmedizin Berlin, Berlin 10117, Germany.
| |
Collapse
|
6
|
Huang J, Wu C, Kloeber JA, Gao H, Gao M, Zhu Q, Chang Y, Zhao F, Guo G, Luo K, Dai H, Liu S, Huang Q, Kim W, Zhou Q, Zhu S, Wu Z, Tu X, Yin P, Deng M, Wang L, Yuan J, Lou Z. SLFN5-mediated chromatin dynamics sculpt higher-order DNA repair topology. Mol Cell 2023; 83:1043-1060.e10. [PMID: 36854302 PMCID: PMC10467573 DOI: 10.1016/j.molcel.2023.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 12/23/2022] [Accepted: 02/01/2023] [Indexed: 03/02/2023]
Abstract
Repair of DNA double-strand breaks (DSBs) elicits three-dimensional (3D) chromatin topological changes. A recent finding reveals that 53BP1 assembles into a 3D chromatin topology pattern around DSBs. How this formation of a higher-order structure is configured and regulated remains enigmatic. Here, we report that SLFN5 is a critical factor for 53BP1 topological arrangement at DSBs. Using super-resolution imaging, we find that SLFN5 binds to 53BP1 chromatin domains to assemble a higher-order microdomain architecture by driving damaged chromatin dynamics at both DSBs and deprotected telomeres. Mechanistically, we propose that 53BP1 topology is shaped by two processes: (1) chromatin mobility driven by the SLFN5-LINC-microtubule axis and (2) the assembly of 53BP1 oligomers mediated by SLFN5. In mammals, SLFN5 deficiency disrupts the DSB repair topology and impairs non-homologous end joining, telomere fusions, class switch recombination, and sensitivity to poly (ADP-ribose) polymerase inhibitor. We establish a molecular mechanism that shapes higher-order chromatin topologies to safeguard genomic stability.
Collapse
Affiliation(s)
- Jinzhou Huang
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Chenming Wu
- Key Laboratory of Arrhythmias of the Ministry of Education of China, Research Center for Translational Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China
| | - Jake A Kloeber
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA; Medical Scientist Training Program, Mayo Clinic, Rochester, MN 55905, USA
| | - Huanyao Gao
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN 55905, USA
| | - Ming Gao
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Qian Zhu
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Yiming Chang
- Jinzhou Medical University, Shanghai East Hospital, Shanghai 200120, China
| | - Fei Zhao
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Guijie Guo
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Kuntian Luo
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Haiming Dai
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Sijia Liu
- Department of Artificial Intelligence and Informatics, Mayo Clinic, Rochester, MN 55905, USA
| | - Qiru Huang
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Wootae Kim
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Qin Zhou
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Shouhai Zhu
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Zheming Wu
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Xinyi Tu
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Ping Yin
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Min Deng
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Liewei Wang
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN 55905, USA
| | - Jian Yuan
- Key Laboratory of Arrhythmias of the Ministry of Education of China, Research Center for Translational Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China; Department of Biochemistry and Molecular Biology, Tongji University School of Medicine, Shanghai 200092, China.
| | - Zhenkun Lou
- Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA.
| |
Collapse
|
7
|
Hao Q, Zhan C, Lian C, Luo S, Cao W, Wang B, Xie X, Ye X, Gui T, Voena C, Pighi C, Wang Y, Tian Y, Wang X, Dai P, Cai Y, Liu X, Ouyang S, Sun S, Hu Q, Liu J, Ye Y, Zhao J, Lu A, Wang JY, Huang C, Su B, Meng FL, Chiarle R, Pan-Hammarström Q, Yeap LS. DNA repair mechanisms that promote insertion-deletion events during immunoglobulin gene diversification. Sci Immunol 2023; 8:eade1167. [PMID: 36961908 PMCID: PMC10351598 DOI: 10.1126/sciimmunol.ade1167] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 03/01/2023] [Indexed: 03/26/2023]
Abstract
Insertions and deletions (indels) are low-frequency deleterious genomic DNA alterations. Despite their rarity, indels are common, and insertions leading to long complementarity-determining region 3 (CDR3) are vital for antigen-binding functions in broadly neutralizing and polyreactive antibodies targeting viruses. Because of challenges in detecting indels, the mechanism that generates indels during immunoglobulin diversification processes remains poorly understood. We carried out ultra-deep profiling of indels and systematically dissected the underlying mechanisms using passenger-immunoglobulin mouse models. We found that activation-induced cytidine deaminase-dependent ±1-base pair (bp) indels are the most prevalent indel events, biasing deleterious outcomes, whereas longer in-frame indels, especially insertions that can extend the CDR3 length, are rare outcomes. The ±1-bp indels are channeled by base excision repair, but longer indels require additional DNA-processing factors. Ectopic expression of a DNA exonuclease or perturbation of the balance of DNA polymerases can increase the frequency of longer indels, thus paving the way for models that can generate antibodies with long CDR3. Our study reveals the mechanisms that generate beneficial and deleterious indels during the process of antibody somatic hypermutation and has implications in understanding the detrimental genomic alterations in various conditions, including tumorigenesis.
Collapse
Affiliation(s)
- Qian Hao
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Department of Endocrinology and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Chuanzong Zhan
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Department of Endocrinology and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Chaoyang Lian
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Simin Luo
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Wenyi Cao
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Binbin Wang
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Xia Xie
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences; 320 Yueyang Road, Shanghai 200031, China
| | - Xiaofei Ye
- Department of Biosciences and Nutrition, Karolinska Institutet; SE141-83, Huddinge, Stockholm, Sweden
- Present address: Kindstar Global Precision Medicine Institute, Wuhan, China and Kindstar Biotech, Wuhan, China
| | - Tuantuan Gui
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Claudia Voena
- Department of Molecular Biotechnology and Health Sciences, University of Torino; 10126 Torino, Italy
| | - Chiara Pighi
- Department of Molecular Biotechnology and Health Sciences, University of Torino; 10126 Torino, Italy
- Department of Pathology, Boston Children’s Hospital, and Harvard Medical School; Boston, MA 02115, USA
| | - Yanyan Wang
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences; 320 Yueyang Road, Shanghai 200031, China
| | - Ying Tian
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Xin Wang
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Pengfei Dai
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences; 320 Yueyang Road, Shanghai 200031, China
| | - Yanni Cai
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences; 320 Yueyang Road, Shanghai 200031, China
| | - Xiaojing Liu
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences; 320 Yueyang Road, Shanghai 200031, China
| | - Shengqun Ouyang
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Department of Endocrinology and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Shiqi Sun
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Qianwen Hu
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Jun Liu
- Department of Immunology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Youqiong Ye
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Jingkun Zhao
- Department of General Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Aiguo Lu
- Department of General Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Ji-Yang Wang
- Department of Immunology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
- Department of Microbiology and Immunology, College of Basic Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Chuanxin Huang
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| | - Bing Su
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Departments of Endocrinology and Gastroenterology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
- Shanghai Jiao Tong University School of Medicine-Yale Institute for Immune Metabolism, Shanghai Jiao Tong University School of Medicine, Shanghai 200025
| | - Fei-Long Meng
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences; 320 Yueyang Road, Shanghai 200031, China
| | - Roberto Chiarle
- Department of Molecular Biotechnology and Health Sciences, University of Torino; 10126 Torino, Italy
- Department of Pathology, Boston Children’s Hospital, and Harvard Medical School; Boston, MA 02115, USA
| | - Qiang Pan-Hammarström
- Department of Biosciences and Nutrition, Karolinska Institutet; SE141-83, Huddinge, Stockholm, Sweden
| | - Leng-Siew Yeap
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Department of Endocrinology and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Jiao Tong University School of Medicine; 280 South Chongqing Road, Shanghai, 200025, China
| |
Collapse
|
8
|
Refaat AM, Nakata M, Husain A, Kosako H, Honjo T, Begum NA. HNRNPU facilitates antibody class-switch recombination through C-NHEJ promotion and R-loop suppression. Cell Rep 2023; 42:112284. [PMID: 36943867 DOI: 10.1016/j.celrep.2023.112284] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 10/23/2022] [Accepted: 03/03/2023] [Indexed: 03/22/2023] Open
Abstract
B cells generate functionally different classes of antibodies through class-switch recombination (CSR), which requires classical non-homologous end joining (C-NHEJ) to join the DNA breaks at the donor and acceptor switch (S) regions. We show that the RNA-binding protein HNRNPU promotes C-NHEJ-mediated S-S joining through the 53BP1-shieldin DNA-repair complex. Notably, HNRNPU binds to the S region RNA/DNA G-quadruplexes, contributing to regulating R-loop and single-stranded DNA (ssDNA) accumulation. HNRNPU is an intrinsically disordered protein that interacts with both C-NHEJ and R-loop complexes in an RNA-dependent manner. Strikingly, recruitment of HNRNPU and the C-NHEJ factors is highly sensitive to liquid-liquid phase separation inhibitors, suggestive of DNA-repair condensate formation. We propose that HNRNPU facilitates CSR by forming and stabilizing the C-NHEJ ribonucleoprotein complex and preventing excessive R-loop accumulation, which otherwise would cause persistent DNA breaks and aberrant DNA repair, leading to genomic instability.
Collapse
Affiliation(s)
- Ahmed M Refaat
- Department of Immunology and Genomic Medicine, Center for Cancer Immunotherapy and Immunobiology, Kyoto University Graduate School of Medicine, Kyoto 606-8501, Japan; Zoology Department, Faculty of Science, Minia University, El-Minia 61519, Egypt
| | - Mikiyo Nakata
- Department of Immunology and Genomic Medicine, Center for Cancer Immunotherapy and Immunobiology, Kyoto University Graduate School of Medicine, Kyoto 606-8501, Japan
| | - Afzal Husain
- Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, Uttar Pradesh 202002, India
| | - Hidetaka Kosako
- Division of Cell Signaling, Institute of Advanced Medical Sciences, University of Tokushima, Tokushima 770-8503, Japan
| | - Tasuku Honjo
- Department of Immunology and Genomic Medicine, Center for Cancer Immunotherapy and Immunobiology, Kyoto University Graduate School of Medicine, Kyoto 606-8501, Japan.
| | - Nasim A Begum
- Department of Immunology and Genomic Medicine, Center for Cancer Immunotherapy and Immunobiology, Kyoto University Graduate School of Medicine, Kyoto 606-8501, Japan
| |
Collapse
|
9
|
Schimmel J, van Wezel MD, van Schendel R, Tijsterman M. Chromosomal breaks at the origin of small tandem DNA duplications. Bioessays 2023; 45:e2200168. [PMID: 36385254 DOI: 10.1002/bies.202200168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 11/01/2022] [Accepted: 11/03/2022] [Indexed: 11/18/2022]
Abstract
Small tandem DNA duplications in the range of 15 to 300 base-pairs play an important role in the aetiology of human disease and contribute to genome diversity. Here, we discuss different proposed mechanisms for their occurrence and argue that this type of structural variation mainly results from mutagenic repair of chromosomal breaks. This hypothesis is supported by both bioinformatical analysis of insertions occurring in the genome of different species and disease alleles, as well as by CRISPR/Cas9-based experimental data from different model systems. Recent work points to fill-in synthesis at double-stranded DNA breaks with complementary sequences, regulated by end-joining mechanisms, to account for small tandem duplications. We will review the prevalence of small tandem duplications in the population, and we will speculate on the potential sources of DNA damage that could give rise to this mutational signature. With the development of novel algorithms to analyse sequencing data, small tandem duplications are now more frequently detected in the human genome and identified as oncogenic gain-of-function mutations. Understanding their origin could lead to optimized treatment regimens to prevent therapy-induced activation of oncogenes and might expose novel vulnerabilities in cancer.
Collapse
Affiliation(s)
- Joost Schimmel
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Marloes D van Wezel
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Robin van Schendel
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Marcel Tijsterman
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| |
Collapse
|
10
|
Rass E, Willaume S, Bertrand P. 53BP1: Keeping It under Control, Even at a Distance from DNA Damage. Genes (Basel) 2022; 13:genes13122390. [PMID: 36553657 PMCID: PMC9778356 DOI: 10.3390/genes13122390] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 12/02/2022] [Accepted: 12/07/2022] [Indexed: 12/23/2022] Open
Abstract
Double-strand breaks (DSBs) are toxic lesions that can be generated by exposure to genotoxic agents or during physiological processes, such as during V(D)J recombination. The repair of these DSBs is crucial to prevent genomic instability and to maintain cellular homeostasis. Two main pathways participate in repairing DSBs, namely, non-homologous end joining (NHEJ) and homologous recombination (HR). The P53-binding protein 1 (53BP1) plays a pivotal role in the choice of DSB repair mechanism, promotes checkpoint activation and preserves genome stability upon DSBs. By preventing DSB end resection, 53BP1 promotes NHEJ over HR. Nonetheless, the balance between DSB repair pathways remains crucial, as unscheduled NHEJ or HR events at different phases of the cell cycle may lead to genomic instability. Therefore, the recruitment of 53BP1 to chromatin is tightly regulated and has been widely studied. However, less is known about the mechanism regulating 53BP1 recruitment at a distance from the DNA damage. The present review focuses on the mechanism of 53BP1 recruitment to damage and on recent studies describing novel mechanisms keeping 53BP1 at a distance from DSBs.
Collapse
Affiliation(s)
- Emilie Rass
- Université Paris Cité, INSERM, CEA, Stabilité Génétique Cellules Souches et Radiations, LREV/iRCM/IBFJ, F-92260 Fontenay-aux-Roses, France
- Université Paris-Saclay, INSERM, CEA, Stabilité Génétique Cellules Souches et Radiations, LREV/iRCM/IBFJ, F-92260 Fontenay-aux-Roses, France
- Correspondence:
| | - Simon Willaume
- Université Paris Cité, INSERM, CEA, Stabilité Génétique Cellules Souches et Radiations, LREV/iRCM/IBFJ, F-92260 Fontenay-aux-Roses, France
- Université Paris-Saclay, INSERM, CEA, Stabilité Génétique Cellules Souches et Radiations, LREV/iRCM/IBFJ, F-92260 Fontenay-aux-Roses, France
| | - Pascale Bertrand
- Université Paris Cité, INSERM, CEA, Stabilité Génétique Cellules Souches et Radiations, LREV/iRCM/IBFJ, F-92260 Fontenay-aux-Roses, France
- Université Paris-Saclay, INSERM, CEA, Stabilité Génétique Cellules Souches et Radiations, LREV/iRCM/IBFJ, F-92260 Fontenay-aux-Roses, France
| |
Collapse
|
11
|
Kolobynina KG, Rapp A, Cardoso MC. Chromatin Ubiquitination Guides DNA Double Strand Break Signaling and Repair. Front Cell Dev Biol 2022; 10:928113. [PMID: 35865631 PMCID: PMC9294282 DOI: 10.3389/fcell.2022.928113] [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] [Received: 04/25/2022] [Accepted: 06/16/2022] [Indexed: 11/13/2022] Open
Abstract
Chromatin is the context for all DNA-based molecular processes taking place in the cell nucleus. The initial chromatin structure at the site of the DNA damage determines both, lesion generation and subsequent activation of the DNA damage response (DDR) pathway. In turn, proceeding DDR changes the chromatin at the damaged site and across large fractions of the genome. Ubiquitination, besides phosphorylation and methylation, was characterized as an important chromatin post-translational modification (PTM) occurring at the DNA damage site and persisting during the duration of the DDR. Ubiquitination appears to function as a highly versatile “signal-response” network involving several types of players performing various functions. Here we discuss how ubiquitin modifiers fine-tune the DNA damage recognition and response and how the interaction with other chromatin modifications ensures cell survival.
Collapse
|
12
|
Vincendeau E, Wei W, Zhang X, Planchais C, Yu W, Lenden-Hasse H, Cokelaer T, Pipoli da Fonseca J, Mouquet H, Adams DJ, Alt FW, Jackson SP, Balmus G, Lescale C, Deriano L. SHLD1 is dispensable for 53BP1-dependent V(D)J recombination but critical for productive class switch recombination. Nat Commun 2022; 13:3707. [PMID: 35764636 PMCID: PMC9240092 DOI: 10.1038/s41467-022-31287-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 06/13/2022] [Indexed: 11/21/2022] Open
Abstract
SHLD1 is part of the Shieldin (SHLD) complex, which acts downstream of 53BP1 to counteract DNA double-strand break (DSB) end resection and promote DNA repair via non-homologous end-joining (NHEJ). While 53BP1 is essential for immunoglobulin heavy chain class switch recombination (CSR), long-range V(D)J recombination and repair of RAG-induced DSBs in XLF-deficient cells, the function of SHLD during these processes remains elusive. Here we report that SHLD1 is dispensable for lymphocyte development and RAG-mediated V(D)J recombination, even in the absence of XLF. By contrast, SHLD1 is essential for restricting resection at AID-induced DSB ends in both NHEJ-proficient and NHEJ-deficient B cells, providing an end-protection mechanism that permits productive CSR by NHEJ and alternative end-joining. Finally, we show that this SHLD1 function is required for orientation-specific joining of AID-initiated DSBs. Our data thus suggest that 53BP1 promotes V(D)J recombination and CSR through two distinct mechanisms: SHLD-independent synapsis of V(D)J segments and switch regions within chromatin, and SHLD-dependent protection of AID-DSB ends against resection.
Collapse
Affiliation(s)
- Estelle Vincendeau
- Institut Pasteur, Université Paris Cité, INSERM U1223, Équipe Labellisée Ligue Contre Le Cancer, Genome Integrity, Immunity and Cancer Unit, 75015, Paris, France
| | - Wenming Wei
- Institut Pasteur, Université Paris Cité, INSERM U1223, Équipe Labellisée Ligue Contre Le Cancer, Genome Integrity, Immunity and Cancer Unit, 75015, Paris, France
| | - Xuefei Zhang
- Howard Hughes Medical Institute, Program in Cellular and Molecular Medicine at Boston Children's Hospital, Department of Genetics, Harvard Medical School, Boston, MA, 02115, USA
- Biomedical Pioneering Innovation Center (BIOPIC) and Beijing Advanced Innovation Center for Genomics (ICG), Peking University, Beijing, 100871, China
| | - Cyril Planchais
- Institut Pasteur, Université de Paris, INSERM U1222, Laboratory of Humoral Immunology, 75015, Paris, France
| | - Wei Yu
- Institut Pasteur, Université Paris Cité, INSERM U1223, Équipe Labellisée Ligue Contre Le Cancer, Genome Integrity, Immunity and Cancer Unit, 75015, Paris, France
| | - Hélène Lenden-Hasse
- Institut Pasteur, Université Paris Cité, INSERM U1223, Équipe Labellisée Ligue Contre Le Cancer, Genome Integrity, Immunity and Cancer Unit, 75015, Paris, France
| | - Thomas Cokelaer
- Institut Pasteur, Plate-forme Technologique Biomics, Centre de Ressources et Recherches Technologiques, 75015, Paris, France
- Institut Pasteur, Hub de Bioinformatique et Biostatistique, Département de Biologie Computationnelle, 75015, Paris, France
| | - Juliana Pipoli da Fonseca
- Institut Pasteur, Plate-forme Technologique Biomics, Centre de Ressources et Recherches Technologiques, 75015, Paris, France
| | - Hugo Mouquet
- Institut Pasteur, Université de Paris, INSERM U1222, Laboratory of Humoral Immunology, 75015, Paris, France
| | - David J Adams
- Wellcome Trust Sanger Institute, Cambridge, CB10 1SA, UK
| | - Frederick W Alt
- Howard Hughes Medical Institute, Program in Cellular and Molecular Medicine at Boston Children's Hospital, Department of Genetics, Harvard Medical School, Boston, MA, 02115, USA
| | - Stephen P Jackson
- Wellcome Trust/Cancer Research UK Gurdon Institute, Department of Biochemistry, University of Cambridge, Cambridge, CB2 1QN, UK
| | - Gabriel Balmus
- UK Dementia Research Institute at University of Cambridge, Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 0AH, UK
| | - Chloé Lescale
- Institut Pasteur, Université Paris Cité, INSERM U1223, Équipe Labellisée Ligue Contre Le Cancer, Genome Integrity, Immunity and Cancer Unit, 75015, Paris, France.
| | - Ludovic Deriano
- Institut Pasteur, Université Paris Cité, INSERM U1223, Équipe Labellisée Ligue Contre Le Cancer, Genome Integrity, Immunity and Cancer Unit, 75015, Paris, France.
| |
Collapse
|
13
|
Abstract
Activation-induced cytidine deaminase (AID) initiates somatic hypermutation of immunoglobulin (Ig) gene variable regions and class switch recombination (CSR) of Ig heavy chain constant regions. Two decades of intensive research has greatly expanded our knowledge of how AID functions in peripheral B cells to optimize antibody responses against infections, while maintaining tight regulation of AID to restrain its activity to protect B cell genomic integrity. The many exciting recent advances in the field include: 1) the first description of AID's molecular structure, 2) remarkable advances in high throughput approaches that precisely track AID targeting genome-wide, and 3) the discovery that the cohesion-mediate loop extrusion mechanism [initially discovered in V(D)J recombination studies] also governs AID-medicated CSR. These advances have significantly advanced our understanding of AID's biochemical properties in vitro and AID's function and regulation in vivo. This mini review will discuss these recent discoveries and outline the challenges and questions that remain to be addressed.
Collapse
|
14
|
Luo S, Qiao R, Zhang X. DNA Damage Response and Repair in Adaptive Immunity. Front Cell Dev Biol 2022; 10:884873. [PMID: 35663402 PMCID: PMC9157429 DOI: 10.3389/fcell.2022.884873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Accepted: 03/31/2022] [Indexed: 11/16/2022] Open
Abstract
The diversification of B-cell receptor (BCR), as well as its secreted product, antibody, is a hallmark of adaptive immunity, which has more specific roles in fighting against pathogens. The antibody diversification is from recombination-activating gene (RAG)-initiated V(D)J recombination, activation-induced cytidine deaminase (AID)-initiated class switch recombination (CSR), and V(D)J exon somatic hypermutation (SHM). The proper repair of RAG- and AID-initiated DNA lesions and double-strand breaks (DSBs) is required for promoting antibody diversification, suppressing genomic instability, and oncogenic translocations. DNA damage response (DDR) factors and DSB end-joining factors are recruited to the RAG- and AID-initiated DNA lesions and DSBs to coordinately resolve them for generating productive recombination products during antibody diversification. Recently, cohesin-mediated loop extrusion is proposed to be the underlying mechanism of V(D)J recombination and CSR, which plays essential roles in promoting the orientation-biased deletional end-joining . Here, we will discuss the mechanism of DNA damage repair in antibody diversification.
Collapse
Affiliation(s)
- Sha Luo
- Biomedical Pioneering Innovation Center, Innovation Center for Genomics, Peking University, Beijing, China
- Academy for Advanced Interdisciplinery Studies, Peking University, Beijing, China
| | - Ruolin Qiao
- Biomedical Pioneering Innovation Center, Innovation Center for Genomics, Peking University, Beijing, China
- Academy for Advanced Interdisciplinery Studies, Peking University, Beijing, China
| | - Xuefei Zhang
- Biomedical Pioneering Innovation Center, Innovation Center for Genomics, Peking University, Beijing, China
| |
Collapse
|
15
|
Lei T, Du S, Peng Z, Chen L. Multifaceted regulation and functions of 53BP1 in NHEJ‑mediated DSB repair (Review). Int J Mol Med 2022; 50:90. [PMID: 35583003 PMCID: PMC9162042 DOI: 10.3892/ijmm.2022.5145] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Accepted: 04/29/2022] [Indexed: 12/02/2022] Open
Abstract
The repair of DNA double-strand breaks (DSBs) is crucial for the preservation of genomic integrity and the maintenance of cellular homeostasis. Non-homologous DNA end joining (NHEJ) is the predominant repair mechanism for any type of DNA DSB during the majority of the cell cycle. NHEJ defects regulate tumor sensitivity to ionizing radiation and anti-neoplastic agents, resulting in immunodeficiencies and developmental abnormalities in malignant cells. p53-binding protein 1 (53BP1) is a key mediator involved in DSB repair, which functions to maintain a balance in the repair pathway choices and in preserving genomic stability. 53BP1 promotes DSB repair via NHEJ and antagonizes DNA end overhang resection. At present, novel lines of evidence have revealed the molecular mechanisms underlying the recruitment of 53BP1 and DNA break-responsive effectors to DSB sites, and the promotion of NHEJ-mediated DSB repair via 53BP1, while preventing homologous recombination. In the present review article, recent advances made in the elucidation of the structural and functional characteristics of 53BP1, the mechanisms of 53BP1 recruitment and interaction with the reshaping of the chromatin architecture around DSB sites, the post-transcriptional modifications of 53BP1, and the up- and downstream pathways of 53BP1 are discussed. The present review article also focuses on the application perspectives, current challenges and future directions of 53BP1 research.
Collapse
Affiliation(s)
- Tiantian Lei
- Department of Pharmacy, Women and Children's Hospital of Chongqing Medical University, Chongqing 401147, P.R. China
| | - Suya Du
- Department of Clinical Pharmacy, Sichuan Cancer Hospital and Institute, Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan 610041, P.R. China
| | - Zhe Peng
- Department of Pharmacy, Women and Children's Hospital of Chongqing Medical University, Chongqing 401147, P.R. China
| | - Lin Chen
- Department of Pharmacy, Women and Children's Hospital of Chongqing Medical University, Chongqing 401147, P.R. China
| |
Collapse
|
16
|
RIF1 acts in DNA repair through phosphopeptide recognition of 53BP1. Mol Cell 2022; 82:1359-1371.e9. [PMID: 35216668 PMCID: PMC8995355 DOI: 10.1016/j.molcel.2022.01.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 12/09/2021] [Accepted: 01/27/2022] [Indexed: 12/14/2022]
Abstract
The chromatin-binding protein 53BP1 promotes DNA repair by orchestrating the recruitment of downstream effectors including PTIP, RIF1, and shieldin to DNA double-strand break sites. While we know how PTIP recognizes 53BP1, the molecular details of RIF1 recruitment to DNA-damage sites remains undefined. Here, we report that RIF1 is a phosphopeptide-binding protein that directly interacts with three phosphorylated 53BP1 epitopes. The RIF1-binding sites on 53BP1 share an essential LxL motif followed by two closely apposed phosphorylated residues. Simultaneous mutation of these sites on 53BP1 abrogates RIF1 accumulation into ionizing-radiation-induced foci, but surprisingly, only fully compromises 53BP1-dependent DNA repair when an alternative mode of shieldin recruitment to DNA-damage sites is also disabled. Intriguingly, this alternative mode of recruitment still depends on RIF1 but does not require its interaction with 53BP1. RIF1 therefore employs phosphopeptide recognition to promote DNA repair but also modifies shieldin action independently of 53BP1 binding.
Collapse
|
17
|
Sun X, Bai J, Xu J, Xi X, Gu M, Zhu C, Xue H, Chen C, Dong J. Multiple DSB Resection Activities Redundantly Promote Alternative End Joining-Mediated Class Switch Recombination. Front Cell Dev Biol 2021; 9:767624. [PMID: 34926456 PMCID: PMC8671047 DOI: 10.3389/fcell.2021.767624] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 10/25/2021] [Indexed: 01/13/2023] Open
Abstract
Alternative end joining (A-EJ) catalyzes substantial level of antibody class switch recombination (CSR) in B cells deficient for classical non-homologous end joining, featuring increased switch (S) region DSB resection and junctional microhomology (MH). While resection has been suggested to initiate A-EJ in model DSB repair systems using engineered endonucleases, the contribution of resection factors to A-EJ-mediated CSR remains unclear. In this study, we systematically dissected the requirement for individual DSB resection factors in A-EJ-mediated class switching with a cell-based assay system and high-throughput sequencing. We show that while CtIP and Mre11 both are mildly required for CSR in WT cells, they play more critical roles in mediating A-EJ CSR, which depend on the exonuclease activity of Mre11. While DNA2 and the helicase/HRDC domain of BLM are required for A-EJ by mediating long S region DSB resection, in contrast, Exo1's resection-related function does not play any obvious roles for class switching in either c-NHEJ or A-EJ cells, or mediated in an AID-independent manner by joining of Cas9 breaks. Furthermore, ATM and its kinase activity functions at least in part independent of CtIP/Mre11 to mediate A-EJ switching in Lig4-deficient cells. In stark contrast to Lig4 deficiency, 53BP1-deficient cells do not depend on ATM/Mre11/CtIP for residual joining. We discuss the roles for each resection factor in A-EJ-mediated CSR and suggest that the extent of requirements for resection is context dependent.
Collapse
Affiliation(s)
- Xikui Sun
- Department of Immunology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.,Key Laboratory of Tropical Disease Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China
| | - Jingning Bai
- Department of Immunology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.,Key Laboratory of Tropical Disease Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China
| | - Jiejie Xu
- Department of Immunology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.,Key Laboratory of Tropical Disease Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China
| | - Xiaoli Xi
- Department of Gastroenterology, the Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Mingyu Gu
- Department of Immunology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.,Key Laboratory of Tropical Disease Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China
| | - Chengming Zhu
- Research Center of the Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
| | - Hongman Xue
- Department of Pediatrics, the Seventh Affiliated Hospital of Sun Yat-Sen University, Shenzhen, China
| | - Chun Chen
- Department of Pediatrics, the Seventh Affiliated Hospital of Sun Yat-Sen University, Shenzhen, China
| | - Junchao Dong
- Department of Immunology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.,Key Laboratory of Tropical Disease Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China.,Department of Pediatrics, the Seventh Affiliated Hospital of Sun Yat-Sen University, Shenzhen, China
| |
Collapse
|
18
|
Ye Z, Shi Y, Lees-Miller SP, Tainer JA. Function and Molecular Mechanism of the DNA Damage Response in Immunity and Cancer Immunotherapy. Front Immunol 2021; 12:797880. [PMID: 34970273 PMCID: PMC8712645 DOI: 10.3389/fimmu.2021.797880] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 11/15/2021] [Indexed: 12/21/2022] Open
Abstract
The DNA damage response (DDR) is an organized network of multiple interwoven components evolved to repair damaged DNA and maintain genome fidelity. Conceptually the DDR includes damage sensors, transducer kinases, and effectors to maintain genomic stability and accurate transmission of genetic information. We have recently gained a substantially improved molecular and mechanistic understanding of how DDR components are interconnected to inflammatory and immune responses to stress. DDR shapes both innate and adaptive immune pathways: (i) in the context of innate immunity, DDR components mainly enhance cytosolic DNA sensing and its downstream STimulator of INterferon Genes (STING)-dependent signaling; (ii) in the context of adaptive immunity, the DDR is needed for the assembly and diversification of antigen receptor genes that is requisite for T and B lymphocyte development. Imbalances between DNA damage and repair impair tissue homeostasis and lead to replication and transcription stress, mutation accumulation, and even cell death. These impacts from DDR defects can then drive tumorigenesis, secretion of inflammatory cytokines, and aberrant immune responses. Yet, DDR deficiency or inhibition can also directly enhance innate immune responses. Furthermore, DDR defects plus the higher mutation load in tumor cells synergistically produce primarily tumor-specific neoantigens, which are powerfully targeted in cancer immunotherapy by employing immune checkpoint inhibitors to amplify immune responses. Thus, elucidating DDR-immune response interplay may provide critical connections for harnessing immunomodulatory effects plus targeted inhibition to improve efficacy of radiation and chemotherapies, of immune checkpoint blockade, and of combined therapeutic strategies.
Collapse
Affiliation(s)
- Zu Ye
- Department of Molecular and Cellular Oncology, and Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
| | - Yin Shi
- Department of Immunology, Zhejiang University School of Medicine, Hangzhou, China
- Division of Pediatrics, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
| | - Susan P. Lees-Miller
- Department of Biochemistry and Molecular Biology, Robson DNA Science Centre, Charbonneau Cancer Institute, University of Calgary, Calgary, AB, Canada
| | - John A. Tainer
- Department of Molecular and Cellular Oncology, and Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
| |
Collapse
|
19
|
Shen HM, Wuerffel R, Cantillo JF, Priyadarshi S, Lei X, Liang J, Wu YL, Kenter AL. Loop extrusion promotes an alternate pathway for isotype switching. Cell Rep 2021; 37:110059. [PMID: 34818547 PMCID: PMC8979556 DOI: 10.1016/j.celrep.2021.110059] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 07/22/2021] [Accepted: 11/03/2021] [Indexed: 01/02/2023] Open
Abstract
Class-switch recombination (CSR) involves replacement of the Cμ
constant region with another downstream CH region. CSR is initiated
by activation-induced cytidine deaminase (AID)-mediated DNA breaks that are
targeted to transcriptionally active switch (S) regions. S region promoters
(Prs) direct synapsis by associating with the Eμ and 3′Eα
enhancers that jointly anchor a chromatin loop. We report that asymmetric loop
extrusion allows 3′Eα to track along the locus and form Pr-Pr-E
interactions that mediate CSR between downstream S regions, followed by
switching to donor Sμ. This alternative pathway bypasses sequential
switching and creates immunoglobulin (Ig)E+ B cells in the absence of
IgG1 expression. Based on the analysis of diagnostic CSR products in B cell
subsets, we identify a BCR-negative cell intermediate that is pivotal to
efficient CSR. Shen et al. report that 3′Eα tracks along the Igh locus via
unidirectional loop extrusion to form germline transcript promoter (Pr)-Pr-E
interactions that mediate an alternative CSR pathway. B cell intermediates of
CSR are identified, which are AID-dependent, surface BCR-negative, and in the
G1 phase of the cell cycle.
Collapse
Affiliation(s)
- Hong Ming Shen
- Department of Microbiology and Immunology, University of Illinois College of Medicine, Chicago, IL 60612-7344, USA
| | - Robert Wuerffel
- Department of Microbiology and Immunology, University of Illinois College of Medicine, Chicago, IL 60612-7344, USA
| | - Jose F Cantillo
- Department of Microbiology and Immunology, University of Illinois College of Medicine, Chicago, IL 60612-7344, USA
| | - Saurabh Priyadarshi
- Department of Microbiology and Immunology, University of Illinois College of Medicine, Chicago, IL 60612-7344, USA
| | - Xue Lei
- Department of Bioengineering, University of Illinois Colleges of Engineering and Medicine, Chicago, IL 60612-7344, USA
| | - Jie Liang
- Department of Bioengineering, University of Illinois Colleges of Engineering and Medicine, Chicago, IL 60612-7344, USA
| | - Yee Ling Wu
- Department of Microbiology and Immunology, Loyola University Chicago, Maywood, IL 60153, USA
| | - Amy L Kenter
- Department of Microbiology and Immunology, University of Illinois College of Medicine, Chicago, IL 60612-7344, USA.
| |
Collapse
|
20
|
ASTE1 promotes shieldin-complex-mediated DNA repair by attenuating end resection. Nat Cell Biol 2021; 23:894-904. [PMID: 34354233 DOI: 10.1038/s41556-021-00723-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 06/25/2021] [Indexed: 12/23/2022]
Abstract
The shieldin complex functions as the downstream effector of 53BP1-RIF1 to promote DNA double-strand break end-joining by restricting end resection. The SHLD2 subunit binds to single-stranded DNA ends and blocks end resection through OB-fold domains. Besides blocking end resection, it is unclear how the shieldin complex processes SHLD2-bound single-stranded DNA and promotes non-homologous end-joining. Here, we identify a downstream effector of the shieldin complex, ASTE1, as a structure-specific DNA endonuclease that specifically cleaves single-stranded DNA and 3' overhang DNA. ASTE1 localizes to DNA damage sites in a shieldin-dependent manner. Loss of ASTE1 impairs non-homologous end-joining, leads to hyper-resection and causes defective immunoglobulin class switch recombination. ASTE1 deficiency also causes resistance to poly(ADP-ribose) polymerase inhibitors in BRCA1-deficient cells owing to restoration of homologous recombination. These findings suggest that ASTE1-mediated 3' single-stranded DNA end cleavage contributes to the control of DSB repair choice by 53BP1, RIF1 and shieldin.
Collapse
|
21
|
Repair pathway choice for double-strand breaks. Essays Biochem 2021; 64:765-777. [PMID: 32648897 DOI: 10.1042/ebc20200007] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 06/10/2020] [Accepted: 06/12/2020] [Indexed: 12/20/2022]
Abstract
Deoxyribonucleic acid (DNA) is at a constant risk of damage from endogenous substances, environmental radiation, and chemical stressors. DNA double-strand breaks (DSBs) pose a significant threat to genomic integrity and cell survival. There are two major pathways for DSB repair: nonhomologous end-joining (NHEJ) and homologous recombination (HR). The extent of DNA end resection, which determines the length of the 3' single-stranded DNA (ssDNA) overhang, is the primary factor that determines whether repair is carried out via NHEJ or HR. NHEJ, which does not require a 3' ssDNA tail, occurs throughout the cell cycle. 53BP1 and the cofactors PTIP or RIF1-shieldin protect the broken DNA end, inhibit long-range end resection and thus promote NHEJ. In contrast, HR mainly occurs during the S/G2 phase and requires DNA end processing to create a 3' tail that can invade a homologous region, ensuring faithful gene repair. BRCA1 and the cofactors CtIP, EXO1, BLM/DNA2, and the MRE11-RAD50-NBS1 (MRN) complex promote DNA end resection and thus HR. DNA resection is influenced by the cell cycle, the chromatin environment, and the complexity of the DNA end break. Herein, we summarize the key factors involved in repair pathway selection for DSBs and discuss recent related publications.
Collapse
|
22
|
The dystonia gene THAP1 controls DNA double-strand break repair choice. Mol Cell 2021; 81:2611-2624.e10. [PMID: 33857404 DOI: 10.1016/j.molcel.2021.03.034] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 02/01/2021] [Accepted: 03/19/2021] [Indexed: 12/26/2022]
Abstract
The Shieldin complex shields double-strand DNA breaks (DSBs) from nucleolytic resection. Curiously, the penultimate Shieldin component, SHLD1, is one of the least abundant mammalian proteins. Here, we report that the transcription factors THAP1, YY1, and HCF1 bind directly to the SHLD1 promoter, where they cooperatively maintain the low basal expression of SHLD1, thereby ensuring a proper balance between end protection and resection during DSB repair. The loss of THAP1-dependent SHLD1 expression confers cross-resistance to poly (ADP-ribose) polymerase (PARP) inhibitor and cisplatin in BRCA1-deficient cells and shorter progression-free survival in ovarian cancer patients. Moreover, the embryonic lethality and PARPi sensitivity of BRCA1-deficient mice is rescued by ablation of SHLD1. Our study uncovers a transcriptional network that directly controls DSB repair choice and suggests a potential link between DNA damage and pathogenic THAP1 mutations, found in patients with the neurodevelopmental movement disorder adult-onset torsion dystonia type 6.
Collapse
|
23
|
RepID-deficient cancer cells are sensitized to a drug targeting p97/VCP segregase. Mol Cell Toxicol 2021. [DOI: 10.1007/s13273-021-00121-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Abstract
Background
The p97/valosin-containing protein (VCP) complex is a crucial factor for the segregation of ubiquitinated proteins in the DNA damage response and repair pathway.
Objective
We investigated whether blocking the p97/VCP function can inhibit the proliferation of RepID-deficient cancer cells using immunofluorescence, clonogenic survival assay, fluorescence-activated cell sorting, and immunoblotting.
Result
p97/VCP was recruited to chromatin and colocalized with DNA double-strand breaks in RepID-deficient cancer cells that undergo spontaneous DNA damage. Inhibition of p97/VCP induced death of RepID-depleted cancer cells. This study highlights the potential of targeting p97/VCP complex as an anticancer therapeutic approach.
Conclusion
Our results show that RepID is required to prevent excessive DNA damage at the endogenous levels. Localization of p97/VCP to DSB sites was induced based on spontaneous DNA damage in RepID-depleted cancer cells. Anticancer drugs targeting p97/VCP may be highly potent in RepID-deficient cells. Therefore, we suggest that p97/VCP inhibitors synergize with RepID depletion to kill cancer cells.
Collapse
|
24
|
Repair of programmed DNA lesions in antibody class switch recombination: common and unique features. ACTA ACUST UNITED AC 2021; 2:115-125. [PMID: 33817557 PMCID: PMC7996122 DOI: 10.1007/s42764-021-00035-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 02/22/2021] [Accepted: 03/04/2021] [Indexed: 01/31/2023]
Abstract
The adaptive immune system can diversify the antigen receptors to eliminate various pathogens through programmed DNA lesions at antigen receptor genes. In immune diversification, general DNA repair machineries are applied to transform the programmed DNA lesions into gene mutation or recombination events with common and unique features. Here we focus on antibody class switch recombination (CSR), and review the initiation of base damages, the conversion of damaged base to DNA double-strand break, and the ligation of broken ends. With an emphasis on the unique features in CSR, we discuss recent advances in the understanding of DNA repair/replication coordination, and ERCC6L2-mediated deletional recombination. We further elaborate the application of CSR in end-joining, resection and translesion synthesis assays. In the time of the COVID-19 pandemic, we hope it help to understand the generation of therapeutic antibodies.
Collapse
|
25
|
Discovery of a novel 53BP1 inhibitor through AlphaScreen-based high-throughput screening. Bioorg Med Chem 2021; 34:116054. [PMID: 33571875 DOI: 10.1016/j.bmc.2021.116054] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 01/18/2021] [Accepted: 01/26/2021] [Indexed: 11/23/2022]
Abstract
Tumor suppressor p53-binding protein 1 (53BP1), a tantem tudor domain (TTD) protein, takes part in DNA Damage Repair (DDR) pathways through the specific recognition of lysine methylation on histones. The dysregulation of 53BP1 is closely related to the development of many diseases including cancer. Moreover, recent studies found that deficiency of 53BP1 could increase the efficiency of precise CRISPR/Cas9 genome editing. Thus, discovery of inhibitor is beneficial to the study of biological functions of 53BP1 and the application of CRISPR/Cas9 genome editing. UNC2170 and its derivatives have been reported as 53BP1 targeted small molecular inhibitors with modest activities. Hence, to discover better 53BP1 inhibitors, we conducted an AlphaScreen assay based high-throughput screening (HTS) and identified a novel and effective 53BP1-TTD inhibitor DP308 which disrupts the binding between 53BP1 and H4K20me2 peptide with an IC50 value of 1.69 ± 0.73 μM. Both Microscale Themophoresis (MST) and Surface Plasmon Resonance (SPR) assays confirmed the direct binding between DP308 and 53BP1-TTD protein with binding affinity (Kd) of about 2.7 μM. Molecular docking studies further suggested that DP308 possibly occupies the H4K20me2 binding pocket of the 53BP1-TTD aromatic cage. These results demonstrated that DP308 is a promising small molecule inhibitor for further optimization towards a more potent chemical probe of 53BP1. Additionally, it could be a potential valuable tool for applying to gene editing therapy by increasing the efficiency of CRISPR/Cas9 genome editing.
Collapse
|
26
|
Helfricht A, Thijssen PE, Rother MB, Shah RG, Du L, Takada S, Rogier M, Moritz J, IJspeert H, Stoepker C, van Ostaijen-Ten Dam MM, Heyer V, Luijsterburg MS, de Groot A, Jak R, Grootaers G, Wang J, Rao P, Vertegaal ACO, van Tol MJD, Pan-Hammarström Q, Reina-San-Martin B, Shah GM, van der Burg M, van der Maarel SM, van Attikum H. Loss of ZBTB24 impairs nonhomologous end-joining and class-switch recombination in patients with ICF syndrome. J Exp Med 2021; 217:152060. [PMID: 32865561 PMCID: PMC7526497 DOI: 10.1084/jem.20191688] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 04/06/2020] [Accepted: 05/19/2020] [Indexed: 12/12/2022] Open
Abstract
The autosomal recessive immunodeficiency, centromeric instability, and facial anomalies (ICF) syndrome is a genetically heterogeneous disorder. Despite the identification of the underlying gene defects, it is unclear how mutations in any of the four known ICF genes cause a primary immunodeficiency. Here we demonstrate that loss of ZBTB24 in B cells from mice and ICF2 patients affects nonhomologous end-joining (NHEJ) during immunoglobulin class-switch recombination and consequently impairs immunoglobulin production and isotype balance. Mechanistically, we found that ZBTB24 associates with poly(ADP-ribose) polymerase 1 (PARP1) and stimulates its auto-poly(ADP-ribosyl)ation. The zinc-finger in ZBTB24 binds PARP1-associated poly(ADP-ribose) chains and mediates the PARP1-dependent recruitment of ZBTB24 to DNA breaks. Moreover, through its association with poly(ADP-ribose) chains, ZBTB24 protects them from degradation by poly(ADP-ribose) glycohydrolase (PARG). This facilitates the poly(ADP-ribose)-dependent assembly of the LIG4/XRCC4 complex at DNA breaks, thereby promoting error-free NHEJ. Thus, we uncover ZBTB24 as a regulator of PARP1-dependent NHEJ and class-switch recombination, providing a molecular basis for the immunodeficiency in ICF2 syndrome.
Collapse
Affiliation(s)
- Angela Helfricht
- Department of Human Genetics, Leiden University Medical Center, Leiden, Netherlands
| | - Peter E Thijssen
- Department of Human Genetics, Leiden University Medical Center, Leiden, Netherlands
| | - Magdalena B Rother
- Department of Human Genetics, Leiden University Medical Center, Leiden, Netherlands
| | - Rashmi G Shah
- CHU de Québec Research Centre (site CHUL) and Laboratory for Skin Cancer Research and Axe Neuroscience, Université Laval, Québec, Canada
| | - Likun Du
- Department of Biosciences and Nutrition, Karolinska Institute, Solna, Sweden
| | - Sanami Takada
- Laboratory for Pediatric Immunology, Department of Pediatrics, Willem Alexander Children's Hospital, Leiden University Medical Center, Leiden, Netherlands
| | - Mélanie Rogier
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France.,Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U1258, Illkirch, France.,Université de Strasbourg, Illkirch, France
| | - Jacques Moritz
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France.,Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U1258, Illkirch, France.,Université de Strasbourg, Illkirch, France
| | - Hanna IJspeert
- Department of Immunology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, Netherlands
| | - Chantal Stoepker
- Department of Human Genetics, Leiden University Medical Center, Leiden, Netherlands
| | - Monique M van Ostaijen-Ten Dam
- Laboratory for Pediatric Immunology, Department of Pediatrics, Willem Alexander Children's Hospital, Leiden University Medical Center, Leiden, Netherlands
| | - Vincent Heyer
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France.,Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U1258, Illkirch, France.,Université de Strasbourg, Illkirch, France
| | | | - Anton de Groot
- Department of Human Genetics, Leiden University Medical Center, Leiden, Netherlands
| | - Rianca Jak
- Department of Human Genetics, Leiden University Medical Center, Leiden, Netherlands
| | - Gwendolynn Grootaers
- Department of Human Genetics, Leiden University Medical Center, Leiden, Netherlands
| | - Jun Wang
- Department of Human Genetics, Leiden University Medical Center, Leiden, Netherlands
| | | | - Alfred C O Vertegaal
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, Netherlands
| | - Maarten J D van Tol
- Laboratory for Pediatric Immunology, Department of Pediatrics, Willem Alexander Children's Hospital, Leiden University Medical Center, Leiden, Netherlands
| | | | - Bernardo Reina-San-Martin
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France.,Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U1258, Illkirch, France.,Université de Strasbourg, Illkirch, France
| | - Girish M Shah
- CHU de Québec Research Centre (site CHUL) and Laboratory for Skin Cancer Research and Axe Neuroscience, Université Laval, Québec, Canada
| | - Mirjam van der Burg
- Laboratory for Pediatric Immunology, Department of Pediatrics, Willem Alexander Children's Hospital, Leiden University Medical Center, Leiden, Netherlands
| | | | - Haico van Attikum
- Department of Human Genetics, Leiden University Medical Center, Leiden, Netherlands
| |
Collapse
|
27
|
Three-dimensional genome rewiring during the development of antibody-secreting cells. Biochem Soc Trans 2021; 48:1109-1119. [PMID: 32453419 PMCID: PMC7329350 DOI: 10.1042/bst20191104] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 04/26/2020] [Accepted: 04/28/2020] [Indexed: 01/08/2023]
Abstract
The development of B lymphocytes into antibody-secreting plasma cells is central to the adaptive immune system in that it confers protective and specific antibody response against invading pathogen. This developmental process involves extensive morphological and functional alterations that begin early after antigenic stimulation. These include chromatin restructuring that is critical in regulating gene expression, DNA rearrangement and other cellular processes. Here we outline the recent understanding of the three-dimensional architecture of the genome, specifically focused on its contribution to the process of B cell activation and terminal differentiation into antibody-secreting cells.
Collapse
|
28
|
Luong TMH, Matsuda K, Niino D, Kurohama H, Ito M, Nakashima M. Significance of abnormal 53BP1 expression as a novel molecular pathologic parameter of follicular-shaped B-cell lymphoid lesions in human digestive tract. Sci Rep 2021; 11:3074. [PMID: 33542453 PMCID: PMC7862599 DOI: 10.1038/s41598-021-82867-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Accepted: 01/19/2021] [Indexed: 11/24/2022] Open
Abstract
The digestive tract is a common site of extranodal malignant lymphomas (MLs) and benign lymphoid lesions (BLs). TP53-binding protein 1 (53BP1) expression has been widely investigated in class switch recombination but rarely in human lymphoid tissues with respect to tumorigenesis. We previously reported that immunofluorescence (IF) analysis of 53BP1 nuclear foci (NF), reflecting DNA double strand breaks, is useful for estimating genomic instability in different tumor types. In this study, we evaluated the potential of IF-based analysis of 53BP1 expression in differentiating MLs from BLs. We examined 231 biopsied tissue samples of primary MLs and BLs in the digestive tract. The 53BP1 immunoreactivity pattern was determined by multicolor IF. Compared to BLs, MLs showed a high frequency of abnormal 53BP1 expression (p < 0.0001). Statistically, abnormal 53BP1 expression is an effective test for distinguishing follicular lymphomas from BLs (specificity 98.6%, sensitivity 86.8%) and for distinguishing small B-cell lymphomas from BLs (specificity 98.3%, sensitivity 77.6%). Furthermore, a high frequency of abnormal 53BP1 expression was associated with "high-risk" MALT lymphomas, which exhibited t(11;18)(q21;21) (p = 0.0145). Collectively, these results suggest that IF-based analysis of 53BP1 expression in biopsy samples is a promising technique for diagnosing MLs in the digestive system.
Collapse
Affiliation(s)
- Thi My Hanh Luong
- Department of Tumor and Diagnostic Pathology, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan
| | - Katsuya Matsuda
- Department of Tumor and Diagnostic Pathology, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan
| | - Daisuke Niino
- Department of Pathology, Local Incorporated Administrative Agency Sasebo City General Hospital, Sasebo, Japan
| | - Hirokazu Kurohama
- Department of Tumor and Diagnostic Pathology, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan
| | - Masahiro Ito
- Department of Pathology, National Hospital Organization Nagasaki Medical Center, Omura, Japan
| | - Masahiro Nakashima
- Department of Tumor and Diagnostic Pathology, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan.
| |
Collapse
|
29
|
Zhang F, Gong Z. Regulation of DNA double-strand break repair pathway choice: a new focus on 53BP1. J Zhejiang Univ Sci B 2021; 22:38-46. [PMID: 33448186 DOI: 10.1631/jzus.b2000306] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Maintenance of cellular homeostasis and genome integrity is a critical responsibility of DNA double-strand break (DSB) signaling. P53-binding protein 1 (53BP1) plays a critical role in coordinating the DSB repair pathway choice and promotes the non-homologous end-joining (NHEJ)-mediated DSB repair pathway that rejoins DSB ends. New insights have been gained into a basic molecular mechanism that is involved in 53BP1 recruitment to the DNA lesion and how 53BP1 then recruits the DNA break-responsive effectors that promote NHEJ-mediated DSB repair while inhibiting homologous recombination (HR) signaling. This review focuses on the up- and downstream pathways of 53BP1 and how 53BP1 promotes NHEJ-mediated DSB repair, which in turn promotes the sensitivity of poly(ADP-ribose) polymerase inhibitor (PARPi) in BRCA1-deficient cancers and consequently provides an avenue for improving cancer therapy strategies.
Collapse
Affiliation(s)
- Fan Zhang
- Department of Cancer Biology, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA
| | - Zihua Gong
- Department of Cancer Biology, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA.
| |
Collapse
|
30
|
Panigrahi R, Glover JNM. Structural insights into DNA double-strand break signaling. Biochem J 2021; 478:135-156. [PMID: 33439989 DOI: 10.1042/bcj20200066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 12/10/2020] [Accepted: 12/15/2020] [Indexed: 12/14/2022]
Abstract
Genomic integrity is most threatened by double-strand breaks, which, if left unrepaired, lead to carcinogenesis or cell death. The cell generates a network of protein-protein signaling interactions that emanate from the DNA damage which are now recognized as a rich basis for anti-cancer therapy development. Deciphering the structures of signaling proteins has been an uphill task owing to their large size and complex domain organization. Recent advances in mammalian protein expression/purification and cryo-EM-based structure determination have led to significant progress in our understanding of these large multidomain proteins. This review is an overview of the structural principles that underlie some of the key signaling proteins that function at the double-strand break site. We also discuss some plausible ideas that could be considered for future structural approaches to visualize and build a more complete understanding of protein dynamics at the break site.
Collapse
Affiliation(s)
- Rashmi Panigrahi
- Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - J N Mark Glover
- Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
| |
Collapse
|
31
|
Zhang J, Yan Z, Wang Y, Wang Y, Guo X, Jing J, Dong X, Dong S, Liu X, Yu X, Wu C. Cancer-associated 53BP1 mutations induce DNA damage repair defects. Cancer Lett 2020; 501:43-54. [PMID: 33359708 DOI: 10.1016/j.canlet.2020.12.033] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 12/18/2020] [Accepted: 12/21/2020] [Indexed: 12/29/2022]
Abstract
TP53 binding protein 1 (53BP1) plays an important role in DNA damage repair and maintaining genomic stability. However, the mutations of 53BP1 in human cancers have not been systematically examined. Here, we have analyzed 541 somatic mutations of 53BP1 across 34 types of human cancer from databases of The Cancer Genome Atlas, International Cancer Genome Consortium and Catalogue of Somatic Mutations in Cancer. Among these cancer-associated 53BP1 mutations, truncation mutations disrupt the nuclear localization of 53BP1 thus abolish its biological functions in DNA damage repair. Moreover, with biochemical analyses and structural modeling, we have examined the detailed molecular mechanism by which missense mutations in the key domains causes the DNA damage repair defects. Taken together, our results reveal the functional defects of a set of cancer-associated 53BP1 mutations.
Collapse
Affiliation(s)
- Jiajia Zhang
- School of Life Sciences, Institute of Life Sciences and Green Development, Hebei University, Baoding, 071002, Hebei, China
| | - Zhenzhen Yan
- School of Life Sciences, Institute of Life Sciences and Green Development, Hebei University, Baoding, 071002, Hebei, China
| | - Yukun Wang
- School of Life Sciences, Institute of Life Sciences and Green Development, Hebei University, Baoding, 071002, Hebei, China
| | - Yaguang Wang
- School of Life Sciences, Institute of Life Sciences and Green Development, Hebei University, Baoding, 071002, Hebei, China
| | - Xin Guo
- School of Life Sciences, Institute of Life Sciences and Green Development, Hebei University, Baoding, 071002, Hebei, China
| | - Ju Jing
- School of Life Sciences, Institute of Life Sciences and Green Development, Hebei University, Baoding, 071002, Hebei, China
| | - Xiangnan Dong
- School of Life Sciences, Institute of Life Sciences and Green Development, Hebei University, Baoding, 071002, Hebei, China
| | - Shasha Dong
- School of Life Sciences, Institute of Life Sciences and Green Development, Hebei University, Baoding, 071002, Hebei, China
| | - Xiuhua Liu
- School of Life Sciences, Institute of Life Sciences and Green Development, Hebei University, Baoding, 071002, Hebei, China.
| | - Xiaochun Yu
- School of Life Sciences, Westlake University, Hangzhou, Zhejiang, 310024, China.
| | - Chen Wu
- School of Life Sciences, Institute of Life Sciences and Green Development, Hebei University, Baoding, 071002, Hebei, China.
| |
Collapse
|
32
|
Saha T, Sundaravinayagam D, Di Virgilio M. Charting a DNA Repair Roadmap for Immunoglobulin Class Switch Recombination. Trends Biochem Sci 2020; 46:184-199. [PMID: 33250286 DOI: 10.1016/j.tibs.2020.10.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 10/08/2020] [Accepted: 10/23/2020] [Indexed: 01/18/2023]
Abstract
Immunoglobulin (Ig) class switch recombination (CSR) is the process occurring in mature B cells that diversifies the effector component of antibody responses. CSR is initiated by the activity of the B cell-specific enzyme activation-induced cytidine deaminase (AID), which leads to the formation of programmed DNA double-strand breaks (DSBs) at the Ig heavy chain (Igh) locus. Mature B cells use a multilayered and complex regulatory framework to ensure that AID-induced DNA breaks are channeled into productive repair reactions leading to CSR, and to avoid aberrant repair events causing lymphomagenic chromosomal translocations. Here, we review the DNA repair pathways acting on AID-induced DSBs and their functional interplay, with a particular focus on the latest developments in their molecular composition and mechanistic regulation.
Collapse
Affiliation(s)
- Tannishtha Saha
- Laboratory of Genome Diversification and Integrity, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin 13125, Germany
| | - Devakumar Sundaravinayagam
- Laboratory of Genome Diversification and Integrity, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin 13125, Germany.
| | - Michela Di Virgilio
- Laboratory of Genome Diversification and Integrity, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin 13125, Germany; Charité-Universitätsmedizin Berlin, Berlin 10117, Germany.
| |
Collapse
|
33
|
Emerging roles of lamins and DNA damage repair mechanisms in ovarian cancer. Biochem Soc Trans 2020; 48:2317-2333. [DOI: 10.1042/bst20200713] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 09/14/2020] [Accepted: 09/21/2020] [Indexed: 02/06/2023]
Abstract
Lamins are type V intermediate filament proteins which are ubiquitously present in all metazoan cells providing a platform for binding of chromatin and related proteins, thereby serving a wide range of nuclear functions including DNA damage repair. Altered expression of lamins in different subtypes of cancer is evident from researches worldwide. But whether cancer is a consequence of this change or this change is a consequence of cancer is a matter of future investigation. However changes in the expression levels of lamins is reported to have direct or indirect association with cancer progression or have regulatory roles in common neoplastic symptoms like higher nuclear deformability, increased genomic instability and reduced susceptibility to DNA damaging agents. It has already been proved that loss of A type lamin positively regulates cathepsin L, eventually leading to degradation of several DNA damage repair proteins, hence impairing DNA damage repair pathways and increasing genomic instability. It is established in ovarian cancer, that the extent of alteration in nuclear morphology can determine the degree of genetic changes and thus can be utilized to detect low to high form of serous carcinoma. In this review, we have focused on ovarian cancer which is largely caused by genomic alterations in the DNA damage response pathways utilizing proteins like RAD51, BRCA1, 53BP1 which are regulated by lamins. We have elucidated the current understanding of lamin expression in ovarian cancer and its implications in the regulation of DNA damage response pathways that ultimately result in telomere deformation and genomic instability.
Collapse
|
34
|
Sundaravinayagam D, Rahjouei A, Andreani M, Tupiņa D, Balasubramanian S, Saha T, Delgado-Benito V, Coralluzzo V, Daumke O, Di Virgilio M. 53BP1 Supports Immunoglobulin Class Switch Recombination Independently of Its DNA Double-Strand Break End Protection Function. Cell Rep 2020; 28:1389-1399.e6. [PMID: 31390554 PMCID: PMC6693562 DOI: 10.1016/j.celrep.2019.06.035] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 05/16/2019] [Accepted: 06/07/2019] [Indexed: 01/29/2023] Open
Abstract
Class switch recombination (CSR) is a DNA recombination reaction that diversifies the effector functions of antibodies. CSR occurs via the formation and non-homologous end joining (NHEJ) repair of programmed DNA double-strand breaks (DSBs) at the immunoglobulin heavy chain locus. The DNA repair factors 53BP1 and Rif1 promote NHEJ and CSR by protecting DSBs against resection. However, to what extent repression of DNA end resection contributes to CSR is unknown. Here, we show that B lymphocytes devoid of 53BP1-Rif1-dependent DSB end protection activity undergo robust CSR. Inactivation of specific sets of phospho-sites within 53BP1 N-terminal SQ/TQ motifs abrogates Rif1 recruitment and inhibition of resection but only mildly reduces CSR. Furthermore, mutations within 53BP1 oligomerization domain abolish CSR without substantially affecting DNA end processing. Thus, inhibition of DNA end resection does not correlate with CSR efficiency, indicating that regulation of DSB processing is not a key determinant step in CSR. 53BP1 oligomerization is largely dispensable for inhibition of DSB resection 53BP1 higher order oligomerization is a pre-requisite for CSR B lymphocytes devoid of 53BP1-Rif1 DSB end protection activity undergo robust CSR 53BP1-mediated DSB end mobility is dispensable for CSR
Collapse
Affiliation(s)
- Devakumar Sundaravinayagam
- Laboratory of DNA Repair and Maintenance of Genome Stability, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
| | - Ali Rahjouei
- Laboratory of DNA Repair and Maintenance of Genome Stability, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
| | - Matteo Andreani
- Laboratory of DNA Repair and Maintenance of Genome Stability, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
| | - Dagnija Tupiņa
- Laboratory of Structural Biology of Membrane-Associated Processes, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
| | - Sandhya Balasubramanian
- Laboratory of DNA Repair and Maintenance of Genome Stability, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
| | - Tannishtha Saha
- Laboratory of DNA Repair and Maintenance of Genome Stability, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
| | - Verónica Delgado-Benito
- Laboratory of DNA Repair and Maintenance of Genome Stability, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
| | - Violeta Coralluzzo
- Laboratory of DNA Repair and Maintenance of Genome Stability, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
| | - Oliver Daumke
- Laboratory of Structural Biology of Membrane-Associated Processes, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
| | - Michela Di Virgilio
- Laboratory of DNA Repair and Maintenance of Genome Stability, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany.
| |
Collapse
|
35
|
Tang M, Feng X, Pei G, Srivastava M, Wang C, Chen Z, Li S, Zhang H, Zhao Z, Li X, Chen J. FOXK1 Participates in DNA Damage Response by Controlling 53BP1 Function. Cell Rep 2020; 32:108018. [PMID: 32783940 PMCID: PMC7458625 DOI: 10.1016/j.celrep.2020.108018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 06/09/2020] [Accepted: 07/17/2020] [Indexed: 01/28/2023] Open
Abstract
53BP1 plays a central role in dictating DNA repair choice between non-homologous end joining (NHEJ) and homologous recombination (HR), which is important for the sensitivity to poly(ADP-ribose) polymerase inhibitors (PARPis) of BRCA1-deficient cancers. In this study, we show that FOXK1 associates with 53BP1 and regulates 53BP1-dependent functions. FOXK1-53BP1 interaction is significantly enhanced upon DNA damage during the S phase in an ATM/CHK2-dependent manner, which reduces the association of 53BP1 with its downstream factors RIF1 and PTIP. Depletion of FOXK1 impairs DNA repair and induces compromised cell survival upon DNA damage. Overexpression of FOXK1 diminishes 53BP1 foci formation, which leads to resistance to PARPis and elevation of HR in BRCA1-deficient cells and decreased telomere fusion in TRF2-depleted cells. Collectively, our findings demonstrate that FOXK1 negatively regulates 53BP1 function by inhibiting 53BP1 localization to sites of DNA damage, which alters the DSB-induced protein complexes centering on 53BP1 and thus influences DNA repair choice.
Collapse
Affiliation(s)
- Mengfan Tang
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Xu Feng
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Guangsheng Pei
- Center for Precision Health, School of Biomedical Informatics, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Mrinal Srivastava
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Chao Wang
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Zhen Chen
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Siting Li
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Huimin Zhang
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Zhongming Zhao
- Center for Precision Health, School of Biomedical Informatics, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Xu Li
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Junjie Chen
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
| |
Collapse
|
36
|
Oster S, Aqeilan RI. Programmed DNA Damage and Physiological DSBs: Mapping, Biological Significance and Perturbations in Disease States. Cells 2020; 9:cells9081870. [PMID: 32785139 PMCID: PMC7463922 DOI: 10.3390/cells9081870] [Citation(s) in RCA: 5] [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: 07/13/2020] [Revised: 08/02/2020] [Accepted: 08/05/2020] [Indexed: 12/12/2022] Open
Abstract
DNA double strand breaks (DSBs) are known to be the most toxic and threatening of the various types of breaks that may occur to the DNA. However, growing evidence continuously sheds light on the regulatory roles of programmed DSBs. Emerging studies demonstrate the roles of DSBs in processes such as T and B cell development, meiosis, transcription and replication. A significant recent progress in the last few years has contributed to our advanced knowledge regarding the functions of DSBs is the development of many next generation sequencing (NGS) methods, which have considerably advanced our capabilities. Other studies have focused on the implications of programmed DSBs on chromosomal aberrations and tumorigenesis. This review aims to summarize what is known about DNA damage in its physiological context. In addition, we will examine the advancements of the past several years, which have made an impact on the study of genome landscape and its organization.
Collapse
Affiliation(s)
- Sara Oster
- The Concern Foundation Laboratories, The Lautenberg Center for Immunology and Cancer Research, Department of Immunology and Cancer Research-IMRIC, Hebrew University-Hadassah Medical School, Jerusalem 9112001, Israel;
| | - Rami I. Aqeilan
- The Concern Foundation Laboratories, The Lautenberg Center for Immunology and Cancer Research, Department of Immunology and Cancer Research-IMRIC, Hebrew University-Hadassah Medical School, Jerusalem 9112001, Israel;
- Department of Cancer Biology and Genetics, Wexner Medical Center, The Ohio State University, Columbus, OH 43210, USA
- Correspondence:
| |
Collapse
|
37
|
Gilat N, Torchinsky D, Margalit S, Michaeli Y, Avraham S, Sharim H, Elkoshi N, Levy C, Zirkin S, Ebenstein Y. Rapid Quantification of Oxidation and UV Induced DNA Damage by Repair Assisted Damage Detection-(Rapid RADD). Anal Chem 2020; 92:9887-9894. [PMID: 32578422 DOI: 10.1021/acs.analchem.0c01393] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Knowing the amount and type of DNA damage is of great significance for a broad range of clinical and research applications. However, existing methods are either lacking in their ability to distinguish between types of DNA damage or limited in their sensitivity and reproducibility. The method described herein enables rapid and robust quantification of type-specific single-strand DNA damage. The method is based on repair-assisted damage detection (RADD) by which fluorescent nucleotides are incorporated into DNA damage sites using type-specific repair enzymes. Up to 90 DNA samples are then deposited on a multiwell glass slide, and analyzed by a conventional slide scanner for quantification of DNA damage levels. Accurate and sensitive measurements of oxidative or UV-induced DNA damage levels and repair kinetics are presented for both in vitro and in vivo models.
Collapse
Affiliation(s)
- Noa Gilat
- School of Chemistry, Center for Nanoscience and Nanotechnology, Center for Light-Matter Interaction, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Dmitry Torchinsky
- School of Chemistry, Center for Nanoscience and Nanotechnology, Center for Light-Matter Interaction, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Sapir Margalit
- School of Chemistry, Center for Nanoscience and Nanotechnology, Center for Light-Matter Interaction, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Yael Michaeli
- School of Chemistry, Center for Nanoscience and Nanotechnology, Center for Light-Matter Interaction, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Sigal Avraham
- School of Chemistry, Center for Nanoscience and Nanotechnology, Center for Light-Matter Interaction, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Hila Sharim
- School of Chemistry, Center for Nanoscience and Nanotechnology, Center for Light-Matter Interaction, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Nadav Elkoshi
- Department of Human Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Carmit Levy
- Department of Human Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Shahar Zirkin
- School of Chemistry, Center for Nanoscience and Nanotechnology, Center for Light-Matter Interaction, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Yuval Ebenstein
- School of Chemistry, Center for Nanoscience and Nanotechnology, Center for Light-Matter Interaction, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, Israel
| |
Collapse
|
38
|
Wang XS, Lee BJ, Zha S. The recent advances in non-homologous end-joining through the lens of lymphocyte development. DNA Repair (Amst) 2020; 94:102874. [PMID: 32623318 DOI: 10.1016/j.dnarep.2020.102874] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 05/16/2020] [Accepted: 05/24/2020] [Indexed: 12/17/2022]
Abstract
Lymphocyte development requires ordered assembly and subsequent modifications of the antigen receptor genes through V(D)J recombination and Immunoglobulin class switch recombination (CSR), respectively. While the programmed DNA cleavage events are initiated by lymphocyte-specific factors, the resulting DNA double-strand break (DSB) intermediates activate the ATM kinase-mediated DNA damage response (DDR) and rely on the ubiquitously expressed classical non-homologous end-joining (cNHEJ) pathway including the DNA-dependent protein kinase (DNA-PK), and, in the case of CSR, also the alternative end-joining (Alt-EJ) pathway, for repair. Correspondingly, patients and animal models with cNHEJ or DDR defects develop distinct types of immunodeficiency reflecting their specific DNA repair deficiency. The unique end-structure, sequence context, and cell cycle regulation of V(D)J recombination and CSR also provide a valuable platform to study the mechanisms of, and the interplay between, cNHEJ and DDR. Here, we compare and contrast the genetic consequences of DNA repair defects in V(D)J recombination and CSR with a focus on the newly discovered cNHEJ factors and the kinase-dependent structural roles of ATM and DNA-PK in animal models. Throughout, we try to highlight the pending questions and emerging differences that will extend our understanding of cNHEJ and DDR in the context of primary immunodeficiency and lymphoid malignancies.
Collapse
Affiliation(s)
- Xiaobin S Wang
- Institute for Cancer Genetics, Vagelos College of Physicians and Surgeons, Columbia University, New York City, NY 10032, United States; Graduate Program of Pathobiology and Molecular Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York City, NY 10032, United States
| | - Brian J Lee
- Institute for Cancer Genetics, Vagelos College of Physicians and Surgeons, Columbia University, New York City, NY 10032, United States
| | - Shan Zha
- Institute for Cancer Genetics, Vagelos College of Physicians and Surgeons, Columbia University, New York City, NY 10032, United States; Department of Pediatrics, Vagelos College of Physicians and Surgeons, Columbia University, New York City, NY 10032, United States; Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York City, NY 10032, United States; Department of Immunology and Microbiology, Vagelos College of Physicians and Surgeons, Columbia University, New York City, NY 10032, United States.
| |
Collapse
|
39
|
Ling AK, Munro M, Chaudhary N, Li C, Berru M, Wu B, Durocher D, Martin A. SHLD2 promotes class switch recombination by preventing inactivating deletions within the Igh locus. EMBO Rep 2020; 21:e49823. [PMID: 32558186 DOI: 10.15252/embr.201949823] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 05/19/2020] [Accepted: 05/25/2020] [Indexed: 12/12/2022] Open
Abstract
The newly identified shieldin complex, composed of SHLD1, SHLD2, SHLD3, and REV7, lies downstream of 53BP1 and acts to inhibit DNA resection and promote NHEJ. Here, we show that Shld2-/- mice have defective class switch recombination (CSR) and that loss of SHLD2 can suppress the embryonic lethality of a Brca1Δ11 mutation, highlighting its role as a key effector of 53BP1. Lymphocyte development and RAG1/2-mediated recombination were unaffected by SHLD2 deficiency. Interestingly, a significant fraction of Shld2-/- primary B-cells and 53BP1- and shieldin-deficient CH12F3-2 B-cells permanently lose expression of immunoglobulin upon induction of CSR; this population of Ig-negative cells is also seen in other NHEJ-deficient cells and to a much lesser extent in WT cells. This loss of Ig is due to recombination coupled with overactive resection and loss of coding exons in the downstream acceptor constant region. Collectively, these data show that SHLD2 is the key effector of 53BP1 and critical for CSR in vivo by suppressing large deletions within the Igh locus.
Collapse
Affiliation(s)
- Alexanda K Ling
- Department of Immunology, University of Toronto, Toronto, ON, Canada
| | - Meagan Munro
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada
| | - Natasha Chaudhary
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada
| | - Conglei Li
- Department of Immunology, University of Toronto, Toronto, ON, Canada
| | - Maribel Berru
- Department of Immunology, University of Toronto, Toronto, ON, Canada
| | - Brendan Wu
- Department of Immunology, University of Toronto, Toronto, ON, Canada
| | - Daniel Durocher
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Alberto Martin
- Department of Immunology, University of Toronto, Toronto, ON, Canada
| |
Collapse
|
40
|
Yang D, Sun Y, Chen J, Zhang Y, Fan S, Huang M, Xie X, Cai Y, Shang Y, Gui T, Sun L, Hu J, Dong J, Yeap LS, Wang X, Xiao W, Meng FL. REV7 is required for processing AID initiated DNA lesions in activated B cells. Nat Commun 2020; 11:2812. [PMID: 32499490 PMCID: PMC7272641 DOI: 10.1038/s41467-020-16632-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 05/13/2020] [Indexed: 01/10/2023] Open
Abstract
Activation-induced cytidine deaminase (AID) initiates both antibody class switch recombination (CSR) and somatic hypermutation (SHM) in antibody diversification. DNA double-strand break response (DSBR) factors promote rearrangement in CSR, while translesion synthesis (TLS) polymerases generate mutations in SHM. REV7, a component of TLS polymerase zeta, is also a downstream effector of 53BP1-RIF1 DSBR pathway. Here, we study the multi-functions of REV7 and find that REV7 is required for the B cell survival upon AID-deamination, which is independent of its roles in DSBR, G2/M transition or REV1-mediated TLS. The cell death in REV7-deficient activated B cells can be fully rescued by AID-deficiency in vivo. We further identify that REV7-depedent TLS across UNG-processed apurinic/apyrimidinic sites is required for cell survival upon AID/APOBEC deamination. This study dissects the multiple roles of Rev7 in antibody diversification, and discovers that TLS is not only required for sequence diversification but also B cell survival upon AID-initiated lesions. REV7 has emerged as a critical regulator of DNA double-strand breaks repair. Here, the authors show that REV7 is crucial for both antibody class switch recombination and somatic hypermutation in activated B cells, in addition to their survival upon AID-deamination.
Collapse
Affiliation(s)
- Dingpeng Yang
- State Key Laboratory of Molecular Biology, Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, 200031, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ying Sun
- College of Life Sciences, Capital Normal University, Beijing, 100048, China
| | - Jingjing Chen
- Department of Immunology, State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, Jiangsu, 211166, China
| | - Ying Zhang
- State Key Laboratory of Molecular Biology, Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Shuangshuang Fan
- State Key Laboratory of Molecular Biology, Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Min Huang
- State Key Laboratory of Molecular Biology, Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, 200031, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xia Xie
- State Key Laboratory of Molecular Biology, Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, 200031, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yanni Cai
- State Key Laboratory of Molecular Biology, Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Yafang Shang
- State Key Laboratory of Molecular Biology, Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, 200031, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Tuantuan Gui
- Department of Immunology and Microbiology, Shanghai Institute of Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Liming Sun
- State Key Laboratory of Molecular Biology, Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, 200031, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jiazhi Hu
- The MOE Key Laboratory of Cell Proliferation and Differentiation, Genome Editing Research Center, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Junchao Dong
- Department of Immunology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China
| | - Leng-Siew Yeap
- Department of Immunology and Microbiology, Shanghai Institute of Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Xiaoming Wang
- Department of Immunology, State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, Jiangsu, 211166, China
| | - Wei Xiao
- College of Life Sciences, Capital Normal University, Beijing, 100048, China
| | - Fei-Long Meng
- State Key Laboratory of Molecular Biology, Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, 200031, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China.
| |
Collapse
|
41
|
A role of the 53BP1 protein in genome protection: structural and functional characteristics of 53BP1-dependent DNA repair. Aging (Albany NY) 2020; 11:2488-2511. [PMID: 30996128 PMCID: PMC6519998 DOI: 10.18632/aging.101917] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Accepted: 04/10/2019] [Indexed: 12/13/2022]
Abstract
Nuclear architecture plays a significant role in DNA repair mechanisms. It is evident that proteins involved in DNA repair are compartmentalized in not only spontaneously occurring DNA lesions or ionizing radiation-induced foci (IRIF), but a specific clustering of these proteins can also be observed within the whole cell nucleus. For example, 53BP1-positive and BRCA1-positive DNA repair foci decorate chromocenters and can appear close to nuclear speckles. Both 53BP1 and BRCA1 are well-described factors that play an essential role in double-strand break (DSB) repair. These proteins are members of two protein complexes: 53BP1-RIF1-PTIP and BRCA1-CtIP, which make a “decision” determining whether canonical nonhomologous end joining (NHEJ) or homology-directed repair (HDR) is activated. It is generally accepted that 53BP1 mediates the NHEJ mechanism, while HDR is activated via a BRCA1-dependent signaling pathway. Interestingly, the 53BP1 protein appears relatively quickly at DSB sites, while BRCA1 is functional at later stages of DNA repair, as soon as the Mre11-Rad50-Nbs1 complex is recruited to the DNA lesions. A function of the 53BP1 protein is also linked to a specific histone signature, including phosphorylation of histone H2AX (γH2AX) or methylation of histone H4 at the lysine 20 position (H4K20me); therefore, we also discuss an epigenetic landscape of 53BP1-positive DNA lesions.
Collapse
|
42
|
Innes CL, Hesse JE, Morales AJ, Helmink BA, Schurman SH, Sleckman BP, Paules RS. DNA damage responses in murine Pre-B cells with genetic deficiencies in damage response genes. Cell Cycle 2020; 19:67-83. [PMID: 31757180 PMCID: PMC6927727 DOI: 10.1080/15384101.2019.1693118] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 10/29/2019] [Accepted: 11/07/2019] [Indexed: 01/11/2023] Open
Abstract
DNA damage can be generated in multiple ways from genotoxic and physiologic sources. Genotoxic damage is known to disrupt cellular functions and is lethal if not repaired properly. We compare the transcriptional programs activated in response to genotoxic DNA damage induced by ionizing radiation (IR) in abl pre-B cells from mice deficient in DNA damage response (DDR) genes Atm, Mre11, Mdc1, H2ax, 53bp1, and DNA-PKcs. We identified a core IR-specific transcriptional response that occurs in abl pre-B cells from WT mice and compared the response of the other genotypes to the WT response. We also identified genotype specific responses and compared those to each other. The WT response includes many processes involved in lymphocyte development and immune response, as well as responses associated with the molecular mechanisms of cancer, such as TP53 signaling. As expected, there is a range of similarity in transcriptional profiles in comparison to WT cells, with Atm-/- cells being the most different from the core WT DDR and Mre11 hypomorph (Mre11A/A) cells also very dissimilar to WT and other genotypes. For example, NF-kB-related signaling and CD40 signaling are deficient in both Atm-/- and Mre11A/A cells, but present in all other genotypes. In contrast, IR-induced TP53 signaling is seen in the Mre11A/A cells, while these responses are not seen in the Atm-/- cells. By examining the similarities and differences in the signaling pathways in response to IR when specific genes are absent, our results further illustrate the contribution of each gene to the DDR. The microarray gene expression data discussed in this paper have been deposited in NCBI's Gene Expression Omnibus (GEO) (http://www.ncbi.nlm.nih.gov/geo/) and are accessible under accession number GSE116388.
Collapse
Affiliation(s)
- Cynthia L. Innes
- Environmental Stress and Cancer Group, Division of Intramural Research, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - Jill E. Hesse
- Environmental Stress and Cancer Group, Division of Intramural Research, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - Abigail J. Morales
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - Beth A. Helmink
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - Shepherd H. Schurman
- Clinical Research Branch, Division of Intramural Research, National Institute of Environmental Health Sciences, Research Triangle Park, Durham, NC, USA
| | - Barry P. Sleckman
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - Richard S. Paules
- Environmental Stress and Cancer Group, Division of Intramural Research, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| |
Collapse
|
43
|
Beck C, Castañeda-Zegarra S, Huse C, Xing M, Oksenych V. Mediator of DNA Damage Checkpoint Protein 1 Facilitates V(D)J Recombination in Cells Lacking DNA Repair Factor XLF. Biomolecules 2019; 10:biom10010060. [PMID: 31905950 PMCID: PMC7023129 DOI: 10.3390/biom10010060] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 12/23/2019] [Accepted: 12/24/2019] [Indexed: 11/16/2022] Open
Abstract
DNA double-strand breaks (DSBs) trigger the Ataxia telangiectasia mutated (ATM)-dependent DNA damage response (DDR), which consists of histone H2AX, MDC1, RNF168, 53BP1, PTIP, RIF1, Rev7, and Shieldin. Early stages of B and T lymphocyte development are dependent on recombination activating gene (RAG)-induced DSBs that form the basis for further V(D)J recombination. Non-homologous end joining (NHEJ) pathway factors recognize, process, and ligate DSBs. Based on numerous loss-of-function studies, DDR factors were thought to be dispensable for the V(D)J recombination. In particular, mice lacking Mediator of DNA Damage Checkpoint Protein 1 (MDC1) possessed nearly wild-type levels of mature B and T lymphocytes in the spleen, thymus, and bone marrow. NHEJ factor XRCC4-like factor (XLF)/Cernunnos is functionally redundant with ATM, histone H2AX, and p53-binding protein 1 (53BP1) during the lymphocyte development in mice. Here, we genetically inactivated MDC1, XLF, or both MDC1 and XLF in murine vAbl pro-B cell lines and, using chromosomally integrated substrates, demonstrated that MDC1 stimulates the V(D)J recombination in cells lacking XLF. Moreover, combined inactivation of MDC1 and XLF in mice resulted in synthetic lethality. Together, these findings suggest that MDC1 and XLF are functionally redundant during the mouse development, in general, and the V(D)J recombination, in particular.
Collapse
Affiliation(s)
- Carole Beck
- Department of Clinical and Molecular Medicine (IKOM), Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway
- St. Olavs Hospital, Trondheim University Hospital, Clinic of Medicine, Postboks 3250 Sluppen, 7006 Trondheim, Norway
| | - Sergio Castañeda-Zegarra
- Department of Clinical and Molecular Medicine (IKOM), Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway
- St. Olavs Hospital, Trondheim University Hospital, Clinic of Medicine, Postboks 3250 Sluppen, 7006 Trondheim, Norway
| | - Camilla Huse
- Department of Clinical and Molecular Medicine (IKOM), Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway
- St. Olavs Hospital, Trondheim University Hospital, Clinic of Medicine, Postboks 3250 Sluppen, 7006 Trondheim, Norway
| | - Mengtan Xing
- Department of Clinical and Molecular Medicine (IKOM), Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway
- St. Olavs Hospital, Trondheim University Hospital, Clinic of Medicine, Postboks 3250 Sluppen, 7006 Trondheim, Norway
| | - Valentyn Oksenych
- Department of Clinical and Molecular Medicine (IKOM), Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway
- St. Olavs Hospital, Trondheim University Hospital, Clinic of Medicine, Postboks 3250 Sluppen, 7006 Trondheim, Norway
- Department of Biosciences and Nutrition (BioNuT), Karolinska Institutet, 14183 Huddinge, Sweden
- Correspondence:
| |
Collapse
|
44
|
Salvador Moreno N, Liu J, Haas KM, Parker LL, Chakraborty C, Kron SJ, Hodges K, Miller LD, Langefeld C, Robinson PJ, Lelièvre SA, Vidi PA. The nuclear structural protein NuMA is a negative regulator of 53BP1 in DNA double-strand break repair. Nucleic Acids Res 2019; 47:2703-2715. [PMID: 30812030 PMCID: PMC6451129 DOI: 10.1093/nar/gkz138] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 02/09/2019] [Accepted: 02/18/2019] [Indexed: 01/13/2023] Open
Abstract
P53-binding protein 1 (53BP1) mediates DNA repair pathway choice and promotes checkpoint activation. Chromatin marks induced by DNA double-strand breaks and recognized by 53BP1 enable focal accumulation of this multifunctional repair factor at damaged chromatin. Here, we unveil an additional level of regulation of 53BP1 outside repair foci. 53BP1 movements are constrained throughout the nucleoplasm and increase in response to DNA damage. 53BP1 interacts with the structural protein NuMA, which controls 53BP1 diffusion. This interaction, and colocalization between the two proteins in vitro and in breast tissues, is reduced after DNA damage. In cell lines and breast carcinoma NuMA prevents 53BP1 accumulation at DNA breaks, and high NuMA expression predicts better patient outcomes. Manipulating NuMA expression alters PARP inhibitor sensitivity of BRCA1-null cells, end-joining activity, and immunoglobulin class switching that rely on 53BP1. We propose a mechanism involving the sequestration of 53BP1 by NuMA in the absence of DNA damage. Such a mechanism may have evolved to disable repair functions and may be a decisive factor for tumor responses to genotoxic treatments.
Collapse
Affiliation(s)
- Naike Salvador Moreno
- Department of Cancer Biology, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | - Jing Liu
- Department of Physics, Indiana university-Purdue University Indianapolis, Indianapolis, IN 46202, USA
| | - Karen M Haas
- Department of Microbiology and Immunology, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | - Laurie L Parker
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Saint Paul, MN 55108, USA
| | - Chaitali Chakraborty
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA
| | - Stephen J Kron
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA
| | - Kurt Hodges
- Department of Pathology and Laboratory Medicine, University of Cincinnati, Cincinnati, OH 45219, USA
| | - Lance D Miller
- Department of Cancer Biology, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA.,Comprehensive Cancer Center of Wake Forest University
| | - Carl Langefeld
- Comprehensive Cancer Center of Wake Forest University.,Department of Biostatistical Sciences, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | - Paul J Robinson
- Department of Basic Medical Sciences and Center for Cancer Research, Purdue University, West Lafayette, IN 47907, USA
| | - Sophie A Lelièvre
- Department of Basic Medical Sciences and Center for Cancer Research, Purdue University, West Lafayette, IN 47907, USA
| | - Pierre-Alexandre Vidi
- Department of Cancer Biology, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA.,Comprehensive Cancer Center of Wake Forest University
| |
Collapse
|
45
|
Polyphenols: Major regulators of key components of DNA damage response in cancer. DNA Repair (Amst) 2019; 82:102679. [DOI: 10.1016/j.dnarep.2019.102679] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Revised: 07/27/2019] [Accepted: 07/27/2019] [Indexed: 02/06/2023]
|
46
|
Densham RM, Morris JR. Moving Mountains-The BRCA1 Promotion of DNA Resection. Front Mol Biosci 2019; 6:79. [PMID: 31552267 PMCID: PMC6733915 DOI: 10.3389/fmolb.2019.00079] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 08/20/2019] [Indexed: 12/26/2022] Open
Abstract
DNA double-strand breaks (DSBs) occur in our cells in the context of chromatin. This type of lesion is toxic, entirely preventing genome continuity and causing cell death or terminal arrest. Several repair mechanisms can act on DNA surrounding a DSB, only some of which carry a low risk of mutation, so that which repair process is utilized is critical to the stability of genetic material of cells. A key component of repair outcome is the degree of DNA resection directed to either side of the break site. This in turn determines the subsequent forms of repair in which DNA homology plays a part. Here we will focus on chromatin and chromatin-bound complexes which constitute the "mountains" that block resection, with a particular focus on how the breast and ovarian cancer predisposition protein-1 (BRCA1) contributes to repair outcomes through overcoming these blocks.
Collapse
Affiliation(s)
| | - Joanna R. Morris
- Birmingham Centre for Genome Biology, Institute of Cancer and Genomic Sciences, Medical and Dental Schools, University of Birmingham, Birmingham, United Kingdom
| |
Collapse
|
47
|
Arnould C, Legube G. The Secret Life of Chromosome Loops upon DNA Double-Strand Break. J Mol Biol 2019; 432:724-736. [PMID: 31401119 PMCID: PMC7057266 DOI: 10.1016/j.jmb.2019.07.036] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 07/24/2019] [Accepted: 07/30/2019] [Indexed: 12/22/2022]
Abstract
DNA double-strand breaks (DSBs) are harmful lesions that severely challenge genomic integrity, and recent evidence suggests that DSBs occur more frequently on the genome than previously thought. These lesions activate a complex and multilayered response called the DNA damage response, which allows to coordinate their repair with the cell cycle progression. While the mechanistic details of repair processes have been narrowed, thanks to several decades of intense studies, our knowledge of the impact of DSB on chromatin composition and chromosome architecture is still very sparse. However, the recent development of various tools to induce DSB at annotated loci, compatible with next-generation sequencing-based approaches, is opening a new framework to tackle these questions. Here we discuss the influence of initial and DSB-induced chromatin conformation and the strong potential of 3C-based technologies to decipher the contribution of chromosome architecture during DSB repair.
Collapse
Affiliation(s)
- Coline Arnould
- LBCMCP, Centre de Biologie Integrative (CBI), CNRS, Université de Toulouse, UT3, Toulouse, France
| | - Gaëlle Legube
- LBCMCP, Centre de Biologie Integrative (CBI), CNRS, Université de Toulouse, UT3, Toulouse, France.
| |
Collapse
|
48
|
Cadmium disrupts the DNA damage response by destabilizing RNF168. Food Chem Toxicol 2019; 133:110745. [PMID: 31376412 DOI: 10.1016/j.fct.2019.110745] [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: 05/09/2019] [Revised: 07/30/2019] [Accepted: 07/30/2019] [Indexed: 01/01/2023]
Abstract
Cadmium (Cd) is a dispensable element for the human body and is usually considered a carcinogen. Occupational and environmental Cd exposure leads to sustained cellular proliferation in some tissues and tumorigenesis via an unclear mechanism. Here, we evaluated the role of Cd in the DNA damage response (DDR). We found that Cd exposure causes extensive DNA double-strand breaks (DSBs) and prevents accumulation of ubiquitination signals at these sites of DNA damage. Cd treatment compromises 53BP1 and BRCA1 recruitment to DSBs induced by itself or DNA damaging agents and partially inactivates the G2/M checkpoint. Mechanistically, Cd directly binds to the E3 ubiquitin ligase RNF168, induces the ubiquitin-proteasome pathway that mediates RNF168 degradation and suppresses RNF168 ubiquitin-ligase activity in vitro. Our study raises the possibility that Cd may target RNF168 to disrupt proper DSB signaling in cultured cells. This pathway may represent a novel mechanism for carcinogenesis induced by Cd.
Collapse
|
49
|
Luo Y, Liu Y, Wu L, Ma X, Liu Q, Huang F, Zhang X, Zhang Y, Zhang J, Luo H, Yang Y, Lu G, Tang X, Li L, Zeng Y, Pan T, Zhang H. CUL7 E3 Ubiquitin Ligase Mediates the Degradation of Activation-Induced Cytidine Deaminase and Regulates the Ig Class Switch Recombination in B Lymphocytes. THE JOURNAL OF IMMUNOLOGY 2019; 203:269-281. [PMID: 31092637 DOI: 10.4049/jimmunol.1900125] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 04/18/2019] [Indexed: 12/17/2022]
Abstract
Activation-induced cytidine deaminase (AID) initiates class switch recombination and somatic hypermutation in Ig genes. The activity and protein levels of AID are tightly controlled by various mechanisms. In this study, we found that CUL7 E3 ubiquitin ligases specifically mediated AID ubiquitination. CUL7 overexpression or knockdown influenced the decay of AID, affecting AID protein levels and subsequently IgA class switching in CH12F3 cells, a mouse B lymphocyte cell line. Further analysis indicated that CUL7 mediated AID ubiquitination by forming a complex with FBXW11. In a CUL7 fl/fl CD19 cre+ mouse model, we demonstrated that CUL7 knockout significantly enhanced AID protein levels in B cells in the germinal center and increased both the IgG1 and IgA class switching. Collectively, our results reveal a subtle regulation mechanism for tightly controlling AID protein levels. The manipulation of this pathway may be useful for regulating AID abundance and efficiency of Ig class switching and is therefore a potential target for developing immunologic adjuvants for vaccines of various pathogens such as HIV-1 and influenza viruses.
Collapse
Affiliation(s)
- Yuewen Luo
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.,Key Laboratory of Tropical Disease Control of Ministry of Education, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.,Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Yang Liu
- Department of Experimental Research, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Guangzhou 510060, China
| | - Liyang Wu
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.,Key Laboratory of Tropical Disease Control of Ministry of Education, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.,Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Xiancai Ma
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.,Key Laboratory of Tropical Disease Control of Ministry of Education, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.,Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Qin Liu
- Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Stomatology, Guangzhou 510060, Guangdong, China
| | - Feng Huang
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.,Key Laboratory of Tropical Disease Control of Ministry of Education, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.,Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.,Department of Respiration, Affiliated Guangzhou Women and Children's Hospital, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China; and
| | - Xu Zhang
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.,Key Laboratory of Tropical Disease Control of Ministry of Education, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.,Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Yiwen Zhang
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.,Key Laboratory of Tropical Disease Control of Ministry of Education, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.,Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Junsong Zhang
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.,Key Laboratory of Tropical Disease Control of Ministry of Education, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.,Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Haihua Luo
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.,Key Laboratory of Tropical Disease Control of Ministry of Education, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.,Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Yanyan Yang
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Gen Lu
- Department of Respiration, Affiliated Guangzhou Women and Children's Hospital, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China; and
| | - Xiaoping Tang
- Department of Infectious Diseases, Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou 510060, China
| | - Linghua Li
- Department of Infectious Diseases, Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou 510060, China
| | - Yixin Zeng
- Department of Experimental Research, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Guangzhou 510060, China
| | - Ting Pan
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; .,Key Laboratory of Tropical Disease Control of Ministry of Education, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.,Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Hui Zhang
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; .,Key Laboratory of Tropical Disease Control of Ministry of Education, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.,Guangdong Engineering Research Center for Antimicrobial Agent and Immunotechnology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| |
Collapse
|
50
|
Setiaputra D, Durocher D. Shieldin - the protector of DNA ends. EMBO Rep 2019; 20:embr.201847560. [PMID: 30948458 DOI: 10.15252/embr.201847560] [Citation(s) in RCA: 143] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 01/26/2019] [Accepted: 02/06/2019] [Indexed: 12/29/2022] Open
Abstract
DNA double-strand breaks are a threat to genome integrity and cell viability. The nucleolytic processing of broken DNA ends plays a central role in dictating the repair processes that will mend these lesions. Usually, DNA end resection promotes repair by homologous recombination, whereas minimally processed ends are repaired by non-homologous end joining. Important in this process is the chromatin-binding protein 53BP1, which inhibits DNA end resection. How 53BP1 shields DNA ends from nucleases has been an enduring mystery. The recent discovery of shieldin, a four-subunit protein complex with single-stranded DNA-binding activity, illuminated a strong candidate for the ultimate effector of 53BP1-dependent end protection. Shieldin consists of REV7, a known 53BP1-pathway component, and three hitherto uncharacterized proteins: C20orf196 (SHLD1), FAM35A (SHLD2), and CTC-534A2.2 (SHLD3). Shieldin promotes many 53BP1-associated activities, such as the protection of DNA ends, non-homologous end joining, and immunoglobulin class switching. This review summarizes the identification of shieldin and the various models of shieldin action and highlights some outstanding questions requiring answers to gain a full molecular understanding of shieldin function.
Collapse
Affiliation(s)
- Dheva Setiaputra
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada
| | - Daniel Durocher
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada .,Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| |
Collapse
|