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Alvaro-Aranda L, Petitalot A, Djeghmoum Y, Panigada D, Singh J, Ehlén Å, Vugic D, Martin C, Miron S, Contreras-Perez A, Nhiri N, Boucherit V, Lafitte P, Dumoulin I, Quiles F, Rouleau E, Jacquet E, Feliubadaló L, del Valle J, Sharan SK, Stoppa-Lyonnet D, Zinn-Justin S, Lázaro C, Caputo S, Carreira A. The BRCA2 R2645G variant increases DNA binding and induces hyper-recombination. Nucleic Acids Res 2024; 52:6964-6976. [PMID: 38142462 PMCID: PMC11229362 DOI: 10.1093/nar/gkad1222] [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: 08/08/2023] [Revised: 11/30/2023] [Accepted: 12/12/2023] [Indexed: 12/26/2023] Open
Abstract
BRCA2 tumor suppressor protein ensures genome integrity by mediating DNA repair via homologous recombination (HR). This function is executed in part by its canonical DNA binding domain located at the C-terminus (BRCA2CTD), the only folded domain of the protein. Most germline pathogenic missense variants are located in this highly conserved region which binds to single-stranded DNA (ssDNA) and to the acidic protein DSS1. These interactions are essential for the HR function of BRCA2. Here, we report that the variant R2645G, identified in breast cancer and located at the DSS1 interface, unexpectedly increases the ssDNA binding activity of BRCA2CTDin vitro. Human cells expressing this variant display a hyper-recombination phenotype, chromosomal instability in the form of chromatid gaps when exposed to DNA damage, and increased PARP inhibitor sensitivity. In mouse embryonic stem cells (mES), this variant alters viability and confers sensitivity to cisplatin and Mitomycin C. These results suggest that BRCA2 interaction with ssDNA needs to be tightly regulated to limit HR and prevent chromosomal instability and we propose that this control mechanism involves DSS1. Given that several missense variants located within this region have been identified in breast cancer patients, these findings might have clinical implications for carriers.
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Affiliation(s)
- Lucia Alvaro-Aranda
- Genome Instability and Cancer Predisposition Laboratory, Centro de Biologia Molecular Severo Ochoa (CBMSO), CSIC-UAM, Madrid 28049, Spain
| | - Ambre Petitalot
- Department of Genetics, Institut Curie, Paris 75005, France
- PSL Research University, Paris 75005, France
| | - Yasmina Djeghmoum
- Institut Curie, PSL Research University, CNRS, UMR3348, F-91405 Orsay, France
- Paris-Saclay University CNRS, UMR3348, F-91405 Orsay, France
| | - Davide Panigada
- Institut Curie, PSL Research University, CNRS, UMR3348, F-91405 Orsay, France
- Paris-Saclay University CNRS, UMR3348, F-91405 Orsay, France
| | - Jenny Kaur Singh
- Institut Curie, PSL Research University, CNRS, UMR3348, F-91405 Orsay, France
- Paris-Saclay University CNRS, UMR3348, F-91405 Orsay, France
| | - Åsa Ehlén
- Institut Curie, PSL Research University, CNRS, UMR3348, F-91405 Orsay, France
- Paris-Saclay University CNRS, UMR3348, F-91405 Orsay, France
| | - Domagoj Vugic
- Institut Curie, PSL Research University, CNRS, UMR3348, F-91405 Orsay, France
- Paris-Saclay University CNRS, UMR3348, F-91405 Orsay, France
| | - Charlotte Martin
- Institut Curie, PSL Research University, CNRS, UMR3348, F-91405 Orsay, France
- Paris-Saclay University CNRS, UMR3348, F-91405 Orsay, France
| | - Simona Miron
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Paris-Saclay University, 91190 Gif-sur-Yvette, France
| | - Aida Contreras-Perez
- Genome Instability and Cancer Predisposition Laboratory, Centro de Biologia Molecular Severo Ochoa (CBMSO), CSIC-UAM, Madrid 28049, Spain
| | - Naima Nhiri
- Institut de Chimie des Substances Naturelles, Paris-Saclay University, CNRS, 91190 Gif-sur-Yvette, France
| | - Virginie Boucherit
- Institut Curie, PSL Research University, CNRS, UMR3348, F-91405 Orsay, France
- Paris-Saclay University CNRS, UMR3348, F-91405 Orsay, France
| | - Philippe Lafitte
- Department of Genetics, Institut Curie, Paris 75005, France
- PSL Research University, Paris 75005, France
| | - Isaac Dumoulin
- Institut Curie, PSL Research University, CNRS, UMR3348, F-91405 Orsay, France
- Paris-Saclay University CNRS, UMR3348, F-91405 Orsay, France
| | - Francisco Quiles
- Hereditary Cancer Program, Catalan Institute of Oncology (ICO), Hereditary Cancer Group, Molecular Mechanisms and Experimental Therapy in Oncology Program, Institut d’Investigació Biomèdica de Bellvitge (IDIBELL), L’Hospitalet de Llobregat, Spain
- Ciber Oncología (CIBERONC), Instituto Salud Carlos III, Madrid, Spain
| | - Etienne Rouleau
- Department of Genetics, Institut Curie, Paris 75005, France
- PSL Research University, Paris 75005, France
| | - Eric Jacquet
- Institut de Chimie des Substances Naturelles, Paris-Saclay University, CNRS, 91190 Gif-sur-Yvette, France
| | - Lidia Feliubadaló
- Hereditary Cancer Program, Catalan Institute of Oncology (ICO), Hereditary Cancer Group, Molecular Mechanisms and Experimental Therapy in Oncology Program, Institut d’Investigació Biomèdica de Bellvitge (IDIBELL), L’Hospitalet de Llobregat, Spain
- Ciber Oncología (CIBERONC), Instituto Salud Carlos III, Madrid, Spain
| | - Jesús del Valle
- Hereditary Cancer Program, Catalan Institute of Oncology (ICO), Hereditary Cancer Group, Molecular Mechanisms and Experimental Therapy in Oncology Program, Institut d’Investigació Biomèdica de Bellvitge (IDIBELL), L’Hospitalet de Llobregat, Spain
- Ciber Oncología (CIBERONC), Instituto Salud Carlos III, Madrid, Spain
| | - Shyam K Sharan
- Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, USA
| | - Dominique Stoppa-Lyonnet
- Department of Genetics, Institut Curie, Paris 75005, France
- Paris-Cité University, Paris, France
- INSERM U830, Institut Curie, Paris 75005, France
| | - Sophie Zinn-Justin
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Paris-Saclay University, 91190 Gif-sur-Yvette, France
| | - Conxi Lázaro
- Hereditary Cancer Program, Catalan Institute of Oncology (ICO), Hereditary Cancer Group, Molecular Mechanisms and Experimental Therapy in Oncology Program, Institut d’Investigació Biomèdica de Bellvitge (IDIBELL), L’Hospitalet de Llobregat, Spain
- Ciber Oncología (CIBERONC), Instituto Salud Carlos III, Madrid, Spain
| | - Sandrine M Caputo
- Department of Genetics, Institut Curie, Paris 75005, France
- PSL Research University, Paris 75005, France
| | - Aura Carreira
- Genome Instability and Cancer Predisposition Laboratory, Centro de Biologia Molecular Severo Ochoa (CBMSO), CSIC-UAM, Madrid 28049, Spain
- Institut Curie, PSL Research University, CNRS, UMR3348, F-91405 Orsay, France
- Paris-Saclay University CNRS, UMR3348, F-91405 Orsay, France
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Meyer D, Ceballos SJ, Gore S, Liu J, Reginato G, Cano-Linares MI, Maslowska KH, Villafañez F, Ede C, Pagès V, Prado F, Cejka P, Heyer WD. Rad51 determines pathway usage in post-replication repair. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.14.599120. [PMID: 38915629 PMCID: PMC11195247 DOI: 10.1101/2024.06.14.599120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
Stalled replication forks can be processed by several distinct mechanisms collectively called post-replication repair which includes homologous recombination, fork regression, and translesion DNA synthesis. However, the regulation of the usage between these pathways is not fully understood. The Rad51 protein plays a pivotal role in maintaining genomic stability through its roles in HR and in protecting stalled replication forks from degradation. We report the isolation of separation-of-function mutations in Saccharomyces cerevisiae Rad51 that retain their recombination function but display a defect in fork protection leading to a shift in post-replication repair pathway usage from HR to alternate pathways including mutagenic translesion synthesis. Rad51-E135D and Rad51-K305N show normal in vivo and in vitro recombination despite changes in their DNA binding profiles, in particular to dsDNA, with a resulting effect on their ATPase activities. The mutants lead to a defect in Rad51 recruitment to stalled forks in vivo as well as a defect in the protection of dsDNA from degradation by Dna2-Sgs1 and Exo1 in vitro . A high-resolution cryo-electron microscopy structure of the Rad51-ssDNA filament at 2.4 Å resolution provides a structural basis for a mechanistic understanding of the mutant phenotypes. Together, the evidence suggests a model in which Rad51 binding to duplex DNA is critical to control pathway usage at stalled replication forks.
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Son MY, Belan O, Spirek M, Cibulka J, Nikulenkov F, Kim YY, Hwang S, Myung K, Montagna C, Kim TM, Krejci L, Hasty P. RAD51 separation of function mutation disables replication fork maintenance but preserves DSB repair. iScience 2024; 27:109524. [PMID: 38577109 PMCID: PMC10993188 DOI: 10.1016/j.isci.2024.109524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 03/01/2023] [Accepted: 03/14/2024] [Indexed: 04/06/2024] Open
Abstract
Homologous recombination (HR) protects replication forks (RFs) and repairs DNA double-strand breaks (DSBs). Within HR, BRCA2 regulates RAD51 via two interaction regions: the BRC repeats to form filaments on single-stranded DNA and exon 27 (Ex27) to stabilize the filament. Here, we identified a RAD51 S181P mutant that selectively disrupted the RAD51-Ex27 association while maintaining interaction with BRC repeat and proficiently forming filaments capable of DNA binding and strand invasion. Interestingly, RAD51 S181P was defective for RF protection/restart but proficient for DSB repair. Our data suggest that Ex27-mediated stabilization of RAD51 filaments is required for the protection of RFs, while it seems dispensable for the repair of DSBs.
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Affiliation(s)
- Mi Young Son
- Department of Molecular Medicine, The Barshop Institute for Longevity and Aging Studies, The Cancer Therapy Research Center, UT Health San Antonio, San Antonio, TX 78229, USA
| | - Ondrej Belan
- Department of Biology, Masaryk University, 625 00 Brno, Czech Republic
| | - Mario Spirek
- Department of Biology, Masaryk University, 625 00 Brno, Czech Republic
- National Centre for Biomolecular Research, Masaryk University, 625 00 Brno, Czech Republic
| | - Jakub Cibulka
- Department of Biology, Masaryk University, 625 00 Brno, Czech Republic
| | - Fedor Nikulenkov
- Department of Biology, Masaryk University, 625 00 Brno, Czech Republic
| | - You Young Kim
- Center for Genomic Integrity Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
| | - Sunyoung Hwang
- Center for Genomic Integrity Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
| | - Kyungjae Myung
- Center for Genomic Integrity Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
| | - Cristina Montagna
- Department of Genetics, Albert Einstein College of Medicine of Yeshiva University, Bronx, NY 10461, USA
| | - Tae Moon Kim
- Department of Molecular Medicine, The Barshop Institute for Longevity and Aging Studies, The Cancer Therapy Research Center, UT Health San Antonio, San Antonio, TX 78229, USA
- Center for Genomic Integrity Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
| | - Lumir Krejci
- Department of Biology, Masaryk University, 625 00 Brno, Czech Republic
- National Centre for Biomolecular Research, Masaryk University, 625 00 Brno, Czech Republic
| | - Paul Hasty
- Department of Molecular Medicine, The Barshop Institute for Longevity and Aging Studies, The Cancer Therapy Research Center, UT Health San Antonio, San Antonio, TX 78229, USA
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Ito M, Fujita Y, Shinohara A. Positive and negative regulators of RAD51/DMC1 in homologous recombination and DNA replication. DNA Repair (Amst) 2024; 134:103613. [PMID: 38142595 DOI: 10.1016/j.dnarep.2023.103613] [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: 08/02/2023] [Revised: 12/10/2023] [Accepted: 12/10/2023] [Indexed: 12/26/2023]
Abstract
RAD51 recombinase plays a central role in homologous recombination (HR) by forming a nucleoprotein filament on single-stranded DNA (ssDNA) to catalyze homology search and strand exchange between the ssDNA and a homologous double-stranded DNA (dsDNA). The catalytic activity of RAD51 assembled on ssDNA is critical for the DNA-homology-mediated repair of DNA double-strand breaks in somatic and meiotic cells and restarting stalled replication forks during DNA replication. The RAD51-ssDNA complex also plays a structural role in protecting the regressed/reversed replication fork. Two types of regulators control RAD51 filament formation, stability, and dynamics, namely positive regulators, including mediators, and negative regulators, so-called remodelers. The appropriate balance of action by the two regulators assures genome stability. This review describes the roles of positive and negative RAD51 regulators in HR and DNA replication and its meiosis-specific homolog DMC1 in meiotic recombination. We also provide future study directions for a comprehensive understanding of RAD51/DMC1-mediated regulation in maintaining and inheriting genome integrity.
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Affiliation(s)
- Masaru Ito
- Institute for Protein Research, Osaka University, Yamadaoka 3-2, Suita, Osaka 565-0871, Japan.
| | - Yurika Fujita
- Institute for Protein Research, Osaka University, Yamadaoka 3-2, Suita, Osaka 565-0871, Japan.
| | - Akira Shinohara
- Institute for Protein Research, Osaka University, Yamadaoka 3-2, Suita, Osaka 565-0871, Japan.
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5
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Minello A, Carreira A. BRCA1/2 Haploinsufficiency: Exploring the Impact of Losing one Allele. J Mol Biol 2024; 436:168277. [PMID: 37714298 DOI: 10.1016/j.jmb.2023.168277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 09/07/2023] [Accepted: 09/08/2023] [Indexed: 09/17/2023]
Abstract
Since their discovery in the late 20th century, significant progress has been made in elucidating the functions of the tumor suppressor proteins BRCA1 and BRCA2. These proteins play vital roles in maintaining genome integrity, including DNA repair, replication fork protection, and chromosome maintenance. It is well-established that germline mutations in BRCA1 and BRCA2 increase the risk of breast and ovarian cancer; however, the precise mechanism underlying tumor formation in this context is not fully understood. Contrary to the long-standing belief that the loss of the second wild-type allele is necessary for tumor development, a growing body of evidence suggests that tumorigenesis can occur despite the presence of a single functional allele. This entails that heterozygosity in BRCA1/2 confers haploinsufficiency, where a single copy of the gene is not sufficient to fully suppress tumor formation. Here we provide an overview of the findings and the ongoing debate regarding BRCA haploinsufficiency. We further put out the challenges in studying this topic and discuss its potential relevance in the prevention and treatment of BRCA-related cancers.
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Affiliation(s)
- Anna Minello
- Institut Curie, PSL Research University, CNRS, UMR3348, F-91405 Orsay, France; Paris-Saclay University CNRS, UMR3348, F-91405 Orsay, France
| | - Aura Carreira
- Institut Curie, PSL Research University, CNRS, UMR3348, F-91405 Orsay, France; Paris-Saclay University CNRS, UMR3348, F-91405 Orsay, France; Genome Instability and Cancer Predisposition Lab, Department of Genome Dynamics and Function, Centro de Biologia Molecular Severo Ochoa (CBMSO, CSIC-UAM), Madrid 28049, Spain.
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6
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Liu Z, Feng C, Li C, He T, Wu G, Fu C, Li H, Shen M, Liu H. IGF-I protects porcine granulosa cells from hypoxia-induced apoptosis by promoting homologous recombination repair through the PI3K/AKT/E2F8/RAD51 pathway. FASEB J 2024; 38:e23332. [PMID: 38095232 DOI: 10.1096/fj.202301464r] [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: 07/18/2023] [Revised: 10/27/2023] [Accepted: 11/13/2023] [Indexed: 12/18/2023]
Abstract
Severe hypoxia induced by vascular compromise (ovarian torsion, surgery), obliteration of vessels (aging, chemotherapy, particularly platinum drugs) can cause massive follicle atresia. On the other hand, hypoxia increases the occurrence of DNA double-strand breaks (DSBs) and triggers cellular damage repair mechanisms; however, if the damage is not promptly repaired, it can also induce the apoptosis program. Insulin-like growth factor-I (IGF-I) is a polypeptide hormone that plays essential roles in stimulating mammalian follicular development. Here, we report a novel role for IGF-I in protecting hypoxic GCs from apoptosis by promoting DNA repair through the homologous recombination (HR) process. Indeed, the hypoxic environment within follicles significantly inhibited the efficiency of HR-directed DNA repair. The presence of IGF-I-induced HR pathway to alleviate hypoxia-induced DNA damage and apoptosis primarily through upregulating the expression of the RAD51 recombinase. Importantly, we identified a new transcriptional regulator of RAD51, namely E2F8, which mediates the protective effects of IGF-I on hypoxic GCs by facilitating the transcriptional activation of RAD51. Furthermore, we demonstrated that the PI3K/AKT pathway is crucial for IGF-I-induced E2F8 expression, resulting in increased RAD51 expression and enhanced HR activity, which mitigates hypoxia-induced DNA damage and thereby protects against GCs apoptosis. Together, these findings define a novel mechanism of IGF-I-mediated GCs protection by activating the HR repair through the PI3K/AKT/E2F8/RAD51 pathway under hypoxia.
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Affiliation(s)
- Zhaojun Liu
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Chungang Feng
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Chengyu Li
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Tong He
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Gang Wu
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Chen Fu
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Hongmin Li
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Ming Shen
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Honglin Liu
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
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7
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Ronson GE, Starowicz K, Anthony EJ, Piberger AL, Clarke LC, Garvin AJ, Beggs AD, Whalley CM, Edmonds MJ, Beesley JFJ, Morris JR. Mechanisms of synthetic lethality between BRCA1/2 and 53BP1 deficiencies and DNA polymerase theta targeting. Nat Commun 2023; 14:7834. [PMID: 38030626 PMCID: PMC10687250 DOI: 10.1038/s41467-023-43677-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 11/16/2023] [Indexed: 12/01/2023] Open
Abstract
A synthetic lethal relationship exists between disruption of polymerase theta (Polθ), and loss of either 53BP1 or homologous recombination (HR) proteins, including BRCA1; however, the mechanistic basis of these observations are unclear. Here we reveal two distinct mechanisms of Polθ synthetic lethality, identifying dual influences of 1) whether Polθ is lost or inhibited, and 2) the underlying susceptible genotype. Firstly, we find that the sensitivity of BRCA1/2- and 53BP1-deficient cells to Polθ loss, and 53BP1-deficient cells to Polθ inhibition (ART558) requires RAD52, and appropriate reduction of RAD52 can ameliorate these phenotypes. We show that in the absence of Polθ, RAD52 accumulations suppress ssDNA gap-filling in G2/M and encourage MRE11 nuclease accumulation. In contrast, the survival of BRCA1-deficient cells treated with Polθ inhibitor are not restored by RAD52 suppression, and ssDNA gap-filling is prevented by the chemically inhibited polymerase itself. These data define an additional role for Polθ, reveal the mechanism underlying synthetic lethality between 53BP1, BRCA1/2 and Polθ loss, and indicate genotype-dependent Polθ inhibitor mechanisms.
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Affiliation(s)
- George E Ronson
- Birmingham Centre for Genome Biology and Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - Katarzyna Starowicz
- Birmingham Centre for Genome Biology and Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
- Adthera Bio, Lyndon House, 62 Hagley Road, Birmingham, B16 8PE, UK
| | - Elizabeth J Anthony
- Birmingham Centre for Genome Biology and Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - Ann Liza Piberger
- Birmingham Centre for Genome Biology and Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - Lucy C Clarke
- Birmingham Centre for Genome Biology and Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
- West Midlands Regional Genetics Laboratory, Birmingham Women's Hospital, Mindelsohn Way, Birmingham, B15 2TG, UK
| | - Alexander J Garvin
- Birmingham Centre for Genome Biology and Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
- University of Leeds, Leeds, UK
| | - Andrew D Beggs
- Birmingham Centre for Genome Biology and Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
- Genomics Birmingham, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - Celina M Whalley
- Genomics Birmingham, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - Matthew J Edmonds
- Birmingham Centre for Genome Biology and Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
- Certara Insight, Danebrook Court, Oxford Office Village, Kidlington, Oxfordshire, OX5 1LQ, UK
| | - James F J Beesley
- Birmingham Centre for Genome Biology and Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - Joanna R Morris
- Birmingham Centre for Genome Biology and Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK.
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8
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Trouillard O, Dupaigne P, Dunoyer M, Doulazmi M, Herlin MK, Frismand S, Riou A, Legros V, Chevreux G, Veaute X, Busso D, Fouquet C, Saint-Martin C, Méneret A, Trembleau A, Dusart I, Dubacq C, Roze E. Congenital mirror movements are associated with defective polymerisation of RAD51. J Med Genet 2023; 60:1116-1126. [PMID: 37308287 DOI: 10.1136/jmg-2023-109189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 05/21/2023] [Indexed: 06/14/2023]
Abstract
BACKGROUND Mirror movements are involuntary movements of one hand that mirror intentional movements of the other hand. Congenital mirror movements (CMM) is a rare genetic disorder with autosomal dominant inheritance, in which mirror movements are the main neurological manifestation. CMM is associated with an abnormal decussation of the corticospinal tract, a major motor tract for voluntary movements. RAD51 is known to play a key role in homologous recombination with a critical function in DNA repair. While RAD51 haploinsufficiency was first proposed to explain CMM, other mechanisms could be involved. METHODS We performed Sanger sequencing of RAD51 in five newly identified CMM families to identify new pathogenic variants. We further investigated the expression of wild-type and mutant RAD51 in the patients' lymphoblasts at mRNA and protein levels. We then characterised the functions of RAD51 altered by non-truncating variants using biochemical approaches. RESULTS The level of wild-type RAD51 protein was lower in the cells of all patients with CMM compared with their non-carrier relatives. The reduction was less pronounced in asymptomatic carriers. In vitro, mutant RAD51 proteins showed loss-of-function for polymerisation, DNA binding and strand exchange activity. CONCLUSION Our study demonstrates that RAD51 haploinsufficiency, including loss-of-function of non-truncating variants, results in CMM. The incomplete penetrance likely results from post-transcriptional compensation. Changes in RAD51 levels and/or polymerisation properties could influence guidance of the corticospinal axons during development. Our findings open up new perspectives to understand the role of RAD51 in neurodevelopment.
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Affiliation(s)
- Oriane Trouillard
- INSERM, CNRS, Institut de Biologie Paris Seine, IBPS, Neuroscience Paris Seine, NPS, Sorbonne Université, F-75005 Paris, France
- Institut du Cerveau-Paris Brain Institute-ICM, Inserm, CNRS, AP-HP, Hôpital Pitié-Salpêtrière, Sorbonne Université, Paris, France
| | - Pauline Dupaigne
- Genome Maintenance and Molecular Microscopy UMR9019 CNRS, Université Paris-Saclay, Gustave Roussy, F-94805 Villejuif Cedex, France
| | - Margaux Dunoyer
- Hôpital Pitié-Salpêtrière, Département de Neurologie, AP-HP, Paris, France
| | - Mohamed Doulazmi
- INSERM, CNRS, Institut de Biologie Paris Seine, IBPS, Biological Adaptation and Ageing, B2A, Sorbonne Université, F-75005 Paris, France
| | - Morten Krogh Herlin
- Department of Clinical Genetics, Aarhus University Hospital, Aarhus, Denmark
| | | | - Audrey Riou
- Service de génétique clinique & Service de neurologie, CHU Rennes, Rennes, France
| | - Véronique Legros
- CNRS, Institut Jacques Monod, Université Paris Cité, F-75013 Paris, France
| | - Guillaume Chevreux
- CNRS, Institut Jacques Monod, Université Paris Cité, F-75013 Paris, France
| | - Xavier Veaute
- Université Paris-Saclay, Inserm, CEA, Stabilité Génétique Cellules Souches et Radiations, CIGEx/iRCM/IBFJ, Université Paris Cité, F-92260 Fontenay-aux-Roses, France
| | - Didier Busso
- Université Paris-Saclay, Inserm, CEA, Stabilité Génétique Cellules Souches et Radiations, CIGEx/iRCM/IBFJ, Université Paris Cité, F-92260 Fontenay-aux-Roses, France
| | - Coralie Fouquet
- INSERM, CNRS, Institut de Biologie Paris Seine, IBPS, Neuroscience Paris Seine, NPS, Sorbonne Université, F-75005 Paris, France
| | - Cécile Saint-Martin
- AP-HP, Hôpital Pitié-Salpêtrière, Département de Génétique Médicale, Sorbonne Université, Paris, France
| | - Aurélie Méneret
- Institut du Cerveau-Paris Brain Institute-ICM, Inserm, CNRS, AP-HP, Hôpital Pitié-Salpêtrière, Sorbonne Université, Paris, France
- Hôpital Pitié-Salpêtrière, DMU Neuroscience 6, AP-HP, Paris, France
| | - Alain Trembleau
- INSERM, CNRS, Institut de Biologie Paris Seine, IBPS, Neuroscience Paris Seine, NPS, Sorbonne Université, F-75005 Paris, France
| | - Isabelle Dusart
- INSERM, CNRS, Institut de Biologie Paris Seine, IBPS, Neuroscience Paris Seine, NPS, Sorbonne Université, F-75005 Paris, France
| | - Caroline Dubacq
- INSERM, CNRS, Institut de Biologie Paris Seine, IBPS, Neuroscience Paris Seine, NPS, Sorbonne Université, F-75005 Paris, France
| | - Emmanuel Roze
- Institut du Cerveau-Paris Brain Institute-ICM, Inserm, CNRS, AP-HP, Hôpital Pitié-Salpêtrière, Sorbonne Université, Paris, France
- Hôpital Pitié-Salpêtrière, DMU Neuroscience 6, AP-HP, Paris, France
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9
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Previtali V, Myers SH, Poppi L, Wynne K, Casamassima I, Girotto S, Di Stefano G, Farabegoli F, Roberti M, Oliviero G, Cavalli A. Preomic profile of BxPC-3 cells after treatment with BRC4. J Proteomics 2023; 288:104983. [PMID: 37536521 DOI: 10.1016/j.jprot.2023.104983] [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: 07/26/2023] [Accepted: 07/26/2023] [Indexed: 08/05/2023]
Abstract
BRCA2 and RAD51 are two proteins that play a central role in homologous recombination (HR) and DNA double strand break (DSB) repair. BRCA2 assists RAD51 fibrillation and defibrillation through binding with its eight BRC repeats, with BRC4 being one of the most efficient and best characterized. RAD51 inactivation by small molecules has been proposed as a strategy to impair BRCA2/RAD51 binding and, ultimately, the HR pathway, with the aim of making cancer cells more sensitive to PARP inhibitors (PARPi). This strategy, which mimics a synthetic lethality (SL) approach, has been successfully performed in vitro by using the myristoylated derivative of BRC4 (myr-BRC4), designed for a more efficient cell entry. The present study applies a method to obtain a proteomic fingerprint after cellular treatment with the myr-BRC4 peptide using a mass spectroscopy (MS) proteomic approach. (Data are available via ProteomeXchange with identifier PXD042696.) We performed a comparative proteomic profiling of the myr-BRC4 treated vs. untreated BxPC-3 pancreatic cancer cells and evaluated the differential expression of proteins. Among the identified proteins, we focused our attention on proteins shared by both the RAD51 and the BRCA2 interactomes, and on those whose reduction showed high statistical significance. Three downregulated proteins were identified (FANCI, FANCD2, and RPA3), and protein downregulation was confirmed through immunoblotting analysis, validating the MS approach. Our results suggest that, being a direct consequence of myr-BRC4 treatment, the detection of FANCD2, FANCI, and RPA3 downregulation could be used as an indicator for monitoring HR impairment. SIGNIFICANCE: RAD51's inhibition has gained increasing attention because of its possible implications in personalized medicine through the SL approach. Chemical disruption of protein-protein interactions (PPIs) between RAD51 and BRCA2, or some of its partner proteins, could potentiate PARPi DNA damage-induced cell death. This could have application for difficult to treat cancers, such as BRCA-competent and olaparib (PARPi) resistant pancreatic adenocarcinoma. Despite RAD51 being a widely studied target, researchers still lack detailed mechanistic information. This has stifled progress in the field with only a few RAD51 inhibitors having been identified, none of which have gained regulatory approval. Nevertheless, the peptide BRC4 is one of the most specific and best characterized RAD51 binder and inhibitor reported to date. Our study is the first to report the proteomic fingerprint consequent to cellular treatment of myr-BRC4, to offer a reference for the discovery of specific protein/pathway alterations within DNA damage repair. Our results suggest that, being a direct consequence of myr-BRC4 treatment, and ultimately ofBRCA2/RAD51 disruption, the detection of FANCD2, FANCI, and RPA3 downregulation could be used as an indicator for monitoring DNA damage repair impairment and therefore be used to potentiate the development of new effective therapeutic strategies.
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Affiliation(s)
- Viola Previtali
- Computational & Chemical Biology, Istituto Italiano di Tecnologia, 16163 Genova, Italy
| | - Samuel H Myers
- Computational & Chemical Biology, Istituto Italiano di Tecnologia, 16163 Genova, Italy
| | - Laura Poppi
- Department of Pharmacy and Biotechnology, University of Bologna, 40126 Bologna, Italy
| | - Kieran Wynne
- Systems Biology Ireland, School of Medicine, University College Dublin, Belfield Dublin 4, Ireland; Conway Institute of Biomolecular & Biomedical Research, University College Dublin, Dublin 4, Ireland
| | - Irene Casamassima
- Computational & Chemical Biology, Istituto Italiano di Tecnologia, 16163 Genova, Italy
| | - Stefania Girotto
- Computational & Chemical Biology, Istituto Italiano di Tecnologia, 16163 Genova, Italy; Structural Biophysics and Translational Pharmacology Facility, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genova, Italy
| | - Giuseppina Di Stefano
- Department of Surgical and Medical Sciences, University of Bologna, 40126 Bologna, Italy
| | - Fulvia Farabegoli
- Department of Pharmacy and Biotechnology, University of Bologna, 40126 Bologna, Italy
| | - Marinella Roberti
- Department of Pharmacy and Biotechnology, University of Bologna, 40126 Bologna, Italy
| | - Giorgio Oliviero
- Systems Biology Ireland, School of Medicine, University College Dublin, Belfield Dublin 4, Ireland
| | - Andrea Cavalli
- Computational & Chemical Biology, Istituto Italiano di Tecnologia, 16163 Genova, Italy; Department of Pharmacy and Biotechnology, University of Bologna, 40126 Bologna, Italy.
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10
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Liu W, Polaczek P, Roubal I, Meng Y, Choe WC, Caron MC, Sedgeman C, Xi Y, Liu C, Wu Q, Zheng L, Masson JY, Shen B, Campbell J. FANCD2 and RAD51 recombinase directly inhibit DNA2 nuclease at stalled replication forks and FANCD2 acts as a novel RAD51 mediator in strand exchange to promote genome stability. Nucleic Acids Res 2023; 51:9144-9165. [PMID: 37526271 PMCID: PMC10516637 DOI: 10.1093/nar/gkad624] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 06/17/2023] [Accepted: 07/28/2023] [Indexed: 08/02/2023] Open
Abstract
FANCD2 protein, a key coordinator and effector of the interstrand crosslink repair pathway, is also required to prevent excessive nascent strand degradation at hydroxyurea-induced stalled forks. The RAD51 recombinase has also been implicated in regulation of resection at stalled replication forks. The mechanistic contributions of these proteins to fork protection are not well understood. Here, we used purified FANCD2 and RAD51 to study how each protein regulates DNA resection at stalled forks. We characterized three mechanisms of FANCD2-mediated fork protection: (1) The N-terminal domain of FANCD2 inhibits the essential DNA2 nuclease activity by directly binding to DNA2 accounting for over-resection in FANCD2 defective cells. (2) Independent of dimerization with FANCI, FANCD2 itself stabilizes RAD51 filaments to inhibit multiple nucleases, including DNA2, MRE11 and EXO1. (3) Unexpectedly, we uncovered a new FANCD2 function: by stabilizing RAD51 filaments, FANCD2 acts to stimulate the strand exchange activity of RAD51. Our work biochemically explains non-canonical mechanisms by which FANCD2 and RAD51 protect stalled forks. We propose a model in which the strand exchange activity of FANCD2 provides a simple molecular explanation for genetic interactions between FANCD2 and BRCA2 in the FA/BRCA fork protection pathway.
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Affiliation(s)
- Wenpeng Liu
- Braun Laboratories, California Institute of Technology, Pasadena, CA 91125, USA
- Colleges of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Piotr Polaczek
- Braun Laboratories, California Institute of Technology, Pasadena, CA 91125, USA
| | - Ivan Roubal
- Braun Laboratories, California Institute of Technology, Pasadena, CA 91125, USA
| | - Yuan Meng
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, 1500 East Duarte Road, Duarte, CA 91010-3000, USA
- Colleges of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Won-chae Choe
- Braun Laboratories, California Institute of Technology, Pasadena, CA 91125, USA
| | - Marie-Christine Caron
- Genome Stability Laboratory, CHU de Québec Research Center, HDQ Pavilion, Oncology Division, 9 McMahon, Québec City, QC G1R 3S3, Canada
| | - Carl A Sedgeman
- Braun Laboratories, California Institute of Technology, Pasadena, CA 91125, USA
| | - Yu Xi
- Colleges of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Changwei Liu
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, 1500 East Duarte Road, Duarte, CA 91010-3000, USA
- Colleges of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Qiong Wu
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, 1500 East Duarte Road, Duarte, CA 91010-3000, USA
| | - Li Zheng
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, 1500 East Duarte Road, Duarte, CA 91010-3000, USA
| | - Jean-Yves Masson
- Genome Stability Laboratory, CHU de Québec Research Center, HDQ Pavilion, Oncology Division, 9 McMahon, Québec City, QC G1R 3S3, Canada
- Department of Molecular Biology, Medical Biochemistry and Pathology; Laval University Cancer Research Center, Québec City, QC G1V 0A6, Canada
| | - Binghui Shen
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, 1500 East Duarte Road, Duarte, CA 91010-3000, USA
| | - Judith L Campbell
- Braun Laboratories, California Institute of Technology, Pasadena, CA 91125, USA
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11
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Belan O, Greenhough L, Kuhlen L, Anand R, Kaczmarczyk A, Gruszka DT, Yardimci H, Zhang X, Rueda DS, West SC, Boulton SJ. Visualization of direct and diffusion-assisted RAD51 nucleation by full-length human BRCA2 protein. Mol Cell 2023; 83:2925-2940.e8. [PMID: 37499663 PMCID: PMC7615647 DOI: 10.1016/j.molcel.2023.06.031] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 06/09/2023] [Accepted: 06/26/2023] [Indexed: 07/29/2023]
Abstract
Homologous recombination (HR) is essential for error-free repair of DNA double-strand breaks, perturbed replication forks (RFs), and post-replicative single-stranded DNA (ssDNA) gaps. To initiate HR, the recombination mediator and tumor suppressor protein BRCA2 facilitates nucleation of RAD51 on ssDNA prior to stimulation of RAD51 filament growth by RAD51 paralogs. Although ssDNA binding by BRCA2 has been implicated in RAD51 nucleation, the function of double-stranded DNA (dsDNA) binding by BRCA2 remains unclear. Here, we exploit single-molecule (SM) imaging to visualize BRCA2-mediated RAD51 nucleation in real time using purified proteins. We report that BRCA2 nucleates and stabilizes RAD51 on ssDNA either directly or through an unappreciated diffusion-assisted delivery mechanism involving binding to and sliding along dsDNA, which requires the cooperative action of multiple dsDNA-binding modules in BRCA2. Collectively, our work reveals two distinct mechanisms of BRCA2-dependent RAD51 loading onto ssDNA, which we propose are critical for its diverse functions in maintaining genome stability and cancer suppression.
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Affiliation(s)
- Ondrej Belan
- DSB Repair Metabolism Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Luke Greenhough
- DNA Recombination and Repair Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Lucas Kuhlen
- Section of Structural Biology, Faculty of Medicine, Imperial College London, Sir Alexander Fleming Building, South Kensington, London SW7 2AZ, UK
| | - Roopesh Anand
- DSB Repair Metabolism Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Artur Kaczmarczyk
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, London W12 0NN, UK; Single Molecule Imaging Group, MRC-London Institute of Medical Sciences, London W12 0NN, UK
| | - Dominika T Gruszka
- Single Molecule Imaging of Genome Duplication and Maintenance Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Hasan Yardimci
- Single Molecule Imaging of Genome Duplication and Maintenance Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Xiaodong Zhang
- Section of Structural Biology, Faculty of Medicine, Imperial College London, Sir Alexander Fleming Building, South Kensington, London SW7 2AZ, UK
| | - David S Rueda
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, London W12 0NN, UK; Single Molecule Imaging Group, MRC-London Institute of Medical Sciences, London W12 0NN, UK
| | - Stephen C West
- DNA Recombination and Repair Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Simon J Boulton
- DSB Repair Metabolism Laboratory, The Francis Crick Institute, London NW1 1AT, UK.
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12
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Liu G, Li J, He B, Yan J, Zhao J, Wang X, Zhao X, Xu J, Wu Y, Zhang S, Gan X, Zhou C, Li X, Zhang X, Chen X. Bre1/RNF20 promotes Rad51-mediated strand exchange and antagonizes the Srs2/FBH1 helicases. Nat Commun 2023; 14:3024. [PMID: 37230987 DOI: 10.1038/s41467-023-38617-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 05/10/2023] [Indexed: 05/27/2023] Open
Abstract
Central to homologous recombination (HR) is the assembly of Rad51 recombinase on single-strand DNA (ssDNA), forming the Rad51-ssDNA filament. How the Rad51 filament is efficiently established and sustained remains partially understood. Here, we find that the yeast ubiquitin ligase Bre1 and its human homolog RNF20, a tumor suppressor, function as recombination mediators, promoting Rad51 filament formation and subsequent reactions via multiple mechanisms independent of their ligase activities. We show that Bre1/RNF20 interacts with Rad51, directs Rad51 to ssDNA, and facilitates Rad51-ssDNA filament assembly and strand exchange in vitro. In parallel, Bre1/RNF20 interacts with the Srs2 or FBH1 helicase to counteract their disrupting effect on the Rad51 filament. We demonstrate that the above functions of Bre1/RNF20 contribute to HR repair in cells in a manner additive to the mediator protein Rad52 in yeast or BRCA2 in human. Thus, Bre1/RNF20 provides an additional layer of mechanism to directly control Rad51 filament dynamics.
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Affiliation(s)
- Guangxue Liu
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, TaiKang Center for Life and Medical Sciences, Frontier Science Centre of Immunology and Metabolism, Department of Oncology, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, China
| | - Jimin Li
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, TaiKang Center for Life and Medical Sciences, Frontier Science Centre of Immunology and Metabolism, Department of Oncology, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, China
| | - Boxue He
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX, USA
| | - Jiaqi Yan
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, TaiKang Center for Life and Medical Sciences, Frontier Science Centre of Immunology and Metabolism, Department of Oncology, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, China
| | - Jingyu Zhao
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, TaiKang Center for Life and Medical Sciences, Frontier Science Centre of Immunology and Metabolism, Department of Oncology, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, China
| | - Xuejie Wang
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, TaiKang Center for Life and Medical Sciences, Frontier Science Centre of Immunology and Metabolism, Department of Oncology, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, China
| | - Xiaocong Zhao
- The Institute for Advanced Studies, Wuhan University, Wuhan, China
| | - Jingyan Xu
- Department of Hematology, Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| | - Yeyao Wu
- School of Public Health, Zhejiang University School of Medicine, Hangzhou, China
| | - Simin Zhang
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, TaiKang Center for Life and Medical Sciences, Frontier Science Centre of Immunology and Metabolism, Department of Oncology, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, China
| | - Xiaoli Gan
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, TaiKang Center for Life and Medical Sciences, Frontier Science Centre of Immunology and Metabolism, Department of Oncology, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, China
| | - Chun Zhou
- School of Public Health, Zhejiang University School of Medicine, Hangzhou, China
| | - Xiangpan Li
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, TaiKang Center for Life and Medical Sciences, Frontier Science Centre of Immunology and Metabolism, Department of Oncology, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, China
| | - Xinghua Zhang
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, TaiKang Center for Life and Medical Sciences, Frontier Science Centre of Immunology and Metabolism, Department of Oncology, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, China
- The Institute for Advanced Studies, Wuhan University, Wuhan, China
| | - Xuefeng Chen
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, TaiKang Center for Life and Medical Sciences, Frontier Science Centre of Immunology and Metabolism, Department of Oncology, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, China.
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13
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Sutherland JH, Holloman WK. Determinants governing BRC function evaluated by mutational analysis of Brh2 in Ustilago maydis. DNA Repair (Amst) 2023; 127:103511. [PMID: 37141696 DOI: 10.1016/j.dnarep.2023.103511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 03/31/2023] [Accepted: 04/24/2023] [Indexed: 05/06/2023]
Abstract
BRC is a short evolutionarily conserved sequence motif generally arranged in multiple tandem repeats that is present as a defining feature in members of the BRCA2 tumor suppressor protein family. From crystallographic studies of a co-complex, the human BRC4 was found to form a structural element that interacts with RAD51, a key component in the DNA repair machinery directed by homologous recombination. The BRC is distinguished by two tetrameric sequence modules with characteristic hydrophobic residues separated by an intervening spacer region marked by certain highly conserved residues forming a hydrophobic surface for interaction with RAD51. It is present as a single copy in Brh2 of Ustilago maydis, the only reported example of a fungal BRCA2 ortholog. By comparative sequence analysis, examples of BRCA2 orthologs were identified in other fungal phyla, some of which featured multiple tandem repeats like those found in mammals. An expeditious biological assay system was developed for evaluating the two-tetramer module model and assessing the importance of particular conserved amino acid residues of BRC contributing to Brh2 functionality in DNA repair. This work was aided by the finding that the human BRC4 repeat could substitute completely for the endogenous BRC element in Brh2, while the human BRC5 repeat could not. In a survey of point mutations of certain residues, certain BRC mutant variants termed antimorphs were identified that caused a DNA repair phenotype more severe than the null.
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Affiliation(s)
- Jeanette H Sutherland
- Department of Microbiology and Immunology, Cornell University Weill Medical College, New York, NY 10065, USA; Department of Biology, Farmingdale State College, Farmingdale, NY 11735, USA.
| | - William K Holloman
- Department of Microbiology and Immunology, Cornell University Weill Medical College, New York, NY 10065, USA
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14
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Bell JC, Dombrowski CC, Plank JL, Jensen RB, Kowalczykowski SC. BRCA2 chaperones RAD51 to single molecules of RPA-coated ssDNA. Proc Natl Acad Sci U S A 2023; 120:e2221971120. [PMID: 36976771 PMCID: PMC10083600 DOI: 10.1073/pnas.2221971120] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 02/24/2023] [Indexed: 03/29/2023] Open
Abstract
Mutations in the breast cancer susceptibility gene, BRCA2, greatly increase an individual's lifetime risk of developing breast and ovarian cancers. BRCA2 suppresses tumor formation by potentiating DNA repair via homologous recombination. Central to recombination is the assembly of a RAD51 nucleoprotein filament, which forms on single-stranded DNA (ssDNA) generated at or near the site of chromosomal damage. However, replication protein-A (RPA) rapidly binds to and continuously sequesters this ssDNA, imposing a kinetic barrier to RAD51 filament assembly that suppresses unregulated recombination. Recombination mediator proteins-of which BRCA2 is the defining member in humans-alleviate this kinetic barrier to catalyze RAD51 filament formation. We combined microfluidics, microscopy, and micromanipulation to directly measure both the binding of full-length BRCA2 to-and the assembly of RAD51 filaments on-a region of RPA-coated ssDNA within individual DNA molecules designed to mimic a resected DNA lesion common in replication-coupled recombinational repair. We demonstrate that a dimer of RAD51 is minimally required for spontaneous nucleation; however, growth self-terminates below the diffraction limit. BRCA2 accelerates nucleation of RAD51 to a rate that approaches the rapid association of RAD51 to naked ssDNA, thereby overcoming the kinetic block imposed by RPA. Furthermore, BRCA2 eliminates the need for the rate-limiting nucleation of RAD51 by chaperoning a short preassembled RAD51 filament onto the ssDNA complexed with RPA. Therefore, BRCA2 regulates recombination by initiating RAD51 filament formation.
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Affiliation(s)
- Jason C. Bell
- Department of Microbiology and Molecular Genetics, University of California, Davis, CA95616
- Department of Molecular and Cellular Biology, University of California, Davis, CA95616
| | - Christopher C. Dombrowski
- Department of Microbiology and Molecular Genetics, University of California, Davis, CA95616
- Department of Molecular and Cellular Biology, University of California, Davis, CA95616
| | - Jody L. Plank
- Department of Microbiology and Molecular Genetics, University of California, Davis, CA95616
- Department of Molecular and Cellular Biology, University of California, Davis, CA95616
| | - Ryan B. Jensen
- Department of Microbiology and Molecular Genetics, University of California, Davis, CA95616
- Department of Molecular and Cellular Biology, University of California, Davis, CA95616
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT06520
| | - Stephen C. Kowalczykowski
- Department of Microbiology and Molecular Genetics, University of California, Davis, CA95616
- Department of Molecular and Cellular Biology, University of California, Davis, CA95616
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15
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Emmenecker C, Mézard C, Kumar R. Repair of DNA double-strand breaks in plant meiosis: role of eukaryotic RecA recombinases and their modulators. PLANT REPRODUCTION 2023; 36:17-41. [PMID: 35641832 DOI: 10.1007/s00497-022-00443-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 05/09/2022] [Indexed: 06/15/2023]
Abstract
Homologous recombination during meiosis is crucial for the DNA double-strand breaks (DSBs) repair that promotes the balanced segregation of homologous chromosomes and enhances genetic variation. In most eukaryotes, two recombinases RAD51 and DMC1 form nucleoprotein filaments on single-stranded DNA generated at DSB sites and play a central role in the meiotic DSB repair and genome stability. These nucleoprotein filaments perform homology search and DNA strand exchange to initiate repair using homologous template-directed sequences located elsewhere in the genome. Multiple factors can regulate the assembly, stability, and disassembly of RAD51 and DMC1 nucleoprotein filaments. In this review, we summarize the current understanding of the meiotic functions of RAD51 and DMC1 and the role of their positive and negative modulators. We discuss the current models and regulators of homology searches and strand exchange conserved during plant meiosis. Manipulation of these repair factors during plant meiosis also holds a great potential to accelerate plant breeding for crop improvements and productivity.
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Affiliation(s)
- Côme Emmenecker
- Institut Jean-Pierre Bourgin (IJPB), Université Paris-Saclay, INRAE, AgroParisTech, 78000, Versailles, France
- University of Paris-Sud, Université Paris-Saclay, 91405, Orsay, France
| | - Christine Mézard
- Institut Jean-Pierre Bourgin (IJPB), CNRS, Université Paris-Saclay, INRAE, AgroParisTech, 78000, Versailles, France.
| | - Rajeev Kumar
- Institut Jean-Pierre Bourgin (IJPB), Université Paris-Saclay, INRAE, AgroParisTech, 78000, Versailles, France.
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16
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Replication gap suppression depends on the double-strand DNA binding activity of BRCA2. Nat Commun 2023; 14:446. [PMID: 36707518 PMCID: PMC9883520 DOI: 10.1038/s41467-023-36149-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 01/17/2023] [Indexed: 01/28/2023] Open
Abstract
Replication stress (RS) is a major source of genomic instability and is intrinsic to cancer cells. RS is also the consequence of chemotherapeutic drugs for treating cancer. However, adaptation to RS is also a mechanism of resistance to chemotherapy. BRCA2 deficiency results in replication stress in human cells. BRCA2 protein's main functions include DNA repair by homologous recombination (HR) both at induced DNA double-strand breaks (DSB) and spontaneous replicative lesions. At stalled replication forks, BRCA2 protects the DNA from aberrant nucleolytic degradation and is thought to limit the appearance of ssDNA gaps by arresting replication and via post-replicative HR. However, whether and how BRCA2 acts to limit the formation of ssDNA gaps or mediate their repair, remains ill-defined. Here, we use breast cancer variants affecting different domains of BRCA2 to shed light on this function. We demonstrate that the N-terminal DNA binding domain (NTD), and specifically, its dsDNA binding activity, is required to prevent and repair/fill-in ssDNA gaps upon nucleotide depletion but not to limit PARPi-induced ssDNA gaps. Thus, these findings suggest that nucleotide depletion and PARPi trigger gaps via distinct mechanisms and that the NTD of BRCA2 prevents nucleotide depletion-induced ssDNA gaps.
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17
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Kwon Y, Rösner H, Zhao W, Selemenakis P, He Z, Kawale AS, Katz JN, Rogers CM, Neal FE, Badamchi Shabestari A, Petrosius V, Singh AK, Joel MZ, Lu L, Holloway SP, Burma S, Mukherjee B, Hromas R, Mazin A, Wiese C, Sørensen CS, Sung P. DNA binding and RAD51 engagement by the BRCA2 C-terminus orchestrate DNA repair and replication fork preservation. Nat Commun 2023; 14:432. [PMID: 36702902 PMCID: PMC9879961 DOI: 10.1038/s41467-023-36211-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 01/19/2023] [Indexed: 01/27/2023] Open
Abstract
The tumor suppressor BRCA2 participates in DNA double-strand break repair by RAD51-dependent homologous recombination and protects stressed DNA replication forks from nucleolytic attack. We demonstrate that the C-terminal Recombinase Binding (CTRB) region of BRCA2, encoded by gene exon 27, harbors a DNA binding activity. CTRB alone stimulates the DNA strand exchange activity of RAD51 and permits the utilization of RPA-coated ssDNA by RAD51 for strand exchange. Moreover, CTRB functionally synergizes with the Oligonucleotide Binding fold containing DNA binding domain and BRC4 repeat of BRCA2 in RPA-RAD51 exchange on ssDNA. Importantly, we show that the DNA binding and RAD51 interaction attributes of the CTRB are crucial for homologous recombination and protection of replication forks against MRE11-mediated attrition. Our findings shed light on the role of the CTRB region in genome repair, reveal remarkable functional plasticity of BRCA2, and help explain why deletion of Brca2 exon 27 impacts upon embryonic lethality.
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Affiliation(s)
- Youngho Kwon
- Department of Biochemistry and Structural Biology and Greehey Children's Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Heike Rösner
- Biotech Research and Innovation Centre, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200, Copenhagen N, Denmark
| | - Weixing Zhao
- Department of Biochemistry and Structural Biology and Greehey Children's Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Platon Selemenakis
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO, USA
- Department of Cancer Biology, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Zhuoling He
- Department of Biochemistry and Structural Biology and Greehey Children's Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Ajinkya S Kawale
- Department of Biochemistry and Structural Biology and Greehey Children's Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA, 02129, USA
| | - Jeffrey N Katz
- Department of Biochemistry and Structural Biology and Greehey Children's Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Cody M Rogers
- Department of Biochemistry and Structural Biology and Greehey Children's Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Francisco E Neal
- Department of Biochemistry and Structural Biology and Greehey Children's Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Aida Badamchi Shabestari
- Department of Biochemistry and Structural Biology and Greehey Children's Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Valdemaras Petrosius
- Biotech Research and Innovation Centre, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200, Copenhagen N, Denmark
| | - Akhilesh K Singh
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT, USA
- GentiBio Inc., 150 Cambridgepark Dr, Cambridge, MA, 02140, USA
| | - Marina Z Joel
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT, USA
- Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Lucy Lu
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT, USA
| | - Stephen P Holloway
- Department of Biochemistry and Structural Biology and Greehey Children's Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Sandeep Burma
- Department of Biochemistry and Structural Biology and Greehey Children's Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
- Department of Neurosurgery, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Bipasha Mukherjee
- Department of Neurosurgery, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Robert Hromas
- Department of Medicine, University of Texas Health at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX, 78229, USA
| | - Alexander Mazin
- Department of Biochemistry and Structural Biology and Greehey Children's Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Claudia Wiese
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO, USA.
| | - Claus S Sørensen
- Biotech Research and Innovation Centre, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200, Copenhagen N, Denmark.
| | - Patrick Sung
- Department of Biochemistry and Structural Biology and Greehey Children's Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA.
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18
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Liu S, Li X, Liu X, Wang J, Li L, Kong D. RNA polymerase III directly participates in DNA homologous recombination. Trends Cell Biol 2022; 32:988-995. [PMID: 35811227 DOI: 10.1016/j.tcb.2022.06.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 06/05/2022] [Accepted: 06/14/2022] [Indexed: 01/21/2023]
Abstract
A recent study showed that RNA transcription is directly involved in DNA homologous recombination (HR). The first step in HR is end resection, which degrades a few kilobases or more from the 5'-end strand at DNA breaks, but the 3'-end strand remains strictly intact. Such protection of the 3'-end strand is achieved by the transient formation of an RNA-DNA hybrid structure. The RNA strand in the hybrid is newly synthesized by RNA polymerase III. The revelation of the existence of an RNA-DNA hybrid intermediate should further help resolve several long-standing questions of HR. In this article, we also put forward our views on some controversial issues related to RNA-DNA hybrids, RNA polymerases, and the protection of 3'-end strands.
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Affiliation(s)
- Sijie Liu
- Peking-Tsinghua Center for Life Sciences, The National Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, China.
| | - Xizhou Li
- Department of Breast and Thyroid Surgery, Changhai Hospital, The Naval Military Medical University, Shanghai, China
| | - Xiaoqin Liu
- Peking-Tsinghua Center for Life Sciences, The National Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, China; Institute of Brain Science, Shanxi Datong University, Datong 037009, China
| | - Jingna Wang
- Peking-Tsinghua Center for Life Sciences, The National Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, China
| | - Lingyan Li
- Peking-Tsinghua Center for Life Sciences, The National Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, China
| | - Daochun Kong
- Peking-Tsinghua Center for Life Sciences, The National Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, China.
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19
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Jimenez-Sainz J, Mathew J, Moore G, Lahiri S, Garbarino J, Eder JP, Rothenberg E, Jensen RB. BRCA2 BRC missense variants disrupt RAD51-dependent DNA repair. eLife 2022; 11:e79183. [PMID: 36098506 PMCID: PMC9545528 DOI: 10.7554/elife.79183] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 09/12/2022] [Indexed: 11/24/2022] Open
Abstract
Pathogenic mutations in the BRCA2 tumor suppressor gene predispose to breast, ovarian, pancreatic, prostate, and other cancers. BRCA2 maintains genome stability through homology-directed repair (HDR) of DNA double-strand breaks (DSBs) and replication fork protection. Nonsense or frameshift mutations leading to truncation of the BRCA2 protein are typically considered pathogenic; however, missense mutations resulting in single amino acid substitutions can be challenging to functionally interpret. The majority of missense mutations in BRCA2 have been classified as Variants of Uncertain Significance (VUS) with unknown functional consequences. In this study, we identified three BRCA2 VUS located within the BRC repeat region to determine their impact on canonical HDR and fork protection functions. We provide evidence that S1221P and T1980I, which map to conserved residues in the BRC2 and BRC7 repeats, compromise the cellular response to chemotherapeutics and ionizing radiation, and display deficits in fork protection. We further demonstrate biochemically that S1221P and T1980I disrupt RAD51 binding and diminish the ability of BRCA2 to stabilize RAD51-ssDNA complexes. The third variant, T1346I, located within the spacer region between BRC2 and BRC3 repeats, is fully functional. We conclude that T1346I is a benign allele, whereas S1221P and T1980I are hypomorphic disrupting the ability of BRCA2 to fully engage and stabilize RAD51 nucleoprotein filaments. Our results underscore the importance of correctly classifying BRCA2 VUS as pathogenic variants can impact both future cancer risk and guide therapy selection during cancer treatment.
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Affiliation(s)
| | - Joshua Mathew
- Department of Therapeutic Radiology, Yale UniversityNew HavenUnited States
| | - Gemma Moore
- Department of Therapeutic Radiology, Yale UniversityNew HavenUnited States
| | - Sudipta Lahiri
- Department of Therapeutic Radiology, Yale UniversityNew HavenUnited States
| | - Jennifer Garbarino
- Department of Therapeutic Radiology, Yale UniversityNew HavenUnited States
| | - Joseph P Eder
- Department of Medical Oncology, Yale University School of Medicine, Yale Cancer CenterNew HavenUnited States
| | - Eli Rothenberg
- Department of Biochemistry and Molecular Pharmacology, New York UniversityNew YorkUnited States
| | - Ryan B Jensen
- Department of Therapeutic Radiology, Yale UniversityNew HavenUnited States
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20
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Halder S, Sanchez A, Ranjha L, Reginato G, Ceppi I, Acharya A, Anand R, Cejka P. Double-stranded DNA binding function of RAD51 in DNA protection and its regulation by BRCA2. Mol Cell 2022; 82:3553-3565.e5. [PMID: 36070766 DOI: 10.1016/j.molcel.2022.08.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 06/16/2022] [Accepted: 08/10/2022] [Indexed: 11/26/2022]
Abstract
RAD51 and the breast cancer suppressor BRCA2 have critical functions in DNA double-strand (dsDNA) break repair by homologous recombination and the protection of newly replicated DNA from nucleolytic degradation. The recombination function of RAD51 requires its binding to single-stranded DNA (ssDNA), whereas binding to dsDNA is inhibitory. Using reconstituted MRE11-, EXO1-, and DNA2-dependent nuclease reactions, we show that the protective function of RAD51 unexpectedly depends on its binding to dsDNA. The BRC4 repeat of BRCA2 abrogates RAD51 binding to dsDNA and accordingly impairs the function of RAD51 in protection. The BRCA2 C-terminal RAD51-binding segment (TR2) acts in a dominant manner to overcome the effect of BRC4. Mechanistically, TR2 stabilizes RAD51 binding to dsDNA, even in the presence of BRC4, promoting DNA protection. Our data suggest that RAD51's dsDNA-binding capacity may have evolved together with its function in replication fork protection and provide a mechanistic basis for the DNA-protection function of BRCA2.
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Affiliation(s)
- Swagata Halder
- Institute for Research in Biomedicine, Università della Svizzera italiana (USI), Faculty of Biomedical Sciences, 6500 Bellinzona, Switzerland
| | - Aurore Sanchez
- Institute for Research in Biomedicine, Università della Svizzera italiana (USI), Faculty of Biomedical Sciences, 6500 Bellinzona, Switzerland
| | - Lepakshi Ranjha
- Institute for Research in Biomedicine, Università della Svizzera italiana (USI), Faculty of Biomedical Sciences, 6500 Bellinzona, Switzerland
| | - Giordano Reginato
- Institute for Research in Biomedicine, Università della Svizzera italiana (USI), Faculty of Biomedical Sciences, 6500 Bellinzona, Switzerland; Department of Biology, Institute of Biochemistry, Eidgenössische Technische Hochschule (ETH), 8049 Zürich, Switzerland
| | - Ilaria Ceppi
- Institute for Research in Biomedicine, Università della Svizzera italiana (USI), Faculty of Biomedical Sciences, 6500 Bellinzona, Switzerland; Department of Biology, Institute of Biochemistry, Eidgenössische Technische Hochschule (ETH), 8049 Zürich, Switzerland
| | - Ananya Acharya
- Institute for Research in Biomedicine, Università della Svizzera italiana (USI), Faculty of Biomedical Sciences, 6500 Bellinzona, Switzerland; Department of Biology, Institute of Biochemistry, Eidgenössische Technische Hochschule (ETH), 8049 Zürich, Switzerland
| | - Roopesh Anand
- Institute for Research in Biomedicine, Università della Svizzera italiana (USI), Faculty of Biomedical Sciences, 6500 Bellinzona, Switzerland
| | - Petr Cejka
- Institute for Research in Biomedicine, Università della Svizzera italiana (USI), Faculty of Biomedical Sciences, 6500 Bellinzona, Switzerland; Department of Biology, Institute of Biochemistry, Eidgenössische Technische Hochschule (ETH), 8049 Zürich, Switzerland.
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21
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Histone chaperone ASF1 acts with RIF1 to promote DNA end joining in BRCA1-deficient cells. J Biol Chem 2022; 298:101979. [PMID: 35472331 PMCID: PMC9127577 DOI: 10.1016/j.jbc.2022.101979] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 04/12/2022] [Accepted: 04/13/2022] [Indexed: 12/29/2022] Open
Abstract
Replication timing regulatory factor 1 (RIF1) acts downstream of p53-binding protein 53BP1 to inhibit the resection of DNA broken ends, which plays critical roles in determining the DNA double-strand break repair pathway choice between nonhomologous end joining and homologous recombination (HR). However, the mechanism by which this choice is made is not yet clear. In this study, we identified that histone chaperone protein ASF1 associates with RIF1 and regulates RIF1-dependent functions in the DNA damage response. Similar to loss of RIF1, we found that loss of ASF1 resulted in resistance to poly (ADP-ribose) polymerase (PARP) inhibition in BRCA1-deficient cells with restored HR and decreased telomere fusion in telomeric repeat–binding protein 2 (TRF2)-depleted cells. Moreover, we showed that these functions of ASF1 are dependent on its interaction with RIF1 but not on its histone chaperone activity. Thus, our study supports a new role for ASF1 in dictating double-strand break repair choice. Considering that the status of 53BP1–RIF1 axis is important in determining the outcome of PARP inhibitor–based therapy in BRCA1- or HR-deficient cancers, the identification of ASF1 function in this critical pathway uncovers an interesting connection between these S-phase events, which may reveal new strategies to overcome PARP inhibitor resistance.
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22
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Lavoro A, Scalisi A, Candido S, Zanghì GN, Rizzo R, Gattuso G, Caruso G, Libra M, Falzone L. Identification of the most common BRCA alterations through analysis of germline mutation databases: Is droplet digital PCR an additional strategy for the assessment of such alterations in breast and ovarian cancer families? Int J Oncol 2022; 60:58. [PMID: 35383859 PMCID: PMC8997337 DOI: 10.3892/ijo.2022.5349] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 03/24/2022] [Indexed: 11/06/2022] Open
Abstract
Breast and ovarian cancer represent two of the most common tumor types in females worldwide. Over the years, several non‑modifiable and modifiable risk factors have been associated with the onset and progression of these tumors, including age, reproductive factors, ethnicity, socioeconomic status and lifestyle factors, as well as family history and genetic factors. Of note, BRCA1 and BRCA2 are two tumor suppressor genes with a key role in DNA repair processes, whose mutations may induce genomic instability and increase the risk of cancer development. Specifically, females with a family history of breast or ovarian cancer harboring BRCA1/2 germline mutations have a 60‑70% increased risk of developing breast cancer and a 15‑40% increased risk for ovarian cancer. Different databases have collected the most frequent germline mutations affecting BRCA1/2. Through the analysis of such databases, it is possible to identify frequent hotspot mutations that may be analyzed with next‑generation sequencing (NGS) and novel innovative strategies. In this context, NGS remains the gold standard method for the assessment of BRCA1/2 mutations, while novel techniques, including droplet digital PCR (ddPCR), may improve the sensitivity to identify such mutations in the hereditary forms of breast and ovarian cancer. On these bases, the present study aimed to provide an update of the current knowledge on the frequency of BRCA1/2 mutations and cancer susceptibility, focusing on the diagnostic potential of the most recent methods, such as ddPCR.
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Affiliation(s)
- Alessandro Lavoro
- Department of Biomedical and Biotechnological Sciences, University of Catania, I‑95123 Catania, Italy
| | - Aurora Scalisi
- Italian League Against Cancer, Section of Catania, I‑95122 Catania, Italy
| | - Saverio Candido
- Department of Biomedical and Biotechnological Sciences, University of Catania, I‑95123 Catania, Italy
| | - Guido Nicola Zanghì
- Department of General Surgery and Medical‑Surgical Specialties, Policlinico‑Vittorio Emanuele Hospital, University of Catania, I‑95123 Catania, Italy
| | - Roberta Rizzo
- Department of Biomedical and Biotechnological Sciences, University of Catania, I‑95123 Catania, Italy
| | - Giuseppe Gattuso
- Department of Biomedical and Biotechnological Sciences, University of Catania, I‑95123 Catania, Italy
| | - Giuseppe Caruso
- Department of Biomedical and Biotechnological Sciences, University of Catania, I‑95123 Catania, Italy
| | - Massimo Libra
- Department of Biomedical and Biotechnological Sciences, University of Catania, I‑95123 Catania, Italy
| | - Luca Falzone
- Epidemiology and Biostatistics Unit, National Cancer Institute IRCCS Fondazione 'G. Pascale', I‑80131 Naples, Italy
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23
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Hariharasudhan G, Jeong SY, Kim MJ, Jung SM, Seo G, Moon JR, Lee S, Chang IY, Kee Y, You H, Lee JH. OUP accepted manuscript. Nucleic Acids Res 2022; 50:1501-1516. [PMID: 35061896 PMCID: PMC8860612 DOI: 10.1093/nar/gkac009] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 12/23/2021] [Accepted: 01/13/2022] [Indexed: 11/24/2022] Open
Abstract
Homologous recombination (HR) is critical for error-free repair of DNA double-strand breaks. Chromatin loading of RAD51, a key protein that mediates the recombination, is a crucial step in the execution of the HR repair. Here, we present evidence that SUMOylation of RAD51 is crucial for the RAD51 recruitment to chromatin and HR repair. We found that topoisomerase 1-binding arginine/serine-rich protein (TOPORS) induces the SUMOylation of RAD51 at lysine residues 57 and 70 in response to DNA damaging agents. The SUMOylation was facilitated by an ATM-induced phosphorylation of TOPORS at threonine 515 upon DNA damage. Knockdown of TOPORS or expression of SUMOylation-deficient RAD51 mutants caused reduction in supporting normal RAD51 functions during the HR repair, suggesting the physiological importance of the modification. We found that the SUMOylation-deficient RAD51 reduces the association with its crucial binding partner BRCA2, explaining its deficiency in supporting the HR repair. These findings altogether demonstrate a crucial role for TOPORS-mediated RAD51 SUMOylation in promoting HR repair and genomic maintenance.
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Affiliation(s)
- Gurusamy Hariharasudhan
- Laboratory of Genomic Instability and Cancer Therapeutics, Chosun University School of Medicine, 309 Pilmun-daero, Dong-gu, Gwangju 61452, Republic of Korea
- Department of Cellular and Molecular Medicine, Chosun University School of Medicine, 309 Pilmun-daero, Dong-gu, Gwangju 61452, Republic of Korea
| | - Seo-Yeon Jeong
- Laboratory of Genomic Instability and Cancer Therapeutics, Chosun University School of Medicine, 309 Pilmun-daero, Dong-gu, Gwangju 61452, Republic of Korea
- Department of Pharmacology, Chosun University School of Medicine, 309 Pilmun-daero, Dong-gu, Gwangju 61452, Republic of Korea
| | - Min-Ji Kim
- Laboratory of Genomic Instability and Cancer Therapeutics, Chosun University School of Medicine, 309 Pilmun-daero, Dong-gu, Gwangju 61452, Republic of Korea
- Department of Cellular and Molecular Medicine, Chosun University School of Medicine, 309 Pilmun-daero, Dong-gu, Gwangju 61452, Republic of Korea
| | - Sung Mi Jung
- Laboratory of Genomic Instability and Cancer Therapeutics, Chosun University School of Medicine, 309 Pilmun-daero, Dong-gu, Gwangju 61452, Republic of Korea
- Department of Cellular and Molecular Medicine, Chosun University School of Medicine, 309 Pilmun-daero, Dong-gu, Gwangju 61452, Republic of Korea
| | - Gwanwoo Seo
- Laboratory of Genomic Instability and Cancer Therapeutics, Chosun University School of Medicine, 309 Pilmun-daero, Dong-gu, Gwangju 61452, Republic of Korea
- Department of Pharmacology, Chosun University School of Medicine, 309 Pilmun-daero, Dong-gu, Gwangju 61452, Republic of Korea
| | - Ju-Ran Moon
- Laboratory of Genomic Instability and Cancer Therapeutics, Chosun University School of Medicine, 309 Pilmun-daero, Dong-gu, Gwangju 61452, Republic of Korea
- Department of Cellular and Molecular Medicine, Chosun University School of Medicine, 309 Pilmun-daero, Dong-gu, Gwangju 61452, Republic of Korea
| | - Sumi Lee
- Laboratory of Genomic Instability and Cancer Therapeutics, Chosun University School of Medicine, 309 Pilmun-daero, Dong-gu, Gwangju 61452, Republic of Korea
- Department of Cellular and Molecular Medicine, Chosun University School of Medicine, 309 Pilmun-daero, Dong-gu, Gwangju 61452, Republic of Korea
| | - In-Youb Chang
- Department of Anatomy, Chosun University School of Medicine, 309 Pilmun-daero, Dong-gu, Gwangju 61452, Republic of Korea
| | - Younghoon Kee
- Correspondence may also be addressed to Younghoon Kee. Tel: +82 53 785 1610;
| | - Ho Jin You
- Correspondence may also be addressed to Ho Jin You. Tel: +82 62 230 6337;
| | - Jung-Hee Lee
- To whom correspondence should be addressed. Tel: +82 62 230 6399;
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24
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Mechanism of mitotic recombination: insights from C. elegans. Curr Opin Genet Dev 2021; 71:10-18. [PMID: 34186335 PMCID: PMC8683258 DOI: 10.1016/j.gde.2021.06.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 05/18/2021] [Accepted: 06/07/2021] [Indexed: 11/23/2022]
Abstract
Homologous recombination (HR) plays a critical role in largely error-free repair of mitotic and meiotic DNA double-strand breaks (DSBs). DSBs are one of the most deleterious DNA lesions, which are repaired by non-homologous end joining (NHEJ), homologous recombination (HR) or, if compromised, micro-homology mediated end joining (MMEJ). If left unrepaired, DSBs can lead to cell death or if repaired incorrectly can result in chromosome rearrangements that drive cancer development. Here, we describe recent advances in the field of mitotic HR made using Caenorhabditis elegans roundworm, as a model system.
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25
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Llorens-Agost M, Ensminger M, Le HP, Gawai A, Liu J, Cruz-García A, Bhetawal S, Wood RD, Heyer WD, Löbrich M. POLθ-mediated end joining is restricted by RAD52 and BRCA2 until the onset of mitosis. Nat Cell Biol 2021; 23:1095-1104. [PMID: 34616022 PMCID: PMC8675436 DOI: 10.1038/s41556-021-00764-0] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 08/30/2021] [Indexed: 01/25/2023]
Abstract
BRCA2-mutant cells are defective in homologous recombination, making them vulnerable to the inactivation of other pathways for the repair of DNA double-strand breaks (DSBs). This concept can be clinically exploited but is currently limited due to insufficient knowledge about how DSBs are repaired in the absence of BRCA2. We show that DNA polymerase θ (POLθ)-mediated end joining (TMEJ) repairs DSBs arising during the S phase in BRCA2-deficient cells only after the onset of the ensuing mitosis. This process is regulated by RAD52, whose loss causes the premature usage of TMEJ and the formation of chromosomal fusions. Purified RAD52 and BRCA2 proteins both block the DNA polymerase function of POLθ, suggesting a mechanism explaining their synthetic lethal relationships. We propose that the delay of TMEJ until mitosis ensures the conversion of originally one-ended DSBs into two-ended DSBs. Mitotic chromatin condensation might further serve to juxtapose correct break ends and limit chromosomal fusions.
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Affiliation(s)
- Marta Llorens-Agost
- Radiation Biology and DNA Repair, Technical University of Darmstadt, Darmstadt, Germany
| | - Michael Ensminger
- Radiation Biology and DNA Repair, Technical University of Darmstadt, Darmstadt, Germany
| | - Hang Phuong Le
- Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, CA, USA
| | - Anugrah Gawai
- Radiation Biology and DNA Repair, Technical University of Darmstadt, Darmstadt, Germany
| | - Jie Liu
- Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, CA, USA
| | - Andrés Cruz-García
- Radiation Biology and DNA Repair, Technical University of Darmstadt, Darmstadt, Germany
| | - Sarita Bhetawal
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Smithville, TX, USA
| | - Richard D Wood
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Smithville, TX, USA
| | - Wolf-Dietrich Heyer
- Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, CA, USA
| | - Markus Löbrich
- Radiation Biology and DNA Repair, Technical University of Darmstadt, Darmstadt, Germany.
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26
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Prado F. Non-Recombinogenic Functions of Rad51, BRCA2, and Rad52 in DNA Damage Tolerance. Genes (Basel) 2021; 12:genes12101550. [PMID: 34680945 PMCID: PMC8535942 DOI: 10.3390/genes12101550] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 09/20/2021] [Accepted: 09/23/2021] [Indexed: 12/28/2022] Open
Abstract
The DNA damage tolerance (DDT) response is aimed to timely and safely complete DNA replication by facilitating the advance of replication forks through blocking lesions. This process is associated with an accumulation of single-strand DNA (ssDNA), both at the fork and behind the fork. Lesion bypass and ssDNA filling can be performed by translation synthesis (TLS) and template switching mechanisms. TLS uses low-fidelity polymerases to incorporate a dNTP opposite the blocking lesion, whereas template switching uses a Rad51/ssDNA nucleofilament and the sister chromatid to bypass the lesion. Rad51 is loaded at this nucleofilament by two mediator proteins, BRCA2 and Rad52, and these three factors are critical for homologous recombination (HR). Here, we review recent advances showing that Rad51, BRCA2, and Rad52 perform some of these functions through mechanisms that do not require the strand exchange activity of Rad51: the formation and protection of reversed fork structures aimed to bypass blocking lesions, and the promotion of TLS. These findings point to the central HR proteins as potential molecular switches in the choice of the mechanism of DDT.
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Affiliation(s)
- Félix Prado
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Consejo Superior de Investigaciones Científicas, Universidad de Sevilla, Universidad Pablo de Olavide, 41092 Seville, Spain
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27
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Špírek M, Taylor MRG, Belan O, Boulton SJ, Krejci L. Nucleotide proofreading functions by nematode RAD51 paralogs facilitate optimal RAD51 filament function. Nat Commun 2021; 12:5545. [PMID: 34545070 PMCID: PMC8452638 DOI: 10.1038/s41467-021-25830-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 09/02/2021] [Indexed: 12/30/2022] Open
Abstract
The RAD51 recombinase assembles as helical nucleoprotein filaments on single-stranded DNA (ssDNA) and mediates invasion and strand exchange with homologous duplex DNA (dsDNA) during homologous recombination (HR), as well as protection and restart of stalled replication forks. Strand invasion by RAD51-ssDNA complexes depends on ATP binding. However, RAD51 can bind ssDNA in non-productive ADP-bound or nucleotide-free states, and ATP-RAD51-ssDNA complexes hydrolyse ATP over time. Here, we define unappreciated mechanisms by which the RAD51 paralog complex RFS-1/RIP-1 limits the accumulation of RAD-51-ssDNA complexes with unfavorable nucleotide content. We find RAD51 paralogs promote the turnover of ADP-bound RAD-51 from ssDNA, in striking contrast to their ability to stabilize productive ATP-bound RAD-51 nucleoprotein filaments. In addition, RFS-1/RIP-1 inhibits binding of nucleotide-free RAD-51 to ssDNA. We propose that ‘nucleotide proofreading’ activities of RAD51 paralogs co-operate to ensure the enrichment of active, ATP-bound RAD-51 filaments on ssDNA to promote HR. A RAD51 paralog complex, RFS-1/RIP-1, is shown to control ssDNA binding and dissociation by RAD-51 differentially in the presence and absence of nucleotide cofactors. These nucleotide proofreading activities drive a preferential accumulation of RAD-51-ssDNA complexes with optimal nucleotide content.
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Affiliation(s)
- Mário Špírek
- International Clinical Research Center, St. Anne's University Hospital in Brno, 62500, Brno, Czech Republic.,Department of Biology Masaryk University, 62500, Brno, Czech Republic
| | | | - Ondrej Belan
- The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK.,National Centre for Biomolecular Research, Masaryk University, 62500, Brno, Czech Republic
| | - Simon J Boulton
- The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Lumir Krejci
- International Clinical Research Center, St. Anne's University Hospital in Brno, 62500, Brno, Czech Republic. .,Department of Biology Masaryk University, 62500, Brno, Czech Republic. .,National Centre for Biomolecular Research, Masaryk University, 62500, Brno, Czech Republic.
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28
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Le HP, Heyer WD, Liu J. Guardians of the Genome: BRCA2 and Its Partners. Genes (Basel) 2021; 12:genes12081229. [PMID: 34440403 PMCID: PMC8394001 DOI: 10.3390/genes12081229] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 08/04/2021] [Accepted: 08/06/2021] [Indexed: 12/28/2022] Open
Abstract
The tumor suppressor BRCA2 functions as a central caretaker of genome stability, and individuals who carry BRCA2 mutations are predisposed to breast, ovarian, and other cancers. Recent research advanced our mechanistic understanding of BRCA2 and its various interaction partners in DNA repair, DNA replication support, and DNA double-strand break repair pathway choice. In this review, we discuss the biochemical and structural properties of BRCA2 and examine how these fundamental properties contribute to DNA repair and replication fork stabilization in living cells. We highlight selected BRCA2 binding partners and discuss their role in BRCA2-mediated homologous recombination and fork protection. Improved mechanistic understanding of how BRCA2 functions in genome stability maintenance can enable experimental evidence-based evaluation of pathogenic BRCA2 mutations and BRCA2 pseudo-revertants to support targeted therapy.
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Affiliation(s)
- Hang Phuong Le
- Department of Microbiology and Molecular Genetics, University of California, Davis, CA 95616, USA; (H.P.L.); (W.-D.H.)
| | - Wolf-Dietrich Heyer
- Department of Microbiology and Molecular Genetics, University of California, Davis, CA 95616, USA; (H.P.L.); (W.-D.H.)
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA
| | - Jie Liu
- Department of Microbiology and Molecular Genetics, University of California, Davis, CA 95616, USA; (H.P.L.); (W.-D.H.)
- Correspondence: ; Tel.: +1-530-752-3016
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Missense Variants of Uncertain Significance: A Powerful Genetic Tool for Function Discovery with Clinical Implications. Cancers (Basel) 2021; 13:cancers13153719. [PMID: 34359619 PMCID: PMC8345083 DOI: 10.3390/cancers13153719] [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: 06/08/2021] [Revised: 07/19/2021] [Accepted: 07/21/2021] [Indexed: 11/16/2022] Open
Abstract
Simple Summary Variants of uncertain significance in the breast cancer susceptibility gene BRCA2 represent 50–80% of the results from genetic testing. These mutations may lead to the dysfunction of the gene, thus conferring breast cancer predisposition; however, because they are rare and their impact on the function is not easy to predict, their classification into benign or pathogenic variants remains a challenge. By focusing on three specific rare missense variants identified in breast cancer patients, in this review, we discuss how the functional evaluation of this type of variants can be used to reveal novel activities of BRCA2. Based on these findings, we suggest additional functional tests that might be required for accurate variant classification and how their characterization may be leveraged to find novel clinical strategies for patients bearing these mutations. Abstract The breast cancer susceptibility gene BRCA2 encodes a multifunctional protein required for the accurate repair of DNA double-strand breaks and replicative DNA lesions. In addition, BRCA2 exhibits emerging important roles in mitosis. As a result, mutations in BRCA2 may affect chromosomal integrity in multiple ways. However, many of the BRCA2 mutations found in breast cancer patients and their families are single amino acid substitutions, sometimes unique, and their relevance in cancer risk remains difficult to assess. In this review, we focus on three recent reports that investigated variants of uncertain significance (VUS) located in the N-terminal region of BRCA2. In this framework, we make the case for how the functional evaluation of VUS can be a powerful genetic tool not only for revealing novel aspects of BRCA2 function but also for re-evaluating cancer risk. We argue that other functions beyond homologous recombination deficiency or “BRCAness” may influence cancer risk. We hope our discussion will help the reader appreciate the potential of these functional studies in the prevention and diagnostics of inherited breast and ovarian cancer. Moreover, these novel aspects in BRCA2 function might help find new therapeutic strategies.
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Zhang G, Zhang J, Zhu Y, Liu H, Shi Y, Mi K, Li M, Zhao Q, Huang Z, Huang J. Association of somatic mutations in BRCA2 BRC domain with chemotherapy sensitivity and survival in high grade serous ovarian cancer. Exp Cell Res 2021; 406:112742. [PMID: 34302857 DOI: 10.1016/j.yexcr.2021.112742] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 06/29/2021] [Accepted: 07/19/2021] [Indexed: 11/19/2022]
Abstract
BACKGROUND Mutations at sites crucial for the interaction between RAD51 and BRC domains impair the ability of BRCA2 homologous recombination. We aimed to clarify whether BRCA2 BRC domain-associated mutation correlates with sensibility of platinum-based chemotherapy and survival in high-grade serous ovarian cancer (HGSOC). METHODS We identified BRCA2 BRC domain mutations by sequencing PCR-amplified amplicons of genomic DNA isolated from tumor tissues and peripheral blood leukocytes (PBL)in 113 patients with advanced EOC, and assessed platinum-free interval (PFI), progression-free survival (PFS) and overall survival (OS). RESULTS 21.23% (24 of 113) cases with somatic missense mutation but not germline mutation were identified. Among 24 cases with mutation, 33.3% (8 of 24) cases with nonsense mutation (C-terminal truncation) significantly prolonged median PFI (37 vs 8 months,P = 0.000), PFS (43 vs 14 months, p = 0.000) and OS (56 vs 31 months, P = 0.002); 66.7% (16 of 24) cases with missense mutation also prolonged median PFI (15 vs 8 months, P = 0.044), PFS (21 vs 14 months, P = 0.049) and OS (38 vs 31 months, P = 0.037), compared to those without any mutation. CONCLUSIONS Somatic mutations in BRCA2 BRC domain confer a higher sensitivity to platinum-based therapy and are associated with a favourable survival in HGSOC.
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Affiliation(s)
- Guonan Zhang
- Department of Gynecologic Oncology, Sichuan Cancer Hospital, Chengdu, 610041, PR China
| | - Jie Zhang
- Department of Gynecologic Oncology, Sichuan Cancer Hospital, Chengdu, 610041, PR China
| | - Yi Zhu
- Department of Gynecologic Oncology, Sichuan Cancer Hospital, Chengdu, 610041, PR China; Department of Ultrasound, Sichuan Cancer Hospital, Chengdu, 610041, PR China
| | - Hong Liu
- Department of Gynecologic Oncology, Sichuan Cancer Hospital, Chengdu, 610041, PR China
| | - Yu Shi
- Department of Gynecologic Oncology, Sichuan Cancer Hospital, Chengdu, 610041, PR China
| | - Kun Mi
- Department of Biochemistry & Molecular Biology, Sichuan Cancer Institute, Chengdu, 610041, PR China
| | - Meiying Li
- Department of Biochemistry & Molecular Biology, Sichuan Cancer Institute, Chengdu, 610041, PR China
| | - Qi Zhao
- Department of Biochemistry & Molecular Biology, Sichuan Cancer Institute, Chengdu, 610041, PR China
| | - Ziyi Huang
- Department of Bioinformatics, Basic Medical College of Chongqing Medical University, Chongqing, PR China
| | - Jianming Huang
- Department of Biochemistry & Molecular Biology, Sichuan Cancer Institute, Chengdu, 610041, PR China.
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31
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Julien M, Ghouil R, Petitalot A, Caputo SM, Carreira A, Zinn-Justin S. Intrinsic Disorder and Phosphorylation in BRCA2 Facilitate Tight Regulation of Multiple Conserved Binding Events. Biomolecules 2021; 11:1060. [PMID: 34356684 PMCID: PMC8301801 DOI: 10.3390/biom11071060] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 07/09/2021] [Accepted: 07/13/2021] [Indexed: 12/26/2022] Open
Abstract
The maintenance of genome integrity in the cell is an essential process for the accurate transmission of the genetic material. BRCA2 participates in this process at several levels, including DNA repair by homologous recombination, protection of stalled replication forks, and cell division. These activities are regulated and coordinated via cell-cycle dependent modifications. Pathogenic variants in BRCA2 cause genome instability and are associated with breast and/or ovarian cancers. BRCA2 is a very large protein of 3418 amino acids. Most well-characterized variants causing a strong predisposition to cancer are mutated in the C-terminal 700 residues DNA binding domain of BRCA2. The rest of the BRCA2 protein is predicted to be disordered. Interactions involving intrinsically disordered regions (IDRs) remain difficult to identify both using bioinformatics tools and performing experimental assays. However, the lack of well-structured binding sites provides unique functional opportunities for BRCA2 to bind to a large set of partners in a tightly regulated manner. We here summarize the predictive and experimental arguments that support the presence of disorder in BRCA2. We describe how BRCA2 IDRs mediate self-assembly and binding to partners during DNA double-strand break repair, mitosis, and meiosis. We highlight how phosphorylation by DNA repair and cell-cycle kinases regulate these interactions. We finally discuss the impact of cancer-associated variants on the function of BRCA2 IDRs and more generally on genome stability and cancer risk.
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Affiliation(s)
- Manon Julien
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, 91190 Gif-sur-Yvette, France; (M.J.); (R.G.)
- L’Institut de Biologie Intégrative de la Cellule (I2BC), UMR 9198, Paris-Saclay University, 91190 Gif-sur-Yvette, France;
| | - Rania Ghouil
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, 91190 Gif-sur-Yvette, France; (M.J.); (R.G.)
- L’Institut de Biologie Intégrative de la Cellule (I2BC), UMR 9198, Paris-Saclay University, 91190 Gif-sur-Yvette, France;
| | - Ambre Petitalot
- Service de Génétique, Unité de Génétique Constitutionnelle, Institut Curie, 75005 Paris, France; (A.P.); (S.M.C.)
- Institut Curie, Paris Sciences Lettres Research University, 75005 Paris, France
| | - Sandrine M. Caputo
- Service de Génétique, Unité de Génétique Constitutionnelle, Institut Curie, 75005 Paris, France; (A.P.); (S.M.C.)
- Institut Curie, Paris Sciences Lettres Research University, 75005 Paris, France
| | - Aura Carreira
- L’Institut de Biologie Intégrative de la Cellule (I2BC), UMR 9198, Paris-Saclay University, 91190 Gif-sur-Yvette, France;
- Institut Curie, Paris Sciences Lettres Research University, 75005 Paris, France
- Unité Intégrité du Génome, ARN et Cancer, Institut Curie, CNRS UMR3348, 91405 Orsay, France
| | - Sophie Zinn-Justin
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, 91190 Gif-sur-Yvette, France; (M.J.); (R.G.)
- L’Institut de Biologie Intégrative de la Cellule (I2BC), UMR 9198, Paris-Saclay University, 91190 Gif-sur-Yvette, France;
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Ackerson SM, Romney C, Schuck PL, Stewart JA. To Join or Not to Join: Decision Points Along the Pathway to Double-Strand Break Repair vs. Chromosome End Protection. Front Cell Dev Biol 2021; 9:708763. [PMID: 34322492 PMCID: PMC8311741 DOI: 10.3389/fcell.2021.708763] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 06/17/2021] [Indexed: 01/01/2023] Open
Abstract
The regulation of DNA double-strand breaks (DSBs) and telomeres are diametrically opposed in the cell. DSBs are considered one of the most deleterious forms of DNA damage and must be quickly recognized and repaired. Telomeres, on the other hand, are specialized, stable DNA ends that must be protected from recognition as DSBs to inhibit unwanted chromosome fusions. Decisions to join DNA ends, or not, are therefore critical to genome stability. Yet, the processing of telomeres and DSBs share many commonalities. Accordingly, key decision points are used to shift DNA ends toward DSB repair vs. end protection. Additionally, DSBs can be repaired by two major pathways, namely homologous recombination (HR) and non-homologous end joining (NHEJ). The choice of which repair pathway is employed is also dictated by a series of decision points that shift the break toward HR or NHEJ. In this review, we will focus on these decision points and the mechanisms that dictate end protection vs. DSB repair and DSB repair choice.
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Affiliation(s)
- Stephanie M Ackerson
- Department of Biological Sciences, University of South Carolina, Columbia, SC, United States
| | - Carlan Romney
- Department of Biological Sciences, University of South Carolina, Columbia, SC, United States
| | - P Logan Schuck
- Department of Biological Sciences, University of South Carolina, Columbia, SC, United States
| | - Jason A Stewart
- Department of Biological Sciences, University of South Carolina, Columbia, SC, United States
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Lee M, Shorthouse D, Mahen R, Hall BA, Venkitaraman AR. Cancer-causing BRCA2 missense mutations disrupt an intracellular protein assembly mechanism to disable genome maintenance. Nucleic Acids Res 2021; 49:5588-5604. [PMID: 33978741 PMCID: PMC8191791 DOI: 10.1093/nar/gkab308] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 04/11/2021] [Accepted: 04/28/2021] [Indexed: 12/13/2022] Open
Abstract
Cancer-causing missense mutations in the 3418 amino acid BRCA2 breast and ovarian cancer suppressor protein frequently affect a short (∼340 residue) segment in its carboxyl-terminal domain (DBD). Here, we identify a shared molecular mechanism underlying their pathogenicity. Pathogenic BRCA2 missense mutations cluster in the DBD’s helical domain (HD) and OB1-fold motifs, which engage the partner protein DSS1. Pathogenic - but not benign – DBD mutations weaken or abolish DSS1-BRCA2 assembly, provoking mutant BRCA2 oligomers that are excluded from the cell nucleus, and disable DNA repair by homologous DNA recombination (HDR). DSS1 inhibits the intracellular oligomerization of wildtype, but not mutant, forms of BRCA2. Remarkably, DSS1 expression corrects defective HDR in cells bearing pathogenic BRCA2 missense mutants with weakened, but not absent, DSS1 binding. Our findings identify a DSS1-mediated intracellular protein assembly mechanism that is disrupted by cancer-causing BRCA2 missense mutations, and suggest an approach for its therapeutic correction.
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Affiliation(s)
- Miyoung Lee
- Medical Research Council Cancer Unit, University of Cambridge, Hills Road, Cambridge CB2 0XZ, UK
| | - David Shorthouse
- Medical Research Council Cancer Unit, University of Cambridge, Hills Road, Cambridge CB2 0XZ, UK
| | - Robert Mahen
- Medical Research Council Cancer Unit, University of Cambridge, Hills Road, Cambridge CB2 0XZ, UK
| | - Benjamin A Hall
- Medical Research Council Cancer Unit, University of Cambridge, Hills Road, Cambridge CB2 0XZ, UK
| | - Ashok R Venkitaraman
- Medical Research Council Cancer Unit, University of Cambridge, Hills Road, Cambridge CB2 0XZ, UK.,The Cancer Science Institute of Singapore, National University of Singapore, 14 Medical Drive, Singapore 117599 & Agency for Science, Technology and Research (A*STAR), 8A Biomedical Grove 138648, Singapore
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34
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Andreassen PR, Seo J, Wiek C, Hanenberg H. Understanding BRCA2 Function as a Tumor Suppressor Based on Domain-Specific Activities in DNA Damage Responses. Genes (Basel) 2021; 12:genes12071034. [PMID: 34356050 PMCID: PMC8307705 DOI: 10.3390/genes12071034] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 06/23/2021] [Accepted: 06/29/2021] [Indexed: 01/14/2023] Open
Abstract
BRCA2 is an essential genome stability gene that has various functions in cells, including roles in homologous recombination, G2 checkpoint control, protection of stalled replication forks, and promotion of cellular resistance to numerous types of DNA damage. Heterozygous mutation of BRCA2 is associated with an increased risk of developing cancers of the breast, ovaries, pancreas, and other sites, thus BRCA2 acts as a classic tumor suppressor gene. However, understanding BRCA2 function as a tumor suppressor is severely limited by the fact that ~70% of the encoded protein has not been tested or assigned a function in the cellular DNA damage response. Remarkably, even the specific role(s) of many known domains in BRCA2 are not well characterized, predominantly because stable expression of the very large BRCA2 protein in cells, for experimental purposes, is challenging. Here, we review what is known about these domains and the assay systems that are available to study the cellular roles of BRCA2 domains in DNA damage responses. We also list criteria for better testing systems because, ultimately, functional assays for assessing the impact of germline and acquired mutations identified in genetic screens are important for guiding cancer prevention measures and for tailored cancer treatments.
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Affiliation(s)
- Paul R. Andreassen
- Division of Experimental Hematology and Cancer Biology, Cancer and Blood Diseases Institute, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA;
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
- Correspondence: ; Tel.: +1-(513)-636-0499
| | - Joonbae Seo
- Division of Experimental Hematology and Cancer Biology, Cancer and Blood Diseases Institute, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA;
| | - Constanze Wiek
- Department of Otorhinolaryngology and Head/Neck Surgery, Heinrich Heine University, 40225 Düsseldorf, Germany; (C.W.); (H.H.)
| | - Helmut Hanenberg
- Department of Otorhinolaryngology and Head/Neck Surgery, Heinrich Heine University, 40225 Düsseldorf, Germany; (C.W.); (H.H.)
- Department of Pediatrics III, Children’s Hospital, University of Duisburg-Essen, 45122 Essen, Germany
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35
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Shkundina IS, Gall AA, Dick A, Cocklin S, Mazin AV. New RAD51 Inhibitors to Target Homologous Recombination in Human Cells. Genes (Basel) 2021; 12:genes12060920. [PMID: 34208492 PMCID: PMC8235719 DOI: 10.3390/genes12060920] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 06/10/2021] [Accepted: 06/11/2021] [Indexed: 12/31/2022] Open
Abstract
Targeting DNA repair proteins with small-molecule inhibitors became a proven anti-cancer strategy. Previously, we identified an inhibitor of a major protein of homologous recombination (HR) RAD51, named B02. B02 inhibited HR in human cells and sensitized them to chemotherapeutic drugs in vitro and in vivo. Here, using a medicinal chemistry approach, we aimed to improve the potency of B02. We identified the B02 analog, B02-isomer, which inhibits HR in human cells with significantly higher efficiency. We also show that B02-iso sensitizes triple-negative breast cancer MDA-MB-231 cells to the PARP inhibitor (PARPi) olaparib.
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Affiliation(s)
- Irina S. Shkundina
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102, USA; (I.S.S.); (A.D.); (S.C.)
| | | | - Alexej Dick
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102, USA; (I.S.S.); (A.D.); (S.C.)
| | - Simon Cocklin
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102, USA; (I.S.S.); (A.D.); (S.C.)
| | - Alexander V. Mazin
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102, USA; (I.S.S.); (A.D.); (S.C.)
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX 78229, USA
- Correspondence:
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36
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Jimenez-Sainz J, Jensen RB. Imprecise Medicine: BRCA2 Variants of Uncertain Significance (VUS), the Challenges and Benefits to Integrate a Functional Assay Workflow with Clinical Decision Rules. Genes (Basel) 2021; 12:genes12050780. [PMID: 34065235 PMCID: PMC8161351 DOI: 10.3390/genes12050780] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 05/14/2021] [Accepted: 05/18/2021] [Indexed: 12/20/2022] Open
Abstract
Pathological mutations in homology-directed repair (HDR) genes impact both future cancer risk and therapeutic options for patients. HDR is a high-fidelity DNA repair pathway for resolving DNA double-strand breaks throughout the genome. BRCA2 is an essential protein that mediates the loading of RAD51 onto resected DNA breaks, a key step in HDR. Germline mutations in BRCA2 are associated with an increased risk for breast, ovarian, prostate, and pancreatic cancer. Clinical findings of germline or somatic BRCA2 mutations in tumors suggest treatment with platinum agents or PARP inhibitors. However, when genetic analysis reveals a variant of uncertain significance (VUS) in the BRCA2 gene, precision medicine-based decisions become complex. VUS are genetic changes with unknown pathological impact. Current statistics indicate that between 10–20% of BRCA sequencing results are VUS, and of these, more than 50% are missense mutations. Functional assays to determine the pathological outcome of VUS are urgently needed to provide clinical guidance regarding cancer risk and treatment options. In this review, we provide a brief overview of BRCA2 functions in HDR, describe how BRCA2 VUS are currently assessed in the clinic, and how genetic and biochemical functional assays could be integrated into the clinical decision process. We suggest a multi-step workflow composed of robust and accurate functional assays to correctly evaluate the potential pathogenic or benign nature of BRCA2 VUS. Success in this precision medicine endeavor will offer actionable information to patients and their physicians.
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Affiliation(s)
- Judit Jimenez-Sainz
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT 06520, USA
- Correspondence: (J.J.-S.); (R.B.J.); Tel.:+1-203-737-6456 (R.B.J.)
| | - Ryan B. Jensen
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT 06520, USA
- Department of Pathology, Yale University School of Medicine, New Haven, CT 06520, USA
- Correspondence: (J.J.-S.); (R.B.J.); Tel.:+1-203-737-6456 (R.B.J.)
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37
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Tang M, Li S, Chen J. Ubiquitylation in DNA double-strand break repair. DNA Repair (Amst) 2021; 103:103129. [PMID: 33990032 DOI: 10.1016/j.dnarep.2021.103129] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 04/26/2021] [Accepted: 05/05/2021] [Indexed: 12/28/2022]
Abstract
Genome integrity is constantly challenged by various DNA lesions with DNA double-strand breaks (DSBs) as the most cytotoxic lesions. In order to faithfully repair DSBs, DNA damage response (DDR) signaling networks have evolved, which organize many multi-protein complexes to deal with the encountered DNA damage. Spatiotemporal dynamics of these protein complexes at DSBs are mainly modulated by post-translational modifications (PTMs). One of the most well-studied PTMs in DDR is ubiquitylation which can orchestrate cellular responses to DSBs, promote accurate DNA repair, and maintain genome integrity. Here, we summarize the recent advances of ubiquitin-dependent signaling in DDR and discuss how ubiquitylation crosstalks with other PTMs to control fundamental biological processes in DSB repair.
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Affiliation(s)
- Mengfan Tang
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Siting Li
- 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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38
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Mouse Models for Deciphering the Impact of Homologous Recombination on Tumorigenesis. Cancers (Basel) 2021; 13:cancers13092083. [PMID: 33923105 PMCID: PMC8123484 DOI: 10.3390/cancers13092083] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 04/19/2021] [Accepted: 04/20/2021] [Indexed: 12/15/2022] Open
Abstract
Homologous recombination (HR) is a fundamental evolutionarily conserved process that plays prime role(s) in genome stability maintenance through DNA repair and through the protection and resumption of arrested replication forks. Many HR genes are deregulated in cancer cells. Notably, the breast cancer genes BRCA1 and BRCA2, two important HR players, are the most frequently mutated genes in familial breast and ovarian cancer. Transgenic mice constitute powerful tools to unravel the intricate mechanisms controlling tumorigenesis in vivo. However, the genes central to HR are essential in mammals, and their knockout leads to early embryonic lethality in mice. Elaborated strategies have been developed to overcome this difficulty, enabling one to analyze the consequences of HR disruption in vivo. In this review, we first briefly present the molecular mechanisms of HR in mammalian cells to introduce each factor in the HR process. Then, we present the different mouse models of HR invalidation and the consequences of HR inactivation on tumorigenesis. Finally, we discuss the use of mouse models for the development of targeted cancer therapies as well as perspectives on the future potential for understanding the mechanisms of HR inactivation-driven tumorigenesis in vivo.
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Li Q, Engebrecht J. BRCA1 and BRCA2 Tumor Suppressor Function in Meiosis. Front Cell Dev Biol 2021; 9:668309. [PMID: 33996823 PMCID: PMC8121103 DOI: 10.3389/fcell.2021.668309] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 03/19/2021] [Indexed: 12/12/2022] Open
Abstract
Meiosis is a specialized cell cycle that results in the production of haploid gametes for sexual reproduction. During meiosis, homologous chromosomes are connected by chiasmata, the physical manifestation of crossovers. Crossovers are formed by the repair of intentionally induced double strand breaks by homologous recombination and facilitate chromosome alignment on the meiotic spindle and proper chromosome segregation. While it is well established that the tumor suppressors BRCA1 and BRCA2 function in DNA repair and homologous recombination in somatic cells, the functions of BRCA1 and BRCA2 in meiosis have received less attention. Recent studies in both mice and the nematode Caenorhabditis elegans have provided insight into the roles of these tumor suppressors in a number of meiotic processes, revealing both conserved and organism-specific functions. BRCA1 forms an E3 ubiquitin ligase as a heterodimer with BARD1 and appears to have regulatory roles in a number of key meiotic processes. BRCA2 is a very large protein that plays an intimate role in homologous recombination. As women with no indication of cancer but carrying BRCA mutations show decreased ovarian reserve and accumulated oocyte DNA damage, studies in these systems may provide insight into why BRCA mutations impact reproductive success in addition to their established roles in cancer.
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Affiliation(s)
- Qianyan Li
- Department of Molecular and Cellular Biology, and Biochemistry, Molecular, Cellular and Developmental Biology Graduate Group, University of California, Davis, Davis, CA, United States
| | - JoAnne Engebrecht
- Department of Molecular and Cellular Biology, and Biochemistry, Molecular, Cellular and Developmental Biology Graduate Group, University of California, Davis, Davis, CA, United States
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40
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Ehlén Å, Sessa G, Zinn-Justin S, Carreira A. The phospho-dependent role of BRCA2 on the maintenance of chromosome integrity. Cell Cycle 2021; 20:731-741. [PMID: 33691600 PMCID: PMC8098065 DOI: 10.1080/15384101.2021.1892994] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 01/21/2021] [Accepted: 02/16/2021] [Indexed: 12/18/2022] Open
Abstract
Chromosomal instability is a hallmark of cancer. The tumor suppressor protein BRCA2 performs an important role in the maintenance of genome integrity particularly in interphase; as a mediator of homologous recombination DNA repair pathway, it participates in the repair of DNA double-strand breaks, inter-strand crosslinks and replicative DNA lesions. BRCA2 also protects stalled replication forks from aberrant degradation. Defects in these functions lead to structural chromosomal aberrations. BRCA2 is a large protein containing highly disordered regions that are heavily phosphorylated particularly in mitosis. The functions of these modifications are getting elucidated and reveal emerging activities in chromosome alignment, chromosome segregation and abscission during cell division. Defects in these activities result in numerical chromosomal aberrations. In addition to BRCA2, other factors of the DNA damage response (DDR) participate in mitosis in close association with cell cycle kinases and phosphatases suggesting that the maintenance of genome integrity functions of these factors extends beyond DNA repair. Here we will discuss the regulation of BRCA2 functions through phosphorylation by cell cycle kinases particularly in mitosis, and illustrate with some examples how BRCA2 and other DDR proteins partially rewire their interactions, essentially via phosphorylation, to fulfill mitotic specific functions that ensure chromosome stability.
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Affiliation(s)
- Åsa Ehlén
- Institut Curie, PSL University, CNRS, UMR3348, Orsay, France
- Paris-Saclay University CNRS, UMR3348, Orsay, France
| | - Gaetana Sessa
- Institut Curie, PSL University, CNRS, UMR3348, Orsay, France
- Paris-Saclay University CNRS, UMR3348, Orsay, France
| | - Sophie Zinn-Justin
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette Cedex, France
| | - Aura Carreira
- Institut Curie, PSL University, CNRS, UMR3348, Orsay, France
- Paris-Saclay University CNRS, UMR3348, Orsay, France
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41
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Adolph MB, Mohamed TM, Balakrishnan S, Xue C, Morati F, Modesti M, Greene EC, Chazin WJ, Cortez D. RADX controls RAD51 filament dynamics to regulate replication fork stability. Mol Cell 2021; 81:1074-1083.e5. [PMID: 33453169 PMCID: PMC7935748 DOI: 10.1016/j.molcel.2020.12.036] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 11/02/2020] [Accepted: 12/21/2020] [Indexed: 01/10/2023]
Abstract
The RAD51 recombinase forms nucleoprotein filaments to promote double-strand break repair, replication fork reversal, and fork stabilization. The stability of these filaments is highly regulated, as both too little and too much RAD51 activity can cause genome instability. RADX is a single-strand DNA (ssDNA) binding protein that regulates DNA replication. Here, we define its mechanism of action. We find that RADX inhibits RAD51 strand exchange and D-loop formation activities. RADX directly and selectively interacts with ATP-bound RAD51, stimulates ATP hydrolysis, and destabilizes RAD51 nucleofilaments. The RADX interaction with RAD51, in addition to its ssDNA binding capability, is required to maintain replication fork elongation rates and fork stability. Furthermore, BRCA2 can overcome the RADX-dependent RAD51 inhibition. Thus, RADX functions in opposition to BRCA2 in regulating RAD51 nucleofilament stability to ensure the right level of RAD51 function during DNA replication.
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Affiliation(s)
- Madison B Adolph
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Taha M Mohamed
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Swati Balakrishnan
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, USA; Center for Structural Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Chaoyou Xue
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY USA
| | - Florian Morati
- Cancer Research Center of Marseille, CNRS UMR7258, Inserm U1068, Institut Paoli-Calmettes, Aix-Marseille Université U105, Marseille, France
| | - Mauro Modesti
- Cancer Research Center of Marseille, CNRS UMR7258, Inserm U1068, Institut Paoli-Calmettes, Aix-Marseille Université U105, Marseille, France
| | - Eric C Greene
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY USA
| | - Walter J Chazin
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, USA; Center for Structural Biology, Vanderbilt University School of Medicine, Nashville, TN, USA.
| | - David Cortez
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, USA.
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42
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Scott DE, Francis-Newton NJ, Marsh ME, Coyne AG, Fischer G, Moschetti T, Bayly AR, Sharpe TD, Haas KT, Barber L, Valenzano CR, Srinivasan R, Huggins DJ, Lee M, Emery A, Hardwick B, Ehebauer M, Dagostin C, Esposito A, Pellegrini L, Perrior T, McKenzie G, Blundell TL, Hyvönen M, Skidmore J, Venkitaraman AR, Abell C. A small-molecule inhibitor of the BRCA2-RAD51 interaction modulates RAD51 assembly and potentiates DNA damage-induced cell death. Cell Chem Biol 2021; 28:835-847.e5. [PMID: 33662256 PMCID: PMC8219027 DOI: 10.1016/j.chembiol.2021.02.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 12/18/2020] [Accepted: 02/03/2021] [Indexed: 12/11/2022]
Abstract
BRCA2 controls RAD51 recombinase during homologous DNA recombination (HDR) through eight evolutionarily conserved BRC repeats, which individually engage RAD51 via the motif Phe-x-x-Ala. Using structure-guided molecular design, templated on a monomeric thermostable chimera between human RAD51 and archaeal RadA, we identify CAM833, a 529 Da orthosteric inhibitor of RAD51:BRC with a Kd of 366 nM. The quinoline of CAM833 occupies a hotspot, the Phe-binding pocket on RAD51 and the methyl of the substituted α-methylbenzyl group occupies the Ala-binding pocket. In cells, CAM833 diminishes formation of damage-induced RAD51 nuclear foci; inhibits RAD51 molecular clustering, suppressing extended RAD51 filament assembly; potentiates cytotoxicity by ionizing radiation, augmenting 4N cell-cycle arrest and apoptotic cell death and works with poly-ADP ribose polymerase (PARP)1 inhibitors to suppress growth in BRCA2-wildtype cells. Thus, chemical inhibition of the protein-protein interaction between BRCA2 and RAD51 disrupts HDR and potentiates DNA damage-induced cell death, with implications for cancer therapy.
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Affiliation(s)
- Duncan E Scott
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - Nicola J Francis-Newton
- Medical Research Council Cancer Unit, University of Cambridge, Hutchison/MRC Research Centre, Hills Road, Cambridge CB2 0XZ, UK
| | - May E Marsh
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, UK
| | - Anthony G Coyne
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - Gerhard Fischer
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, UK
| | - Tommaso Moschetti
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, UK
| | - Andrew R Bayly
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - Timothy D Sharpe
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, UK
| | - Kalina T Haas
- Medical Research Council Cancer Unit, University of Cambridge, Hutchison/MRC Research Centre, Hills Road, Cambridge CB2 0XZ, UK
| | - Lorraine Barber
- Medical Research Council Cancer Unit, University of Cambridge, Hutchison/MRC Research Centre, Hills Road, Cambridge CB2 0XZ, UK
| | - Chiara R Valenzano
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - Rajavel Srinivasan
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - David J Huggins
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK; Medical Research Council Cancer Unit, University of Cambridge, Hutchison/MRC Research Centre, Hills Road, Cambridge CB2 0XZ, UK
| | - Miyoung Lee
- Medical Research Council Cancer Unit, University of Cambridge, Hutchison/MRC Research Centre, Hills Road, Cambridge CB2 0XZ, UK
| | - Amy Emery
- Medical Research Council Cancer Unit, University of Cambridge, Hutchison/MRC Research Centre, Hills Road, Cambridge CB2 0XZ, UK
| | - Bryn Hardwick
- Medical Research Council Cancer Unit, University of Cambridge, Hutchison/MRC Research Centre, Hills Road, Cambridge CB2 0XZ, UK
| | - Matthias Ehebauer
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, UK
| | - Claudio Dagostin
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - Alessandro Esposito
- Medical Research Council Cancer Unit, University of Cambridge, Hutchison/MRC Research Centre, Hills Road, Cambridge CB2 0XZ, UK
| | - Luca Pellegrini
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, UK
| | - Trevor Perrior
- Excellium Consulting, Brook Farm Barn, Lackford, Bury St Edmunds IP28 6HL, UK
| | - Grahame McKenzie
- Medical Research Council Cancer Unit, University of Cambridge, Hutchison/MRC Research Centre, Hills Road, Cambridge CB2 0XZ, UK
| | - Tom L Blundell
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, UK
| | - Marko Hyvönen
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, UK.
| | - John Skidmore
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
| | - Ashok R Venkitaraman
- Medical Research Council Cancer Unit, University of Cambridge, Hutchison/MRC Research Centre, Hills Road, Cambridge CB2 0XZ, UK.
| | - Chris Abell
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
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43
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Sessa G, Gómez-González B, Silva S, Pérez-Calero C, Beaurepere R, Barroso S, Martineau S, Martin C, Ehlén Å, Martínez JS, Lombard B, Loew D, Vagner S, Aguilera A, Carreira A. BRCA2 promotes DNA-RNA hybrid resolution by DDX5 helicase at DNA breaks to facilitate their repair‡. EMBO J 2021; 40:e106018. [PMID: 33634895 DOI: 10.15252/embj.2020106018] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 01/22/2021] [Accepted: 01/25/2021] [Indexed: 12/19/2022] Open
Abstract
The BRCA2 tumor suppressor is a DNA double-strand break (DSB) repair factor essential for maintaining genome integrity. BRCA2-deficient cells spontaneously accumulate DNA-RNA hybrids, a known source of genome instability. However, the specific role of BRCA2 on these structures remains poorly understood. Here we identified the DEAD-box RNA helicase DDX5 as a BRCA2-interacting protein. DDX5 associates with DNA-RNA hybrids that form in the vicinity of DSBs, and this association is enhanced by BRCA2. Notably, BRCA2 stimulates the DNA-RNA hybrid-unwinding activity of DDX5 helicase. An impaired BRCA2-DDX5 interaction, as observed in cells expressing the breast cancer variant BRCA2-T207A, reduces the association of DDX5 with DNA-RNA hybrids, decreases the number of RPA foci, and alters the kinetics of appearance of RAD51 foci upon irradiation. Our findings are consistent with DNA-RNA hybrids constituting an impediment for the repair of DSBs by homologous recombination and reveal BRCA2 and DDX5 as active players in their removal.
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Affiliation(s)
- Gaetana Sessa
- Institut Curie, Université PSL, CNRS UMR3348, Orsay, France.,Université Paris-Saclay, CNRS UMR3348, Orsay, France
| | - Belén Gómez-González
- Andalusian Molecular Biology and Regenerative Medicine Centre-CABIMER, University of Seville-CSIC, Seville, Spain.,Departamento de Genética, Facultad de Biología, University of Seville, Seville, Spain
| | - Sonia Silva
- Andalusian Molecular Biology and Regenerative Medicine Centre-CABIMER, University of Seville-CSIC, Seville, Spain.,Departamento de Genética, Facultad de Biología, University of Seville, Seville, Spain
| | - Carmen Pérez-Calero
- Andalusian Molecular Biology and Regenerative Medicine Centre-CABIMER, University of Seville-CSIC, Seville, Spain.,Departamento de Genética, Facultad de Biología, University of Seville, Seville, Spain
| | - Romane Beaurepere
- Institut Curie, Université PSL, CNRS UMR3348, Orsay, France.,Université Paris-Saclay, CNRS UMR3348, Orsay, France
| | - Sonia Barroso
- Andalusian Molecular Biology and Regenerative Medicine Centre-CABIMER, University of Seville-CSIC, Seville, Spain.,Departamento de Genética, Facultad de Biología, University of Seville, Seville, Spain
| | - Sylvain Martineau
- Institut Curie, Université PSL, CNRS UMR3348, Orsay, France.,Université Paris-Saclay, CNRS UMR3348, Orsay, France
| | - Charlotte Martin
- Institut Curie, Université PSL, CNRS UMR3348, Orsay, France.,Université Paris-Saclay, CNRS UMR3348, Orsay, France
| | - Åsa Ehlén
- Institut Curie, Université PSL, CNRS UMR3348, Orsay, France.,Université Paris-Saclay, CNRS UMR3348, Orsay, France
| | - Juan S Martínez
- Institut Curie, Université PSL, CNRS UMR3348, Orsay, France.,Université Paris-Saclay, CNRS UMR3348, Orsay, France
| | - Bérangère Lombard
- Laboratoire de Spectrométrie de Masse Protéomique, Institut Curie, PSL Research University, Paris, France
| | - Damarys Loew
- Laboratoire de Spectrométrie de Masse Protéomique, Institut Curie, PSL Research University, Paris, France
| | - Stephan Vagner
- Institut Curie, Université PSL, CNRS UMR3348, Orsay, France.,Université Paris-Saclay, CNRS UMR3348, Orsay, France
| | - Andrés Aguilera
- Andalusian Molecular Biology and Regenerative Medicine Centre-CABIMER, University of Seville-CSIC, Seville, Spain.,Departamento de Genética, Facultad de Biología, University of Seville, Seville, Spain
| | - Aura Carreira
- Institut Curie, Université PSL, CNRS UMR3348, Orsay, France.,Université Paris-Saclay, CNRS UMR3348, Orsay, France
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44
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El Dika M. Use of Xenopus laevis cell-free extracts to study BRCA2 role in chromosome alignment. DNA Repair (Amst) 2021; 100:103053. [PMID: 33550028 DOI: 10.1016/j.dnarep.2021.103053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2021] [Revised: 01/19/2021] [Accepted: 01/23/2021] [Indexed: 11/18/2022]
Affiliation(s)
- Mohammed El Dika
- Department of Biochemistry and University of Vermont Cancer Center, University of Vermont, Burlington, VT, USA; Institut Curie, PSL Research University, CNRS, UMR3348, Orsay, France; Paris Sud University, Paris-Saclay University, CNRS, UMR3348, Orsay, France.
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45
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Abstract
The homologous recombination (HR) pathway maintains genomic integrity by repairing DNA double-strand breaks (DSBs), single-strand DNA gaps, and collapsed replication forks. The process of HR involves strand invasion, homology search, and DNA strand exchange between paired DNA molecules. HR is critical for the high-fidelity repair of DNA DSBs in mitotic cells and for the exchange of genetic information during meiosis. Here we describe a DNA strand exchange reaction in vitro utilizing purified proteins and defined DNA substrates to measure the strand invasion and pairing activities of the human RAD51 protein. We further discuss how this reaction can be catalytically stimulated by the mediator protein BRCA2.
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Affiliation(s)
- Sudipta Lahiri
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT, USA
| | - Ryan B Jensen
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT, USA.
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46
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Chang HY, Lee CY, Lu CH, Lee W, Yang HL, Yeh HY, Li HW, Chi P. Microcephaly family protein MCPH1 stabilizes RAD51 filaments. Nucleic Acids Res 2020; 48:9135-9146. [PMID: 32735676 PMCID: PMC7498314 DOI: 10.1093/nar/gkaa636] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 06/30/2020] [Accepted: 07/22/2020] [Indexed: 01/19/2023] Open
Abstract
Microcephalin 1 (MCPH1) was identified from genetic mutations in patients with primary autosomal recessive microcephaly. In response to DNA double-strand breaks (DSBs), MCPH1 forms damage-induced foci and recruits BRCA2-RAD51 complex, a key component of the DSB repair machinery for homologous recombination (HR), to damage sites. Accordingly, the efficiency of HR is significantly attenuated upon depletion of MCPH1. The biochemical characteristics of MCPH1 and its functional interaction with the HR machinery had remained unclear due to lack of highly purified MCPH1 recombinant protein for functional study. Here, we established a mammalian expression system to express and purify MCPH1 protein. We show that MCPH1 is a bona fide DNA-binding protein and provide direct biochemical analysis of this MCPH family protein. Furthermore, we reveal that MCPH1 directly interacts with RAD51 at multiple contact points, providing evidence for how MCPH1 physically engages with the HR machinery. Importantly, we demonstrate that MCPH1 enhances the stability of RAD51 on single-strand DNA, a prerequisite step for RAD51-mediated recombination. Single-molecule tethered particle motion analysis showed a ∼2-fold increase in the lifetime of RAD51-ssDNA filaments in the presence of MCPH1. Thus, our study demonstrates direct crosstalk between microcephaly protein MCPH1 and the recombination component RAD51 for DSB repair.
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Affiliation(s)
- Hao-Yen Chang
- Institute of Biochemical Sciences, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan
| | - Chia-Yi Lee
- Institute of Biochemical Sciences, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan
| | - Chih-Hao Lu
- Department of Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan
| | - Wei Lee
- Department of Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan
| | - Han-Lin Yang
- Department of Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan
| | - Hsin-Yi Yeh
- Institute of Biochemical Sciences, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan
| | - Hung-Wen Li
- Department of Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan
| | - Peter Chi
- Institute of Biochemical Sciences, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan.,Institute of Biological Chemistry, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei 11529, Taiwan
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47
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Sanese P, Fasano C, Buscemi G, Bottino C, Corbetta S, Fabini E, Silvestri V, Valentini V, Disciglio V, Forte G, Lepore Signorile M, De Marco K, Bertora S, Grossi V, Guven U, Porta N, Di Maio V, Manoni E, Giannelli G, Bartolini M, Del Rio A, Caretti G, Ottini L, Simone C. Targeting SMYD3 to Sensitize Homologous Recombination-Proficient Tumors to PARP-Mediated Synthetic Lethality. iScience 2020; 23:101604. [PMID: 33205017 PMCID: PMC7648160 DOI: 10.1016/j.isci.2020.101604] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 08/07/2020] [Accepted: 09/21/2020] [Indexed: 12/17/2022] Open
Abstract
SMYD3 is frequently overexpressed in a wide variety of cancers. Indeed, its inactivation reduces tumor growth in preclinical in vivo animal models. However, extensive characterization in vitro failed to clarify SMYD3 function in cancer cells, although confirming its importance in carcinogenesis. Taking advantage of a SMYD3 mutant variant identified in a high-risk breast cancer family, here we show that SMYD3 phosphorylation by ATM enables the formation of a multiprotein complex including ATM, SMYD3, CHK2, and BRCA2, which is required for the final loading of RAD51 at DNA double-strand break sites and completion of homologous recombination (HR). Remarkably, SMYD3 pharmacological inhibition sensitizes HR-proficient cancer cells to PARP inhibitors, thereby extending the potential of the synthetic lethality approach in human tumors. SMYD3 phosphorylation by ATM favors the formation of HR complexes during DSB response SMYD3 mediates DSB repair by promoting RAD51 recruitment at DNA damage sites SMYD3 inhibition triggers a compensatory PARP-dependent DNA damage response Co-targeting SMYD3/PARP leads to synthetic lethality in HR-proficient cancer cells
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Affiliation(s)
- Paola Sanese
- Medical Genetics, National Institute of Gastroenterology "S. de Bellis" Research Hospital, Castellana Grotte, Bari 70013, Italy
| | - Candida Fasano
- Medical Genetics, National Institute of Gastroenterology "S. de Bellis" Research Hospital, Castellana Grotte, Bari 70013, Italy
| | - Giacomo Buscemi
- Institute of Molecular Genetics, IGM "Luigi Luca Cavalli-Sforza", National Research Council (CNR), Pavia 27100, Italy
| | - Cinzia Bottino
- Department of Biosciences, University of Milan, Milan 20133, Italy
| | - Silvia Corbetta
- Department of Biosciences, University of Milan, Milan 20133, Italy
| | - Edoardo Fabini
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum University of Bologna, Bologna 40126, Italy.,BioChemoInformatics Unit, Institute of Organic Synthesis and Photoreactivity (ISOF), National Research Council (CNR), Bologna 40129, Italy
| | - Valentina Silvestri
- Department of Molecular Medicine, University of Roma "La Sapienza", Roma 00185, Italy
| | - Virginia Valentini
- Department of Molecular Medicine, University of Roma "La Sapienza", Roma 00185, Italy
| | - Vittoria Disciglio
- Medical Genetics, National Institute of Gastroenterology "S. de Bellis" Research Hospital, Castellana Grotte, Bari 70013, Italy
| | - Giovanna Forte
- Medical Genetics, National Institute of Gastroenterology "S. de Bellis" Research Hospital, Castellana Grotte, Bari 70013, Italy
| | - Martina Lepore Signorile
- Medical Genetics, National Institute of Gastroenterology "S. de Bellis" Research Hospital, Castellana Grotte, Bari 70013, Italy
| | - Katia De Marco
- Medical Genetics, National Institute of Gastroenterology "S. de Bellis" Research Hospital, Castellana Grotte, Bari 70013, Italy
| | - Stefania Bertora
- Medical Genetics, National Institute of Gastroenterology "S. de Bellis" Research Hospital, Castellana Grotte, Bari 70013, Italy
| | - Valentina Grossi
- Medical Genetics, National Institute of Gastroenterology "S. de Bellis" Research Hospital, Castellana Grotte, Bari 70013, Italy
| | - Ummu Guven
- Department of Biosciences, University of Milan, Milan 20133, Italy
| | - Natale Porta
- Department of Medical-Surgical Sciences and Biotechnology, Polo Pontino University of Roma "La Sapienza", Latina 04100, Italy
| | - Valeria Di Maio
- Department of Medical-Surgical Sciences and Biotechnology, Polo Pontino University of Roma "La Sapienza", Latina 04100, Italy
| | - Elisabetta Manoni
- BioChemoInformatics Unit, Institute of Organic Synthesis and Photoreactivity (ISOF), National Research Council (CNR), Bologna 40129, Italy
| | - Gianluigi Giannelli
- Medical Genetics, National Institute of Gastroenterology "S. de Bellis" Research Hospital, Castellana Grotte, Bari 70013, Italy
| | - Manuela Bartolini
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum University of Bologna, Bologna 40126, Italy
| | - Alberto Del Rio
- BioChemoInformatics Unit, Institute of Organic Synthesis and Photoreactivity (ISOF), National Research Council (CNR), Bologna 40129, Italy.,Innovamol Consulting Srl, Modena 41123, Italy
| | | | - Laura Ottini
- Department of Molecular Medicine, University of Roma "La Sapienza", Roma 00185, Italy
| | - Cristiano Simone
- Medical Genetics, National Institute of Gastroenterology "S. de Bellis" Research Hospital, Castellana Grotte, Bari 70013, Italy.,Department of Biomedical Sciences and Human Oncology (DIMO), Medical Genetics; University of Bari Aldo Moro, Bari 70124, Italy
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48
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Abstract
Accurate DNA repair and replication are critical for genomic stability and cancer prevention. RAD51 and its gene family are key regulators of DNA fidelity through diverse roles in double-strand break repair, replication stress, and meiosis. RAD51 is an ATPase that forms a nucleoprotein filament on single-stranded DNA. RAD51 has the function of finding and invading homologous DNA sequences to enable accurate and timely DNA repair. Its paralogs, which arose from ancient gene duplications of RAD51, have evolved to regulate and promote RAD51 function. Underscoring its importance, misregulation of RAD51, and its paralogs, is associated with diseases such as cancer and Fanconi anemia. In this review, we focus on the mammalian RAD51 structure and function and highlight the use of model systems to enable mechanistic understanding of RAD51 cellular roles. We also discuss how misregulation of the RAD51 gene family members contributes to disease and consider new approaches to pharmacologically inhibit RAD51.
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Affiliation(s)
- Braulio Bonilla
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA;
| | - Sarah R Hengel
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA;
| | - McKenzie K Grundy
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA;
| | - Kara A Bernstein
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA;
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49
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Design of BRC analogous peptides based on the complex BRC8-RAD51 and the preliminary study on the peptide structures. Amino Acids 2020; 52:831-839. [PMID: 32417964 DOI: 10.1007/s00726-020-02856-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 04/30/2020] [Indexed: 10/24/2022]
Abstract
BRCA2 is an important tumor suppressor gene that plays a critical role in preserving the stability of cellular genetic information, participating in DNA repair by engaging in binding interactions with RAD51 proteins. However, the lack of structural data on BRCA2 and RAD51 makes the study of their interaction mechanism still a great challenge. We characterize the structure of the BRC8-RAD51 complex using ZDOCK protein docking software and identify the potential non-conserved active site of BRC8 via virtual alanine scanning, utilizing the obtained results to synthesize BRC8, its six analogous peptides (BRC8-1 to BRC8-6), and critical peptide fragment of RAD51 (RAD51(231-260)) by Fmoc solid-phase synthesis. The analogous peptides are found to exhibit a secondary structure significantly different from that of BRC8 by circular dichroism spectroscopy, which indicates that mutation sites determined by computer-aided simulation correspond to key amino acid residues substantially affecting polypeptide structure. On the other hand, the secondary structure of RAD51(231-260) was also considerably influenced by its interaction with BRC8 and analogs, e.g., the fraction of the α-helical structure in RAD51(231-260) increased to 23.6, 15.1, and 13.5% upon interaction with BRC8-1, BRC8-3, and BRC8-6, respectively. The results show that the properties of C-terminal amino acid residues significantly influence peptide-peptide interactions, in agreement with the results of virtual alanine scanning. Therefore, computer-aided simulation was confirmed to be a technique that is useful for narrowing down the range of sites responsible for interactions between peptides or proteins, and provides new inspirations for the design of peptides with strong interactions.
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Subramanyam S, Spies M. RAD51 discrimination between single- and double-strand DNA: a matter of flexibility and enthalpy. EMBO J 2020; 39:e104547. [PMID: 32090346 PMCID: PMC7110141 DOI: 10.15252/embj.2020104547] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2024] Open
Abstract
In selecting ssDNA over dsDNA, the RAD51 DNA strand exchange protein has to overcome the entropy associated with straightening of single-strand DNA upon nucleoprotein filament formation. New work in The EMBO Journal (Paoletti et al, 2020), combined biophysical analysis of the RAD51-ssDNA interaction with mathematical modeling to show that the flexibility of DNA positively correlates with nucleation and extension of the RAD51 nucleoprotein filament and that the entropic penalty associated with restricting ssDNA flexibility is offset by a strong RAD51-RAD51 interaction within the nucleoprotein filament.
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Affiliation(s)
- Shyamal Subramanyam
- Department of Radiation OncologyMemorial Sloan Kettering Cancer CenterNew YorkNYUSA
| | - Maria Spies
- Department of BiochemistryCarver College of MedicineUniversity of IowaIowa CityIAUSA
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