1
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Liu HL, Nan H, Zhao WW, Wan XB, Fan XJ. Phase separation in DNA double-strand break response. Nucleus 2024; 15:2296243. [PMID: 38146123 PMCID: PMC10761171 DOI: 10.1080/19491034.2023.2296243] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 12/12/2023] [Indexed: 12/27/2023] Open
Abstract
DNA double-strand break (DSB) is the most dangerous type of DNA damage, which may lead to cell death or oncogenic mutations. Homologous recombination (HR) and nonhomologous end-joining (NHEJ) are two typical DSB repair mechanisms. Recently, many studies have revealed that liquid-liquid phase separation (LLPS) plays a pivotal role in DSB repair and response. Through LLPS, the crucial biomolecules are quickly recruited to damaged sites with a high concentration to ensure DNA repair is conducted quickly and efficiently, which facilitates DSB repair factors activating downstream proteins or transmitting signals. In addition, the dysregulation of the DSB repair factor's phase separation has been reported to promote the development of a variety of diseases. This review not only provides a comprehensive overview of the emerging roles of LLPS in the repair of DSB but also sheds light on the regulatory patterns of phase separation in relation to the DNA damage response (DDR).
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Affiliation(s)
- Huan-Lei Liu
- Henan Provincial Key Laboratory of Radiation Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, P.R. China
- Department of Radiation Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, P.R. China
- Academy of Medical Science, Zhengzhou University, Zhengzhou, Henan, P.R. China
- College of Life Sciences, Northwest AF University, Yangling, Shaanxi, China
| | - Hao Nan
- College of Life Sciences, Northwest AF University, Yangling, Shaanxi, China
| | - Wan-Wen Zhao
- Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, P.R. China
- Department of Radiation Oncology, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, P.R. China
| | - Xiang-Bo Wan
- Henan Provincial Key Laboratory of Radiation Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, P.R. China
- Department of Radiation Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, P.R. China
- Academy of Medical Science, Zhengzhou University, Zhengzhou, Henan, P.R. China
- Department of Radiation Oncology, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, P.R. China
| | - Xin-Juan Fan
- Henan Provincial Key Laboratory of Radiation Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, P.R. China
- Academy of Medical Science, Zhengzhou University, Zhengzhou, Henan, P.R. China
- Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, P.R. China
- Department of Pathology, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, P.R. China
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2
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Joo JH, Hong S, Higashide MT, Choi EH, Yoon S, Lee MS, Kang HA, Shinohara A, Kleckner N, Kim KP. RPA interacts with Rad52 to promote meiotic crossover and noncrossover recombination. Nucleic Acids Res 2024; 52:3794-3809. [PMID: 38340339 DOI: 10.1093/nar/gkae083] [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: 02/19/2023] [Revised: 01/24/2024] [Accepted: 01/27/2024] [Indexed: 02/12/2024] Open
Abstract
Meiotic recombination is initiated by programmed double-strand breaks (DSBs). Studies in Saccharomyces cerevisiae have shown that, following rapid resection to generate 3' single-stranded DNA (ssDNA) tails, one DSB end engages a homolog partner chromatid and is extended by DNA synthesis, whereas the other end remains associated with its sister. Then, after regulated differentiation into crossover- and noncrossover-fated types, the second DSB end participates in the reaction by strand annealing with the extended first end, along both pathways. This second-end capture is dependent on Rad52, presumably via its known capacity to anneal two ssDNAs. Here, using physical analysis of DNA recombination, we demonstrate that this process is dependent on direct interaction of Rad52 with the ssDNA binding protein, replication protein A (RPA). Furthermore, the absence of this Rad52-RPA joint activity results in a cytologically-prominent RPA spike, which emerges from the homolog axes at sites of crossovers during the pachytene stage of the meiotic prophase. Our findings suggest that this spike represents the DSB end of a broken chromatid caused by either the displaced leading DSB end or the second DSB end, which has been unable to engage with the partner homolog-associated ssDNA. These and other results imply a close correspondence between Rad52-RPA roles in meiotic recombination and mitotic DSB repair.
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Affiliation(s)
- Jeong H Joo
- Department of Life Sciences, Chung-Ang University, Seoul 06974, South Korea
| | - Soogil Hong
- Department of Life Sciences, Chung-Ang University, Seoul 06974, South Korea
| | - Mika T Higashide
- Institute for Protein Research, Graduate School of Science, Osaka University, Osaka 565-0871, Japan
| | - Eui-Hwan Choi
- Department of Life Sciences, Chung-Ang University, Seoul 06974, South Korea
- New Drug Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Deagu 41061, South Korea
| | - Seobin Yoon
- Department of Life Sciences, Chung-Ang University, Seoul 06974, South Korea
| | - Min-Su Lee
- Department of Life Sciences, Chung-Ang University, Seoul 06974, South Korea
| | - Hyun Ah Kang
- Department of Life Sciences, Chung-Ang University, Seoul 06974, South Korea
| | - Akira Shinohara
- Institute for Protein Research, Graduate School of Science, Osaka University, Osaka 565-0871, Japan
| | - Nancy Kleckner
- Department of Molecular and Cellular Biology, Harvard University, Cambridge 02138, USA
| | - Keun P Kim
- Department of Life Sciences, Chung-Ang University, Seoul 06974, South Korea
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3
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Zou M, Shabala S, Zhao C, Zhou M. Molecular mechanisms and regulation of recombination frequency and distribution in plants. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2024; 137:86. [PMID: 38512498 PMCID: PMC10957645 DOI: 10.1007/s00122-024-04590-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 02/28/2024] [Indexed: 03/23/2024]
Abstract
KEY MESSAGE Recent developments in understanding the distribution and distinctive features of recombination hotspots are reviewed and approaches are proposed to increase recombination frequency in coldspot regions. Recombination events during meiosis provide the foundation and premise for creating new varieties of crops. The frequency of recombination in different genomic regions differs across eukaryote species, with recombination generally occurring more frequently at the ends of chromosomes. In most crop species, recombination is rare in centromeric regions. If a desired gene variant is linked in repulsion with an undesired variant of a second gene in a region with a low recombination rate, obtaining a recombinant plant combining two favorable alleles will be challenging. Traditional crop breeding involves combining desirable genes from parental plants into offspring. Therefore, understanding the mechanisms of recombination and factors affecting the occurrence of meiotic recombination is important for crop breeding. Here, we review chromosome recombination types, recombination mechanisms, genes and proteins involved in the meiotic recombination process, recombination hotspots and their regulation systems and discuss how to increase recombination frequency in recombination coldspot regions.
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Affiliation(s)
- Meilin Zou
- Tasmanian Institute of Agriculture, University of Tasmania, Private Bag 1375, Prospect, TAS, 7250, Australia
| | - Sergey Shabala
- Tasmanian Institute of Agriculture, University of Tasmania, Private Bag 1375, Prospect, TAS, 7250, Australia
- School of Biological Sciences, University of Western Australia, 35 Stirling Highway, Perth, 6009, Australia
| | - Chenchen Zhao
- Tasmanian Institute of Agriculture, University of Tasmania, Private Bag 1375, Prospect, TAS, 7250, Australia
| | - Meixue Zhou
- Tasmanian Institute of Agriculture, University of Tasmania, Private Bag 1375, Prospect, TAS, 7250, Australia.
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4
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Gilhooly NS, Kowalczykowski SC. Specific anchoring of large topologically closed DNA for single-molecule protein:DNA interactions. BIOPHYSICAL REPORTS 2024; 4:100144. [PMID: 38390466 PMCID: PMC10881311 DOI: 10.1016/j.bpr.2024.100144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Accepted: 01/22/2024] [Indexed: 02/24/2024]
Abstract
Single-molecule and bulk biophysical approaches to study protein-DNA interactions on surface-immobilized nucleic acid templates typically rely on modifying the ends of linear DNA molecules to enable surface-DNA attachments. Unless both strands are constrained, this results in topologically free DNA molecules and the inability to observe supercoiling-dependent biological processes or requires additional means to micromanipulate the free DNA end to impose rotational constraints or induce supercoiling. We developed a method using RecA protein to induce the formation of a circularized compliment-stabilized D-loop. The resulting joint molecule is topologically closed, surface anchorable, and stable under microfluidic flow. Importantly, the method obviates the need for subsequent manipulation of surface-tethered DNA; tethered molecules remain supercoiled and retain accessibility to DNA-binding proteins. This approach adds to the toolkit for those studying processes on DNA that require supercoiled DNA templates or topologically constrained systems.
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Affiliation(s)
- Neville S Gilhooly
- Department of Microbiology and Molecular Genetics and Department of Molecular and Cellular Biology, University of California, Davis, Davis, California
| | - Stephen C Kowalczykowski
- Department of Microbiology and Molecular Genetics and Department of Molecular and Cellular Biology, University of California, Davis, Davis, California
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5
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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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6
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Hu J, Ferlez B, Dau J, Crickard JB. Rad53 regulates the lifetime of Rdh54 at homologous recombination intermediates. Nucleic Acids Res 2023; 51:11688-11705. [PMID: 37850655 PMCID: PMC10681728 DOI: 10.1093/nar/gkad848] [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: 05/22/2023] [Revised: 09/12/2023] [Accepted: 09/21/2023] [Indexed: 10/19/2023] Open
Abstract
Rdh54 is a conserved DNA translocase that participates in homologous recombination (HR), DNA checkpoint adaptation, and chromosome segregation. Saccharomyces cerevisiae Rdh54 is a known target of the Mec1/Rad53 signaling axis, which globally protects genome integrity during DNA metabolism. While phosphorylation of DNA repair proteins by Mec1/Rad53 is critical for HR progression little is known about how specific post translational modifications alter HR reactions. Phosphorylation of Rdh54 is linked to protection of genomic integrity but the consequences of modification remain poorly understood. Here, we demonstrate that phosphorylation of the Rdh54 C-terminus by the effector kinase Rad53 regulates Rdh54 clustering activity as revealed by single molecule imaging. This stems from phosphorylation dependent and independent interactions between Rdh54 and Rad53. Genetic assays reveal that loss of phosphorylation leads to phenotypic changes resulting in loss-of-heterozygosity (LOH) outcomes. Our data highlight Rad53 as a key regulator of HR intermediates through activation and attenuation of Rdh54 motor function.
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Affiliation(s)
- Jingyi Hu
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Bryan Ferlez
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Jennifer Dau
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - J Brooks Crickard
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
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7
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Kang Y, An S, Min D, Lee JY. Single-molecule fluorescence imaging techniques reveal molecular mechanisms underlying deoxyribonucleic acid damage repair. Front Bioeng Biotechnol 2022; 10:973314. [PMID: 36185427 PMCID: PMC9520083 DOI: 10.3389/fbioe.2022.973314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 08/25/2022] [Indexed: 11/13/2022] Open
Abstract
Advances in single-molecule techniques have uncovered numerous biological secrets that cannot be disclosed by traditional methods. Among a variety of single-molecule methods, single-molecule fluorescence imaging techniques enable real-time visualization of biomolecular interactions and have allowed the accumulation of convincing evidence. These techniques have been broadly utilized for studying DNA metabolic events such as replication, transcription, and DNA repair, which are fundamental biological reactions. In particular, DNA repair has received much attention because it maintains genomic integrity and is associated with diverse human diseases. In this review, we introduce representative single-molecule fluorescence imaging techniques and survey how each technique has been employed for investigating the detailed mechanisms underlying DNA repair pathways. In addition, we briefly show how live-cell imaging at the single-molecule level contributes to understanding DNA repair processes inside cells.
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Affiliation(s)
- Yujin Kang
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan, South Korea
| | - Soyeong An
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan, South Korea
| | - Duyoung Min
- Department of Chemistry, Ulsan National Institute of Science and Technology, Ulsan, South Korea
| | - Ja Yil Lee
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan, South Korea
- Center for Genomic Integrity, Institute of Basic Sciences, Ulsan, South Korea
- *Correspondence: Ja Yil Lee,
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8
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Keymakh M, Dau J, Hu J, Ferlez B, Lisby M, Crickard JB. Rdh54 stabilizes Rad51 at displacement loop intermediates to regulate genetic exchange between chromosomes. PLoS Genet 2022; 18:e1010412. [PMID: 36099310 PMCID: PMC9506641 DOI: 10.1371/journal.pgen.1010412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 09/23/2022] [Accepted: 09/04/2022] [Indexed: 11/20/2022] Open
Abstract
Homologous recombination (HR) is a double-strand break DNA repair pathway that preserves chromosome structure. To repair damaged DNA, HR uses an intact donor DNA sequence located elsewhere in the genome. After the double-strand break is repaired, DNA sequence information can be transferred between donor and recipient DNA molecules through different mechanisms, including DNA crossovers that form between homologous chromosomes. Regulation of DNA sequence transfer is an important step in effectively completing HR and maintaining genome integrity. For example, mitotic exchange of information between homologous chromosomes can result in loss-of-heterozygosity (LOH), and in higher eukaryotes, the development of cancer. The DNA motor protein Rdh54 is a highly conserved DNA translocase that functions during HR. Several existing phenotypes in rdh54Δ strains suggest that Rdh54 may regulate effective exchange of DNA during HR. In our current study, we used a combination of biochemical and genetic techniques to dissect the role of Rdh54 on the exchange of genetic information during DNA repair. Our data indicate that RDH54 regulates DNA strand exchange by stabilizing Rad51 at an early HR intermediate called the displacement loop (D-loop). Rdh54 acts in opposition to Rad51 removal by the DNA motor protein Rad54. Furthermore, we find that expression of a catalytically inactivate allele of Rdh54, rdh54K318R, favors non-crossover outcomes. From these results, we propose a model for how Rdh54 may kinetically regulate strand exchange during homologous recombination. Homologous recombination is an important pathway in repairing DNA double strand breaks. For the purposes of this study, HR can be divided into two stages. The first is a DNA repair stage in which the broken DNA molecule is fixed. In the second stage, information can move from one DNA molecule to another. Enzymes that use the power of ATP hydrolysis to move along dsDNA aid in regulating both stages of HR. In this work we focused on the understudied DNA motor protein Rdh54. We combined genetic and biochemical approaches to show that Rdh54 regulates HR by stabilizing the recombinase protein Rad51 at early HR intermediates.
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Affiliation(s)
- Margaret Keymakh
- Deparment of Molecular Biology and Genetics, Cornell University Ithaca, Ithaca, New York, United States of America
| | - Jennifer Dau
- Deparment of Molecular Biology and Genetics, Cornell University Ithaca, Ithaca, New York, United States of America
| | - Jingyi Hu
- Deparment of Molecular Biology and Genetics, Cornell University Ithaca, Ithaca, New York, United States of America
| | - Bryan Ferlez
- Deparment of Molecular Biology and Genetics, Cornell University Ithaca, Ithaca, New York, United States of America
| | - Michael Lisby
- Department of Biology, University of Copenhagen, Copenhagen N, Denmark
| | - J. Brooks Crickard
- Deparment of Molecular Biology and Genetics, Cornell University Ithaca, Ithaca, New York, United States of America
- * E-mail:
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9
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Feng W, Smith CM, Simpson DA, Gupta GP. Targeting Non-homologous and Alternative End Joining Repair to Enhance Cancer Radiosensitivity. Semin Radiat Oncol 2021; 32:29-41. [PMID: 34861993 DOI: 10.1016/j.semradonc.2021.09.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Many cancer therapies, including radiotherapy, induce DSBs as the major driving mechanism for inducing cancer cell death. Thus, modulating DSB repair has immense potential for radiosensitization, although such interventions must be carefully designed to be tumor selective to ensure that normal tissue toxicities are not also increased. Here, we review mechanisms of error-prone DSB repair through a highly efficient process called end joining. There are two major pathways of end-joining repair: non-homologous end joining (NHEJ) and alternative end joining (a-EJ), both of which can be selectively upregulated in cancer and thus represent attractive therapeutic targets for radiosensitization. These EJ pathways each have therapeutically targetable pioneer factors - DNA-dependent protein kinase catalytic subunit (DNA-PKcs) for NHEJ and DNA Polymerase Theta (Pol θ) for a-EJ. We summarize the current status of therapeutic targeting of NHEJ and a-EJ to enhance the effects of radiotherapy - focusing on challenges that must be overcome and opportunities that require further exploration. By leveraging preclinical insights into mechanisms of altered DSB repair programs in cancer, selective radiosensitization through NHEJ and/or a-EJ targeting remains a highly attractive avenue for ongoing and future clinical investigation.
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Affiliation(s)
| | - Chelsea M Smith
- Lineberger Comprehensive Cancer Center; Pathobiology and Translational Science Graduate Program
| | | | - Gaorav P Gupta
- Lineberger Comprehensive Cancer Center; Pathobiology and Translational Science Graduate Program; Department of Radiation Oncology; Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC.
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10
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Sharma AB, Erasimus H, Pinto L, Caron MC, Gopaul D, Peterlini T, Neumann K, Nazarov PV, Fritah S, Klink B, Herold-Mende CC, Niclou SP, Pasero P, Calsou P, Masson JY, Britton S, Van Dyck E. XAB2 promotes Ku eviction from single-ended DNA double-strand breaks independently of the ATM kinase. Nucleic Acids Res 2021; 49:9906-9925. [PMID: 34500463 PMCID: PMC8464071 DOI: 10.1093/nar/gkab785] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 08/16/2021] [Accepted: 09/01/2021] [Indexed: 12/18/2022] Open
Abstract
Replication-associated single-ended DNA double-strand breaks (seDSBs) are repaired predominantly through RAD51-mediated homologous recombination (HR). Removal of the non-homologous end-joining (NHEJ) factor Ku from resected seDSB ends is crucial for HR. The coordinated actions of MRE11-CtIP nuclease activities orchestrated by ATM define one pathway for Ku eviction. Here, we identify the pre-mRNA splicing protein XAB2 as a factor required for resistance to seDSBs induced by the chemotherapeutic alkylator temozolomide. Moreover, we show that XAB2 prevents Ku retention and abortive HR at seDSBs induced by temozolomide and camptothecin, via a pathway that operates in parallel to the ATM-CtIP-MRE11 axis. Although XAB2 depletion preserved RAD51 focus formation, the resulting RAD51-ssDNA associations were unproductive, leading to increased NHEJ engagement in S/G2 and genetic instability. Overexpression of RAD51 or RAD52 rescued the XAB2 defects and XAB2 loss was synthetically lethal with RAD52 inhibition, providing potential perspectives in cancer therapy.
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Affiliation(s)
- Abhishek Bharadwaj Sharma
- DNA Repair and Chemoresistance Group, Department of Oncology, Luxembourg Institute of Health (LIH), Luxembourg, Luxembourg
| | - Hélène Erasimus
- DNA Repair and Chemoresistance Group, Department of Oncology, Luxembourg Institute of Health (LIH), Luxembourg, Luxembourg.,Faculty of Science, Technology and Communication, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Lia Pinto
- DNA Repair and Chemoresistance Group, Department of Oncology, Luxembourg Institute of Health (LIH), Luxembourg, Luxembourg.,Faculty of Science, Technology and Communication, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Marie-Christine Caron
- CHU de Québec Research Center, Oncology Division, Québec City, Canada.,Department of Molecular Biology, Medical Biochemistry and Pathology, Laval University Cancer Research Center, Québec City, Canada
| | - Diyavarshini Gopaul
- Institut de Génétique Humaine, CNRS et Université de Montpellier, Equipe Labellisée Ligue Contre le Cancer, Montpellier, France
| | - Thibaut Peterlini
- CHU de Québec Research Center, Oncology Division, Québec City, Canada.,Department of Molecular Biology, Medical Biochemistry and Pathology, Laval University Cancer Research Center, Québec City, Canada
| | - Katrin Neumann
- DNA Repair and Chemoresistance Group, Department of Oncology, Luxembourg Institute of Health (LIH), Luxembourg, Luxembourg
| | - Petr V Nazarov
- Quantitative Biology Unit, Multiomics Data Science Group, LIH, Luxembourg
| | - Sabrina Fritah
- NorLux Neuro-Oncology Laboratory, Department of Oncology, LIH, Luxembourg
| | - Barbara Klink
- National Center of Genetics, Laboratoire National de Santé, Dudelange, Luxembourg.,Functional Tumour Genetics Group, Department of Oncology, LIH, Luxembourg
| | | | - Simone P Niclou
- NorLux Neuro-Oncology Laboratory, Department of Oncology, LIH, Luxembourg.,Department of Biomedicine, University of Bergen, Norway
| | - Philippe Pasero
- Institut de Génétique Humaine, CNRS et Université de Montpellier, Equipe Labellisée Ligue Contre le Cancer, Montpellier, France
| | - Patrick Calsou
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France, Equipe Labellisée Ligue Nationale Contre le Cancer 2018
| | - Jean-Yves Masson
- CHU de Québec Research Center, Oncology Division, Québec City, Canada.,Department of Molecular Biology, Medical Biochemistry and Pathology, Laval University Cancer Research Center, Québec City, Canada
| | - Sébastien Britton
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France, Equipe Labellisée Ligue Nationale Contre le Cancer 2018
| | - Eric Van Dyck
- DNA Repair and Chemoresistance Group, Department of Oncology, Luxembourg Institute of Health (LIH), Luxembourg, Luxembourg
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11
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Al-Zain AM, Symington LS. The dark side of homology-directed repair. DNA Repair (Amst) 2021; 106:103181. [PMID: 34311272 DOI: 10.1016/j.dnarep.2021.103181] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 07/16/2021] [Accepted: 07/16/2021] [Indexed: 10/20/2022]
Abstract
DNA double strand breaks (DSB) are cytotoxic lesions that can lead to genome rearrangements and genomic instability, which are hallmarks of cancer. The two main DSB repair pathways are non-homologous end joining and homologous recombination (HR). While HR is generally highly accurate, it has the potential for rearrangements that occur directly or through intermediates generated during the repair process. Whole genome sequencing of cancers has revealed numerous types of structural rearrangement signatures that are often indicative of repair mediated by sequence homology. However, it can be challenging to delineate repair mechanisms from sequence analysis of rearrangement end products from cancer genomes, or even model systems, because the same rearrangements can be generated by different pathways. Here, we review homology-directed repair pathways and their consequences. Exploring those pathways can lead to a greater understanding of rearrangements that occur in cancer cells.
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Affiliation(s)
- Amr M Al-Zain
- Program in Biological Sciences, Columbia University, New York, NY, 10027, United States; Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY, 10032, United States
| | - Lorraine S Symington
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY, 10032, United States; Department of Genetics & Development, Columbia University Irving Medical Center, New York, NY, 10032, United States.
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12
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Pham N, Yan Z, Yu Y, Faria Afreen M, Malkova A, Haber JE, Ira G. Mechanisms restraining break-induced replication at two-ended DNA double-strand breaks. EMBO J 2021; 40:e104847. [PMID: 33844333 DOI: 10.15252/embj.2020104847] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 03/04/2021] [Accepted: 03/09/2021] [Indexed: 11/09/2022] Open
Abstract
DNA synthesis during homologous recombination is highly mutagenic and prone to template switches. Two-ended DNA double-strand breaks (DSBs) are usually repaired by gene conversion with a short patch of DNA synthesis, thus limiting the mutation load to the vicinity of the DSB. Single-ended DSBs are repaired by break-induced replication (BIR), which involves extensive and mutagenic DNA synthesis spanning up to hundreds of kilobases. It remains unknown how mutagenic BIR is suppressed at two-ended DSBs. Here, we demonstrate that BIR is suppressed at two-ended DSBs by proteins coordinating the usage of two ends of a DSB: (i) ssDNA annealing proteins Rad52 and Rad59 that promote second end capture, (ii) D-loop unwinding helicase Mph1, and (iii) Mre11-Rad50-Xrs2 complex that promotes synchronous resection of two ends of a DSB. Finally, BIR is also suppressed when Sir2 silences a normally heterochromatic repair template. All of these proteins are particularly important for limiting BIR when recombination occurs between short repetitive sequences, emphasizing the significance of these mechanisms for species carrying many repetitive elements such as humans.
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Affiliation(s)
- Nhung Pham
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Zhenxin Yan
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Yang Yu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Mosammat Faria Afreen
- Department of Biology, Rosenstiel Basic Medical Sciences Research Center, Waltham, MA, USA
| | - Anna Malkova
- Department of Biology, University of Iowa, Iowa City, IA, USA
| | - James E Haber
- Department of Biology, Rosenstiel Basic Medical Sciences Research Center, Waltham, MA, USA
| | - Grzegorz Ira
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
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13
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Yasuda T, Takizawa K, Ui A, Hama M, Kagawa W, Sugasawa K, Tajima K. Human SIRT2 and SIRT3 deacetylases function in DNA homologous recombinational repair. Genes Cells 2021; 26:328-335. [PMID: 33624391 DOI: 10.1111/gtc.12842] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 02/04/2021] [Accepted: 02/19/2021] [Indexed: 12/14/2022]
Abstract
SIRT2 and SIRT3 protein deacetylases maintain genome integrity and stability. However, their mechanisms for maintaining the genome remain unclear. To examine the roles of SIRT2 and SIRT3 in DSB repair, I-SceI-based GFP reporter assays for HR, single-strand annealing (SSA) and nonhomologous end joining (NHEJ) repair were performed under SIRT2- or SIRT3-depleted conditions. SIRT2 or SIRT3 depletion inhibited HR repair equally to RAD52 depletion, but did not affect SSA and NHEJ repairs. SIRT2 or SIRT3 depletion disturbed the recruitment of RAD51 to DSB sites, an essential step for RAD51-dependent HR repair, but not directly through RAD52 deacetylation. SIRT2 or SIRT3 depletion decreased the colocalization of γH2AX foci with RPA1, and thus, they might be involved in initiating DSB end resection for the recruitment of RAD51 to DSB sites at an early step in HR repair. These results show the novel underlying mechanism of the SIRT2 and SIRT3 functions in HR for genome stability.
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Affiliation(s)
- Takeshi Yasuda
- National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Sciences and Technology (QST), Chiba, Japan
| | - Kazuya Takizawa
- National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Sciences and Technology (QST), Chiba, Japan
| | - Ayako Ui
- Department of Molecular Oncology, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan.,Division of Dynamic Proteome in Cancer and Aging, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Michio Hama
- National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Sciences and Technology (QST), Chiba, Japan
| | - Wataru Kagawa
- Program in Chemistry and Life Science, Department of Interdisciplinary Science and Engineering, School of Science and Engineering, Meisei University, Hino, Japan
| | - Kaoru Sugasawa
- Biosignal Research Center, and Graduate School of Science, Kobe University, Kobe, Japan
| | - Katsushi Tajima
- National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Sciences and Technology (QST), Chiba, Japan
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14
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Jalal D, Chalissery J, Iqbal M, Hassan AH. The ATPase Irc20 facilitates Rad51 chromatin enrichment during homologous recombination in yeast Saccharomyces cerevisiae. DNA Repair (Amst) 2020; 97:103019. [PMID: 33202365 DOI: 10.1016/j.dnarep.2020.103019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Revised: 11/02/2020] [Accepted: 11/05/2020] [Indexed: 10/23/2022]
Abstract
DNA double-strand breaks (DSBs) constitute one of the most cytotoxic forms of DNA damage and pose a significant threat to cell viability, survival, and homeostasis. DSBs have the potential to promote aneuploidy, cell death and potentially deleterious mutations that promote tumorigenesis. Homologous recombination (HR) is one of the main DSB repair pathways and while being essential for cell survival under genotoxic stress, it requires proper regulation to avoid chromosome rearrangements. Here, we characterize the Saccharomyces cerevisiae E3 ubiquitin ligase/putative helicase Irc20 as a regulator of HR. Using purified Irc20, we show that it can hydrolyze ATP in the presence and absence of DNA, but does not increase access to DNA within a nucleosome. In addition, we show that both the ATPase and ubiquitin ligase activities of Irc20 are required for suppressing the spontaneous formation of recombination foci. Finally, we demonstrate a role for Irc20 in promoting Rad51 chromatin association and the removal of Rad52 recombinase from chromatin, thus facilitating subsequent HR steps and directing recombination to more error-free modes.
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Affiliation(s)
- Deena Jalal
- Department of Biochemistry, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box 17666, Al-Ain, United Arab Emirates
| | - Jisha Chalissery
- Department of Biochemistry, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box 17666, Al-Ain, United Arab Emirates
| | - Mehwish Iqbal
- Department of Biochemistry, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box 17666, Al-Ain, United Arab Emirates
| | - Ahmed H Hassan
- Department of Biochemistry, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box 17666, Al-Ain, United Arab Emirates.
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15
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Deveryshetty J, Peterlini T, Ryzhikov M, Brahiti N, Dellaire G, Masson JY, Korolev S. Novel RNA and DNA strand exchange activity of the PALB2 DNA binding domain and its critical role for DNA repair in cells. eLife 2019; 8:44063. [PMID: 31017574 PMCID: PMC6533086 DOI: 10.7554/elife.44063] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Accepted: 04/23/2019] [Indexed: 12/14/2022] Open
Abstract
BReast Cancer Associated proteins 1 and 2 (BRCA1, -2) and Partner and Localizer of BRCA2 (PALB2) protein are tumour suppressors linked to a spectrum of malignancies, including breast cancer and Fanconi anemia. PALB2 coordinates functions of BRCA1 and BRCA2 during homology-directed repair (HDR) and interacts with several chromatin proteins. In addition to protein scaffold function, PALB2 binds DNA. The functional role of this interaction is poorly understood. We identified a major DNA-binding site of PALB2, mutations in which reduce RAD51 foci formation and the overall HDR efficiency in cells by 50%. PALB2 N-terminal DNA-binding domain (N-DBD) stimulates the function of RAD51 recombinase. Surprisingly, it possesses the strand exchange activity without RAD51. Moreover, N-DBD stimulates the inverse strand exchange and can use DNA and RNA substrates. Our data reveal a versatile DNA interaction property of PALB2 and demonstrate a critical role of PALB2 DNA binding for chromosome repair in cells.
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Affiliation(s)
- Jaigeeth Deveryshetty
- Edward A Doisy Department of Biochemistry and Molecular BiologySaint Louis University School of MedicineSaint LouisUnited States
| | - Thibaut Peterlini
- Genome Stability LaboratoryCHU de Québec-Université Laval, Oncology Division, Laval University Cancer Research CenterQuébec CityCanada
| | - Mikhail Ryzhikov
- Edward A Doisy Department of Biochemistry and Molecular BiologySaint Louis University School of MedicineSaint LouisUnited States
| | - Nadine Brahiti
- Genome Stability LaboratoryCHU de Québec-Université Laval, Oncology Division, Laval University Cancer Research CenterQuébec CityCanada
| | | | - Jean-Yves Masson
- Genome Stability LaboratoryCHU de Québec-Université Laval, Oncology Division, Laval University Cancer Research CenterQuébec CityCanada
| | - Sergey Korolev
- Edward A Doisy Department of Biochemistry and Molecular BiologySaint Louis University School of MedicineSaint LouisUnited States
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16
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Litwin I, Pilarczyk E, Wysocki R. The Emerging Role of Cohesin in the DNA Damage Response. Genes (Basel) 2018; 9:genes9120581. [PMID: 30487431 PMCID: PMC6316000 DOI: 10.3390/genes9120581] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 11/20/2018] [Accepted: 11/21/2018] [Indexed: 12/23/2022] Open
Abstract
Faithful transmission of genetic material is crucial for all organisms since changes in genetic information may result in genomic instability that causes developmental disorders and cancers. Thus, understanding the mechanisms that preserve genome integrity is of fundamental importance. Cohesin is a multiprotein complex whose canonical function is to hold sister chromatids together from S-phase until the onset of anaphase to ensure the equal division of chromosomes. However, recent research points to a crucial function of cohesin in the DNA damage response (DDR). In this review, we summarize recent advances in the understanding of cohesin function in DNA damage signaling and repair. First, we focus on cohesin architecture and molecular mechanisms that govern sister chromatid cohesion. Next, we briefly characterize the main DDR pathways. Finally, we describe mechanisms that determine cohesin accumulation at DNA damage sites and discuss possible roles of cohesin in DDR.
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Affiliation(s)
- Ireneusz Litwin
- Institute of Experimental Biology, University of Wroclaw, 50-328 Wroclaw, Poland.
| | - Ewa Pilarczyk
- Institute of Experimental Biology, University of Wroclaw, 50-328 Wroclaw, Poland.
| | - Robert Wysocki
- Institute of Experimental Biology, University of Wroclaw, 50-328 Wroclaw, Poland.
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17
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Yeast Srs2 Helicase Promotes Redistribution of Single-Stranded DNA-Bound RPA and Rad52 in Homologous Recombination Regulation. Cell Rep 2018; 21:570-577. [PMID: 29045827 DOI: 10.1016/j.celrep.2017.09.073] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 09/06/2017] [Accepted: 09/22/2017] [Indexed: 12/20/2022] Open
Abstract
Srs2 is a super-family 1 helicase that promotes genome stability by dismantling toxic DNA recombination intermediates. However, the mechanisms by which Srs2 remodels or resolves recombination intermediates remain poorly understood. Here, single-molecule imaging is used to visualize Srs2 in real time as it acts on single-stranded DNA (ssDNA) bound by protein factors that function in recombination. We demonstrate that Srs2 is highly processive and translocates rapidly (∼170 nt per second) in the 3'→5' direction along ssDNA saturated with replication protein A (RPA). We show that RPA is evicted from DNA during the passage of Srs2. Remarkably, Srs2 also readily removes the recombination mediator Rad52 from RPA-ssDNA and, in doing so, promotes rapid redistribution of both Rad52 and RPA. These findings have important mechanistic implications for understanding how Srs2 and related nucleic acid motor proteins resolve potentially pathogenic nucleoprotein intermediates.
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18
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Abstract
Meiosis halves diploid chromosome numbers to haploid levels that are essential for sexual reproduction in most eukaryotes. Meiotic recombination ensures the formation of bivalents between homologous chromosomes (homologs) and their subsequent proper segregation. It also results in genetic diversity among progeny that influences evolutionary responses to selection. Moreover, crop breeding depends upon the action of meiotic recombination to rearrange elite traits between parental chromosomes. An understanding of the molecular mechanisms that drive meiotic recombination is important for both fundamental research and practical applications. This review emphasizes advances made during the past 5 years, primarily in Arabidopsis and rice, by summarizing newly characterized genes and proteins and examining the regulatory mechanisms that modulate their action.
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Affiliation(s)
- Yingxiang Wang
- State Key Laboratory of Genetic Engineering and Collaborative Innovation Center of Genetics and Development, Ministry of Education Key Laboratory of Biodiversity Sciences and Ecological Engineering, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai 200438, China;
| | - Gregory P Copenhaver
- Department of Biology and the Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3280, USA;
- Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599-3280, USA
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19
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Ranjha L, Howard SM, Cejka P. Main steps in DNA double-strand break repair: an introduction to homologous recombination and related processes. Chromosoma 2018; 127:187-214. [PMID: 29327130 DOI: 10.1007/s00412-017-0658-1] [Citation(s) in RCA: 193] [Impact Index Per Article: 32.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 12/15/2017] [Accepted: 12/19/2017] [Indexed: 12/16/2022]
Abstract
DNA double-strand breaks arise accidentally upon exposure of DNA to radiation and chemicals or result from faulty DNA metabolic processes. DNA breaks can also be introduced in a programmed manner, such as during the maturation of the immune system, meiosis, or cancer chemo- or radiotherapy. Cells have developed a variety of repair pathways, which are fine-tuned to the specific needs of a cell. Accordingly, vegetative cells employ mechanisms that restore the integrity of broken DNA with the highest efficiency at the lowest cost of mutagenesis. In contrast, meiotic cells or developing lymphocytes exploit DNA breakage to generate diversity. Here, we review the main pathways of eukaryotic DNA double-strand break repair with the focus on homologous recombination and its various subpathways. We highlight the differences between homologous recombination and end-joining mechanisms including non-homologous end-joining and microhomology-mediated end-joining and offer insights into how these pathways are regulated. Finally, we introduce noncanonical functions of the recombination proteins, in particular during DNA replication stress.
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Affiliation(s)
- Lepakshi Ranjha
- Institute for Research in Biomedicine, Università della Svizzera italiana, Bellinzona, Switzerland
| | - Sean M Howard
- Institute for Research in Biomedicine, Università della Svizzera italiana, Bellinzona, Switzerland
| | - Petr Cejka
- Institute for Research in Biomedicine, Università della Svizzera italiana, Bellinzona, Switzerland. .,Department of Biology, Institute of Biochemistry, ETH Zurich, Zurich, Switzerland.
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20
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Human RAD52 Captures and Holds DNA Strands, Increases DNA Flexibility, and Prevents Melting of Duplex DNA: Implications for DNA Recombination. Cell Rep 2017; 18:2845-2853. [PMID: 28329678 PMCID: PMC5379009 DOI: 10.1016/j.celrep.2017.02.068] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 01/20/2017] [Accepted: 02/21/2017] [Indexed: 11/30/2022] Open
Abstract
Human RAD52 promotes annealing of complementary single-stranded DNA (ssDNA). In-depth knowledge of RAD52-DNA interaction is required to understand how its activity is integrated in DNA repair processes. Here, we visualize individual fluorescent RAD52 complexes interacting with single DNA molecules. The interaction with ssDNA is rapid, static, and tight, where ssDNA appears to wrap around RAD52 complexes that promote intra-molecular bridging. With double-stranded DNA (dsDNA), interaction is slower, weaker, and often diffusive. Interestingly, force spectroscopy experiments show that RAD52 alters the mechanics dsDNA by enhancing DNA flexibility and increasing DNA contour length, suggesting intercalation. RAD52 binding changes the nature of the overstretching transition of dsDNA and prevents DNA melting, which is advantageous for strand clamping during or after annealing. DNA-bound RAD52 is efficient at capturing ssDNA in trans. Together, these effects may help key steps in DNA repair, such as second-end capture during homologous recombination or strand annealing during RAD51-independent recombination reactions. RAD52 binds ssDNA rapidly and tightly using wrapping and bridging modes RAD52 binding to dsDNA is slower, weaker, and often diffusive RAD52 changes dsDNA mechanics and intercalates into the double helix RAD52 prevents DNA melting by clamping DNA strands
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21
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Nickoloff JA, Jones D, Lee SH, Williamson EA, Hromas R. Drugging the Cancers Addicted to DNA Repair. J Natl Cancer Inst 2017; 109:3832892. [PMID: 28521333 PMCID: PMC5436301 DOI: 10.1093/jnci/djx059] [Citation(s) in RCA: 103] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 03/10/2017] [Indexed: 12/29/2022] Open
Abstract
Defects in DNA repair can result in oncogenic genomic instability. Cancers occurring from DNA repair defects were once thought to be limited to rare inherited mutations (such as BRCA1 or 2). It now appears that a clinically significant fraction of cancers have acquired DNA repair defects. DNA repair pathways operate in related networks, and cancers arising from loss of one DNA repair component typically become addicted to other repair pathways to survive and proliferate. Drug inhibition of the rescue repair pathway prevents the repair-deficient cancer cell from replicating, causing apoptosis (termed synthetic lethality). However, the selective pressure of inhibiting the rescue repair pathway can generate further mutations that confer resistance to the synthetic lethal drugs. Many such drugs currently in clinical use inhibit PARP1, a repair component to which cancers arising from inherited BRCA1 or 2 mutations become addicted. It is now clear that drugs inducing synthetic lethality may also be therapeutic in cancers with acquired DNA repair defects, which would markedly broaden their applicability beyond treatment of cancers with inherited DNA repair defects. Here we review how each DNA repair pathway can be attacked therapeutically and evaluate DNA repair components as potential drug targets to induce synthetic lethality. Clinical use of drugs targeting DNA repair will markedly increase when functional and genetic loss of repair components are consistently identified. In addition, future therapies will exploit artificial synthetic lethality, where complementary DNA repair pathways are targeted simultaneously in cancers without DNA repair defects.
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Affiliation(s)
- Jac A Nickoloff
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO, USA
| | - Dennie Jones
- Department of Medicine and the Cancer Center, University of Florida Health, Gainesville, FL, USA
| | - Suk-Hee Lee
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Elizabeth A Williamson
- Department of Medicine and the Cancer Center, University of Florida Health, Gainesville, FL, USA
| | - Robert Hromas
- Department of Medicine and the Cancer Center, University of Florida Health, Gainesville, FL, USA
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22
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Allen CP, Hirakawa H, Nakajima NI, Moore S, Nie J, Sharma N, Sugiura M, Hoki Y, Araki R, Abe M, Okayasu R, Fujimori A, Nickoloff JA. Low- and High-LET Ionizing Radiation Induces Delayed Homologous Recombination that Persists for Two Weeks before Resolving. Radiat Res 2017; 188:82-93. [PMID: 28535128 DOI: 10.1667/rr14748.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Genome instability is a hallmark of cancer cells and dysregulation or defects in DNA repair pathways cause genome instability and are linked to inherited cancer predisposition syndromes. Ionizing radiation can cause immediate effects such as mutation or cell death, observed within hours or a few days after irradiation. Ionizing radiation also induces delayed effects many cell generations after irradiation. Delayed effects include hypermutation, hyper-homologous recombination, chromosome instability and reduced clonogenic survival (delayed death). Delayed hyperrecombination (DHR) is mechanistically distinct from delayed chromosomal instability and delayed death. Using a green fluorescent protein (GFP) direct repeat homologous recombination system, time-lapse microscopy and colony-based assays, we demonstrate that DHR increases several-fold in response to low-LET X rays and high-LET carbon-ion radiation. Time-lapse analyses of DHR revealed two classes of recombinants not detected in colony-based assays, including cells that recombined and then senesced or died. With both low- and high-LET radiation, DHR was evident during the first two weeks postirradiation, but resolved to background levels during the third week. The results indicate that the risk of radiation-induced genome destabilization via DHR is time limited, and suggest that there is little or no additional risk of radiation-induced genome instability mediated by DHR with high-LET radiation compared to low-LET radiation.
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Affiliation(s)
- Christopher P Allen
- a Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, Colorado
| | - Hirokazu Hirakawa
- b Department of Basic Medical Sciences for Radiation Damages, National Institute of Radiological Sciences, Chiba, Japan
| | - Nakako Izumi Nakajima
- b Department of Basic Medical Sciences for Radiation Damages, National Institute of Radiological Sciences, Chiba, Japan
| | - Sophia Moore
- a Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, Colorado
| | - Jingyi Nie
- a Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, Colorado
| | - Neelam Sharma
- a Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, Colorado
| | - Mayumi Sugiura
- c Division of Natural Sciences, Research Group of Biological Sciences, Nara Women's University, Nara, Japan
| | - Yuko Hoki
- b Department of Basic Medical Sciences for Radiation Damages, National Institute of Radiological Sciences, Chiba, Japan
| | - Ryoko Araki
- b Department of Basic Medical Sciences for Radiation Damages, National Institute of Radiological Sciences, Chiba, Japan
| | - Masumi Abe
- b Department of Basic Medical Sciences for Radiation Damages, National Institute of Radiological Sciences, Chiba, Japan
| | - Ryuichi Okayasu
- b Department of Basic Medical Sciences for Radiation Damages, National Institute of Radiological Sciences, Chiba, Japan
| | - Akira Fujimori
- b Department of Basic Medical Sciences for Radiation Damages, National Institute of Radiological Sciences, Chiba, Japan
| | - Jac A Nickoloff
- a Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, Colorado
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23
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The mismatch repair and meiotic recombination endonuclease Mlh1-Mlh3 is activated by polymer formation and can cleave DNA substrates in trans. PLoS Biol 2017; 15:e2001164. [PMID: 28453523 PMCID: PMC5409509 DOI: 10.1371/journal.pbio.2001164] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 03/31/2017] [Indexed: 01/21/2023] Open
Abstract
Crossing over between homologs is initiated in meiotic prophase by the formation of DNA double-strand breaks that occur throughout the genome. In the major interference-responsive crossover pathway in baker’s yeast, these breaks are resected to form 3' single-strand tails that participate in a homology search, ultimately forming double Holliday junctions (dHJs) that primarily include both homologs. These dHJs are resolved by endonuclease activity to form exclusively crossovers, which are critical for proper homolog segregation in Meiosis I. Recent genetic, biochemical, and molecular studies in yeast are consistent with the hypothesis of Mlh1-Mlh3 DNA mismatch repair complex acting as the major endonuclease activity that resolves dHJs into crossovers. However, the mechanism by which the Mlh1-Mlh3 endonuclease is activated is unknown. Here, we provide evidence that Mlh1-Mlh3 does not behave like a structure-specific endonuclease but forms polymers required to generate nicks in DNA. This conclusion is supported by DNA binding studies performed with different-sized substrates that contain or lack polymerization barriers and endonuclease assays performed with varying ratios of endonuclease-deficient and endonuclease-proficient Mlh1-Mlh3. In addition, Mlh1-Mlh3 can generate religatable double-strand breaks and form an active nucleoprotein complex that can nick DNA substrates in trans. Together these observations argue that Mlh1-Mlh3 may not act like a canonical, RuvC-like Holliday junction resolvase and support a novel model in which Mlh1-Mlh3 is loaded onto DNA to form an activated polymer that cleaves DNA. In sexually reproducing organisms, crossing over between homologous chromosomes in meiosis creates physical linkages required to segregate chromosomes into haploid gametes. In baker’s yeast, which utilizes meiotic recombination pathways conserved in mice and humans, the majority of meiotic crossovers are initiated through the formation of a branched DNA intermediate, which is stabilized by the Msh4-Msh5 complex. This DNA intermediate is further processed to form a structure (a double Holliday junction), which requires the endonuclease activity of the Mlh1-Mlh3 DNA mismatch repair factor to be resolved exclusively into a crossover product. Current meiotic recombination models invoke the use of structure-specific enzymes that symmetrically cleave single Holliday junctions. In this study, we provide evidence that the yeast Mlh1-Mlh3 complex is unlikely to act as a structure-specific enzyme. Furthermore, we showed that Mlh1-Mlh3’s endonuclease activity is dependent upon its ability to form a polymer on DNA and suggest that it is capable of cleaving DNA that is captured in an active complex. Together, our biochemical observations support a novel model involving regulated polymerization of Mlh1-Mlh3 for its cleavage function, potentially in meiotic crossovers or in mismatch repair.
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24
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Annealing of Complementary DNA Sequences During Double-Strand Break Repair in Drosophila Is Mediated by the Ortholog of SMARCAL1. Genetics 2017; 206:467-480. [PMID: 28258182 DOI: 10.1534/genetics.117.200238] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Accepted: 02/22/2017] [Indexed: 12/18/2022] Open
Abstract
DNA double-strand breaks (DSBs) pose a serious threat to genomic integrity. If unrepaired, they can lead to chromosome fragmentation and cell death. If repaired incorrectly, they can cause mutations and chromosome rearrangements. DSBs are repaired using end-joining or homology-directed repair strategies, with the predominant form of homology-directed repair being synthesis-dependent strand annealing (SDSA). SDSA is the first defense against genomic rearrangements and information loss during DSB repair, making it a vital component of cell health and an attractive target for chemotherapeutic development. SDSA has also been proposed to be the primary mechanism for integration of large insertions during genome editing with CRISPR/Cas9. Despite the central role for SDSA in genome stability, little is known about the defining step: annealing. We hypothesized that annealing during SDSA is performed by the annealing helicase SMARCAL1, which can anneal RPA-coated single DNA strands during replication-associated DNA damage repair. We used unique genetic tools in Drosophila melanogaster to test whether the fly ortholog of SMARCAL1, Marcal1, mediates annealing during SDSA. Repair that requires annealing is significantly reduced in Marcal1 null mutants in both synthesis-dependent and synthesis-independent (single-strand annealing) assays. Elimination of the ATP-binding activity of Marcal1 also reduced annealing-dependent repair, suggesting that the annealing activity requires translocation along DNA. Unlike the null mutant, however, the ATP-binding defect mutant showed reduced end joining, shedding light on the interaction between SDSA and end-joining pathways.
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25
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Martínez-Miguel RM, Sandoval-Cabrera A, Bazán-Tejeda ML, Torres-Huerta AL, Martínez-Reyes DA, Bermúdez-Cruz RM. Giardia duodenalis Rad52 protein: biochemical characterization and response upon DNA damage. J Biochem 2017; 162:123-135. [DOI: 10.1093/jb/mvx009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 01/10/2017] [Indexed: 11/13/2022] Open
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26
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Paudyal SC, You Z. Sharpening the ends for repair: mechanisms and regulation of DNA resection. Acta Biochim Biophys Sin (Shanghai) 2016; 48:647-57. [PMID: 27174871 DOI: 10.1093/abbs/gmw043] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Accepted: 04/12/2016] [Indexed: 12/23/2022] Open
Abstract
DNA end resection is a key process in the cellular response to DNA double-strand break damage that is essential for genome maintenance and cell survival. Resection involves selective processing of 5' ends of broken DNA to generate ssDNA overhangs, which in turn control both DNA repair and checkpoint signaling. DNA resection is the first step in homologous recombination-mediated repair and a prerequisite for the activation of the ataxia telangiectasia mutated and Rad3-related (ATR)-dependent checkpoint that coordinates repair with cell cycle progression and other cellular processes. Resection occurs in a cell cycle-dependent manner and is regulated by multiple factors to ensure an optimal amount of ssDNA required for proper repair and genome stability. Here, we review the latest findings on the molecular mechanisms and regulation of the DNA end resection process and their implications for cancer formation and treatment.
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Affiliation(s)
- Sharad C Paudyal
- Department of Cell Biology and Physiology, Washington University School of Medicine, St Louis, MO 63110, USA
| | - Zhongsheng You
- Department of Cell Biology and Physiology, Washington University School of Medicine, St Louis, MO 63110, USA
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27
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Silva S, Altmannova V, Eckert-Boulet N, Kolesar P, Gallina I, Hang L, Chung I, Arneric M, Zhao X, Buron LD, Mortensen UH, Krejci L, Lisby M. SUMOylation of Rad52-Rad59 synergistically change the outcome of mitotic recombination. DNA Repair (Amst) 2016; 42:11-25. [PMID: 27130983 DOI: 10.1016/j.dnarep.2016.04.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 04/02/2016] [Accepted: 04/05/2016] [Indexed: 11/18/2022]
Abstract
Homologous recombination (HR) is essential for maintenance of genome stability through double-strand break (DSB) repair, but at the same time HR can lead to loss of heterozygosity and uncontrolled recombination can be genotoxic. The post-translational modification by SUMO (small ubiquitin-like modifier) has been shown to modulate recombination, but the exact mechanism of this regulation remains unclear. Here we show that SUMOylation stabilizes the interaction between the recombination mediator Rad52 and its paralogue Rad59 in Saccharomyces cerevisiae. Although Rad59 SUMOylation is not required for survival after genotoxic stress, it affects the outcome of recombination to promote conservative DNA repair. In some genetic assays, Rad52 and Rad59 SUMOylation act synergistically. Collectively, our data indicate that the described SUMO modifications affect the balance between conservative and non-conservative mechanisms of HR.
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Affiliation(s)
- Sonia Silva
- Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen N, Denmark
| | - Veronika Altmannova
- Department of Biology, Masaryk University, Kamenice 5/A7, 62500 Brno, Czech Republic
| | - Nadine Eckert-Boulet
- Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen N, Denmark
| | - Peter Kolesar
- Department of Biology, Masaryk University, Kamenice 5/A7, 62500 Brno, Czech Republic
| | - Irene Gallina
- Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen N, Denmark
| | - Lisa Hang
- Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA
| | - Inn Chung
- Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA
| | - Milica Arneric
- Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA
| | - Xiaolan Zhao
- Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA
| | - Line Due Buron
- Department of Systems Biology, Technical University of Denmark, Building 223, 2800 Kgs. Lyngby, Denmark
| | - Uffe H Mortensen
- Department of Systems Biology, Technical University of Denmark, Building 223, 2800 Kgs. Lyngby, Denmark
| | - Lumir Krejci
- Department of Biology, Masaryk University, Kamenice 5/A7, 62500 Brno, Czech Republic; National Centre for Biomolecular Research, Masaryk University, Kamenice 5/A4, Brno 625 00, Czech Republic; International Clinical Research Center, Center for Biomolecular and Cellular Engineering, St. Anne's University Hospital Brno, Brno, Czech Republic
| | - Michael Lisby
- Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen N, Denmark.
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28
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Manhart CM, Alani E. Roles for mismatch repair family proteins in promoting meiotic crossing over. DNA Repair (Amst) 2016; 38:84-93. [PMID: 26686657 PMCID: PMC4740264 DOI: 10.1016/j.dnarep.2015.11.024] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 08/14/2015] [Accepted: 11/30/2015] [Indexed: 12/13/2022]
Abstract
The mismatch repair (MMR) family complexes Msh4-Msh5 and Mlh1-Mlh3 act with Exo1 and Sgs1-Top3-Rmi1 in a meiotic double strand break repair pathway that results in the asymmetric cleavage of double Holliday junctions (dHJ) to form crossovers. This review discusses how meiotic roles for Msh4-Msh5 and Mlh1-Mlh3 do not fit paradigms established for post-replicative MMR. We also outline models used to explain how these factors promote the formation of meiotic crossovers required for the accurate segregation of chromosome homologs during the Meiosis I division.
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Affiliation(s)
- Carol M Manhart
- Department of Molecular Biology and Genetics, Cornell University, 457 Biotechnology Building, Ithaca, NY 14853-2703, USA
| | - Eric Alani
- Department of Molecular Biology and Genetics, Cornell University, 457 Biotechnology Building, Ithaca, NY 14853-2703, USA.
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29
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Kowalczykowski SC. An Overview of the Molecular Mechanisms of Recombinational DNA Repair. Cold Spring Harb Perspect Biol 2015; 7:a016410. [PMID: 26525148 PMCID: PMC4632670 DOI: 10.1101/cshperspect.a016410] [Citation(s) in RCA: 313] [Impact Index Per Article: 34.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Recombinational DNA repair is a universal aspect of DNA metabolism and is essential for genomic integrity. It is a template-directed process that uses a second chromosomal copy (sister, daughter, or homolog) to ensure proper repair of broken chromosomes. The key steps of recombination are conserved from phage through human, and an overview of those steps is provided in this review. The first step is resection by helicases and nucleases to produce single-stranded DNA (ssDNA) that defines the homologous locus. The ssDNA is a scaffold for assembly of the RecA/RAD51 filament, which promotes the homology search. On finding homology, the nucleoprotein filament catalyzes exchange of DNA strands to form a joint molecule. Recombination is controlled by regulating the fate of both RecA/RAD51 filaments and DNA pairing intermediates. Finally, intermediates that mature into Holliday structures are disjoined by either nucleolytic resolution or topological dissolution.
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Affiliation(s)
- Stephen C Kowalczykowski
- Department of Microbiology & Molecular Genetics and Department of Molecular and Cellular Biology, University of California, Davis, Davis, California 95616
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30
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Modulation of DNA damage and repair pathways by human tumour viruses. Viruses 2015; 7:2542-91. [PMID: 26008701 PMCID: PMC4452920 DOI: 10.3390/v7052542] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 05/12/2015] [Indexed: 02/07/2023] Open
Abstract
With between 10% and 15% of human cancers attributable to viral infection, there is great interest, from both a scientific and clinical viewpoint, as to how these pathogens modulate host cell functions. Seven human tumour viruses have been identified as being involved in the development of specific malignancies. It has long been known that the introduction of chromosomal aberrations is a common feature of viral infections. Intensive research over the past two decades has subsequently revealed that viruses specifically interact with cellular mechanisms responsible for the recognition and repair of DNA lesions, collectively known as the DNA damage response (DDR). These interactions can involve activation and deactivation of individual DDR pathways as well as the recruitment of specific proteins to sites of viral replication. Since the DDR has evolved to protect the genome from the accumulation of deleterious mutations, deregulation is inevitably associated with an increased risk of tumour formation. This review summarises the current literature regarding the complex relationship between known human tumour viruses and the DDR and aims to shed light on how these interactions can contribute to genomic instability and ultimately the development of human cancers.
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31
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Lee MS, Yu M, Kim KY, Park GH, Kwack K, Kim KP. Functional Validation of Rare Human Genetic Variants Involved in Homologous Recombination Using Saccharomyces cerevisiae. PLoS One 2015; 10:e0124152. [PMID: 25938495 PMCID: PMC4418691 DOI: 10.1371/journal.pone.0124152] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 03/10/2015] [Indexed: 12/02/2022] Open
Abstract
Systems for the repair of DNA double-strand breaks (DSBs) are necessary to maintain genome integrity and normal functionality of cells in all organisms. Homologous recombination (HR) plays an important role in repairing accidental and programmed DSBs in mitotic and meiotic cells, respectively. Failure to repair these DSBs causes genome instability and can induce tumorigenesis. Rad51 and Rad52 are two key proteins in homologous pairing and strand exchange during DSB-induced HR; both are highly conserved in eukaryotes. In this study, we analyzed pathogenic single nucleotide polymorphisms (SNPs) in human RAD51 and RAD52 using the Polymorphism Phenotyping (PolyPhen) and Sorting Intolerant from Tolerant (SIFT) algorithms and observed the effect of mutations in highly conserved domains of RAD51 and RAD52 on DNA damage repair in a Saccharomyces cerevisiae-based system. We identified a number of rad51 and rad52 alleles that exhibited severe DNA repair defects. The functionally inactive SNPs were located near ATPase active site of Rad51 and the DNA binding domain of Rad52. The rad51-F317I, rad52-R52W, and rad52-G107C mutations conferred hypersensitivity to methyl methane sulfonate (MMS)-induced DNA damage and were defective in HR-mediated DSB repair. Our study provides a new approach for detecting functional and loss-of-function genetic polymorphisms and for identifying causal variants in human DNA repair genes that contribute to the initiation or progression of cancer.
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Affiliation(s)
- Min-Soo Lee
- Department of Life Science, Chung-Ang University, Seoul, Korea
| | - Mi Yu
- Department of Life Science, Chung-Ang University, Seoul, Korea
| | - Kyoung-Yeon Kim
- Department of Biomedical Science, CHA University, Seongnam, Korea
| | - Geun-Hee Park
- Department of Life Science, Chung-Ang University, Seoul, Korea
| | - KyuBum Kwack
- Department of Biomedical Science, CHA University, Seongnam, Korea
- * E-mail: (KPK); (KBK)
| | - Keun P. Kim
- Department of Life Science, Chung-Ang University, Seoul, Korea
- * E-mail: (KPK); (KBK)
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32
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Morrical SW. DNA-pairing and annealing processes in homologous recombination and homology-directed repair. Cold Spring Harb Perspect Biol 2015; 7:a016444. [PMID: 25646379 DOI: 10.1101/cshperspect.a016444] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The formation of heteroduplex DNA is a central step in the exchange of DNA sequences via homologous recombination, and in the accurate repair of broken chromosomes via homology-directed repair pathways. In cells, heteroduplex DNA largely arises through the activities of recombination proteins that promote DNA-pairing and annealing reactions. Classes of proteins involved in pairing and annealing include RecA-family DNA-pairing proteins, single-stranded DNA (ssDNA)-binding proteins, recombination mediator proteins, annealing proteins, and nucleases. This review explores the properties of these pairing and annealing proteins, and highlights their roles in complex recombination processes including the double Holliday junction (DhJ) formation, synthesis-dependent strand annealing, and single-strand annealing pathways--DNA transactions that are critical both for genome stability in individual organisms and for the evolution of species.
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Affiliation(s)
- Scott W Morrical
- Department of Biochemistry, University of Vermont College of Medicine, Burlington, Vermont 05405
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33
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Wendeler E, Zobell O, Chrost B, Reiss B. Recombination products suggest the frequent occurrence of aberrant gene replacement in the moss Physcomitrella patens. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 81:548-558. [PMID: 25557140 DOI: 10.1111/tpj.12749] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 11/20/2014] [Accepted: 12/11/2014] [Indexed: 06/04/2023]
Abstract
In gene replacement, a variant of gene targeting, transformed DNA integrates into the genome by homologous recombination (HR) to replace resident sequences. Gene replacement in the moss Physcomitrella patens is extremely efficient, but often large amounts of additional DNA are integrated at the target locus. A detailed analysis of recombination junctions of PpCOL2 gene knockout mutants shows that the integrated DNA can be highly rearranged. Our data suggest that the replaced sequences were excised by HR and became integrated back into the genome by non-homologous end-joining (NHEJ). RAD51-mediated strand-invasion and subsequent strand-exchange is central to the two-end invasion pathway, the major gene replacement pathway in yeast. In this pathway, integration is initiated by the free ends of a single replacement vector-derived donor molecule which then integrates as an entity. Gene replacement in P. patens is entirely RAD51-dependent suggesting the existence of a pathway mechanistically similar to two-end invasion. However, invasion of the two ends does not seem to be stringently coordinated in P. patens. Actually, often only one fragment end became integrated by HR, or one-sided integration of two independent donor fragments occurred simultaneously leading to a double-strand break that is subsequently sealed by NHEJ and thus causes the observed rearrangements.
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Affiliation(s)
- Edelgard Wendeler
- Max-Planck-Institute for Plant Breeding Research, Carl-von-Linne-Weg 10, 50829, Cologne, Germany
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34
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Genetic interactions among homologous recombination mutants in Candida albicans. Fungal Genet Biol 2015; 74:10-20. [DOI: 10.1016/j.fgb.2014.10.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Revised: 10/22/2014] [Accepted: 10/27/2014] [Indexed: 11/22/2022]
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35
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RecQ helicase and RecJ nuclease provide complementary functions to resect DNA for homologous recombination. Proc Natl Acad Sci U S A 2014; 111:E5133-42. [PMID: 25411316 DOI: 10.1073/pnas.1420009111] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Recombinational DNA repair by the RecF pathway of Escherichia coli requires the coordinated activities of RecA, RecFOR, RecQ, RecJ, and single-strand DNA binding (SSB) proteins. These proteins facilitate formation of homologously paired joint molecules between linear double-stranded (dsDNA) and supercoiled DNA. Repair starts with resection of the broken dsDNA by RecQ, a 3'→5' helicase, RecJ, a 5'→3' exonuclease, and SSB protein. The ends of a dsDNA break can be blunt-ended, or they may possess either 5'- or 3'-single-stranded DNA (ssDNA) overhangs of undefined length. Here we show that RecJ nuclease alone can initiate nucleolytic resection of DNA with 5'-ssDNA overhangs, and that RecQ helicase can initiate resection of DNA with blunt-ends or 3'-ssDNA overhangs by DNA unwinding. We establish that in addition to its well-known ssDNA exonuclease activity, RecJ can display dsDNA exonuclease activity, degrading 100-200 nucleotides of the strand terminating with a 5'-ssDNA overhang. The dsDNA product, with a 3'-ssDNA overhang, is an optimal substrate for RecQ, which unwinds this intermediate to reveal the complementary DNA strand with a 5'-end that is degraded iteratively by RecJ. On the other hand, RecJ cannot resect duplex DNA that is either blunt-ended or terminated with 3'-ssDNA; however, such DNA is unwound by RecQ to create ssDNA for RecJ exonuclease. RecJ requires interaction with SSB for exonucleolytic degradation of ssDNA but not dsDNA. Thus, complementary action by RecJ and RecQ permits initiation of recombinational repair from all dsDNA ends: 5'-overhangs, blunt, or 3'-overhangs. Such helicase-nuclease coordination is a common mechanism underlying resection in all organisms.
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36
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Gibb B, Ye LF, Kwon Y, Niu H, Sung P, Greene EC. Protein dynamics during presynaptic-complex assembly on individual single-stranded DNA molecules. Nat Struct Mol Biol 2014; 21:893-900. [PMID: 25195049 PMCID: PMC4190069 DOI: 10.1038/nsmb.2886] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 08/12/2014] [Indexed: 01/03/2023]
Abstract
Homologous recombination is a conserved pathway for repairing double-stranded breaks, which are processed to yield single-stranded DNA overhangs that serve as platforms for presynaptic-complex assembly. Here we use single-molecule imaging to reveal the interplay between Saccharomyces cerevisiae RPA, Rad52 and Rad51 during presynaptic-complex assembly. We show that Rad52 binds RPA-ssDNA and suppresses RPA turnover, highlighting an unanticipated regulatory influence on protein dynamics. Rad51 binding extends the ssDNA, and Rad52-RPA clusters remain interspersed along the presynaptic complex. These clusters promote additional binding of RPA and Rad52. Our work illustrates the spatial and temporal progression of the association of RPA and Rad52 with the presynaptic complex and reveals a new RPA-Rad52-Rad51-ssDNA intermediate, with implications for how the activities of Rad52 and RPA are coordinated with Rad51 during the later stages of recombination.
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Affiliation(s)
- Bryan Gibb
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York, USA
| | - Ling F Ye
- Department of Biological Sciences, Columbia University, New York, New York, USA
| | - YoungHo Kwon
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Hengyao Niu
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Patrick Sung
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Eric C Greene
- 1] Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York, USA. [2] Howard Hughes Medical Institute, Columbia University, New York, New York, USA
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37
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Ryzhikov M, Gupta R, Glickman M, Korolev S. RecO protein initiates DNA recombination and strand annealing through two alternative DNA binding mechanisms. J Biol Chem 2014; 289:28846-55. [PMID: 25170075 DOI: 10.1074/jbc.m114.585117] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Recombination mediator proteins (RMPs) are important for genome stability in all organisms. Several RMPs support two alternative reactions: initiation of homologous recombination and DNA annealing. We examined mechanisms of RMPs in both reactions with Mycobacterium smegmatis RecO (MsRecO) and demonstrated that MsRecO interacts with ssDNA by two distinct mechanisms. Zinc stimulates MsRecO binding to ssDNA during annealing, whereas the recombination function is zinc-independent and is regulated by interaction with MsRecR. Thus, different structural motifs or conformations of MsRecO are responsible for interaction with ssDNA during annealing and recombination. Neither annealing nor recombinase loading depends on MsRecO interaction with the conserved C-terminal tail of single-stranded (ss) DNA-binding protein (SSB), which is known to bind Escherichia coli RecO. However, similarly to E. coli proteins, MsRecO and MsRecOR do not dismiss SSB from ssDNA, suggesting that RMPs form a complex with SSB-ssDNA even in the absence of binding to the major protein interaction motif. We propose that alternative conformations of such complexes define the mechanism by which RMPs initiate the repair of stalled replication and support two different functions during recombinational repair of DNA breaks.
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Affiliation(s)
- Mikhail Ryzhikov
- From the Department of Biochemistry and Molecular Biology, St. Louis University School of Medicine, St. Louis, Missouri 63104 and
| | - Richa Gupta
- Division of Infectious Diseases and Immunology Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065
| | - Michael Glickman
- Division of Infectious Diseases and Immunology Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065
| | - Sergey Korolev
- From the Department of Biochemistry and Molecular Biology, St. Louis University School of Medicine, St. Louis, Missouri 63104 and
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38
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Luo M, Yang F, Leu NA, Landaiche J, Handel MA, Benavente R, La Salle S, Wang PJ. MEIOB exhibits single-stranded DNA-binding and exonuclease activities and is essential for meiotic recombination. Nat Commun 2014; 4:2788. [PMID: 24240703 PMCID: PMC3891831 DOI: 10.1038/ncomms3788] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Accepted: 10/16/2013] [Indexed: 12/21/2022] Open
Abstract
Meiotic recombination enables the reciprocal exchange of genetic material between parental homologous chromosomes, and ensures faithful chromosome segregation during meiosis in sexually reproducing organisms. This process relies on the complex interaction of DNA repair factors and many steps remain poorly understood in mammals. Here we report the identification of MEIOB, a meiosis-specific protein, in a proteomics screen for novel meiotic chromatin-associated proteins in mice. MEIOB contains an OB domain with homology to one of the RPA1 OB folds. MEIOB binds to single-stranded DNA and exhibits 3'-5' exonuclease activity. MEIOB forms a complex with RPA and with SPATA22, and these three proteins co-localize in foci that are associated with meiotic chromosomes. Strikingly, chromatin localization and stability of MEIOB depends on SPATA22 and vice versa. Meiob-null mouse mutants exhibit a failure in meiosis and sterility in both sexes. Our results suggest that MEIOB is required for meiotic recombination and chromosomal synapsis.
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Affiliation(s)
- Mengcheng Luo
- Center for Animal Transgenesis and Germ Cell Research, Department of Animal Biology, University of Pennsylvania School of Veterinary Medicine, 3800 Spruce Street, 200E Old Vet, Philadelphia, Pennsylvania 19104, USA
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39
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Chan YL, Brown MS, Qin D, Handa N, Bishop DK. The third exon of the budding yeast meiotic recombination gene HOP2 is required for calcium-dependent and recombinase Dmc1-specific stimulation of homologous strand assimilation. J Biol Chem 2014; 289:18076-86. [PMID: 24798326 DOI: 10.1074/jbc.m114.558601] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
During meiosis in Saccharomyces cerevisiae, the HOP2 and MND1 genes are essential for recombination. A previous biochemical study has shown that budding yeast Hop2-Mnd1 stimulates the activity of the meiosis-specific strand exchange protein ScDmc1 only 3-fold, whereas analogous studies using mammalian homologs show >30-fold stimulation. The HOP2 gene was recently discovered to contain a second intron that lies near the 3'-end. We show that both HOP2 introns are efficiently spliced during meiosis, forming a predominant transcript that codes for a protein with a C-terminal sequence different from that of the previously studied version of the protein. Using the newly identified HOP2 open reading frame to direct synthesis of wild type Hop2 protein, we show that the Hop2-Mnd1 heterodimer stimulated Dmc1 D-loop activity up to 30-fold, similar to the activity of mammalian Hop2-Mnd1. ScHop2-Mnd1 stimulated ScDmc1 activity in the presence of physiological (micromolar) concentrations of Ca(2+) ions, as long as Mg(2+) was also present at physiological concentrations, leading us to hypothesize that ScDmc1 protomers bind both cations in the active Dmc1 filament. Co-factor requirements and order-of-addition experiments suggested that Hop2-Mnd1-mediated stimulation of Dmc1 involves a process that follows the formation of functional Dmc1-ssDNA filaments. In dramatic contrast to mammalian orthologs, the stimulatory activity of budding yeast Hop2-Mnd1 appeared to be specific to Dmc1; we observed no Hop2-Mnd1-mediated stimulation of the other budding yeast strand exchange protein Rad51. Together, these results support previous genetic experiments indicating that Hop2-Mnd1 specifically stimulates Dmc1 during meiotic recombination in budding yeast.
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Affiliation(s)
- Yuen-Ling Chan
- From the Departments of Radiation and Cellular Oncology and
| | - M Scott Brown
- From the Departments of Radiation and Cellular Oncology and
| | - Daoming Qin
- Molecular Genetics and Cell Biology, Cummings Life Science Center, University of Chicago, Chicago, Illinois 60637 and
| | - Naofumi Handa
- the Department of Microbiology and Molecular Genetics, University of California, Davis, California 95616
| | - Douglas K Bishop
- From the Departments of Radiation and Cellular Oncology and Molecular Genetics and Cell Biology, Cummings Life Science Center, University of Chicago, Chicago, Illinois 60637 and
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40
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Lee M, Lee CH, Demin AA, Munashingha PR, Amangyeld T, Kwon B, Formosa T, Seo YS. Rad52/Rad59-dependent recombination as a means to rectify faulty Okazaki fragment processing. J Biol Chem 2014; 289:15064-79. [PMID: 24711454 DOI: 10.1074/jbc.m114.548388] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The correct removal of 5'-flap structures by Rad27 and Dna2 during Okazaki fragment maturation is crucial for the stable maintenance of genetic materials and cell viability. In this study, we identified RAD52, a key recombination protein, as a multicopy suppressor of dna2-K1080E, a lethal helicase-negative mutant allele of DNA2 in yeasts. In contrast, the overexpression of Rad51, which works conjointly with Rad52 in canonical homologous recombination, failed to suppress the growth defect of the dna2-K1080E mutation, indicating that Rad52 plays a unique and distinct role in Okazaki fragment metabolism. We found that the recombination-defective Rad52-QDDD/AAAA mutant did not rescue dna2-K1080E, suggesting that Rad52-mediated recombination is important for suppression. The Rad52-mediated enzymatic stimulation of Dna2 or Rad27 is not a direct cause of suppression observed in vivo, as both Rad52 and Rad52-QDDD/AAAA proteins stimulated the endonuclease activities of both Dna2 and Rad27 to a similar extent. The recombination mediator activity of Rad52 was dispensable for the suppression, whereas both the DNA annealing activity and its ability to interact with Rad59 were essential. In addition, we found that several cohesion establishment factors, including Rsc2 and Elg1, were required for the Rad52-dependent suppression of dna2-K1080E. Our findings suggest a novel Rad52/Rad59-dependent, but Rad51-independent recombination pathway that could ultimately lead to the removal of faulty flaps in conjunction with cohesion establishment factors.
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Affiliation(s)
- Miju Lee
- From the Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea and
| | - Chul-Hwan Lee
- From the Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea and
| | - Annie Albert Demin
- From the Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea and
| | - Palinda Ruvan Munashingha
- From the Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea and
| | - Tamir Amangyeld
- From the Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea and
| | - Buki Kwon
- From the Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea and
| | - Tim Formosa
- the Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, Utah 84112
| | - Yeon-Soo Seo
- From the Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea and
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41
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Abstract
All species continuously evolve to adapt to changing environments. The genetic variation that fosters such adaptation is caused by a plethora of mechanisms, including meiotic recombination that generates novel allelic combinations in the progeny of two parental lineages. However, a considerable number of eukaryotic species, including many fungi, do not have an apparent sexual cycle and are consequently thought to be limited in their evolutionary potential. As such organisms are expected to have reduced capability to eliminate deleterious mutations, they are often considered as evolutionary dead ends. However, inspired by recent reports we argue that such organisms can be as persistent as organisms with conventional sexual cycles through the use of other mechanisms, such as genomic rearrangements, to foster adaptation.
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Affiliation(s)
- Michael F Seidl
- Laboratory of Phytopathology, Wageningen University, Wageningen, The Netherlands
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42
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Jensen RB. BRCA2: one small step for DNA repair, one giant protein purified. THE YALE JOURNAL OF BIOLOGY AND MEDICINE 2013; 86:479-89. [PMID: 24348212 PMCID: PMC3848102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
DNA damage, malfunctions in DNA repair, and genomic instability are processes that intersect at the crossroads of carcinogenesis. Underscoring the importance of DNA repair in breast and ovarian tumorigenesis is the familial inherited cancer predisposition gene BRCA2. The role of BRCA2 in DNA double-strand break repair was first revealed based on its interaction with RAD51, a central player in homologous recombination. The RAD51 protein forms a nucleoprotein filament on single-stranded DNA, invades a DNA duplex, and initiates a search for homology. Once a homologous DNA sequence is found, the DNA is used as a template for the high-fidelity repair of the DNA break. Many of the biochemical features that allow BRCA2 to choreograph the activities of RAD51 have been elucidated and include: targeting RAD51 to single-stranded DNA while inhibiting binding to dsDNA, reducing the ATPase activity of RAD51, and facilitating the displacement of the single-strand DNA binding protein, Replication Protein A. These reinforcing activities of BRCA2 culminate in the correct positioning of RAD51 onto a processed DNA double-strand break and initiate its faithful repair by homologous recombination. In this review, I will address current biochemical data concerning the BRCA2 protein and highlight unanswered questions regarding BRCA2 function in homologous recombination and cancer.
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Early steps of double-strand break repair in Bacillus subtilis. DNA Repair (Amst) 2013; 12:162-76. [PMID: 23380520 DOI: 10.1016/j.dnarep.2012.12.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 12/04/2012] [Accepted: 12/14/2012] [Indexed: 11/22/2022]
Abstract
All organisms rely on integrated networks to repair DNA double-strand breaks (DSBs) in order to preserve the integrity of the genetic information, to re-establish replication, and to ensure proper chromosomal segregation. Genetic, cytological, biochemical and structural approaches have been used to analyze how Bacillus subtilis senses DNA damage and responds to DSBs. RecN, which is among the first responders to DNA DSBs, promotes the ordered recruitment of repair proteins to the site of a lesion. Cells have evolved different mechanisms for efficient end processing to create a 3'-tailed duplex DNA, the substrate for RecA binding, in the repair of one- and two-ended DSBs. Strand continuity is re-established via homologous recombination (HR), utilizing an intact homologous DNA molecule as a template. In the absence of transient diploidy or of HR, however, two-ended DSBs can be directly re-ligated via error-prone non-homologous end-joining. Here we review recent findings that shed light on the early stages of DSB repair in Firmicutes.
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Costes A, Lambert SAE. Homologous recombination as a replication fork escort: fork-protection and recovery. Biomolecules 2012; 3:39-71. [PMID: 24970156 PMCID: PMC4030885 DOI: 10.3390/biom3010039] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Revised: 12/11/2012] [Accepted: 12/11/2012] [Indexed: 01/03/2023] Open
Abstract
Homologous recombination is a universal mechanism that allows DNA repair and ensures the efficiency of DNA replication. The substrate initiating the process of homologous recombination is a single-stranded DNA that promotes a strand exchange reaction resulting in a genetic exchange that promotes genetic diversity and DNA repair. The molecular mechanisms by which homologous recombination repairs a double-strand break have been extensively studied and are now well characterized. However, the mechanisms by which homologous recombination contribute to DNA replication in eukaryotes remains poorly understood. Studies in bacteria have identified multiple roles for the machinery of homologous recombination at replication forks. Here, we review our understanding of the molecular pathways involving the homologous recombination machinery to support the robustness of DNA replication. In addition to its role in fork-recovery and in rebuilding a functional replication fork apparatus, homologous recombination may also act as a fork-protection mechanism. We discuss that some of the fork-escort functions of homologous recombination might be achieved by loading of the recombination machinery at inactivated forks without a need for a strand exchange step; as well as the consequence of such a model for the stability of eukaryotic genomes.
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Affiliation(s)
- Audrey Costes
- Institut Curie, Centre de Recherche, CNRS, UMR3348, Centre Universitaire, Bat110, 91405, Orsay, France.
| | - Sarah A E Lambert
- Institut Curie, Centre de Recherche, CNRS, UMR3348, Centre Universitaire, Bat110, 91405, Orsay, France.
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Nardozzi JD, Wang X, Mbantenkhu M, Wilkens S, Chen XJ. A properly configured ring structure is critical for the function of the mitochondrial DNA recombination protein, Mgm101. J Biol Chem 2012; 287:37259-68. [PMID: 22948312 PMCID: PMC3481324 DOI: 10.1074/jbc.m112.389965] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Revised: 08/11/2012] [Indexed: 11/06/2022] Open
Abstract
Mgm101 is a Rad52-type recombination protein of bacteriophage origin required for the repair and maintenance of mitochondrial DNA (mtDNA). It forms large oligomeric rings of ∼14-fold symmetry that catalyze the annealing of single-stranded DNAs in vitro. In this study, we investigated the structural elements that contribute to this distinctive higher order structural organization and examined its functional implications. A pair of vicinal cysteines, Cys-216 and Cys-217, was found to be essential for mtDNA maintenance. Mutations to the polar serine, the negatively charged aspartic and glutamic acids, and the hydrophobic amino acid alanine all destabilize mtDNA in vivo. The alanine mutants have an increased propensity of forming macroscopic filaments. In contrast, mutations to aspartic acid drastically destabilize the protein and result in unstructured aggregates with severely reduced DNA binding activity. Interestingly, the serine mutants partially disassemble the Mgm101 rings into smaller oligomers. In the case of the C216S mutant, a moderate increase in DNA binding activity was observed. By using small angle x-ray scattering analysis, we found that Mgm101 forms rings of ∼200 Å diameter in solution, consistent with the structure previously established by transmission electron microscopy. We also found that the C216A/C217A double mutant tends to form broken rings, which likely provide free ends for seeding the growth of the super-stable but functionally defective filaments. Taken together, our data underscore the importance of a delicately maintained ring structure critical for Mgm101 activity. We discuss a potential role of Cys-216 and Cys-217 in regulating Mgm101 function and the repair of damaged mtDNA under stress conditions.
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Affiliation(s)
- Jonathan D. Nardozzi
- From the Department of Biochemistry and Molecular Biology, State University of New York Upstate Medical University, Syracuse, New York 13210
| | - Xiaowen Wang
- From the Department of Biochemistry and Molecular Biology, State University of New York Upstate Medical University, Syracuse, New York 13210
| | - MacMillan Mbantenkhu
- From the Department of Biochemistry and Molecular Biology, State University of New York Upstate Medical University, Syracuse, New York 13210
| | - Stephan Wilkens
- From the Department of Biochemistry and Molecular Biology, State University of New York Upstate Medical University, Syracuse, New York 13210
| | - Xin Jie Chen
- From the Department of Biochemistry and Molecular Biology, State University of New York Upstate Medical University, Syracuse, New York 13210
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Thompson LH. Recognition, signaling, and repair of DNA double-strand breaks produced by ionizing radiation in mammalian cells: the molecular choreography. Mutat Res 2012; 751:158-246. [PMID: 22743550 DOI: 10.1016/j.mrrev.2012.06.002] [Citation(s) in RCA: 261] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Revised: 06/09/2012] [Accepted: 06/16/2012] [Indexed: 12/15/2022]
Abstract
The faithful maintenance of chromosome continuity in human cells during DNA replication and repair is critical for preventing the conversion of normal diploid cells to an oncogenic state. The evolution of higher eukaryotic cells endowed them with a large genetic investment in the molecular machinery that ensures chromosome stability. In mammalian and other vertebrate cells, the elimination of double-strand breaks with minimal nucleotide sequence change involves the spatiotemporal orchestration of a seemingly endless number of proteins ranging in their action from the nucleotide level to nucleosome organization and chromosome architecture. DNA DSBs trigger a myriad of post-translational modifications that alter catalytic activities and the specificity of protein interactions: phosphorylation, acetylation, methylation, ubiquitylation, and SUMOylation, followed by the reversal of these changes as repair is completed. "Superfluous" protein recruitment to damage sites, functional redundancy, and alternative pathways ensure that DSB repair is extremely efficient, both quantitatively and qualitatively. This review strives to integrate the information about the molecular mechanisms of DSB repair that has emerged over the last two decades with a focus on DSBs produced by the prototype agent ionizing radiation (IR). The exponential growth of molecular studies, heavily driven by RNA knockdown technology, now reveals an outline of how many key protein players in genome stability and cancer biology perform their interwoven tasks, e.g. ATM, ATR, DNA-PK, Chk1, Chk2, PARP1/2/3, 53BP1, BRCA1, BRCA2, BLM, RAD51, and the MRE11-RAD50-NBS1 complex. Thus, the nature of the intricate coordination of repair processes with cell cycle progression is becoming apparent. This review also links molecular abnormalities to cellular pathology as much a possible and provides a framework of temporal relationships.
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Affiliation(s)
- Larry H Thompson
- Biology & Biotechnology Division, L452, Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, CA 94551-0808, United States.
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Maher RL, Branagan AM, Morrical SW. Coordination of DNA replication and recombination activities in the maintenance of genome stability. J Cell Biochem 2012; 112:2672-82. [PMID: 21647941 DOI: 10.1002/jcb.23211] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Across the evolutionary spectrum, living organisms depend on high-fidelity DNA replication and recombination mechanisms to maintain genome stability and thus to avoid mutation and disease. The repair of severe lesions in the DNA such as double-strand breaks or stalled replication forks requires the coordinated activities of both the homologous recombination (HR) and DNA replication machineries. Growing evidence indicates that so-called "accessory proteins" in both systems are essential for the effective coupling of recombination to replication which is necessary to restore genome integrity following severe DNA damage. In this article we review the major processes of homology-directed DNA repair (HDR), including the double Holliday Junction (dHJ), synthesis-dependent strand annealing (SDSA), break-induced replication (BIR), and error-free lesion bypass pathways. Each of these pathways involves the coupling of a HR event to DNA synthesis. We highlight two major classes of accessory proteins in recombination and replication that facilitate HDR: Recombination mediator proteins exemplified by T4 UvsY, Saccharomyces cerevisiae Rad52, and human BRCA2; and DNA helicases/translocases exemplified by T4 Gp41/Gp59, E. coli DnaB and PriA, and eukaryotic Mcm2-7, Rad54, and Mph1. We illustrate how these factors help to direct the flow of DNA and protein-DNA intermediates on the pathway from a double-strand break or stalled replication fork to a high-fidelity recombination-dependent replication apparatus that can accurately repair the damage.
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Affiliation(s)
- Robyn L Maher
- Department of Biochemistry, University of Vermont College of Medicine, Burlington, Vermont 05405, USA
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Krejci L, Altmannova V, Spirek M, Zhao X. Homologous recombination and its regulation. Nucleic Acids Res 2012; 40:5795-818. [PMID: 22467216 PMCID: PMC3401455 DOI: 10.1093/nar/gks270] [Citation(s) in RCA: 448] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Homologous recombination (HR) is critical both for repairing DNA lesions in mitosis and for chromosomal pairing and exchange during meiosis. However, some forms of HR can also lead to undesirable DNA rearrangements. Multiple regulatory mechanisms have evolved to ensure that HR takes place at the right time, place and manner. Several of these impinge on the control of Rad51 nucleofilaments that play a central role in HR. Some factors promote the formation of these structures while others lead to their disassembly or the use of alternative repair pathways. In this article, we review these mechanisms in both mitotic and meiotic environments and in different eukaryotic taxa, with an emphasis on yeast and mammal systems. Since mutations in several proteins that regulate Rad51 nucleofilaments are associated with cancer and cancer-prone syndromes, we discuss how understanding their functions can lead to the development of better tools for cancer diagnosis and therapy.
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Affiliation(s)
- Lumir Krejci
- Department of Biology, Masaryk University, Brno, Czech Republic.
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Amunugama R, Fishel R. Homologous Recombination in Eukaryotes. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2012; 110:155-206. [DOI: 10.1016/b978-0-12-387665-2.00007-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Zhang Y, Rohde LH, Wu H. Involvement of nucleotide excision and mismatch repair mechanisms in double strand break repair. Curr Genomics 2011; 10:250-8. [PMID: 19949546 PMCID: PMC2709936 DOI: 10.2174/138920209788488544] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2009] [Revised: 03/28/2009] [Accepted: 03/30/2009] [Indexed: 11/25/2022] Open
Abstract
Living organisms are constantly threatened by environmental DNA-damaging agents, including UV and ionizing radiation (IR). Repair of various forms of DNA damage caused by IR is normally thought to follow lesion-specific repair pathways with distinct enzymatic machinery. DNA double strand break is one of the most serious kinds of damage induced by IR, which is repaired through double strand break (DSB) repair mechanisms, including homologous recombination (HR) and non-homologous end joining (NHEJ). However, recent studies have presented increasing evidence that various DNA repair pathways are not separated, but well interlinked. It has been suggested that non-DSB repair mechanisms, such as Nucleotide Excision Repair (NER), Mismatch Repair (MMR) and cell cycle regulation, are highly involved in DSB repairs. These findings revealed previously unrecognized roles of various non-DSB repair genes and indicated that a successful DSB repair requires both DSB repair mechanisms and non-DSB repair systems. One of our recent studies found that suppressed expression of non-DSB repair genes, such as XPA, RPA and MLH1, influenced the yield of IR induced micronuclei formation and/or chromosome aberrations, suggesting that these genes are highly involved in DSB repair and DSB-related cell cycle arrest, which reveals new roles for these gene products in the DNA repair network. In this review, we summarize current progress on the function of non-DSB repair-related proteins, especially those that participate in NER and MMR pathways, and their influence on DSB repair. In addition, we present our developing view that the DSB repair mechanisms are more complex and are regulated by not only the well known HR/NHEJ pathways, but also a systematically coordinated cellular network.
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Affiliation(s)
- Ye Zhang
- NASA Johnson Space Center, Houston, Texas 77058
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