1
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Ceppi I, Dello Stritto MR, Mütze M, Braunshier S, Mengoli V, Reginato G, Võ HMP, Jimeno S, Acharya A, Roy M, Sanchez A, Halder S, Howard SM, Guérois R, Huertas P, Noordermeer SM, Seidel R, Cejka P. Mechanism of BRCA1-BARD1 function in DNA end resection and DNA protection. Nature 2024:10.1038/s41586-024-07909-9. [PMID: 39261728 DOI: 10.1038/s41586-024-07909-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 08/05/2024] [Indexed: 09/13/2024]
Abstract
DNA double-strand break (DSB) repair by homologous recombination is initiated by DNA end resection, a process involving the controlled degradation of the 5'-terminated strands at DSB sites1,2. The breast cancer suppressor BRCA1-BARD1 not only promotes resection and homologous recombination, but it also protects DNA upon replication stress1,3-9. BRCA1-BARD1 counteracts the anti-resection and pro-non-homologous end-joining factor 53BP1, but whether it functions in resection directly has been unclear10-16. Using purified recombinant proteins, we show here that BRCA1-BARD1 directly promotes long-range DNA end resection pathways catalysed by the EXO1 or DNA2 nucleases. In the DNA2-dependent pathway, BRCA1-BARD1 stimulates DNA unwinding by the Werner or Bloom helicase. Together with MRE11-RAD50-NBS1 and phosphorylated CtIP, BRCA1-BARD1 forms the BRCA1-C complex17,18, which stimulates resection synergistically to an even greater extent. A mutation in phosphorylated CtIP (S327A), which disrupts its binding to the BRCT repeats of BRCA1 and hence the integrity of the BRCA1-C complex19-21, inhibits resection, showing that BRCA1-C is a functionally integrated ensemble. Whereas BRCA1-BARD1 stimulates resection in DSB repair, it paradoxically also protects replication forks from unscheduled degradation upon stress, which involves a homologous recombination-independent function of the recombinase RAD51 (refs. 4-6,8). We show that in the presence of RAD51, BRCA1-BARD1 instead inhibits DNA degradation. On the basis of our data, the presence and local concentration of RAD51 might determine the balance between the pronuclease and the DNA protection functions of BRCA1-BARD1 in various physiological contexts.
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Affiliation(s)
- Ilaria Ceppi
- Institute for Research in Biomedicine, Università della Svizzera italiana (USI), Faculty of Biomedical Sciences, Bellinzona, Switzerland
| | - Maria Rosaria Dello Stritto
- Institute for Research in Biomedicine, Università della Svizzera italiana (USI), Faculty of Biomedical Sciences, Bellinzona, Switzerland
| | - Martin Mütze
- Peter Debye Institute for Soft Matter Physics, Universität Leipzig, Leipzig, Germany
| | - Stefan Braunshier
- Institute for Research in Biomedicine, Università della Svizzera italiana (USI), Faculty of Biomedical Sciences, Bellinzona, Switzerland
| | - Valentina Mengoli
- Institute for Research in Biomedicine, Università della Svizzera italiana (USI), Faculty of Biomedical Sciences, Bellinzona, Switzerland
| | - Giordano Reginato
- Institute for Research in Biomedicine, Università della Svizzera italiana (USI), Faculty of Biomedical Sciences, Bellinzona, Switzerland
| | - Hồ Mỹ Phúc Võ
- Leiden University Medical Center, Leiden, the Netherlands
- Oncode Institute, Utrecht, the Netherlands
| | - Sonia Jimeno
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Sevilla, Spain
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Sevilla, Spain
| | - Ananya Acharya
- Institute for Research in Biomedicine, Università della Svizzera italiana (USI), Faculty of Biomedical Sciences, Bellinzona, Switzerland
| | - Megha Roy
- Institute for Research in Biomedicine, Università della Svizzera italiana (USI), Faculty of Biomedical Sciences, Bellinzona, Switzerland
| | - Aurore Sanchez
- Institute for Research in Biomedicine, Università della Svizzera italiana (USI), Faculty of Biomedical Sciences, Bellinzona, Switzerland
- Institut Curie, Paris Sciences and Lettres University, Sorbonne Université, CNRS UMR 3244, Dynamics of Genetic Information, Paris, France
| | - Swagata Halder
- Institute for Research in Biomedicine, Università della Svizzera italiana (USI), Faculty of Biomedical Sciences, Bellinzona, Switzerland
- Biological Systems Engineering, Plaksha University, Mohali, India
| | - Sean Michael Howard
- Institute for Research in Biomedicine, Università della Svizzera italiana (USI), Faculty of Biomedical Sciences, Bellinzona, Switzerland
- Department of Mechanical and Biomedical Engineering, Boise State University, Boise, ID, USA
| | - Raphaël Guérois
- Institute for Integrative Biology of the Cell (I2BC), Commissariat à l'Energie Atomique, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Pablo Huertas
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Sevilla, Spain
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Sevilla, Spain
| | - Sylvie M Noordermeer
- Leiden University Medical Center, Leiden, the Netherlands
- Oncode Institute, Utrecht, the Netherlands
| | - Ralf Seidel
- Peter Debye Institute for Soft Matter Physics, Universität Leipzig, Leipzig, Germany
| | - Petr Cejka
- Institute for Research in Biomedicine, Università della Svizzera italiana (USI), Faculty of Biomedical Sciences, Bellinzona, Switzerland.
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2
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Li S, Tang M, Xiong Y, Feng X, Wang C, Nie L, Huang M, Zhang H, Yin L, Zhu D, Yang C, Ma T, Chen J. Systematic investigation of BRCA1-A, -B, and -C complexes and their functions in DNA damage response and DNA repair. Oncogene 2024; 43:2621-2634. [PMID: 39068216 DOI: 10.1038/s41388-024-03108-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 07/14/2024] [Accepted: 07/16/2024] [Indexed: 07/30/2024]
Abstract
BRCA1, a breast cancer susceptibility gene, has emerged as a central mediator that brings together multiple signaling complexes in response to DNA damage. The A, B, and C complexes of BRCA1, which are formed based on their phosphorylation-dependent interactions with the BRCA1-C-terminal domains, contribute to the roles of BRCA1 in DNA repair and cell cycle checkpoint control. However, their functions in DNA damage response remain to be fully appreciated. Specifically, there has been no systematic investigation of the roles of BRCA1-A, -B, and -C complexes in the regulation of BRCA1 localization and functions, in part because of cellular lethality associated with loss of CtIP protein, which is an essential component in BRCA1-C complex. To systematically investigate the functions of these complexes in DNA damage response, we depleted a key component in each of these complexes. We used the degradation tag system to inducibly deplete endogenous CtIP and obtained a series of RAP80/FANCJ/CtIP single-, double-, and triple-knockout cells. We showed that loss of BRCA1-B/FANCJ and BRCA1-C/CtIP, but not BRCA1-A/RAP80, resulted in reduced cell proliferation and increased sensitivity to DNA damage. BRCA1-C/CtIP and BRCA1-A/RAP80 were involved in BRCA1 recruitment to sites of DNA damage. However, BRCA1-A/RAP80 was not essential for damage-induced BRCA1 localization. Instead, RAP80/H2AX and CtIP have redundant roles in BRCA1 recruitment. Altogether, our systematic analysis uncovers functional differences between BRCA1-A, -B, and -C complexes and provides new insights into the roles of these BRCA1-associated protein complexes in DNA damage response and DNA repair.
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Affiliation(s)
- Siting Li
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Mengfan Tang
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Department of Immunology, School of Medicine, Nanjing University of Chinese Medicine, Nanjing, China
| | - Yun Xiong
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Xu Feng
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Chao Wang
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Litong Nie
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Min Huang
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Huimin Zhang
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Ling Yin
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Dandan Zhu
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Chang Yang
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Tiantian Ma
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Junjie Chen
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
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3
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Georgieva D, Wang N, Taglialatela A, Jerabek S, Reczek CR, Lim PX, Sung J, Du Q, Horiguchi M, Jasin M, Ciccia A, Baer R, Egli D. BRCA1 and 53BP1 regulate reprogramming efficiency by mediating DNA repair pathway choice at replication-associated double-strand breaks. Cell Rep 2024; 43:114006. [PMID: 38554279 PMCID: PMC11272184 DOI: 10.1016/j.celrep.2024.114006] [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: 02/26/2023] [Revised: 11/26/2023] [Accepted: 03/11/2024] [Indexed: 04/01/2024] Open
Abstract
Reprogramming to pluripotency is associated with DNA damage and requires the functions of the BRCA1 tumor suppressor. Here, we leverage separation-of-function mutations in BRCA1/2 as well as the physical and/or genetic interactions between BRCA1 and its associated repair proteins to ascertain the relevance of homology-directed repair (HDR), stalled fork protection (SFP), and replication gap suppression (RGS) in somatic cell reprogramming. Surprisingly, loss of SFP and RGS is inconsequential for the transition to pluripotency. In contrast, cells deficient in HDR, but proficient in SFP and RGS, reprogram with reduced efficiency. Conversely, the restoration of HDR function through inactivation of 53bp1 rescues reprogramming in Brca1-deficient cells, and 53bp1 loss leads to elevated HDR and enhanced reprogramming in mouse and human cells. These results demonstrate that somatic cell reprogramming is especially dependent on repair of replication-associated double-strand breaks (DSBs) by the HDR activity of BRCA1 and BRCA2 and can be improved in the absence of 53BP1.
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Affiliation(s)
- Daniela Georgieva
- Department of Pediatrics and Naomi Berrie Diabetes Center, Columbia University Irving Medical Center, New York, NY 10032, USA; Columbia University Stem Cell Initiative, New York, NY 10032, USA
| | - Ning Wang
- Department of Pediatrics and Naomi Berrie Diabetes Center, Columbia University Irving Medical Center, New York, NY 10032, USA; Columbia University Stem Cell Initiative, New York, NY 10032, USA
| | - Angelo Taglialatela
- Columbia University Stem Cell Initiative, New York, NY 10032, USA; Department of Genetics and Development, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Stepan Jerabek
- Department of Pediatrics and Naomi Berrie Diabetes Center, Columbia University Irving Medical Center, New York, NY 10032, USA; Columbia University Stem Cell Initiative, New York, NY 10032, USA; Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo namesti 542/2, 160 00 Praha 6, Czech Republic
| | - Colleen R Reczek
- Department of Pathology & Cell Biology, Institute for Cancer Genetics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Pei Xin Lim
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Julie Sung
- Department of Pediatrics and Naomi Berrie Diabetes Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Qian Du
- Department of Pediatrics and Naomi Berrie Diabetes Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Michiko Horiguchi
- Department of Pathology & Cell Biology, Institute for Cancer Genetics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Maria Jasin
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Alberto Ciccia
- Columbia University Stem Cell Initiative, New York, NY 10032, USA; Department of Genetics and Development, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Richard Baer
- Department of Pathology & Cell Biology, Institute for Cancer Genetics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Dieter Egli
- Department of Pediatrics and Naomi Berrie Diabetes Center, Columbia University Irving Medical Center, New York, NY 10032, USA; Columbia University Stem Cell Initiative, New York, NY 10032, USA; Department of Obstetrics and Gynecology, Columbia University Irving Medical Center, New York, NY 10032, USA.
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4
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Wu-Baer F, Wong M, Tschoe L, Lin CS, Jiang W, Zha S, Baer R. ATM/ATR Phosphorylation of CtIP on Its Conserved Sae2-like Domain Is Required for Genotoxin-Induced DNA Resection but Dispensable for Animal Development. Cells 2023; 12:2762. [PMID: 38067190 PMCID: PMC10706839 DOI: 10.3390/cells12232762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 11/09/2023] [Accepted: 12/01/2023] [Indexed: 12/18/2023] Open
Abstract
Homology-directed repair (HDR) of double-strand DNA breaks (DSBs) is dependent on enzymatic resection of DNA ends by the Mre11/Rad50/Nbs1 complex. DNA resection is triggered by the CtIP/Sae2 protein, which allosterically promotes Mre11-mediated endonuclease DNA cleavage at a position internal to the DSB. Although the mechanics of resection, including the initial endonucleolytic step, are largely conserved in eucaryotes, CtIP and its functional counterpart in Saccharomyces cerevisiae (Sae2) share only a modest stretch of amino acid homology. Nonetheless, this stretch contains two highly conserved phosphorylation sites for cyclin-dependent kinases (T843 in mouse) and the damage-induced ATM/ATR kinases (T855 in mouse), both of which are required for DNA resection. To explore the function of ATM/ATR phosphorylation at Ctip-T855, we generated and analyzed mice expressing the Ctip-T855A mutant. Surprisingly, unlike Ctip-null mice and Ctip-T843A-expressing mice, both of which undergo embryonic lethality, homozygous CtipT855A/T855A mice develop normally. Nonetheless, they are hypersensitive to ionizing radiation, and CtipT855A/T855A mouse embryo fibroblasts from these mice display marked defects in DNA resection, chromosomal stability, and HDR-mediated repair of DSBs. Thus, although ATM/ATR phosphorylation of CtIP-T855 is not required for normal animal development, it enhances CtIP-mediated DNA resection in response to acute stress, such as genotoxin exposure.
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Affiliation(s)
- Foon Wu-Baer
- Institute for Cancer Genetics, Columbia University Irving Medical Center, New York, NY 10032, USA; (F.W.-B.); (M.W.); (L.T.); (W.J.); (S.Z.)
- Department of Pathology & Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA;
| | - Madeline Wong
- Institute for Cancer Genetics, Columbia University Irving Medical Center, New York, NY 10032, USA; (F.W.-B.); (M.W.); (L.T.); (W.J.); (S.Z.)
- Department of Pathology & Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA;
| | - Lydia Tschoe
- Institute for Cancer Genetics, Columbia University Irving Medical Center, New York, NY 10032, USA; (F.W.-B.); (M.W.); (L.T.); (W.J.); (S.Z.)
- Department of Pathology & Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA;
| | - Chyuan-Sheng Lin
- Department of Pathology & Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA;
- Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Wenxia Jiang
- Institute for Cancer Genetics, Columbia University Irving Medical Center, New York, NY 10032, USA; (F.W.-B.); (M.W.); (L.T.); (W.J.); (S.Z.)
- Department of Pathology & Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA;
- Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Shan Zha
- Institute for Cancer Genetics, Columbia University Irving Medical Center, New York, NY 10032, USA; (F.W.-B.); (M.W.); (L.T.); (W.J.); (S.Z.)
- Department of Pathology & Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA;
- Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032, USA
- Department of Pediatrics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Richard Baer
- Institute for Cancer Genetics, Columbia University Irving Medical Center, New York, NY 10032, USA; (F.W.-B.); (M.W.); (L.T.); (W.J.); (S.Z.)
- Department of Pathology & Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA;
- Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032, USA
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5
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Ayala-Zambrano C, Yuste M, Frias S, Garcia-de-Teresa B, Mendoza L, Azpeitia E, Rodríguez A, Torres L. A Boolean network model of the double-strand break repair pathway choice. J Theor Biol 2023; 573:111608. [PMID: 37595867 DOI: 10.1016/j.jtbi.2023.111608] [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: 04/11/2023] [Revised: 07/29/2023] [Accepted: 08/09/2023] [Indexed: 08/20/2023]
Abstract
Double strand break (DSB) repair is critical to maintaining the integrity of the genome. DSB repair deficiency underlies multiple pathologies, including cancer, chromosome instability syndromes, and, potentially, neurodevelopmental defects. DSB repair is mainly handled by two pathways: highly accurate homologous recombination (HR), which requires a sister chromatid for template-based repair, limited to S/G2 phases of the cell cycle, and canonical non-homologous end joining (c-NHEJ), available throughout the cell cycle in which minimum homology is sufficient for highly efficient yet error-prone repair. Some circumstances, such as cancer, require alternative highly mutagenic DSB repair pathways like microhomology-mediated end-joining (MMEJ) and single-strand annealing (SSA), which are triggered to attend to DNA damage. These non-canonical repair alternatives are emerging as prominent drivers of resistance in drug-based tumor therapies. Multiple DSB repair options require tight inter-pathway regulation to prevent unscheduled activities. In addition to this complexity, epigenetic modifications of the histones surrounding the DSB region are emerging as critical regulators of the DSB repair pathway choice. Modeling approaches to understanding DSBs repair pathway choice are advantageous to perform simulations and generate predictions on previously uncharacterized aspects of DSBs response. In this work, we present a Boolean network model of the DSB repair pathway choice that incorporates the knowledge, into a dynamic system, of the inter-pathways regulation involved in DSB repair, i.e., HR, c-NHEJ, SSA, and MMEJ. Our model recapitulates the well-characterized HR activity observed in wild-type cells in response to DSBs. It also recovers clinically relevant behaviors of BRCA1/FANCS mutants, and their corresponding drug resistance mechanisms ascribed to DNA repair gain-of-function pathogenic variants. Since epigenetic modifiers are dynamic and possible druggable targets, we incorporated them into our model to better characterize their involvement in DSB repair. Our model predicted that loss of the TIP60 complex and its corresponding histone acetylation activity leads to activation of SSA in response to DSBs. Our experimental validation showed that TIP60 effectively prevents activation of RAD52, a key SSA executor, and confirms the suitable use of Boolean network modeling for understanding DNA DSB repair.
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Affiliation(s)
- Cecilia Ayala-Zambrano
- Laboratorio de Citogenética, Instituto Nacional de Pediatría, Ciudad de México 04530, Mexico; Posgrado en Ciencias Biológicas, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
| | - Mariana Yuste
- Centro de Ciencias Matemáticas, Universidad Nacional Autónoma de México, Morelia, Mexico
| | - Sara Frias
- Laboratorio de Citogenética, Instituto Nacional de Pediatría, Ciudad de México 04530, Mexico; Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Apartado Postal 70228, Ciudad de México 04510, Mexico
| | | | - Luis Mendoza
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Apartado Postal 70228, Ciudad de México 04510, Mexico
| | - Eugenio Azpeitia
- Centro de Ciencias Matemáticas, Universidad Nacional Autónoma de México, Morelia, Mexico
| | - Alfredo Rodríguez
- Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Apartado Postal 70228, Ciudad de México 04510, Mexico; Instituto Nacional de Pediatría, Ciudad de México 04530, Mexico.
| | - Leda Torres
- Laboratorio de Citogenética, Instituto Nacional de Pediatría, Ciudad de México 04530, Mexico.
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6
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Regulation of BRCA1 stability through the tandem UBX domains of isoleucyl-tRNA synthetase 1. Nat Commun 2022; 13:6732. [PMID: 36347866 PMCID: PMC9643514 DOI: 10.1038/s41467-022-34612-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 10/27/2022] [Indexed: 11/11/2022] Open
Abstract
Aminoacyl-tRNA synthetases (ARSs) have evolved to acquire various additional domains. These domains allow ARSs to communicate with other cellular proteins in order to promote non-translational functions. Vertebrate cytoplasmic isoleucyl-tRNA synthetases (IARS1s) have an uncharacterized unique domain, UNE-I. Here, we present the crystal structure of the chicken IARS1 UNE-I complexed with glutamyl-tRNA synthetase 1 (EARS1). UNE-I consists of tandem ubiquitin regulatory X (UBX) domains that interact with a distinct hairpin loop on EARS1 and protect its neighboring proteins in the multi-synthetase complex from degradation. Phosphomimetic mutation of the two serine residues in the hairpin loop releases IARS1 from the complex. IARS1 interacts with BRCA1 in the nucleus, regulates its stability by inhibiting ubiquitylation via the UBX domains, and controls DNA repair function.
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7
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Abate NG, Hendzel MJ. Heterogeneity of Organization of Subcompartments in DSB Repair Foci. Front Genet 2022; 13:887088. [PMID: 35923694 PMCID: PMC9340495 DOI: 10.3389/fgene.2022.887088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 05/26/2022] [Indexed: 11/13/2022] Open
Abstract
Cells assemble compartments around DNA double-strand breaks (DSBs). The assembly of this compartment is dependent on the phosphorylation of histone H2AX, the binding of MDC1 to phosphorylated H2AX, and the assembly of downstream signaling and repair components. The decision on whether to use homologous recombination or nonhomologous end-joining repair depends on competition between 53BP1 and BRCA1. A major point of control appears to be DNA replication and associated changes in the epigenetic state. This includes dilution of histone H4 dimethylation and an increase in acetylation of lysine residues on H2A and H4 that impair 53BP1 binding. In this article, we examined more closely the spatial relationship between 53BP1 and BRCA1 within the cell cycle. We find that 53BP1 can associate with early S-phase replicated chromatin and that the relative concentration of BRCA1 in DSB-associated compartments correlates with increased BRCA1 nuclear abundance as cells progress into and through S phase. In most cases during S phase, both BRCA1 and 53BP1 are recruited to these compartments. This occurs for both IR-induced DSBs and breaks targeted to an integrated LacO array through a LacI-Fok1-mCherry fusion protein. Having established that the array system replicates this heterogeneity, we further examined the spatial relationship between DNA repair components. This enabled us to precisely locate the DNA containing the break and map other proteins relative to that DNA. We find evidence for at least three subcompartments. The damaged DNA, single-stranded DNA generated from end resection of the array, and nuclease CtIP all localized to the center of the compartment. BRCA1 and 53BP1 largely occupied discrete regions of the focus. One of BRCA1 or 53BP1 overlaps with the array, while the other is more peripherally located. The array-overlapping protein occupied a larger volume than the array, CtIP, or single-stranded DNA (ssDNA). Rad51 often occupied a much larger volume than the array itself and was sometimes observed to be depleted in the array volume where the ssDNA exclusively localizes. These results highlight the complexity of molecular compartmentalization within DSB repair compartments.
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8
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Kissling VM, Reginato G, Bianco E, Kasaciunaite K, Tilma J, Cereghetti G, Schindler N, Lee SS, Guérois R, Luke B, Seidel R, Cejka P, Peter M. Mre11-Rad50 oligomerization promotes DNA double-strand break repair. Nat Commun 2022; 13:2374. [PMID: 35501303 PMCID: PMC9061753 DOI: 10.1038/s41467-022-29841-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 04/01/2022] [Indexed: 11/08/2022] Open
Abstract
The conserved Mre11-Rad50 complex is crucial for the detection, signaling, end tethering and processing of DNA double-strand breaks. While it is known that Mre11-Rad50 foci formation at DNA lesions accompanies repair, the underlying molecular assembly mechanisms and functional implications remained unclear. Combining pathway reconstitution in electron microscopy, biochemical assays and genetic studies, we show that S. cerevisiae Mre11-Rad50 with or without Xrs2 forms higher-order assemblies in solution and on DNA. Rad50 mediates such oligomerization, and mutations in a conserved Rad50 beta-sheet enhance or disrupt oligomerization. We demonstrate that Mre11-Rad50-Xrs2 oligomerization facilitates foci formation, DNA damage signaling, repair, and telomere maintenance in vivo. Mre11-Rad50 oligomerization does not affect its exonuclease activity but drives endonucleolytic cleavage at multiple sites on the 5'-DNA strand near double-strand breaks. Interestingly, mutations in the human RAD50 beta-sheet are linked to hereditary cancer predisposition and our findings might provide insights into their potential role in chemoresistance.
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Affiliation(s)
- Vera M Kissling
- Department of Biology, Institute of Biochemistry, Eidgenössische Technische Hochschule (ETH), 8093, Zürich, Switzerland
| | - Giordano Reginato
- Department of Biology, Institute of Biochemistry, Eidgenössische Technische Hochschule (ETH), 8093, Zürich, Switzerland
- Institute for Research in Biomedicine, Università della Svizzera italiana (USI), Faculty of Biomedical Sciences, 6500, Bellinzona, Switzerland
| | - Eliana Bianco
- Department of Biology, Institute of Biochemistry, Eidgenössische Technische Hochschule (ETH), 8093, Zürich, Switzerland
| | - Kristina Kasaciunaite
- Peter Debye Institute for Soft Matter Physics, Universität Leipzig, 04103, Leipzig, Germany
| | - Janny Tilma
- Department of Biology, Institute of Biochemistry, Eidgenössische Technische Hochschule (ETH), 8093, Zürich, Switzerland
| | - Gea Cereghetti
- Department of Biology, Institute of Biochemistry, Eidgenössische Technische Hochschule (ETH), 8093, Zürich, Switzerland
| | - Natalie Schindler
- Institute for Developmental and Neurobiology (IDN), Johannes Gutenberg University, 55128, Mainz, Germany
| | - Sung Sik Lee
- Department of Biology, Institute of Biochemistry, Eidgenössische Technische Hochschule (ETH), 8093, Zürich, Switzerland
- Scientific Center for Optical and Electron Microscopy, Eidgenössische Technische Hochschule (ETH), 8093, Zürich, Switzerland
| | - Raphaël Guérois
- Institute for Integrative Biology of the Cell (I2BC), Commissariat à l'Energie Atomique, CNRS, Université Paris-Sud, Université Paris-Saclay, 91190, Gif-sur-Yvette, France
| | - Brian Luke
- Institute for Developmental and Neurobiology (IDN), Johannes Gutenberg University, 55128, Mainz, Germany
- Institute of Molecular Biology (IMB), 55128, Mainz, Germany
| | - Ralf Seidel
- Peter Debye Institute for Soft Matter Physics, Universität Leipzig, 04103, Leipzig, Germany
| | - Petr Cejka
- Department of Biology, Institute of Biochemistry, Eidgenössische Technische Hochschule (ETH), 8093, Zürich, Switzerland.
- Institute for Research in Biomedicine, Università della Svizzera italiana (USI), Faculty of Biomedical Sciences, 6500, Bellinzona, Switzerland.
| | - Matthias Peter
- Department of Biology, Institute of Biochemistry, Eidgenössische Technische Hochschule (ETH), 8093, Zürich, Switzerland.
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9
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Park D, Gharghabi M, Reczek CR, Plow R, Yungvirt C, Aldaz CM, Huebner K. Wwox Binding to the Murine Brca1-BRCT Domain Regulates Timing of Brip1 and CtIP Phospho-Protein Interactions with This Domain at DNA Double-Strand Breaks, and Repair Pathway Choice. Int J Mol Sci 2022; 23:ijms23073729. [PMID: 35409089 PMCID: PMC8999063 DOI: 10.3390/ijms23073729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 03/21/2022] [Accepted: 03/24/2022] [Indexed: 11/16/2022] Open
Abstract
Wwox-deficient human cells show elevated homologous recombination, leading to resistance to killing by double-strand break-inducing agents. Human Wwox binds to the Brca1 981-PPLF-984 Wwox-binding motif, likely blocking the pChk2 phosphorylation site at Brca1-S988. This phosphorylation site is conserved across mammalian species; the PPLF motif is conserved in primates but not in rodents. We now show that murine Wwox does not bind Brca1 near the conserved mouse Brca1 phospho-S971 site, leaving it open for Chk2 phosphorylation and Brca1 activation. Instead, murine Wwox binds to Brca1 through its BRCT domain, where pAbraxas, pBrip1, and pCtIP, of the A, B, and C binding complexes, interact to regulate double-strand break repair pathway response. In Wwox-deficient mouse cells, the Brca1-BRCT domain is thus accessible for immediate binding of these phospho-proteins. We confirm elevated homologous recombination in Wwox-silenced murine cells, as in human cells. Wwox-deficient murine cells showed increased ionizing radiation-induced Abraxas, Brca1, and CtIP foci and long resected single-strand DNA, early after ionizing radiation. Wwox deletion increased the basal level of Brca1-CtIP interaction and the expression level of the MRN-CtIP protein complex, key players in end-resection, and facilitated Brca1 release from foci. Inhibition of phospho-Chk2 phosphorylation of Brca1-S971 delays the end-resection; the delay of premature end-resection by combining Chk2 inhibition with ionizing radiation or carboplatin treatment restored ionizing radiation and platinum sensitivity in Wwox-deficient murine cells, as in human cells, supporting the use of murine in vitro and in vivo models in preclinical cancer treatment research.
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Affiliation(s)
- Dongju Park
- Department of Cancer Biology and Genetics, The Comprehensive Cancer Center, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA; (M.G.); (R.P.); (C.Y.)
- Correspondence: (D.P.); (K.H.); Tel.: +1-614-685-9124 (D.P.); +1-614-292-4850 (K.H.)
| | - Mehdi Gharghabi
- Department of Cancer Biology and Genetics, The Comprehensive Cancer Center, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA; (M.G.); (R.P.); (C.Y.)
- Department of Outcomes and Translational Sciences, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA
| | - Colleen R. Reczek
- Department of Pathology & Cell Biology, Columbia University Irving Medical Center, Columbia University, New York, NY 10032, USA;
| | - Rebecca Plow
- Department of Cancer Biology and Genetics, The Comprehensive Cancer Center, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA; (M.G.); (R.P.); (C.Y.)
| | - Charles Yungvirt
- Department of Cancer Biology and Genetics, The Comprehensive Cancer Center, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA; (M.G.); (R.P.); (C.Y.)
| | - C. Marcelo Aldaz
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, 1881 East Road, Houston, TX 77054, USA;
| | - Kay Huebner
- Department of Cancer Biology and Genetics, The Comprehensive Cancer Center, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA; (M.G.); (R.P.); (C.Y.)
- Correspondence: (D.P.); (K.H.); Tel.: +1-614-685-9124 (D.P.); +1-614-292-4850 (K.H.)
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10
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Understanding and overcoming resistance to PARP inhibitors in cancer therapy. Nat Rev Clin Oncol 2021; 18:773-791. [PMID: 34285417 DOI: 10.1038/s41571-021-00532-x] [Citation(s) in RCA: 214] [Impact Index Per Article: 71.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/10/2021] [Indexed: 02/07/2023]
Abstract
Developing novel targeted anticancer therapies is a major goal of current research. The use of poly(ADP-ribose) polymerase (PARP) inhibitors in patients with homologous recombination-deficient tumours provides one of the best examples of a targeted therapy that has been successfully translated into the clinic. The success of this approach has so far led to the approval of four different PARP inhibitors for the treatment of several types of cancers and a total of seven different compounds are currently under clinical investigation for various indications. Clinical trials have demonstrated promising response rates among patients receiving PARP inhibitors, although the majority will inevitably develop resistance. Preclinical and clinical data have revealed multiple mechanisms of resistance and current efforts are focused on developing strategies to address this challenge. In this Review, we summarize the diverse processes underlying resistance to PARP inhibitors and discuss the potential strategies that might overcome these mechanisms such as combinations with chemotherapies, targeting the acquired vulnerabilities associated with resistance to PARP inhibitors or suppressing genomic instability.
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11
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Abstract
DNA double-strand breaks (DSBs) are cytotoxic lesions that threaten genome integrity and cell viability. Typically, cells repair DSBs by either nonhomologous end joining (NHEJ) or homologous recombination (HR). The relative use of these two pathways depends on many factors, including cell cycle stage and the nature of the DNA ends. A critical determinant of repair pathway selection is the initiation of 5'→3' nucleolytic degradation of DNA ends, a process referred to as DNA end resection. End resection is essential to create single-stranded DNA overhangs, which serve as the substrate for the Rad51 recombinase to initiate HR and are refractory to NHEJ repair. Here, we review recent insights into the mechanisms of end resection, how it is regulated, and the pathological consequences of its dysregulation.
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Affiliation(s)
- Petr Cejka
- Faculty of Biomedical Sciences, Institute for Research in Biomedicine, Università della Svizzera italiana (USI), 6500 Bellinzona, Switzerland; .,Department of Biology, Institute of Biochemistry, Eidgenössische Technische Hochschule (ETH) Zürich, 8093 Zürich, Switzerland
| | - Lorraine S Symington
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY 10032, USA; .,Department of Genetics & Development, Columbia University Irving Medical Center, New York, NY 10032, USA
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12
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Sanchez A, Lee D, Kim DI, Miller KM. Making Connections: Integrative Signaling Mechanisms Coordinate DNA Break Repair in Chromatin. Front Genet 2021; 12:747734. [PMID: 34659365 PMCID: PMC8514019 DOI: 10.3389/fgene.2021.747734] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 08/31/2021] [Indexed: 01/25/2023] Open
Abstract
DNA double-strand breaks (DSBs) are hazardous to genome integrity and can promote mutations and disease if not handled correctly. Cells respond to these dangers by engaging DNA damage response (DDR) pathways that are able to identify DNA breaks within chromatin leading ultimately to their repair. The recognition and repair of DSBs by the DDR is largely dependent on the ability of DNA damage sensing factors to bind to and interact with nucleic acids, nucleosomes and their modified forms to target these activities to the break site. These contacts orientate and localize factors to lesions within chromatin, allowing signaling and faithful repair of the break to occur. Coordinating these events requires the integration of several signaling and binding events. Studies are revealing an enormously complex array of interactions that contribute to DNA lesion recognition and repair including binding events on DNA, as well as RNA, RNA:DNA hybrids, nucleosomes, histone and non-histone protein post-translational modifications and protein-protein interactions. Here we examine several DDR pathways that highlight and provide prime examples of these emerging concepts. A combination of approaches including genetic, cellular, and structural biology have begun to reveal new insights into the molecular interactions that govern the DDR within chromatin. While many questions remain, a clearer picture has started to emerge for how DNA-templated processes including transcription, replication and DSB repair are coordinated. Multivalent interactions with several biomolecules serve as key signals to recruit and orientate proteins at DNA lesions, which is essential to integrate signaling events and coordinate the DDR within the milieu of the nucleus where competing genome functions take place. Genome architecture, chromatin structure and phase separation have emerged as additional vital regulatory mechanisms that also influence genome integrity pathways including DSB repair. Collectively, recent advancements in the field have not only provided a deeper understanding of these fundamental processes that maintain genome integrity and cellular homeostasis but have also started to identify new strategies to target deficiencies in these pathways that are prevalent in human diseases including cancer.
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Affiliation(s)
- Anthony Sanchez
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, United States.,Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX, United States
| | - Doohyung Lee
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, United States.,Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX, United States
| | - Dae In Kim
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, United States.,Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX, United States
| | - Kyle M Miller
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, United States.,Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX, United States.,Livestrong Cancer Institutes, Dell Medical School, The University of Texas at Austin, Austin, TX, United States
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13
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Hussain SS, Majumdar R, Moore GM, Narang H, Buechelmaier E, Bazil MJ, Ravindran PT, Leeman J, Li Y, Jalan M, Anderson KS, Farina A, Soni R, Mohibullah N, Hamzic E, Rong-Mullins X, Sifuentes C, Damerla RR, Viale A, Powell SN, Higginson D. Measuring nonhomologous end-joining, homologous recombination and alternative end-joining simultaneously at an endogenous locus in any transfectable human cell. Nucleic Acids Res 2021; 49:e74. [PMID: 33877327 PMCID: PMC8287935 DOI: 10.1093/nar/gkab262] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 03/23/2021] [Accepted: 04/01/2021] [Indexed: 02/06/2023] Open
Abstract
Double strand break (DSB) repair primarily occurs through 3 pathways: non-homologous end-joining (NHEJ), alternative end-joining (Alt-EJ), and homologous recombination (HR). Typical methods to measure pathway usage include integrated cassette reporter assays or visualization of DNA damage induced nuclear foci. It is now well understood that repair of Cas9-induced breaks also involves NHEJ, Alt-EJ, and HR pathways, providing a new format to measure pathway usage. Here, we have developed a simple Cas9-based system with validated repair outcomes that accurately represent each pathway and then converted it to a droplet digital PCR (ddPCR) readout, thus obviating the need for Next Generation Sequencing and bioinformatic analysis with the goal to make Cas9-based system accessible to more laboratories. The assay system has reproduced several important insights. First, absence of the key Alt-EJ factor Pol θ only abrogates ∼50% of total Alt-EJ. Second, single-strand templated repair (SSTR) requires BRCA1 and MRE11 activity, but not BRCA2, establishing that SSTR commonly used in genome editing is not conventional HR. Third, BRCA1 promotes Alt-EJ usage at two-ended DSBs in contrast to BRCA2. This assay can be used in any system, which permits Cas9 delivery and, importantly, allows rapid genotype-to-phenotype correlation in isogenic cell line pairs.
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Affiliation(s)
- Suleman S Hussain
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Rahul Majumdar
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Grace M Moore
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Himanshi Narang
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Erika S Buechelmaier
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
- Weill Cornell Medicine, Graduate School of Medical Sciences, New York, NY 10065, USA
| | - Maximilian J Bazil
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | | | - Jonathan E Leeman
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02189, USA
| | - Yi Li
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Manisha Jalan
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Kyrie S Anderson
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Andrea Farina
- Integrated Genomics Operations, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Rekha Soni
- Integrated Genomics Operations, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Neeman Mohibullah
- Integrated Genomics Operations, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Edin Hamzic
- Biocomputix, Sarajevo, 71000, Bosnia and Herzegovina
| | - Xiaoqing Rong-Mullins
- Department of Biostatistics, The Ohio State University College of Public Health, Columbus, OH 43210, USA
| | | | - Rama R Damerla
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Agnes Viale
- Integrated Genomics Operations, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Simon N Powell
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Daniel S Higginson
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
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14
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Raimundo L, Calheiros J, Saraiva L. Exploiting DNA Damage Repair in Precision Cancer Therapy: BRCA1 as a Prime Therapeutic Target. Cancers (Basel) 2021; 13:cancers13143438. [PMID: 34298653 PMCID: PMC8303227 DOI: 10.3390/cancers13143438] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 06/21/2021] [Accepted: 07/07/2021] [Indexed: 12/24/2022] Open
Abstract
Simple Summary Chemical inhibition of central DNA damage repair (DDR) proteins has become a promising approach in precision cancer therapy. In particular, BRCA1 and its DDR-associated proteins constitute important targets for developing DNA repair inhibiting drugs. This review provides relevant insights on DDR biology and pharmacology, aiming to boost the development of more effective DDR targeted therapies. Abstract Precision medicine aims to identify specific molecular alterations, such as driver mutations, allowing tailored and effective anticancer therapies. Poly(ADP)-ribose polymerase inhibitors (PARPi) are the prototypical example of targeted therapy, exploiting the inability of cancer cells to repair DNA damage. Following the concept of synthetic lethality, PARPi have gained great relevance, particularly in BRCA1 dysfunctional cancer cells. In fact, BRCA1 mutations culminate in DNA repair defects that can render cancer cells more vulnerable to therapy. However, the efficacy of these drugs has been greatly affected by the occurrence of resistance due to multi-connected DNA repair pathways that may compensate for each other. Hence, the search for additional effective agents targeting DNA damage repair (DDR) is of crucial importance. In this context, BRCA1 has assumed a central role in developing drugs aimed at inhibiting DNA repair activity. Collectively, this review provides an in-depth understanding of the biology and regulatory mechanisms of DDR pathways, highlighting the potential of DDR-associated molecules, particularly BRCA1 and its interconnected partners, in precision cancer medicine. It also affords an overview about what we have achieved and a reflection on how much remains to be done in this field, further addressing encouraging clues for the advance of DDR targeted therapy.
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15
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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.
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16
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Super-resolution mapping of cellular double-strand break resection complexes during homologous recombination. Proc Natl Acad Sci U S A 2021; 118:2021963118. [PMID: 33707212 PMCID: PMC7980414 DOI: 10.1073/pnas.2021963118] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Homologous recombination (HR) is a major pathway for repair of DNA double-strand breaks (DSBs). The initial step that drives the HR process is resection of DNA at the DSB, during which a multitude of nucleases, mediators, and signaling proteins accumulates at the damage foci in a manner that remains elusive. Using single-molecule localization super-resolution (SR) imaging assays, we specifically visualize the spatiotemporal behavior of key mediator and nuclease proteins as they resect DNA at single-ended double-strand breaks (seDSBs) formed at collapsed replication forks. By characterizing these associations, we reveal the in vivo dynamics of resection complexes involved in generating the long single-stranded DNA (ssDNA) overhang prior to homology search. We show that 53BP1, a protein known to antagonize HR, is recruited to seDSB foci during early resection but is spatially separated from repair activities. Contemporaneously, CtBP-interacting protein (CtIP) and MRN (MRE11-RAD51-NBS1) associate with seDSBs, interacting with each other and BRCA1. The HR nucleases EXO1 and DNA2 are also recruited and colocalize with each other and with the repair helicase Bloom syndrome protein (BLM), demonstrating multiple simultaneous resection events. Quantification of replication protein A (RPA) accumulation and ssDNA generation shows that resection is completed 2 to 4 h after break induction. However, both BRCA1 and BLM persist later into HR, demonstrating potential roles in homology search and repair resolution. Furthermore, we show that initial recruitment of BRCA1 and removal of Ku are largely independent of MRE11 exonuclease activity but dependent on MRE11 endonuclease activity. Combined, our observations provide a detailed description of resection during HR repair.
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17
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Zhao F, Kim W, Kloeber JA, Lou Z. DNA end resection and its role in DNA replication and DSB repair choice in mammalian cells. Exp Mol Med 2020; 52:1705-1714. [PMID: 33122806 PMCID: PMC8080561 DOI: 10.1038/s12276-020-00519-1] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 08/29/2020] [Accepted: 09/09/2020] [Indexed: 12/19/2022] Open
Abstract
DNA end resection has a key role in double-strand break repair and DNA replication. Defective DNA end resection can cause malfunctions in DNA repair and replication, leading to greater genomic instability. DNA end resection is initiated by MRN-CtIP generating short, 3′-single-stranded DNA (ssDNA). This newly generated ssDNA is further elongated by multiple nucleases and DNA helicases, such as EXO1, DNA2, and BLM. Effective DNA end resection is essential for error-free homologous recombination DNA repair, the degradation of incorrectly replicated DNA and double-strand break repair choice. Because of its importance in DNA repair, DNA end resection is strictly regulated. Numerous mechanisms have been reported to regulate the initiation, extension, and termination of DNA end resection. Here, we review the general process of DNA end resection and its role in DNA replication and repair pathway choice. Carefully regulated enzymatic processing of the ends of DNA strands is essential for efficient replication and damage repair while also minimizing the risk of genomic instability. Replication and repair depend on a mechanism known as DNA resection, in which enzymes trim back double-stranded DNA ends to leave single-stranded overhangs. Zhenkun Lou and colleagues at the Mayo Clinic in Rochester, USA, have reviewed the various steps involved in the initiation and control of DNA resection. There are multiple different DNA repair processes, and the manner in which resection occurs can determine which of these processes subsequently takes place. The authors note that cancer cells rely heavily on these repair pathways to survive radiotherapy and chemotherapy, and highlight research opportunities that might reveal therapeutically useful vulnerabilities in the resection mechanism.
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Affiliation(s)
- Fei Zhao
- Department of Oncology, Mayo Clinic, Rochester, MN, 55905, USA
| | - Wootae Kim
- Department of Oncology, Mayo Clinic, Rochester, MN, 55905, USA
| | - Jake A Kloeber
- Department of Oncology, Mayo Clinic, Rochester, MN, 55905, USA.,Mayo Clinic Medical Scientist Training Program, Mayo Clinic, Rochester, MN, 55905, USA.,Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN, 55905, USA
| | - Zhenkun Lou
- Department of Oncology, Mayo Clinic, Rochester, MN, 55905, USA.
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18
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Sadeghi F, Asgari M, Matloubi M, Ranjbar M, Karkhaneh Yousefi N, Azari T, Zaki-Dizaji M. Molecular contribution of BRCA1 and BRCA2 to genome instability in breast cancer patients: review of radiosensitivity assays. Biol Proced Online 2020; 22:23. [PMID: 33013205 PMCID: PMC7528506 DOI: 10.1186/s12575-020-00133-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 08/04/2020] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND DNA repair pathways, cell cycle arrest checkpoints, and cell death induction are present in cells to process DNA damage and prevent genomic instability caused by various extrinsic and intrinsic ionizing factors. Mutations in the genes involved in these pathways enhances the ionizing radiation sensitivity, reduces the individual's capacity to repair DNA damages, and subsequently increases susceptibility to tumorigenesis. BODY BRCA1 and BRCA2 are two highly penetrant genes involved in the inherited breast cancer and contribute to different DNA damage pathways and cell cycle and apoptosis cascades. Mutations in these genes have been associated with hypersensitivity and genetic instability as well as manifesting severe radiotherapy complications in breast cancer patients. The genomic instability and DNA repair capacity of breast cancer patients with BRCA1/2 mutations have been analyzed in different studies using a variety of assays, including micronucleus assay, comet assay, chromosomal assay, colony-forming assay, γ -H2AX and 53BP1 biomarkers, and fluorescence in situ hybridization. The majority of studies confirmed the enhanced spontaneous & radiation-induced radiosensitivity of breast cancer patients compared to healthy controls. Using G2 micronucleus assay and G2 chromosomal assay, most studies have reported the lymphocyte of healthy carriers with BRCA1 mutation are hypersensitive to invitro ionizing radiation compared to non-carriers without a history of breast cancer. However, it seems this approach is not likely to be useful to distinguish the BRCA carriers from non-carrier with familial history of breast cancer. CONCLUSION In overall, breast cancer patients are more radiosensitive compared to healthy control; however, inconsistent results exist about the ability of current radiosensitive techniques in screening BRCA1/2 carriers or those susceptible to radiotherapy complications. Therefore, developing further radiosensitivity assay is still warranted to evaluate the DNA repair capacity of individuals with BRCA1/2 mutations and serve as a predictive factor for increased risk of cancer mainly in the relatives of breast cancer patients. Moreover, it can provide more evidence about who is susceptible to manifest severe complication after radiotherapy.
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Affiliation(s)
- Fatemeh Sadeghi
- Department of Immunology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
- Digestive Diseases Research Institute, Digestive Oncology Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Marzieh Asgari
- Rheumatology Research Center, Tehran University of Medical Sciences, Shariati Hospital, Kargar Ave, Tehran, Iran
| | - Mojdeh Matloubi
- Department of Immunology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Maral Ranjbar
- Department of Immunology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Nahid Karkhaneh Yousefi
- Cancer Research Center, Cancer Institute of Iran, Tehran University of Medical Sciences, Tehran, Iran
| | - Tahereh Azari
- Department of Immunology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Majid Zaki-Dizaji
- Legal Medicine Research Center, Legal Medicine Organization, Tehran, Iran
- Research Center for Immunodeficiencies, Children’s Medical Center, Tehran University of Medical Sciences, Tehran, Iran
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19
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Mozaffari NL, Pagliarulo F, Sartori AA. Human CtIP: A 'double agent' in DNA repair and tumorigenesis. Semin Cell Dev Biol 2020; 113:47-56. [PMID: 32950401 DOI: 10.1016/j.semcdb.2020.09.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 07/20/2020] [Accepted: 09/02/2020] [Indexed: 12/14/2022]
Abstract
Human CtIP was originally identified as an interactor of the retinoblastoma protein and BRCA1, two bona fide tumour suppressors frequently mutated in cancer. CtIP is renowned for its role in the resection of DNA double-strand breaks (DSBs) during homologous recombination, a largely error-free DNA repair pathway crucial in maintaining genome integrity. However, CtIP-dependent DNA end resection is equally accountable for alternative end-joining, a mutagenic DSB repair mechanism implicated in oncogenic chromosomal translocations. In addition, CtIP contributes to transcriptional regulation of G1/S transition, DNA damage checkpoint signalling, and replication fork protection pathways. In this review, we present a perspective on the current state of knowledge regarding the tumour-suppressive and oncogenic properties of CtIP and provide an overview of their relevance for cancer development, progression, and therapy.
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Affiliation(s)
- Nour L Mozaffari
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Fabio Pagliarulo
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Alessandro A Sartori
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland.
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20
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Krais JJ, Johnson N. BRCA1 Mutations in Cancer: Coordinating Deficiencies in Homologous Recombination with Tumorigenesis. Cancer Res 2020; 80:4601-4609. [PMID: 32747362 PMCID: PMC7641968 DOI: 10.1158/0008-5472.can-20-1830] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 07/15/2020] [Accepted: 07/29/2020] [Indexed: 01/08/2023]
Abstract
Cancers that arise from BRCA1 germline mutations are deficient for homologous recombination (HR) DNA repair and are sensitive to DNA-damaging agents such as platinum and PARP inhibitors. In vertebrate organisms, knockout of critical HR genes including BRCA1 and BRCA2 is lethal because HR is required for genome replication. Thus, cancers must develop strategies to cope with loss of HR activity. Furthermore, as established tumors respond to chemotherapy selection pressure, additional genetic adaptations transition cancers to an HR-proficient state. In this review, we discuss biological mechanisms that influence the ability of BRCA1-mutant cancers to perform HR. Furthermore, we consider how the HR status fluctuates throughout the cancer life course, from tumor initiation to the development of therapy refractory disease.
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Affiliation(s)
- John J Krais
- Molecular Therapeutics Program, Fox Chase Cancer Center, Philadelphia, Pennsylvania
| | - Neil Johnson
- Molecular Therapeutics Program, Fox Chase Cancer Center, Philadelphia, Pennsylvania.
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21
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The Effects of Genetic and Epigenetic Alterations of BARD1 on the Development of Non-Breast and Non-Gynecological Cancers. Genes (Basel) 2020; 11:genes11070829. [PMID: 32708251 PMCID: PMC7396976 DOI: 10.3390/genes11070829] [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: 06/28/2020] [Revised: 07/14/2020] [Accepted: 07/17/2020] [Indexed: 02/06/2023] Open
Abstract
Breast Cancer 1 (BRCA1) gene is a well-characterized tumor suppressor gene, mutations of which are primarily found in women with breast and ovarian cancers. BRCA1-associated RING domain 1 (BARD1) gene has also been identified as an important tumor suppressor gene in breast, ovarian, and uterine cancers. Underscoring the functional significance of the BRCA1 and BARD1 interactions, prevalent mutations in the BRCA1 gene are found in its RING domain, through which it binds the RING domain of BARD1. BARD1-BRCA1 heterodimer plays a crucial role in a variety of DNA damage response (DDR) pathways, including DNA damage checkpoint and homologous recombination (HR). However, many mutations in both BARD1 and BRCA1 also exist in other domains that significantly affect their biological functions. Intriguingly, recent genome-wide studies have identified various single nucleotide polymorphisms (SNPs), genetic alterations, and epigenetic modifications in or near the BARD1 gene that manifested profound effects on tumorigenesis in a variety of non-breast and non-gynecological cancers. In this review, we will briefly discuss the molecular functions of BARD1, including its BRCA1-dependent as well as BRCA1-independent functions. We will then focus on evaluating the common BARD1 related SNPs as well as genetic and epigenetic changes that occur in the non-BRCA1-dominant cancers, including neuroblastoma, lung, and gastrointestinal cancers. Furthermore, the pro- and anti-tumorigenic functions of different SNPs and BARD1 variants will also be discussed.
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Reginato G, Cejka P. The MRE11 complex: A versatile toolkit for the repair of broken DNA. DNA Repair (Amst) 2020; 91-92:102869. [PMID: 32480356 DOI: 10.1016/j.dnarep.2020.102869] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 04/30/2020] [Accepted: 05/04/2020] [Indexed: 12/13/2022]
Abstract
When DNA breaks, the ends need to be stabilized and processed to facilitate subsequent repair, which can occur by either direct but error-prone end-joining with another broken DNA molecule or a more accurate homology-directed repair by the recombination machinery. At the same time, the presence of broken DNA triggers a signaling cascade that regulates the repair events and cellular progression through the cell cycle. The MRE11 nuclease, together with RAD50 and NBS1 forms a complex termed MRN that participates in all these processes. Although MRE11 was first identified more than 20 years ago, deep insights into its mechanism of action and regulation are much more recent. Here we review how MRE11 functions within MRN, and how the complex is further regulated by CtIP and its phosphorylation in a cell cycle dependent manner. We describe how RAD50, NBS1 and CtIP convert MRE11, exhibiting per se a 3'→5' exonuclease activity, into an ensemble that instead degrades primarily the 5'-terminated strand by endonucleolytic cleavage at DNA break sites to generate 3' overhangs, as required for the initiation of homologous recombination. The unique mechanism of DNA end resection by MRN-CtIP makes it a very flexible toolkit to process DNA breaks with a variety of secondary structures and protein blocks. Such a block can also be the Ku heterodimer, and emerging evidence suggests that MRN-CtIP may often need to remove Ku from DNA ends before initiating homologous recombination. Misregulation of DNA break repair results in mutations and chromosome rearrangements that can drive cancer development. Therefore, a detailed understanding of the underlying processes is highly relevant for human health.
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Affiliation(s)
- Giordano Reginato
- Institute for Research in Biomedicine, Università della Svizzera Italiana (USI), Faculty of Biomedical Sciences, Bellinzona, Switzerland; Department of Biology, Institute of Biochemistry, Eidgenössische Technische Hochschule (ETH), Zürich, Switzerland
| | - Petr Cejka
- Institute for Research in Biomedicine, Università della Svizzera Italiana (USI), Faculty of Biomedical Sciences, Bellinzona, Switzerland; Department of Biology, Institute of Biochemistry, Eidgenössische Technische Hochschule (ETH), Zürich, Switzerland.
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23
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Ubiquitylation-Mediated Fine-Tuning of DNA Double-Strand Break Repair. Cancers (Basel) 2020; 12:cancers12061617. [PMID: 32570875 PMCID: PMC7352447 DOI: 10.3390/cancers12061617] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 06/15/2020] [Accepted: 06/17/2020] [Indexed: 01/04/2023] Open
Abstract
The proper function of DNA repair is indispensable for eukaryotic cells since accumulation of DNA damages leads to genome instability and is a major cause of oncogenesis. Ubiquitylation and deubiquitylation play a pivotal role in the precise regulation of DNA repair pathways by coordinating the recruitment and removal of repair proteins at the damaged site. Here, we summarize the most important post-translational modifications (PTMs) involved in DNA double-strand break repair. Although we highlight the most relevant PTMs, we focus principally on ubiquitylation-related processes since these are the most robust regulatory pathways among those of DNA repair.
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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.
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25
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Tarsounas M, Sung P. The antitumorigenic roles of BRCA1-BARD1 in DNA repair and replication. Nat Rev Mol Cell Biol 2020; 21:284-299. [PMID: 32094664 PMCID: PMC7204409 DOI: 10.1038/s41580-020-0218-z] [Citation(s) in RCA: 187] [Impact Index Per Article: 46.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/22/2020] [Indexed: 11/09/2022]
Abstract
The tumour suppressor breast cancer type 1 susceptibility protein (BRCA1) promotes DNA double-strand break (DSB) repair by homologous recombination and protects DNA replication forks from attrition. BRCA1 partners with BRCA1-associated RING domain protein 1 (BARD1) and other tumour suppressor proteins to mediate the initial nucleolytic resection of DNA lesions and the recruitment and regulation of the recombinase RAD51. The discovery of the opposing functions of BRCA1 and the p53-binding protein 1 (53BP1)-associated complex in DNA resection sheds light on how BRCA1 influences the choice of homologous recombination over non-homologous end joining and potentially other mutagenic pathways of DSB repair. Understanding the functional crosstalk between BRCA1-BARD1 and its cofactors and antagonists will illuminate the molecular basis of cancers that arise from a deficiency or misregulation of chromosome damage repair and replication fork maintenance. Such knowledge will also be valuable for understanding acquired tumour resistance to poly(ADP-ribose) polymerase (PARP) inhibitors and other therapeutics and for the development of new treatments. In this Review, we discuss recent advances in elucidating the mechanisms by which BRCA1-BARD1 functions in DNA repair, replication fork maintenance and tumour suppression, and its therapeutic relevance.
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Affiliation(s)
- Madalena Tarsounas
- Genome Stability and Tumourigenesis Group, Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, UK.
| | - Patrick Sung
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX, USA.
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26
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Nath S, Nagaraju G. FANCJ helicase promotes DNA end resection by facilitating CtIP recruitment to DNA double-strand breaks. PLoS Genet 2020; 16:e1008701. [PMID: 32251466 PMCID: PMC7162537 DOI: 10.1371/journal.pgen.1008701] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 04/16/2020] [Accepted: 02/28/2020] [Indexed: 12/13/2022] Open
Abstract
FANCJ helicase mutations are known to cause hereditary breast and ovarian cancers as well as bone marrow failure syndrome Fanconi anemia. FANCJ plays an important role in the repair of DNA inter-strand crosslinks and DNA double-strand breaks (DSBs) by homologous recombination (HR). Nonetheless, the molecular mechanism by which FANCJ controls HR mediated DSB repair is obscure. Here, we show that FANCJ promotes DNA end resection by recruiting CtIP to the sites of DSBs. This recruitment of CtIP is dependent on FANCJ K1249 acetylation. Notably, FANCJ acetylation is dependent on FANCJ S990 phosphorylation by CDK. The CDK mediated phosphorylation of FANCJ independently facilitates its interaction with BRCA1 at damaged DNA sites and promotes DNA end resection by CtIP recruitment. Strikingly, mutational studies reveal that ATP binding competent but hydrolysis deficient FANCJ partially supports end resection, indicating that in addition to the scaffolding role of FANCJ in CtIP recruitment, its helicase activity is important for promoting end resection. Together, these data unravel a novel function of FANCJ helicase in DNA end resection and provide mechanistic insights into its role in repairing DSBs by HR and in genome maintenance. Homologous recombination has been considered as an error-free pathway in repairing DSBs and maintaining genome stability. Cyclin-dependent kinases (CDKs) and various factors including MRE11, CtIP, EXO1, and BLM helicase participate in DNA end resection to promote HR mediated DSB repair. Despite the identification of FANCJ helicase role in HR and tumor suppression, the molecular mechanism by which FANCJ helicase participates in HR is obscure. Here, we show that FANCJ helicase controls DNA end resection by recruiting CtIP to the sites of DSBs. The loading of CtIP is dependent on FANCJ acetylation which is mediated by CDK dependent phosphorylation of FANCJ. Moreover, in addition to FANCJ mediated CtIP recruitment, its helicase activity is also essential for DNA end resection. Our data identify FANCJ as a novel player in the DNA end resection and provide insights into its role in HR mediated DSB repair.
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Affiliation(s)
- Sarmi Nath
- Department of Biochemistry, Indian Institute of Science, Bangalore, India
| | - Ganesh Nagaraju
- Department of Biochemistry, Indian Institute of Science, Bangalore, India
- * E-mail:
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27
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Belotserkovskaya R, Raga Gil E, Lawrence N, Butler R, Clifford G, Wilson MD, Jackson SP. PALB2 chromatin recruitment restores homologous recombination in BRCA1-deficient cells depleted of 53BP1. Nat Commun 2020; 11:819. [PMID: 32041954 PMCID: PMC7010753 DOI: 10.1038/s41467-020-14563-y] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 01/17/2020] [Indexed: 02/07/2023] Open
Abstract
Loss of functional BRCA1 protein leads to defects in DNA double-strand break (DSB) repair by homologous recombination (HR) and renders cells hypersensitive to poly (ADP-ribose) polymerase (PARP) inhibitors used to treat BRCA1/2-deficient cancers. However, upon chronic treatment of BRCA1-mutant cells with PARP inhibitors, resistant clones can arise via several mechanisms, including loss of 53BP1 or its downstream co-factors. Defects in the 53BP1 axis partially restore the ability of a BRCA1-deficient cell to form RAD51 filaments at resected DSBs in a PALB2- and BRCA2-dependent manner, and thereby repair DSBs by HR. Here we show that depleting 53BP1 in BRCA1-null cells restores PALB2 accrual at resected DSBs. Moreover, we demonstrate that PALB2 DSB recruitment in BRCA1/53BP1-deficient cells is mediated by an interaction between PALB2's chromatin associated motif (ChAM) and the nucleosome acidic patch region, which in 53BP1-expressing cells is bound by 53BP1's ubiquitin-directed recruitment (UDR) domain.
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Affiliation(s)
- Rimma Belotserkovskaya
- Wellcome Trust CRUK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN, UK.
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1GA, UK.
| | - Elisenda Raga Gil
- Wellcome Trust CRUK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN, UK
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1GA, UK
- School of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH, UK
| | - Nicola Lawrence
- Wellcome Trust CRUK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN, UK
| | - Richard Butler
- Wellcome Trust CRUK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN, UK
| | - Gillian Clifford
- Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Kings Buildings, Mayfield Road, Edinburgh, EH9 3JR, UK
| | - Marcus D Wilson
- Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, Kings Buildings, Mayfield Road, Edinburgh, EH9 3JR, UK.
| | - Stephen P Jackson
- Wellcome Trust CRUK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN, UK.
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1GA, UK.
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28
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Hwang SY, Kang MA, Baik CJ, Lee Y, Hang NT, Kim BG, Han JS, Jeong JH, Park D, Myung K, Lee JS. CTCF cooperates with CtIP to drive homologous recombination repair of double-strand breaks. Nucleic Acids Res 2019; 47:9160-9179. [PMID: 31340001 PMCID: PMC6753481 DOI: 10.1093/nar/gkz639] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 07/01/2019] [Accepted: 07/15/2019] [Indexed: 01/09/2023] Open
Abstract
The pleiotropic CCCTC-binding factor (CTCF) plays a role in homologous recombination (HR) repair of DNA double-strand breaks (DSBs). However, the precise mechanistic role of CTCF in HR remains largely unclear. Here, we show that CTCF engages in DNA end resection, which is the initial, crucial step in HR, through its interactions with MRE11 and CtIP. Depletion of CTCF profoundly impairs HR and attenuates CtIP recruitment at DSBs. CTCF physically interacts with MRE11 and CtIP and promotes CtIP recruitment to sites of DNA damage. Subsequently, CTCF facilitates DNA end resection to allow HR, in conjunction with MRE11–CtIP. Notably, the zinc finger domain of CTCF binds to both MRE11 and CtIP and enables proficient CtIP recruitment, DNA end resection and HR. The N-terminus of CTCF is able to bind to only MRE11 and its C-terminus is incapable of binding to MRE11 and CtIP, thereby resulting in compromised CtIP recruitment, DSB resection and HR. Overall, this suggests an important function of CTCF in DNA end resection through the recruitment of CtIP at DSBs. Collectively, our findings identify a critical role of CTCF at the first control point in selecting the HR repair pathway.
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Affiliation(s)
- Soon Young Hwang
- Department of Life Sciences and Cellulomics Institute Ajou University, Suwon 16499, Korea
| | - Mi Ae Kang
- Department of Life Sciences and Cellulomics Institute Ajou University, Suwon 16499, Korea
| | - Chul Joon Baik
- Department of Life Sciences and Cellulomics Institute Ajou University, Suwon 16499, Korea
| | - Yejin Lee
- Department of Life Sciences and Cellulomics Institute Ajou University, Suwon 16499, Korea
| | - Ngo Thanh Hang
- Department of Life Sciences and Cellulomics Institute Ajou University, Suwon 16499, Korea
| | - Byung-Gyu Kim
- Center for Genomic Integrity, Institute for Basic Science, UNIST, Ulsan 44919, Korea
| | - Joo Seok Han
- Center for Genomic Integrity, Institute for Basic Science, UNIST, Ulsan 44919, Korea
| | - Jae-Hoon Jeong
- Division of Applied Radiation Bioscience, Korea Institute of Radiological and Medical Science, Seoul 01812, Korea
| | - Daechan Park
- Department of Life Sciences and Cellulomics Institute Ajou University, Suwon 16499, Korea
| | - Kyungjae Myung
- Center for Genomic Integrity, Institute for Basic Science, UNIST, Ulsan 44919, Korea
| | - Jong-Soo Lee
- Department of Life Sciences and Cellulomics Institute Ajou University, Suwon 16499, Korea
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Mohiuddin M, Rahman MM, Sale JE, Pearson CE. CtIP-BRCA1 complex and MRE11 maintain replication forks in the presence of chain terminating nucleoside analogs. Nucleic Acids Res 2019; 47:2966-2980. [PMID: 30657944 PMCID: PMC6451104 DOI: 10.1093/nar/gkz009] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 12/30/2018] [Accepted: 01/09/2019] [Indexed: 12/20/2022] Open
Abstract
Chain-terminating nucleoside analogs (CTNAs), which cannot be extended by DNA polymerases, are widely used as antivirals or anti-cancer agents, and can induce cell death. Processing of blocked DNA ends, like camptothecin-induced trapped-topoisomerase I, can be mediated by TDP1, BRCA1, CtIP and MRE11. Here, we investigated whether the CtIP-BRCA1 complex and MRE11 also contribute to cellular tolerance to CTNAs, including 2',3'-dideoxycytidine (ddC), cytarabine (ara-C) and zidovudine (Azidothymidine, AZT). We show that BRCA1-/-, CtIPS332A/-/- and nuclease-dead MRE11D20A/- mutants display increased sensitivity to CTNAs, accumulate more DNA damage (chromosomal breaks, γ-H2AX and neutral comets) when treated with CTNAs and exhibit significant delays in replication fork progression during exposure to CTNAs. Moreover, BRCA1-/-, CtIPS332A/-/- and nuclease-dead MRE11D20A/- mutants failed to resume DNA replication in response to CTNAs, whereas control and CtIP+/-/- cells experienced extensive recovery of DNA replication. In summary, we provide clear evidence that MRE11 and the collaborative action of BRCA1 and CtIP play a critical role in the nuclease-dependent removal of incorporated ddC from replicating genomic DNA. We propose that BRCA1-CTIP and MRE11 prepare nascent DNA ends, blocked from synthesis by CTNAs, for further repair.
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Affiliation(s)
- Mohiuddin Mohiuddin
- Program of Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Md Maminur Rahman
- Department of Radiation Genetics, Kyoto University Graduate School of Medicine, Yoshida Konoe, Sakyo-ku, Kyoto 606-8501, Japan
| | - Julian E Sale
- Medical Research Council Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, UK
| | - Christopher E Pearson
- Program of Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada.,The Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
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30
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Liu X, Wang XS, Lee BJ, Wu-Baer FK, Lin X, Shao Z, Estes VM, Gautier J, Baer R, Zha S. CtIP is essential for early B cell proliferation and development in mice. J Exp Med 2019; 216:1648-1663. [PMID: 31097467 PMCID: PMC6605744 DOI: 10.1084/jem.20181139] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2018] [Revised: 09/10/2018] [Accepted: 04/24/2019] [Indexed: 11/08/2022] Open
Abstract
B cell development requires efficient proliferation and successful assembly and modifications of the immunoglobulin gene products. CtIP is an essential gene implicated in end resection and DNA repair. Here, we show that CtIP is essential for early B cell development but dispensable in naive B cells. CtIP loss is well tolerated in G1-arrested B cells and during V(D)J recombination, but in proliferating B cells, CtIP loss leads to a progressive cell death characterized by ATM hyperactivation, G2/M arrest, genomic instability, and 53BP1 nuclear body formation, indicating that the essential role of CtIP during proliferation underscores its stage-specific requirement in B cells. B cell proliferation requires phosphorylation of CtIP at T847 presumably by CDK, but not its interaction with CtBP or Rb or its nuclease activity. CtIP phosphorylation by ATM/ATR at T859 (T855 in mice) promotes end resection in G1-arrested cells but is dispensable for B cell development and class switch recombination, suggesting distinct roles for T859 and T847 phosphorylation in B cell development.
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Affiliation(s)
- Xiangyu Liu
- Institute for Cancer Genetics, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY
- Guangdong Key Laboratory of Genome Instability and Human Disease Prevention, Shenzhen University Carson Cancer Center, Department of Biochemistry and Molecular Biology, School of Medicine, Shenzhen University, Shenzhen, China
| | - Xiaobin S Wang
- Institute for Cancer Genetics, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY
- Pathobiology and Human Disease Graduate Program, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY
| | - Brian J Lee
- Institute for Cancer Genetics, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY
| | - Foon K Wu-Baer
- Institute for Cancer Genetics, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY
| | - Xiaohui Lin
- Institute for Cancer Genetics, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY
| | - Zhengping Shao
- Institute for Cancer Genetics, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY
| | - Verna M Estes
- Institute for Cancer Genetics, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY
| | - Jean Gautier
- Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY
| | - Richard Baer
- Institute for Cancer Genetics, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY
- Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY
| | - Shan Zha
- Institute for Cancer Genetics, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY
- Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY
- Division of Pediatric Oncology, Hematology and Stem Cell Transplantation, Department of Pediatrics, Vagelos College of Physicians & Surgeons, Columbia University, New York, NY
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32
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Wang H, Qiu Z, Liu B, Wu Y, Ren J, Liu Y, Zhao Y, Wang Y, Hao S, Li Z, Peng B, Xu X. PLK1 targets CtIP to promote microhomology-mediated end joining. Nucleic Acids Res 2018; 46:10724-10739. [PMID: 30202980 PMCID: PMC6237753 DOI: 10.1093/nar/gky810] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 08/08/2018] [Accepted: 08/30/2018] [Indexed: 12/12/2022] Open
Abstract
Proper DNA double-strand break (DSB) repair is essential for maintaining genome integrity. Microhomology-mediated end joining (MMEJ) is an error-prone repair mechanism, which introduces mutations at break sites and contributes to chromosomal translocations and telomere fusions, thus driving carcinogenesis. Mitotic kinases PLK1, CDK1 and Aurora A are important for supporting MMEJ and are often overexpressed in various tumors. However, the functional interplay between these kinases and MMEJ has not been explored. Here, we found that MMEJ is preferentially employed to fix DSBs in cells arrested in mitosis following nocodazole treatment. We further showed that the DSB repair factor CtIP is jointly phosphorylated by CDK1/Aurora A and PLK1. CDK1/Aurora A-mediated CtIP phosphorylation at serine 327 triggers CtIP binding to the PLK1 polo-box domain, which in turn facilitates PLK1 to phosphorylate CtIP mainly at serine 723. A PLK1 phosphor-mimic CtIP mutant fails to initiate extended end resection and is thus unable to mediate homologous recombination and the G2/M checkpoint but can mediate MMEJ. These data imply that PLK1 may target CtIP to promote error-prone MMEJ and inactivate the G2/M checkpoint. These findings have helped elucidate the oncogenic roles of these factors.
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Affiliation(s)
- Hailong Wang
- Beijing Key Laboratory of DNA Damage Response and College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Zhiyu Qiu
- Beijing Key Laboratory of DNA Damage Response and College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Bo Liu
- Beijing Key Laboratory of DNA Damage Response and College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Yan Wu
- Beijing Key Laboratory of DNA Damage Response and College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Jianping Ren
- Beijing Key Laboratory of DNA Damage Response and College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Yaqing Liu
- Beijing Key Laboratory of DNA Damage Response and College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Yuqin Zhao
- Beijing Key Laboratory of DNA Damage Response and College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Ya Wang
- Beijing Key Laboratory of DNA Damage Response and College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Shuailin Hao
- Beijing Key Laboratory of DNA Damage Response and College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Zheng Li
- Beijing Key Laboratory of DNA Damage Response and College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Bin Peng
- Guangdong Key Laboratory for Genome Stability & Disease Prevention, Shenzhen University School of Medicine, Shenzhen, Guangdong 518060, China
| | - Xingzhi Xu
- Guangdong Key Laboratory for Genome Stability & Disease Prevention, Shenzhen University School of Medicine, Shenzhen, Guangdong 518060, China
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33
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Whelan DR, Lee WTC, Yin Y, Ofri DM, Bermudez-Hernandez K, Keegan S, Fenyo D, Rothenberg E. Spatiotemporal dynamics of homologous recombination repair at single collapsed replication forks. Nat Commun 2018; 9:3882. [PMID: 30250272 PMCID: PMC6155164 DOI: 10.1038/s41467-018-06435-3] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 09/06/2018] [Indexed: 01/07/2023] Open
Abstract
Homologous recombination (HR) is a crucial pathway for the repair of DNA double-strand breaks. BRCA1/2 breast cancer proteins are key players in HR via their mediation of RAD51 nucleofilament formation and function; however, their individual roles and crosstalk in vivo are unknown. Here we use super-resolution (SR) imaging to map the spatiotemporal kinetics of HR proteins, revealing the interdependent relationships that govern the dynamic interplay and progression of repair events. We show that initial single-stranded DNA/RAD51 nucleofilament formation is mediated by RAD52 or, in the absence of RAD52, by BRCA2. In contrast, only BRCA2 can orchestrate later RAD51 recombinase activity during homology search and resolution. Furthermore, we establish that upstream BRCA1 activity is critical for BRCA2 function. Our analyses reveal the underlying epistatic landscape of RAD51 functional dependence on RAD52, BRCA1, and BRCA2 during HR and explain the phenotypic similarity of diseases associated with mutations in these proteins.
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Affiliation(s)
- Donna R Whelan
- Department of Biochemistry and Molecular Pharmacology, Perlmutter Cancer Center, New York University School of Medicine, New York, NY, 10016, USA.,Department of Pharmacy and Applied Science, La Trobe Institute for Molecular Science, La Trobe University, Bendigo, VIC, Australia
| | - Wei Ting C Lee
- Department of Biochemistry and Molecular Pharmacology, Perlmutter Cancer Center, New York University School of Medicine, New York, NY, 10016, USA
| | - Yandong Yin
- Department of Biochemistry and Molecular Pharmacology, Perlmutter Cancer Center, New York University School of Medicine, New York, NY, 10016, USA
| | - Dylan M Ofri
- Department of Biochemistry and Molecular Pharmacology, Perlmutter Cancer Center, New York University School of Medicine, New York, NY, 10016, USA
| | - Keria Bermudez-Hernandez
- Department of Biochemistry and Molecular Pharmacology, Perlmutter Cancer Center, New York University School of Medicine, New York, NY, 10016, USA
| | - Sarah Keegan
- Department of Biochemistry and Molecular Pharmacology, Perlmutter Cancer Center, New York University School of Medicine, New York, NY, 10016, USA
| | - David Fenyo
- Department of Biochemistry and Molecular Pharmacology, Perlmutter Cancer Center, New York University School of Medicine, New York, NY, 10016, USA
| | - Eli Rothenberg
- Department of Biochemistry and Molecular Pharmacology, Perlmutter Cancer Center, New York University School of Medicine, New York, NY, 10016, USA.
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Billing D, Horiguchi M, Wu-Baer F, Taglialatela A, Leuzzi G, Nanez SA, Jiang W, Zha S, Szabolcs M, Lin CS, Ciccia A, Baer R. The BRCT Domains of the BRCA1 and BARD1 Tumor Suppressors Differentially Regulate Homology-Directed Repair and Stalled Fork Protection. Mol Cell 2018; 72:127-139.e8. [PMID: 30244837 DOI: 10.1016/j.molcel.2018.08.016] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 06/23/2018] [Accepted: 08/07/2018] [Indexed: 10/28/2022]
Abstract
The BRCA1 tumor suppressor preserves genome integrity through both homology-directed repair (HDR) and stalled fork protection (SFP). In vivo, BRCA1 exists as a heterodimer with the BARD1 tumor suppressor, and both proteins harbor a phosphate-binding BRCT domain. Here, we compare mice with mutations that ablate BRCT phospho-recognition by Bard1 (Bard1S563F and Bard1K607A) or Brca1 (Brca1S1598F). Brca1S1598F abrogates both HDR and SFP, suggesting that both pathways are likely impaired in most BRCA1 mutant tumors. Although not affecting HDR, the Bard1 mutations ablate poly(ADP-ribose)-dependent recruitment of BRCA1/BARD1 to stalled replication forks, resulting in fork degradation and chromosome instability. Nonetheless, Bard1S563F/S563F and Bard1K607A/K607A mice, unlike Brca1S1598F/S1598F mice, are not tumor prone, indicating that HDR alone is sufficient to suppress tumor formation in the absence of SFP. Nevertheless, because SFP, unlike HDR, is also impaired in heterozygous Brca1/Bard1 mutant cells, SFP and HDR may contribute to distinct stages of tumorigenesis in BRCA1/BARD1 mutation carriers.
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Affiliation(s)
- David Billing
- Institute for Cancer Genetics, Columbia University Irving Medical Center, New York, NY 10032, USA; Department of Pathology & Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Michiko Horiguchi
- Institute for Cancer Genetics, Columbia University Irving Medical Center, New York, NY 10032, USA; Department of Pathology & Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Foon Wu-Baer
- Institute for Cancer Genetics, Columbia University Irving Medical Center, New York, NY 10032, USA; Department of Pathology & Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Angelo Taglialatela
- Department of Genetics & Development, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Giuseppe Leuzzi
- Department of Genetics & Development, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Silvia Alvarez Nanez
- Department of Genetics & Development, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Wenxia Jiang
- Institute for Cancer Genetics, Columbia University Irving Medical Center, New York, NY 10032, USA; Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Shan Zha
- Institute for Cancer Genetics, Columbia University Irving Medical Center, New York, NY 10032, USA; Department of Pathology & Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA; Department of Pediatrics, Columbia University Irving Medical Center, New York, NY 10032, USA; Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Matthias Szabolcs
- Department of Pathology & Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA; Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Chyuan-Sheng Lin
- Department of Pathology & Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA; Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Alberto Ciccia
- Department of Genetics & Development, Columbia University Irving Medical Center, New York, NY 10032, USA; Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Richard Baer
- Institute for Cancer Genetics, Columbia University Irving Medical Center, New York, NY 10032, USA; Department of Pathology & Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA; Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032, USA.
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Abstract
Canonical DNA non-homologous end-joining (c-NHEJ) and homologous recombination (HR), the two major DNA double-strand break (DSB) repair pathways, have long been depicted as competitors, fighting a race to rejoin DSBs. In human cells, Ku, an upstream component of NHEJ, is highly abundant and has exquisite end-binding capacity. Emerging evidence has suggested that Ku is the first protein binding most, if not all, DSBs, and creates a block to resection. Although most c-NHEJ proceeds without resection, recent studies have provided strong evidence for a process of resection-dependent c-NHEJ, that repairs a subset of DSBs. HR also repairs a subset of two-ended DSBs in G2 phase and processes one-ended DSBs that arise following replication fork stalling or collapse to promote replication restart. HR also necessitates end-resection. This raises the question of how end-resection takes place despite Ku's avid end-binding capacity. Insight into this enigma has been gained from the analysis of DSBs generated by Spo11 or TOP2, which create protein-bridged DSBs. The progression of repair by HR or NHEJ requires removal of the end-blocking lesions. The MRE11-RAD50-NBS1 (MRN) complex, CtIP and EXO1 play critical roles in this process. Here, we review our current understanding of how resection arises at lesions blocked by covalently bound Spo11 or TOP2 or following Ku binding, which effectively creates a distinct resection-blocking lesion due to its avid end-binding activity and abundance. Our review reveals that Ku plays an active role in determining pathway choice and exposes similarities yet distinctions in the progression of resection that is suited to the optimal repair pathway choice.
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Affiliation(s)
- Atsushi Shibata
- Education and Research Support Center, Graduate School of Medicine, Gunma University, Maebashi, Japan
| | - Penny Jeggo
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton BN19 RQ, UK
| | - Markus Löbrich
- Radiation Biology and DNA Repair, Darmstadt University of Technology, 64287 Darmstadt, Germany.
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36
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Periasamy J, Kurdekar V, Jasti S, Nijaguna MB, Boggaram S, Hurakadli MA, Raina D, Kurup LM, Chintha C, Manjunath K, Goyal A, Sadasivam G, Bharatham K, Padigaru M, Potluri V, Venkitaraman AR. Targeting Phosphopeptide Recognition by the Human BRCA1 Tandem BRCT Domain to Interrupt BRCA1-Dependent Signaling. Cell Chem Biol 2018; 25:677-690.e12. [PMID: 29606576 PMCID: PMC6015222 DOI: 10.1016/j.chembiol.2018.02.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 11/24/2017] [Accepted: 02/22/2018] [Indexed: 02/06/2023]
Abstract
Intracellular signals triggered by DNA breakage flow through proteins containing BRCT (BRCA1 C-terminal) domains. This family, comprising 23 conserved phosphopeptide-binding modules in man, is inaccessible to small-molecule chemical inhibitors. Here, we develop Bractoppin, a drug-like inhibitor of phosphopeptide recognition by the human BRCA1 tandem (t)BRCT domain, which selectively inhibits substrate binding with nanomolar potency in vitro. Structure-activity exploration suggests that Bractoppin engages BRCA1 tBRCT residues recognizing pSer in the consensus motif, pSer-Pro-Thr-Phe, plus an abutting hydrophobic pocket that is distinct in structurally related BRCT domains, conferring selectivity. In cells, Bractoppin inhibits substrate recognition detected by Förster resonance energy transfer, and diminishes BRCA1 recruitment to DNA breaks, in turn suppressing damage-induced G2 arrest and assembly of the recombinase, RAD51. But damage-induced MDC1 recruitment, single-stranded DNA (ssDNA) generation, and TOPBP1 recruitment remain unaffected. Thus, an inhibitor of phosphopeptide recognition selectively interrupts BRCA1 tBRCT-dependent signals evoked by DNA damage. Bractoppin selectively blocks phosphopeptide recognition by the BRCA1 tBRCT domain Bractoppin engages tBRCT residues recognizing pSer, plus an adjacent pocket Bractoppin interrupts BRCA1 tBRCT-dependent cellular signals evoked by DNA damage This work opens avenues to inhibit intracellular signaling by the tBRCT domain family
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Affiliation(s)
- Jayaprakash Periasamy
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Vadiraj Kurdekar
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Subbarao Jasti
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Mamatha B Nijaguna
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Sanjana Boggaram
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Manjunath A Hurakadli
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Dhruv Raina
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Lokavya Meenakshi Kurup
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Chetan Chintha
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Kavyashree Manjunath
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Aneesh Goyal
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Gayathri Sadasivam
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Kavitha Bharatham
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Muralidhara Padigaru
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Vijay Potluri
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Ashok R Venkitaraman
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India; Medical Research Council Cancer Unit, University of Cambridge, Hills Road, Cambridge CB2 0XZ, UK.
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Misenko SM, Patel DS, Her J, Bunting SF. DNA repair and cell cycle checkpoint defects in a mouse model of 'BRCAness' are partially rescued by 53BP1 deletion. Cell Cycle 2018; 17:881-891. [PMID: 29620483 PMCID: PMC6056228 DOI: 10.1080/15384101.2018.1456295] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 04/13/2018] [Accepted: 03/17/2018] [Indexed: 10/17/2022] Open
Abstract
'BRCAness' is a term used to describe cancer cells that behave similarly to tumors with BRCA1 or BRCA2 mutations. The BRCAness phenotype is associated with hypersensitivity to chemotherapy agents including PARP inhibitors, which are a promising class of recently-licensed anti-cancer treatments. This hypersensitivity arises because of a deficiency in the homologous recombination (HR) pathway for DNA double-strand break repair. To gain further insight into how genetic modifiers of HR contribute to the BRCAness phenotype, we created a new mouse model of BRCAness by generating mice that are deficient in BLM helicase and the Exo1 exonuclease, which are involved in the early stages of HR. We find that cells lacking BLM and Exo1 exhibit a BRCAness phenotype, with diminished HR, and hypersensitivity to PARP inhibitors. We further tested how 53BP1, an important regulator of HR, affects repair efficiency in our BRCAness model. We find that deletion of 53BP1 can relieve several of the repair deficiencies observed in cells lacking BLM and Exo1, just as it does in cells lacking BRCA1. These results substantiate the importance of BRCAness as a concept for classification of cancer cases, and further clarify the role of 53BP1 in regulation of DNA repair pathway choice in mammalian cells.
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Affiliation(s)
- Sarah M. Misenko
- Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - Dharm S. Patel
- Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - Joonyoung Her
- Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - Samuel F. Bunting
- Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
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Her J, Bunting SF. How cells ensure correct repair of DNA double-strand breaks. J Biol Chem 2018; 293:10502-10511. [PMID: 29414795 DOI: 10.1074/jbc.tm118.000371] [Citation(s) in RCA: 201] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
DNA double-strand breaks (DSBs) arise regularly in cells and when left unrepaired cause senescence or cell death. Homologous recombination (HR) and nonhomologous end-joining (NHEJ) are the two major DNA-repair pathways. Whereas HR allows faithful DSB repair and healthy cell growth, NHEJ has higher potential to contribute to mutations and malignancy. Many regulatory mechanisms influence which of these two pathways is used in DSB repair. These mechanisms depend on the cell cycle, post-translational modifications, and chromatin effects. Here, we summarize current research into these mechanisms, with a focus on mammalian cells, and also discuss repair by "alternative end-joining" and single-strand annealing.
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Affiliation(s)
- Joonyoung Her
- From the Department of Molecular Biology and Biochemistry, Rutgers, State University of New Jersey, Piscataway, New Jersey 08540
| | - Samuel F Bunting
- From the Department of Molecular Biology and Biochemistry, Rutgers, State University of New Jersey, Piscataway, New Jersey 08540
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39
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Sharma B, Preet Kaur R, Raut S, Munshi A. BRCA1 mutation spectrum, functions, and therapeutic strategies: The story so far. Curr Probl Cancer 2018; 42:189-207. [PMID: 29452958 DOI: 10.1016/j.currproblcancer.2018.01.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 12/19/2017] [Accepted: 01/04/2018] [Indexed: 02/07/2023]
Abstract
BRCA1 gene mutations account for about 25-28% of hereditary Breast Cancer as BRCA1 is included in the category of high penetrance genes. Except for few commonmutations, there is a heterogenous spectrum of BRCA1 mutations in various ethnic groups. 185AGdel and 5382ins Care the most common BRCA1 alterations (founder mutations) which have been identified in most of the population. This review has been compiled with an aim to consolidate the information on genetic variants reported in BRCA1 found in various ethnic groups, their functional implications if known; involvement of BRCA1 in various cellular pathways/processes and potential BRCA1 targeted therapies. The pathological variations of BRCA1 vary among different ethical groups. A systematic search in PubMed and Google scholar for the literature on BRCA1 gene was carried out to figure out structure and function of BRCA1 gene. BRCA1 is a large protein having 1863 amino acids with multiple functional domains and interacts with multiple proteins to carry out various crucial cellular processes. BRCA1 plays a major role in maintaining genome integrity, transcription regulation, chromatin remodeling, cell cycle checkpoint control, DNA damage repair, chromosomal segregation, and apoptosis. Studies investigating the phenotypic response of mutant BRCA1 protein and comparing it to wildtype BRCA1 protein are clinically important as they are involved in homologous recombination and other repair mechanisms. These studies may help in developing more targetted therapies, detecting novel interacting partners, identification of new signaling pathways that BRCA1 is a part of or downstream target genes that BRCA1 affects.
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Affiliation(s)
- Babita Sharma
- Department of Human Genetics and Molecular Medicine, Central University of Punjab, Bathinda, Punjab, India
| | - Raman Preet Kaur
- Department of Human Genetics and Molecular Medicine, Central University of Punjab, Bathinda, Punjab, India
| | - Sonali Raut
- Department of Human Genetics and Molecular Medicine, Central University of Punjab, Bathinda, Punjab, India
| | - Anjana Munshi
- Department of Human Genetics and Molecular Medicine, Central University of Punjab, Bathinda, Punjab, India.
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40
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Reczek CR, Shakya R, Miteva Y, Szabolcs M, Ludwig T, Baer R. The DNA resection protein CtIP promotes mammary tumorigenesis. Oncotarget 2017; 7:32172-83. [PMID: 27058754 PMCID: PMC5078005 DOI: 10.18632/oncotarget.8605] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 03/14/2016] [Indexed: 01/15/2023] Open
Abstract
Many DNA repair factors act to suppress tumor formation by preserving genomic stability. Similarly, the CtIP protein, which interacts with the BRCA1 tumor suppressor, is also thought to have tumor suppression activity. Through its role in DNA end resection, CtIP facilitates DNA double-strand break (DSB) repair by homologous recombination (DSBR-HR) and microhomology-mediated end joining (MMEJ). In addition, however, CtIP has also been implicated in the formation of aberrant chromosomal rearrangements in an MMEJ-dependent manner, an activity that could potentially promote tumor development by increasing genome instability. To clarify whether CtIP acts in vivo to suppress or promote tumorigenesis, we have examined its oncogenic potential in mouse models of human breast cancer. Surprisingly, mice heterozygous for a null Ctip allele did not display an increased susceptibility to tumor formation. Moreover, mammary-specific biallelic CtIP ablation did not elicit breast tumors in a manner reminiscent of BRCA1 loss. Instead, CtIP inactivation dramatically reduced the kinetics of mammary tumorigenesis in mice bearing mammary-specific lesions of the p53 gene. Thus, unlike other repair factors, CtIP is not a tumor suppressor, but has oncogenic properties that can promote tumorigenesis, consistent with its ability to facilitate MMEJ-dependent chromosomal instability. Consequently, inhibition of CtIP-mediated MMEJ may prove effective against tumor types, such as human breast cancer, that display MMEJ-dependent chromosomal rearrangements.
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Affiliation(s)
- Colleen R Reczek
- Institute for Cancer Genetics, Department of Pathology and Cell Biology, and Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, NY 10032, USA
| | - Reena Shakya
- Institute for Cancer Genetics, Department of Pathology and Cell Biology, and Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, NY 10032, USA.,Current address: Department of Molecular Virology, Immunology, and Medical Genetics, Ohio State University Wexner Medical Center and Comprehensive Cancer Center, Columbus, OH 43210, USA
| | - Yana Miteva
- Institute for Cancer Genetics, Department of Pathology and Cell Biology, and Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, NY 10032, USA
| | - Matthias Szabolcs
- Institute for Cancer Genetics, Department of Pathology and Cell Biology, and Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, NY 10032, USA
| | - Thomas Ludwig
- Institute for Cancer Genetics, Department of Pathology and Cell Biology, and Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, NY 10032, USA.,Current address: Department of Molecular Virology, Immunology, and Medical Genetics, Ohio State University Wexner Medical Center and Comprehensive Cancer Center, Columbus, OH 43210, USA
| | - Richard Baer
- Institute for Cancer Genetics, Department of Pathology and Cell Biology, and Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, New York, NY 10032, USA
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41
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Takaoka M, Miki Y. BRCA1 gene: function and deficiency. Int J Clin Oncol 2017; 23:36-44. [PMID: 28884397 DOI: 10.1007/s10147-017-1182-2] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 08/17/2017] [Indexed: 10/18/2022]
Abstract
The BRCA1 protein, a hereditary breast and ovarian cancer-causing gene product, is known as a multifunctional protein that performs various functions in cells. It is well known, along with BRCA 2, to cause hereditary breast and ovarian cancer, but here we will specifically focus on BRCA1. We introduce the mechanism and the latest report on homologous recombination repair, replication, involvement in checkpoint regulation, transcription, chromatin remodeling, and cytoplasmic function (centrosome regulation, apoptosis, selective autophagy), and consider the possibility of carcinogenesis from inhibition of the intracellular functions in each. We also consider the possibility of drug development based on each function. Finally, we will explain, from data obtained through basic research, that an appropriate regimen is important for raising the response rate for poly (ADP)-ribose polymerase inhibitors, in the case of low susceptibility, iatrogenic toxicity, tolerance, etc.
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Affiliation(s)
- Miho Takaoka
- Department of Molecular Genetics, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - Yoshio Miki
- Department of Molecular Genetics, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan. .,Department of Genetic Diagnosis, The Cancer Institute, Japanese Foundation for Cancer Research, 3-10-6 Ariake, Koto-ku, Tokyo, 135-8550, Japan.
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42
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Chen Y, Liu H, Zhang H, Sun C, Hu Z, Tian Q, Peng C, Jiang P, Hua H, Li X, Pei H. And-1 coordinates with CtIP for efficient homologous recombination and DNA damage checkpoint maintenance. Nucleic Acids Res 2017; 45:2516-2530. [PMID: 27940552 PMCID: PMC5389581 DOI: 10.1093/nar/gkw1212] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 11/25/2016] [Indexed: 12/29/2022] Open
Abstract
To prevent genomic instability, cells respond to DNA lesions by blocking cell cycle progression and initiating DNA repair. Homologous recombination repair of DNA breaks requires CtIP-dependent resection of the DNA ends, which is thought to play a key role in activation of CHK1 kinase to induce the cell cycle checkpoint. But the mechanism is still not fully understood. Here, we establish that And-1, a replisome component, promotes DNA-end resection and DNA repair by homologous recombination. Mechanistically, And-1 interacts with CtIP and regulates CtIP recruitment to DNA damage sites. And-1 localizes to sites of DNA damage dependent on MDC1-RNF8 pathway, and is required for resistance to many DNA-damaging and replication stress-inducing agents. Furthermore, we show that And-1-CtIP axis is critically required for sustained ATR-CHK1 checkpoint signaling and for maintaining both the intra-S- and G2-phase checkpoints. Our findings thus identify And-1 as a novel DNA repair regulator and reveal how the replisome regulates the DNA damage induced checkpoint and genomic stability.
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Affiliation(s)
- Yali Chen
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing 100850, China
| | - Hailong Liu
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing 100850, China
| | - Haoxing Zhang
- School of Life Sciences and Oceanography, Shenzhen University, Shenzhen, Guangdong Province 518060, China
| | - Changqing Sun
- Department of neurosurgery, Tianjin Baodi Hospital, Baodi Clinical College of Tianjin Medical University, Tianjin 301800, China
| | - Zhaohua Hu
- Department of Orthopedics, Renhe Hospital of Three Gorges University, Yichang 443001, China
| | - Qingsong Tian
- Department of Orthopedics, Renhe Hospital of Three Gorges University, Yichang 443001, China
| | - Changmin Peng
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Lab, College of Biotechnology, Tianjin University of Science and Technology, No 29, 13ST. TEDA, Tianjin 300457, China
| | - Pei Jiang
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing 100850, China
| | - Hui Hua
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing 100850, China
| | - Xinzhi Li
- Department of Orthopedics, Renhe Hospital of Three Gorges University, Yichang 443001, China
| | - Huadong Pei
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing 100850, China
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43
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Chen CC, Kass EM, Yen WF, Ludwig T, Moynahan ME, Chaudhuri J, Jasin M. ATM loss leads to synthetic lethality in BRCA1 BRCT mutant mice associated with exacerbated defects in homology-directed repair. Proc Natl Acad Sci U S A 2017; 114:7665-7670. [PMID: 28659469 PMCID: PMC5530697 DOI: 10.1073/pnas.1706392114] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
BRCA1 is essential for homology-directed repair (HDR) of DNA double-strand breaks in part through antagonism of the nonhomologous end-joining factor 53BP1. The ATM kinase is involved in various aspects of DNA damage signaling and repair, but how ATM participates in HDR and genetically interacts with BRCA1 in this process is unclear. To investigate this question, we used the Brca1S1598F mouse model carrying a mutation in the BRCA1 C-terminal domain of BRCA1. Whereas ATM loss leads to a mild HDR defect in adult somatic cells, we find that ATM inhibition leads to severely reduced HDR in Brca1S1598F cells. Consistent with a critical role for ATM in HDR in this background, loss of ATM leads to synthetic lethality of Brca1S1598F mice. Whereas both ATM and BRCA1 promote end resection, which can be regulated by 53BP1, 53bp1 deletion does not rescue the HDR defects of Atm mutant cells, in contrast to Brca1 mutant cells. These results demonstrate that ATM has a role in HDR independent of the BRCA1-53BP1 antagonism and that its HDR function can become critical in certain contexts.
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Affiliation(s)
- Chun-Chin Chen
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065
- Biochemistry & Structural Biology, Cell & Developmental Biology, and Molecular Biology (BCMB) Allied Program, Weill Cornell Graduate School of Medical Sciences, Cornell University, New York, NY 10065
| | - Elizabeth M Kass
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065
| | - Wei-Feng Yen
- Biochemistry & Structural Biology, Cell & Developmental Biology, and Molecular Biology (BCMB) Allied Program, Weill Cornell Graduate School of Medical Sciences, Cornell University, New York, NY 10065
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065
| | - Thomas Ludwig
- Department of Cancer Biology and Genetics, Ohio State University College of Medicine, Columbus, OH 43210
| | - Mary Ellen Moynahan
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY 10065
| | - Jayanta Chaudhuri
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065
| | - Maria Jasin
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065;
- Biochemistry & Structural Biology, Cell & Developmental Biology, and Molecular Biology (BCMB) Allied Program, Weill Cornell Graduate School of Medical Sciences, Cornell University, New York, NY 10065
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Schwertman P, Bekker-Jensen S, Mailand N. Regulation of DNA double-strand break repair by ubiquitin and ubiquitin-like modifiers. Nat Rev Mol Cell Biol 2017; 17:379-94. [PMID: 27211488 DOI: 10.1038/nrm.2016.58] [Citation(s) in RCA: 265] [Impact Index Per Article: 37.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
DNA double-strand breaks (DSBs) are highly cytotoxic DNA lesions. The swift recognition and faithful repair of such damage is crucial for the maintenance of genomic stability, as well as for cell and organismal fitness. Signalling by ubiquitin, SUMO and other ubiquitin-like modifiers (UBLs) orchestrates and regulates cellular responses to DSBs at multiple levels, often involving extensive crosstalk between these modifications. Recent findings have revealed compelling insights into the complex mechanisms by which ubiquitin and UBLs regulate protein interactions with DSB sites to promote accurate lesion repair and protection of genome integrity in mammalian cells. These advances offer new therapeutic opportunities for diseases linked to genetic instability.
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Affiliation(s)
- Petra Schwertman
- Ubiquitin Signaling Group, The Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Simon Bekker-Jensen
- Ubiquitin Signaling Group, The Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Niels Mailand
- Ubiquitin Signaling Group, The Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
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Anantha RW, Simhadri S, Foo TK, Miao S, Liu J, Shen Z, Ganesan S, Xia B. Functional and mutational landscapes of BRCA1 for homology-directed repair and therapy resistance. eLife 2017; 6. [PMID: 28398198 PMCID: PMC5432210 DOI: 10.7554/elife.21350] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 04/10/2017] [Indexed: 12/20/2022] Open
Abstract
BRCA1 plays a critical role in homology-directed repair (HDR) of DNA double strand breaks, and the repair defect of BRCA1-mutant cancer cells is being targeted with platinum drugs and poly (ADP-ribose) polymerase (PARP) inhibitors. We have employed relatively simple and sensitive assays to determine the function of BRCA1 variants or mutants in two HDR mechanisms, homologous recombination (HR) and single strand annealing (SSA), and in conferring resistance to cisplatin and olaparib in human cancer cells. Our results define the functionality of the top 22 patient-derived BRCA1 missense variants and the contribution of different domains of BRCA1 and its E3 ubiquitin ligase activity to HDR and drug resistance. Importantly, our results also demonstrate that the BRCA1-PALB2 interaction dictates the choice between HR and SSA. These studies establish functional and mutational landscapes of BRCA1 for HDR and therapy resistance, while revealing novel insights into BRCA1 regulatory mechanisms and HDR pathway choice. DOI:http://dx.doi.org/10.7554/eLife.21350.001 Genes are the instruction manuals of life and contain the information needed to build the proteins that keep cells alive. Over time, genes can accumulate errors or mutations and eventually become faulty, which can lead to diseases like cancer. Sometimes mutations can be passed on through generations and increase the chances of getting cancer. The BRCA1 gene, for example, provides instructions for making a protein that helps to repair or remove damaged DNA and stops cells from growing uncontrollably. When the BRCA1 gene becomes faulty, cells could continue to grow with damaged DNA. This makes it more likely for cancer to develop, especially breast cancer and ovarian cancer. However, not all changes in BRCA1 gene cause the protein to become faulty or lead to cancer. In fact, about 30% of BRCA1 gene changes identified by genetic tests are referred to as ‘variants of uncertain clinical significance’, meaning that it is not clear if these variants are indeed mutations that could affect the clinical outcome of the people that carry them. Software predictions based largely on patient data have categorized many of these variants as not cancer-causing, but the majority still need to be experimentally tested and confirmed. Many studies have tried to determine the effect of selected variants on the BRCA1 protein, but a complete picture remains lacking. Now, Anantha et al. have tested the top 22 common variants in the BRCA1 gene, some of which had known effects and some did not. The study tested how these variants affect the ability of the protein to repair damaged DNA and the efficacy of chemotherapies targeting cancer cells with a DNA repair defect. The experiments revealed that three specific parts of the protein must remain intact in order for the protein to carry out this activity, i.e. mutations that affect these three areas are likely to cause cancer and also make cancer cells vulnerable to these chemotherapies. Anantha et al. also generated a series of 10 artificially shortened BRCA1 proteins, each missing a specific part, to determine the possible effects of other variants in those missing parts. Together the findings reveal previously unknown effects of certain variants that are commonly seen in cancer patients as well new insights into how the BRCA1 protein repairs DNA. The next step will be to assess rarer variants where little data is available. A better understanding of how these variants affect DNA repair and drug response will help to improve the genetic counseling and treatment of patients with breast cancer and ovarian cancer. DOI:http://dx.doi.org/10.7554/eLife.21350.002
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Affiliation(s)
- Rachel W Anantha
- Rutgers Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, New Brunswick, United States.,Department of Radiation Oncology, Rutgers, The State University of New Jersey, New Brunswick, United States
| | - Srilatha Simhadri
- Rutgers Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, New Brunswick, United States.,Department of Radiation Oncology, Rutgers, The State University of New Jersey, New Brunswick, United States.,Department of Medicine, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, New Brunswick, United States
| | - Tzeh Keong Foo
- Rutgers Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, New Brunswick, United States.,Department of Radiation Oncology, Rutgers, The State University of New Jersey, New Brunswick, United States
| | - Susanna Miao
- Department of Genetics, School of Arts and Sciences, Rutgers, The State University of New Jersey, Piscataway, United States
| | - Jingmei Liu
- Rutgers Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, New Brunswick, United States.,Department of Radiation Oncology, Rutgers, The State University of New Jersey, New Brunswick, United States
| | - Zhiyuan Shen
- Rutgers Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, New Brunswick, United States.,Department of Radiation Oncology, Rutgers, The State University of New Jersey, New Brunswick, United States
| | - Shridar Ganesan
- Rutgers Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, New Brunswick, United States.,Department of Radiation Oncology, Rutgers, The State University of New Jersey, New Brunswick, United States.,Department of Medicine, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, New Brunswick, United States
| | - Bing Xia
- Rutgers Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, New Brunswick, United States
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Biehs R, Steinlage M, Barton O, Juhász S, Künzel J, Spies J, Shibata A, Jeggo PA, Löbrich M. DNA Double-Strand Break Resection Occurs during Non-homologous End Joining in G1 but Is Distinct from Resection during Homologous Recombination. Mol Cell 2017; 65:671-684.e5. [PMID: 28132842 PMCID: PMC5316416 DOI: 10.1016/j.molcel.2016.12.016] [Citation(s) in RCA: 153] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2016] [Revised: 09/30/2016] [Accepted: 12/19/2016] [Indexed: 01/01/2023]
Abstract
Canonical non-homologous end joining (c-NHEJ) repairs DNA double-strand breaks (DSBs) in G1 cells with biphasic kinetics. We show that DSBs repaired with slow kinetics, including those localizing to heterochromatic regions or harboring additional lesions at the DSB site, undergo resection prior to repair by c-NHEJ and not alt-NHEJ. Resection-dependent c-NHEJ represents an inducible process during which Plk3 phosphorylates CtIP, mediating its interaction with Brca1 and promoting the initiation of resection. Mre11 exonuclease, EXD2, and Exo1 execute resection, and Artemis endonuclease functions to complete the process. If resection does not commence, then repair can ensue by c-NHEJ, but when executed, Artemis is essential to complete resection-dependent c-NHEJ. Additionally, Mre11 endonuclease activity is dispensable for resection in G1. Thus, resection in G1 differs from the process in G2 that leads to homologous recombination. Resection-dependent c-NHEJ significantly contributes to the formation of deletions and translocations in G1, which represent important initiating events in carcinogenesis.
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Affiliation(s)
- Ronja Biehs
- Radiation Biology and DNA Repair, Darmstadt University of Technology, 64287 Darmstadt, Germany
| | - Monika Steinlage
- Radiation Biology and DNA Repair, Darmstadt University of Technology, 64287 Darmstadt, Germany
| | - Olivia Barton
- Radiation Biology and DNA Repair, Darmstadt University of Technology, 64287 Darmstadt, Germany
| | - Szilvia Juhász
- Radiation Biology and DNA Repair, Darmstadt University of Technology, 64287 Darmstadt, Germany
| | - Julia Künzel
- Radiation Biology and DNA Repair, Darmstadt University of Technology, 64287 Darmstadt, Germany
| | - Julian Spies
- Radiation Biology and DNA Repair, Darmstadt University of Technology, 64287 Darmstadt, Germany
| | - Atsushi Shibata
- Genome Damage and Stability Centre, University of Sussex, Brighton BN1 9RQ, UK; Advanced Scientific Research Leaders Development Unit, Gunma University, Maebashi, Gunma 371-8511, Japan.
| | - Penny A Jeggo
- Genome Damage and Stability Centre, University of Sussex, Brighton BN1 9RQ, UK.
| | - Markus Löbrich
- Radiation Biology and DNA Repair, Darmstadt University of Technology, 64287 Darmstadt, Germany.
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47
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Personalised Medicine: Genome Maintenance Lessons Learned from Studies in Yeast as a Model Organism. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1007:157-178. [PMID: 28840557 DOI: 10.1007/978-3-319-60733-7_9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Yeast research has been tremendously contributing to the understanding of a variety of molecular pathways due to the ease of its genetic manipulation, fast doubling time as well as being cost-effective. The understanding of these pathways did not only help scientists learn more about the cellular functions but also assisted in deciphering the genetic and cellular defects behind multiple diseases. Hence, yeast research not only opened the doors for transforming basic research into applied research, but also paved the roads for improving diagnosis and innovating personalized therapy of different diseases. In this chapter, we discuss how yeast research has contributed to understanding major genome maintenance pathways such as the S-phase checkpoint activation pathways, repair via homologous recombination and non-homologous end joining as well as topoisomerases-induced protein linked DNA breaks repair. Defects in these pathways lead to neurodegenerative diseases and cancer. Thus, the understanding of the exact genetic defects underlying these diseases allowed the development of personalized medicine, improving the diagnosis and treatment and overcoming the detriments of current conventional therapies such as the side effects, toxicity as well as drug resistance.
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Fradet-Turcotte A, Sitz J, Grapton D, Orthwein A. BRCA2 functions: from DNA repair to replication fork stabilization. Endocr Relat Cancer 2016; 23:T1-T17. [PMID: 27530658 DOI: 10.1530/erc-16-0297] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2016] [Accepted: 08/16/2016] [Indexed: 12/12/2022]
Abstract
Maintaining genomic integrity is essential to preserve normal cellular physiology and to prevent the emergence of several human pathologies including cancer. The breast cancer susceptibility gene 2 (BRCA2, also known as the Fanconi anemia (FA) complementation group D1 (FANCD1)) is a potent tumor suppressor that has been extensively studied in DNA double-stranded break (DSB) repair by homologous recombination (HR). However, BRCA2 participates in numerous other processes central to maintaining genome stability, including DNA replication, telomere homeostasis and cell cycle progression. Consequently, inherited mutations in BRCA2 are associated with an increased risk of breast, ovarian and pancreatic cancers. Furthermore, bi-allelic mutations in BRCA2 are linked to FA, a rare chromosome instability syndrome characterized by aplastic anemia in children as well as susceptibility to leukemia and cancer. Here, we discuss the recent developments underlying the functions of BRCA2 in the maintenance of genomic integrity. The current model places BRCA2 as a central regulator of genome stability by repairing DSBs and limiting replication stress. These findings have direct implications for the development of novel anticancer therapeutic approaches.
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Affiliation(s)
- Amélie Fradet-Turcotte
- Laval University Cancer Research CenterCHU de Québec Research Center - Université Laval, Hôtel-Dieu de Québec, Oncology Axis, Quebec City, Canada
| | - Justine Sitz
- Laval University Cancer Research CenterCHU de Québec Research Center - Université Laval, Hôtel-Dieu de Québec, Oncology Axis, Quebec City, Canada
| | - Damien Grapton
- Lady Davis Institute for Medical ResearchSegal Cancer Centre, Jewish General Hospital, Montreal, Canada
| | - Alexandre Orthwein
- Lady Davis Institute for Medical ResearchSegal Cancer Centre, Jewish General Hospital, Montreal, Canada Department of OncologyMcGill University, Montreal, Canada
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Aparicio T, Baer R, Gottesman M, Gautier J. MRN, CtIP, and BRCA1 mediate repair of topoisomerase II-DNA adducts. J Cell Biol 2016; 212:399-408. [PMID: 26880199 PMCID: PMC4754713 DOI: 10.1083/jcb.201504005] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Analyses in Xenopus egg extracts show that the MRN complex, CtIP, BRCA1, and the interaction between CtIP and BRCA1 are required for the removal of Top2–DNA adducts, forsubsequent resection of Top2-adducted double-strand break ends, and for cellular resistance to etoposide during genomic DNA replication. Repair of DNA double-strand breaks (DSBs) with complex ends poses a special challenge, as additional processing is required before DNA ligation. For example, protein–DNA adducts must be removed to allow repair by either nonhomologous end joining or homology-directed repair. Here, we investigated the processing of topoisomerase II (Top2)–DNA adducts induced by treatment with the chemotherapeutic agent etoposide. Through biochemical analysis in Xenopus laevis egg extracts, we establish that the MRN (Mre11, Rad50, and Nbs1) complex, CtIP, and BRCA1 are required for both the removal of Top2–DNA adducts and the subsequent resection of Top2-adducted DSB ends. Moreover, the interaction between CtIP and BRCA1, although dispensable for resection of endonuclease-generated DSB ends, is required for resection of Top2-adducted DSBs, as well as for cellular resistance to etoposide during genomic DNA replication.
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Affiliation(s)
- Tomas Aparicio
- Institute for Cancer Genetics, Columbia University, New York, NY, 10032
| | - Richard Baer
- Institute for Cancer Genetics, Columbia University, New York, NY, 10032
| | - Max Gottesman
- Department of Biochemistry and Biophysics, Columbia University, New York, NY, 10032
| | - Jean Gautier
- Institute for Cancer Genetics, Columbia University, New York, NY, 10032 Department of Genetics and Development, Columbia University, New York, NY, 10032
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50
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Ahrabi S, Sarkar S, Pfister SX, Pirovano G, Higgins GS, Porter ACG, Humphrey TC. A role for human homologous recombination factors in suppressing microhomology-mediated end joining. Nucleic Acids Res 2016; 44:5743-57. [PMID: 27131361 PMCID: PMC4937322 DOI: 10.1093/nar/gkw326] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2015] [Revised: 04/13/2016] [Accepted: 04/14/2016] [Indexed: 12/22/2022] Open
Abstract
DNA double-strand breaks (DSBs) are toxic lesions, which if improperly repaired can result in cell death or genomic instability. DSB repair is usually facilitated by the classical non-homologous end joining (C-NHEJ), or homologous recombination (HR) pathways. However, a mutagenic alternative NHEJ pathway, microhomology-mediated end joining (MMEJ), can also be deployed. While MMEJ is suppressed by C-NHEJ, the relationship between HR and MMEJ is less clear. Here, we describe a role for HR genes in suppressing MMEJ in human cells. By monitoring DSB mis-repair using a sensitive HPRT assay, we found that depletion of HR proteins, including BRCA2, BRCA1 or RPA, resulted in a distinct mutational signature associated with significant increases in break-induced mutation frequencies, deletion lengths and the annealing of short regions of microhomology (2-6 bp) across the break-site. This signature was dependent on CtIP, MRE11, POLQ and PARP, and thus indicative of MMEJ. In contrast to CtIP or MRE11, depletion of BRCA1 resulted in increased partial resection and MMEJ, thus revealing a functional distinction between these early acting HR factors. Together these findings indicate that HR factors suppress mutagenic MMEJ following DSB resection.
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Affiliation(s)
- Sara Ahrabi
- CRUK MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
| | - Sovan Sarkar
- CRUK MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
| | - Sophia X Pfister
- CRUK MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
| | - Giacomo Pirovano
- CRUK MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
| | - Geoff S Higgins
- CRUK MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
| | - Andrew C G Porter
- Gene Targeting Group, Centre for Haematology, Imperial College Faculty of Medicine, London W12 0NN, UK
| | - Timothy C Humphrey
- CRUK MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
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