1
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Chen X, Chen C, Luo C, Liu J, Lin Z. Discovery of UMI-77 as a novel Ku70/80 inhibitor sensitizing cancer cells to DNA damaging agents in vitro and in vivo. Eur J Pharmacol 2024; 975:176647. [PMID: 38754534 DOI: 10.1016/j.ejphar.2024.176647] [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: 12/15/2023] [Revised: 05/14/2024] [Accepted: 05/14/2024] [Indexed: 05/18/2024]
Abstract
The emergence of chemoresistance poses a significant challenge to the efficacy of DNA-damaging agents in cancer treatment, in part due to the inherent DNA repair capabilities of cancer cells. The Ku70/80 protein complex (Ku) plays a central role in double-strand breaks (DSBs) repair through the classical non-homologous end joining (c-NHEJ) pathway, and has proven to be one of the most promising drug target for cancer treatment when combined with radiotherapy or chemotherapy. In this study, we conducted a high-throughput screening of small-molecule inhibitors targeting the Ku complex by using a fluorescence polarization-based DNA binding assay. From a library of 11,745 small molecules, UMI-77 was identified as a potent Ku inhibitor, with an IC50 value of 2.3 μM. Surface plasmon resonance and molecular docking analyses revealed that UMI-77 directly bound the inner side of Ku ring, thereby disrupting Ku binding with DNA. In addition, UMI-77 also displayed potent inhibition against MUS81-EME1, a key player in homologous recombination (HR), demonstrating its potential for blocking both NHEJ- and HR-mediated DSB repair pathways. Further cell-based studies showed that UMI-77 could impair bleomycin-induced DNA damage repair, and significantly sensitized multiple cancer cell lines to the DNA-damaging agents. Finally, in a mouse xenograft tumor model, UMI-77 significantly enhanced the chemotherapeutic efficacy of etoposide with little adverse physiological effects. Our work offers a new avenue to combat chemoresistance in cancer treatment, and suggests that UMI-77 could be further developed as a promising candidate in cancer treatment.
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Affiliation(s)
- Xuening Chen
- College of Chemistry, Fuzhou University, Fuzhou, 350108, China
| | - Changkun Chen
- College of Chemistry, Fuzhou University, Fuzhou, 350108, China
| | - Chengmiao Luo
- College of Chemistry, Fuzhou University, Fuzhou, 350108, China
| | - Jianyong Liu
- College of Chemistry, Fuzhou University, Fuzhou, 350108, China
| | - Zhonghui Lin
- College of Chemistry, Fuzhou University, Fuzhou, 350108, China.
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2
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Zhang D, Xu S, Luo Z, Lin Z. MOC1 cleaves Holliday junctions through a cooperative nick and counter-nick mechanism mediated by metal ions. Nat Commun 2024; 15:5140. [PMID: 38886375 PMCID: PMC11183143 DOI: 10.1038/s41467-024-49490-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 06/06/2024] [Indexed: 06/20/2024] Open
Abstract
Holliday junction resolution is a crucial process in homologous recombination and DNA double-strand break repair. Complete Holliday junction resolution requires two stepwise incisions across the center of the junction, but the precise mechanism of metal ion-catalyzed Holliday junction cleavage remains elusive. Here, we perform a metal ion-triggered catalysis in crystals to investigate the mechanism of Holliday junction cleavage by MOC1. We capture the structures of MOC1 in complex with a nicked Holliday junction at various catalytic states, including the ground state, the one-metal ion binding state, and the two-metal ion binding state. Moreover, we also identify a third metal ion that may aid in the nucleophilic attack on the scissile phosphate. Further structural and biochemical analyses reveal a metal ion-mediated allosteric regulation between the two active sites, contributing to the enhancement of the second strand cleavage following the first strand cleavage, as well as the precise symmetric cleavage across the Holliday junction. Our work provides insights into the mechanism of metal ion-catalyzed Holliday junction resolution by MOC1, with implications for understanding how cells preserve genome integrity during the Holliday junction resolution phase.
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Affiliation(s)
- Danping Zhang
- College of Chemistry, Fuzhou University, Fuzhou, 350108, China
| | - Shenjie Xu
- MOE Key Laboratory of Geriatric Diseases and Immunology, Institute of Molecular Enzymology, School of Biology and Basic Medical Sciences, Suzhou Medical College, Soochow University, Suzhou, 215123, China
| | - Zhipu Luo
- MOE Key Laboratory of Geriatric Diseases and Immunology, Institute of Molecular Enzymology, School of Biology and Basic Medical Sciences, Suzhou Medical College, Soochow University, Suzhou, 215123, China.
| | - Zhonghui Lin
- College of Chemistry, Fuzhou University, Fuzhou, 350108, China.
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3
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Nickoloff JA, Jaiswal AS, Sharma N, Williamson EA, Tran MT, Arris D, Yang M, Hromas R. Cellular Responses to Widespread DNA Replication Stress. Int J Mol Sci 2023; 24:16903. [PMID: 38069223 PMCID: PMC10707325 DOI: 10.3390/ijms242316903] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 11/22/2023] [Accepted: 11/27/2023] [Indexed: 12/18/2023] Open
Abstract
Replicative DNA polymerases are blocked by nearly all types of DNA damage. The resulting DNA replication stress threatens genome stability. DNA replication stress is also caused by depletion of nucleotide pools, DNA polymerase inhibitors, and DNA sequences or structures that are difficult to replicate. Replication stress triggers complex cellular responses that include cell cycle arrest, replication fork collapse to one-ended DNA double-strand breaks, induction of DNA repair, and programmed cell death after excessive damage. Replication stress caused by specific structures (e.g., G-rich sequences that form G-quadruplexes) is localized but occurs during the S phase of every cell division. This review focuses on cellular responses to widespread stress such as that caused by random DNA damage, DNA polymerase inhibition/nucleotide pool depletion, and R-loops. Another form of global replication stress is seen in cancer cells and is termed oncogenic stress, reflecting dysregulated replication origin firing and/or replication fork progression. Replication stress responses are often dysregulated in cancer cells, and this too contributes to ongoing genome instability that can drive cancer progression. Nucleases play critical roles in replication stress responses, including MUS81, EEPD1, Metnase, CtIP, MRE11, EXO1, DNA2-BLM, SLX1-SLX4, XPF-ERCC1-SLX4, Artemis, XPG, FEN1, and TATDN2. Several of these nucleases cleave branched DNA structures at stressed replication forks to promote repair and restart of these forks. We recently defined roles for EEPD1 in restarting stressed replication forks after oxidative DNA damage, and for TATDN2 in mitigating replication stress caused by R-loop accumulation in BRCA1-defective cells. We also discuss how insights into biological responses to genome-wide replication stress can inform novel cancer treatment strategies that exploit synthetic lethal relationships among replication stress response factors.
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Affiliation(s)
- Jac A. Nickoloff
- Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, CO 80523, USA
| | - Aruna S. Jaiswal
- Department of Medicine and the Mays Cancer Center, The University of Texas Health Science Center San Antonio, San Antonio, TX 78229, USA; (A.S.J.); (M.T.T.); (R.H.)
| | - Neelam Sharma
- Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, CO 80523, USA
| | - Elizabeth A. Williamson
- Department of Medicine and the Mays Cancer Center, The University of Texas Health Science Center San Antonio, San Antonio, TX 78229, USA; (A.S.J.); (M.T.T.); (R.H.)
| | - Manh T. Tran
- Department of Medicine and the Mays Cancer Center, The University of Texas Health Science Center San Antonio, San Antonio, TX 78229, USA; (A.S.J.); (M.T.T.); (R.H.)
| | - Dominic Arris
- Department of Medicine and the Mays Cancer Center, The University of Texas Health Science Center San Antonio, San Antonio, TX 78229, USA; (A.S.J.); (M.T.T.); (R.H.)
| | - Ming Yang
- Department of Medicine and the Mays Cancer Center, The University of Texas Health Science Center San Antonio, San Antonio, TX 78229, USA; (A.S.J.); (M.T.T.); (R.H.)
| | - Robert Hromas
- Department of Medicine and the Mays Cancer Center, The University of Texas Health Science Center San Antonio, San Antonio, TX 78229, USA; (A.S.J.); (M.T.T.); (R.H.)
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4
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Premkumar T, Paniker L, Kang R, Biot M, Humphrey E, Destain H, Ferranti I, Okulate I, Nguyen H, Kilaru V, Frasca M, Chakraborty P, Cole F. Genetic dissection of crossover mutants defines discrete intermediates in mouse meiosis. Mol Cell 2023; 83:2941-2958.e7. [PMID: 37595556 PMCID: PMC10469168 DOI: 10.1016/j.molcel.2023.07.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 03/28/2023] [Accepted: 07/21/2023] [Indexed: 08/20/2023]
Abstract
Crossovers (COs), the exchange of homolog arms, are required for accurate chromosome segregation during meiosis. Studies in yeast have described the single-end invasion (SEI) intermediate: a stabilized 3' end annealed with the homolog as the first detectible CO precursor. SEIs are thought to differentiate into double Holliday junctions (dHJs) that are resolved by MutLgamma (MLH1/MLH3) into COs. Currently, we lack knowledge of early steps of mammalian CO recombination or how intermediates are differentiated in any organism. Using comprehensive analysis of recombination in thirteen different genetic conditions with varying levels of compromised CO resolution, we infer CO precursors include asymmetric SEI-like intermediates and dHJs in mouse. In contrast to yeast, MLH3 is structurally required to differentiate CO precursors into dHJs. We verify conservation of aspects of meiotic recombination and show unique features in mouse, providing mechanistic insight into CO formation.
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Affiliation(s)
- Tolkappiyan Premkumar
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Houston, TX, USA; The University of Texas MD Anderson Cancer Center UTHealth Houston Graduate School of Biomedical Sciences, Program in Genetics and Epigenetics, Houston, TX, USA
| | - Lakshmi Paniker
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Rhea Kang
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Houston, TX, USA; The University of Texas MD Anderson Cancer Center UTHealth Houston Graduate School of Biomedical Sciences, Program in Genetics and Epigenetics, Houston, TX, USA
| | - Mathilde Biot
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Ericka Humphrey
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Honorine Destain
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Isabella Ferranti
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Iyinyeoluwa Okulate
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Holly Nguyen
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Vindhya Kilaru
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Melissa Frasca
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Houston, TX, USA; The University of Texas MD Anderson Cancer Center UTHealth Houston Graduate School of Biomedical Sciences, Program in Genetics and Epigenetics, Houston, TX, USA
| | - Parijat Chakraborty
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Francesca Cole
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Houston, TX, USA; The University of Texas MD Anderson Cancer Center UTHealth Houston Graduate School of Biomedical Sciences, Program in Genetics and Epigenetics, Houston, TX, USA.
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5
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Zhang X, Chen X, Lu L, Fang Q, Liu C, Lin Z. Identification of small-molecule inhibitors of human MUS81-EME1/2 by FRET-based high-throughput screening. Bioorg Med Chem 2023; 90:117383. [PMID: 37352577 DOI: 10.1016/j.bmc.2023.117383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Revised: 06/09/2023] [Accepted: 06/17/2023] [Indexed: 06/25/2023]
Abstract
The MUS81-EME1/2 structure-specific endonucleases play a crucial role in the processing of stalled replication forks and recombination intermediates, and have been recognized as an attractive drug target to potentiate the anti-cancer efficacy of DNA-damaging agents. Currently, no bioactive small-molecule inhibitors of MUS81 are available. Here, we performed a high-throughput small-molecule inhibitors screening, using the FRET-based DNA cleavage assay. From 7920 compounds, we identified dyngo-4a as a potent inhibitor of MUS81 complexes. Dyngo-4a effectively inhibits the endonuclease activities of both MUS81-EME1 and MUS81-EME2 complexes, with IC50 values of 0.57 μM and 2.90 μM, respectively. Surface plasmon resonance (SPR) and electrophoretic mobility shift assay (EMSA) assays reveal that dyngo-4a directly binds to MUS81 complexes (KD ∼ 0.61 μM) and prevents them from binding to DNA substrates. In HeLa cells, dyngo-4a significantly suppresses bleomycin-triggered H2AX serine 139 phosphorylation (γH2AX). Together, our results demonstrate that dyngo-4a is a potent MUS81 inhibitor, which could be further developed as a potentially valuable chemical tool to explore more physiological roles of MUS81 in the cells.
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Affiliation(s)
- Xu Zhang
- College of Chemistry, Fuzhou University, Fuzhou 350108, China
| | - Xuening Chen
- College of Chemistry, Fuzhou University, Fuzhou 350108, China
| | - Lian Lu
- College of Chemistry, Fuzhou University, Fuzhou 350108, China
| | - Qianqian Fang
- College of Chemistry, Fuzhou University, Fuzhou 350108, China
| | - Chun Liu
- College of Biological Science and Engineering, Fuzhou University, Fuzhou 350108, China
| | - Zhonghui Lin
- College of Chemistry, Fuzhou University, Fuzhou 350108, China; Key Laboratory of Marine Enzyme Engineering, Fuzhou University, Fuzhou, China.
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6
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Zhang Y, Shi D, Zhang X, Wu S, Liu W, Luo B. Downregulation of MUS81 expression inhibits cell migration and maintains EBV latent infection through miR-BART9-5p in EBV-associated gastric cancer. J Med Virol 2023; 95:e28725. [PMID: 37185865 DOI: 10.1002/jmv.28725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 02/15/2023] [Accepted: 03/30/2023] [Indexed: 05/17/2023]
Abstract
Epstein-Barr virus (EBV) infection is associated with the occurrence and development of gastric cancer (GC). Methyl methanesulfonate and ultraviolet-sensitive gene 81 (MUS81) is the catalytic component of a structure-specific endonuclease and plays an important role in chromosomal stability. However, the link between EBV infection and MUS81 remains unclear. In the present study, we found that MUS81 expression was much lower in EBV-associated GC cells than in EBV-negative GC. MUS81 acts as an oncogene in GC by inducing the cell migration and proliferation. Western blot and luciferase reporter assays revealed that miR-BART9-5p directly targeted MUS81 and downregulated its expression. Additionally, overexpression of MUS81 in EBV-positive GC cells inhibited the expression of EBV nuclear antigen 1 (EBNA1). EBNA1 is critical for the pathogenesis of EBV-associated tumors and the maintenance of a stable copy number of the viral genomes. Altogether, these results indicated that the lowering MUS81 expression might be a mechanism by EBV to maintain its latent infection.
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Affiliation(s)
- Yan Zhang
- Department of Pathogeny Biology, Basic Medicine College, Qingdao University, Qingdao, China
- Department of Clinical Laboratory, Zibo Central Hospital, Zibo, China
| | - Duo Shi
- Department of Pathogeny Biology, Basic Medicine College, Qingdao University, Qingdao, China
| | - Xing Zhang
- Department of Pathogeny Biology, Basic Medicine College, Qingdao University, Qingdao, China
| | - Shuo Wu
- Department of Pathogeny Biology, Basic Medicine College, Qingdao University, Qingdao, China
- Laboratory Medicine Center of Qingdao, Qilu Hospital of Shandong University (Qingdao), Qingdao, China
| | - Wen Liu
- Department of Pathogeny Biology, Basic Medicine College, Qingdao University, Qingdao, China
| | - Bing Luo
- Department of Pathogeny Biology, Basic Medicine College, Qingdao University, Qingdao, China
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7
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Han Z, Andrš M, Madhavan BK, Kaymak S, Sulaj A, Kender Z, Kopf S, Kihm L, Pepperkok R, Janscak P, Nawroth P, Kumar V. The importance of nuclear RAGE-Mcm2 axis in diabetes or cancer-associated replication stress. Nucleic Acids Res 2023; 51:2298-2318. [PMID: 36807739 PMCID: PMC10018352 DOI: 10.1093/nar/gkad085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 01/18/2023] [Accepted: 01/26/2023] [Indexed: 02/23/2023] Open
Abstract
An elevated frequency of DNA replication defects is associated with diabetes and cancer. However, data linking these nuclear perturbations to the onset or progression of organ complications remained unexplored. Here, we report that RAGE (Receptor for Advanced Glycated Endproducts), previously believed to be an extracellular receptor, upon metabolic stress localizes to the damaged forks. There it interacts and stabilizes the minichromosome-maintenance (Mcm2-7) complex. Accordingly, RAGE deficiency leads to slowed fork progression, premature fork collapse, hypersensitivity to replication stress agents and reduction of viability, which was reversed by the reconstitution of RAGE. This was marked by the 53BP1/OPT-domain expression and the presence of micronuclei, premature loss-of-ciliated zones, increased incidences of tubular-karyomegaly, and finally, interstitial fibrosis. More importantly, the RAGE-Mcm2 axis was selectively compromised in cells expressing micronuclei in human biopsies and mouse models of diabetic nephropathy and cancer. Thus, the functional RAGE-Mcm2/7 axis is critical in handling replication stress in vitro and human disease.
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Affiliation(s)
- Zhe Han
- Department of Medicine I and Clinical Chemistry, University Hospital of Heidelberg, INF 410, Heidelberg, Germany
| | - Martin Andrš
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, CZ-14300 Prague, Czech Republic
- Institute of Molecular Cancer Research, University of Zurich, 8057 Zurich, Switzerland
| | - Bindhu K Madhavan
- Department of Medicine I and Clinical Chemistry, University Hospital of Heidelberg, INF 410, Heidelberg, Germany
| | - Serap Kaymak
- Department of Medicine I and Clinical Chemistry, University Hospital of Heidelberg, INF 410, Heidelberg, Germany
| | - Alba Sulaj
- Department of Medicine I and Clinical Chemistry, University Hospital of Heidelberg, INF 410, Heidelberg, Germany
- German Center of Diabetes Research (DZD), Neuherberg, Germany
| | - Zoltan Kender
- Department of Medicine I and Clinical Chemistry, University Hospital of Heidelberg, INF 410, Heidelberg, Germany
- German Center of Diabetes Research (DZD), Neuherberg, Germany
| | - Stefan Kopf
- Department of Medicine I and Clinical Chemistry, University Hospital of Heidelberg, INF 410, Heidelberg, Germany
- German Center of Diabetes Research (DZD), Neuherberg, Germany
| | - Lars Kihm
- Department of Medicine I and Clinical Chemistry, University Hospital of Heidelberg, INF 410, Heidelberg, Germany
| | - Rainer Pepperkok
- European Molecular Biology Laboratory, Advanced Light Microscopy Facility, Heidelberg, Germany
| | - Pavel Janscak
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, CZ-14300 Prague, Czech Republic
- Institute of Molecular Cancer Research, University of Zurich, 8057 Zurich, Switzerland
| | - Peter Nawroth
- Department of Medicine I and Clinical Chemistry, University Hospital of Heidelberg, INF 410, Heidelberg, Germany
- Institute for Immunology, University Hospital of Heidelberg, INF 305, Heidelberg, Germany
- German Center of Diabetes Research (DZD), Neuherberg, Germany
| | - Varun Kumar
- Department of Medicine I and Clinical Chemistry, University Hospital of Heidelberg, INF 410, Heidelberg, Germany
- Institute for Immunology, University Hospital of Heidelberg, INF 305, Heidelberg, Germany
- European Molecular Biology Laboratory, Advanced Light Microscopy Facility, Heidelberg, Germany
- German Center of Diabetes Research (DZD), Neuherberg, Germany
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8
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Fang Q, Hua Z, Lin Z. A protocol to determine the activities of human MUS81-EME1&2 endonucleases. STAR Protoc 2022; 3:101528. [PMID: 35819885 PMCID: PMC9283930 DOI: 10.1016/j.xpro.2022.101528] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 05/17/2022] [Accepted: 06/13/2022] [Indexed: 11/25/2022] Open
Abstract
The human MUS81-EME1&2 complexes are structure-selective endonucleases that play important roles in DNA damage repair. Here, we describe a protocol to determine the endonuclease activities of MUS81-EME1&2 complexes toward various DNA structures. We co-express MUS81 with EME1 or EME2 and purify the complexes with high purity, and determine their activities on the cleavages of 3ˊ flaps, 5ˊ flaps, nicked double-stranded DNAs, and Holliday junctions. This protocol can also be used for the determination of substrate preferences of other structure-selective endonucleases. For complete details on the use and execution of this protocol, please refer to Hua et al. (2022). Expression and purification of human MUS81-EME1&2 complexes Gel-based measurement of the endonuclease activities of MUS81-EME1&2 complexes Quantitative evaluation of the substrate preference of MUS81-EME1&2 endonucleases
Publisher’s note: Undertaking any experimental protocol requires adherence to local institutional guidelines for laboratory safety and ethics.
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Affiliation(s)
- Qianqian Fang
- College of Chemistry, Fuzhou University, Fuzhou 350108, China
| | - Zhengkang Hua
- College of Chemistry, Fuzhou University, Fuzhou 350108, China
| | - Zhonghui Lin
- College of Chemistry, Fuzhou University, Fuzhou 350108, China.
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9
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Expression of MUS81 Mediates the Sensitivity of Castration-Resistant Prostate Cancer to Olaparib. J Immunol Res 2022; 2022:4065580. [PMID: 35910852 PMCID: PMC9334051 DOI: 10.1155/2022/4065580] [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: 03/08/2022] [Revised: 03/24/2022] [Accepted: 04/12/2022] [Indexed: 11/18/2022] Open
Abstract
This project attempts to clarify the expression of MUS81 in castration-resistant prostate cancer (CRPC) and the effect on drug sensitivity to Olaparib. We collected clinical surgical samples of patients who were suffering from benign prostatic hyperplasia (BPH), common prostate cancer (PCa), and castration-resistant prostate cancer (CRPC) and detected the expression of MUS81 in healthy prostate epithelial cells, PCa cells, and androgen-independent PCa cells. We subsequently performed CCK-8 assays, flow cytometry, and Transwell invasion and migration assay to determine the proliferation, apoptosis, invasion, and metastasis abilities of transfected CRPC cells as well as drug toxicity of Olaparib to CRPC cells. The expression of MUS81 indicated marked upregulation in PCa and CRPC tissues, compared with the level of MUS81 in BPH tissues. MUS81 silencing inhibited the proliferation of CRPC cells and promoted their sensitivity to Olaparib. MUS81 silencing in CRPC cells remarkably accelerated cell apoptosis and greatly inhibited cell invasion and metastasis after Olaparib administration. MUS81 silencing in CRPC cells has significantly enhanced the sensitivity of cells to Olaparib, which provides evidence for the prediction of Olaparib resistance in CRPC cells by the MUS81 gene and is expected to become a promising gene target in CRPC therapy.
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Hua Z, Fang Q, Zhang D, Luo Z, Yuan C, Lin Z. Crystal structure of the human MUS81-EME2 complex. Structure 2022; 30:743-752.e3. [DOI: 10.1016/j.str.2022.02.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2021] [Revised: 01/27/2022] [Accepted: 02/16/2022] [Indexed: 10/18/2022]
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Nickoloff JA, Sharma N, Taylor L, Allen SJ, Hromas R. Nucleases and Co-Factors in DNA Replication Stress Responses. DNA 2022; 2:68-85. [PMID: 36203968 PMCID: PMC9534323 DOI: 10.3390/dna2010006] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
DNA replication stress is a constant threat that cells must manage to proliferate and maintain genome integrity. DNA replication stress responses, a subset of the broader DNA damage response (DDR), operate when the DNA replication machinery (replisome) is blocked or replication forks collapse during S phase. There are many sources of replication stress, such as DNA lesions caused by endogenous and exogenous agents including commonly used cancer therapeutics, and difficult-to-replicate DNA sequences comprising fragile sites, G-quadraplex DNA, hairpins at trinucleotide repeats, and telomeres. Replication stress is also a consequence of conflicts between opposing transcription and replication, and oncogenic stress which dysregulates replication origin firing and fork progression. Cells initially respond to replication stress by protecting blocked replisomes, but if the offending problem (e.g., DNA damage) is not bypassed or resolved in a timely manner, forks may be cleaved by nucleases, inducing a DNA double-strand break (DSB) and providing a means to accurately restart stalled forks via homologous recombination. However, DSBs pose their own risks to genome stability if left unrepaired or misrepaired. Here we focus on replication stress response systems, comprising DDR signaling, fork protection, and fork processing by nucleases that promote fork repair and restart. Replication stress nucleases include MUS81, EEPD1, Metnase, CtIP, MRE11, EXO1, DNA2-BLM, SLX1-SLX4, XPF-ERCC1-SLX4, Artemis, XPG, and FEN1. Replication stress factors are important in cancer etiology as suppressors of genome instability associated with oncogenic mutations, and as potential cancer therapy targets to enhance the efficacy of chemo- and radiotherapeutics.
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Affiliation(s)
- Jac A. Nickoloff
- Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, CO 80523, USA
| | - Neelam Sharma
- Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, CO 80523, USA
| | - Lynn Taylor
- Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, CO 80523, USA
| | - Sage J. Allen
- Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, CO 80523, USA
| | - Robert Hromas
- Division of Hematology and Medical Oncology, Department of Medicine and the Mays Cancer Center, University of Texas Health Science Center, San Antonio, TX 78229, USA
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12
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Lappin KM, Barros EM, Jhujh SS, Irwin GW, McMillan H, Liberante FG, Latimer C, LaBonte MJ, Mills KI, Harkin DP, Stewart GS, Savage KI. CANCER-ASSOCIATED SF3B1 MUTATIONS CONFER A BRCA-LIKE CELLULAR PHENOTYPE AND SYNTHETIC LETHALITY TO PARP INHIBITORS. Cancer Res 2022; 82:819-830. [DOI: 10.1158/0008-5472.can-21-1843] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 11/12/2021] [Accepted: 12/27/2021] [Indexed: 11/16/2022]
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Targeting MUS81 promotes the anticancer effect of WEE1 inhibitor and immune checkpoint blocking combination therapy via activating cGAS/STING signaling in gastric cancer cells. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2021; 40:315. [PMID: 34625086 PMCID: PMC8501558 DOI: 10.1186/s13046-021-02120-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Accepted: 09/27/2021] [Indexed: 12/14/2022]
Abstract
Background Identification of genomic biomarkers to predict the anticancer effects of indicated drugs is considered a promising strategy for the development of precision medicine. DNA endonuclease MUS81 plays a pivotal role in various biological processes during malignant diseases, mainly in DNA damage repair and replication fork stability. Our previous study reported that MUS81 was highly expressed and linked to tumor metastasis in gastric cancer; however, its therapeutic value has not been fully elucidated. Methods Bioinformatics analysis was used to define MUS81-related differential genes, which were further validated in clinical tissue samples. Gain or loss of function MUS81 cell models were constructed to elucidate the effect and mechanism of MUS81 on WEE1 expression. Moreover, the antitumor effect of targeting MUS81 combined with WEE1 inhibitors was verified using in vivo and in vitro assays. Thereafter, the cGAS/STING pathway was evaluated, and the therapeutic value of MUS81 for immunotherapy of gastric cancer was determined. Results In this study, MUS81 negatively correlated with the expression of cell cycle checkpoint kinase WEE1. Furthermore, we identified that MUS81 regulated the ubiquitination of WEE1 via E-3 ligase β-TRCP in an enzymatic manner. In addition, MUS81 inhibition could sensitize the anticancer effect of the WEE1 inhibitor MK1775 in gastric cancer in vitro and in vivo. Interestingly, when MUS81 was targeted, it increased the accumulation of cytosolic DNA induced by MK1775 treatment and activated the DNA sensor STING-mediated innate immunity in the gastric cancer cells. Thus, the WEE1 inhibitor MK1775 specifically enhanced the anticancer effect of immune checkpoint blockade therapy in MUS81 deficient gastric cancer cells. Conclusions Our data provide rational evidence that targeting MUS81 could elevate the expression of WEE1 by regulating its ubiquitination and could activate the innate immune response, thereby enhancing the anticancer efficacy of WEE1 inhibitor and immune checkpoint blockade combination therapy in gastric cancer cells. Supplementary Information The online version contains supplementary material available at 10.1186/s13046-021-02120-4.
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González-Acosta D, Blanco-Romero E, Ubieto-Capella P, Mutreja K, Míguez S, Llanos S, García F, Muñoz J, Blanco L, Lopes M, Méndez J. PrimPol-mediated repriming facilitates replication traverse of DNA interstrand crosslinks. EMBO J 2021; 40:e106355. [PMID: 34128550 PMCID: PMC8280817 DOI: 10.15252/embj.2020106355] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 05/04/2021] [Accepted: 05/04/2021] [Indexed: 12/22/2022] Open
Abstract
DNA interstrand crosslinks (ICLs) induced by endogenous aldehydes or chemotherapeutic agents interfere with essential processes such as replication and transcription. ICL recognition and repair by the Fanconi Anemia pathway require the formation of an X‐shaped DNA structure that may arise from convergence of two replication forks at the crosslink or traversing of the lesion by a single replication fork. Here, we report that ICL traverse strictly requires DNA repriming events downstream of the lesion, which are carried out by PrimPol, the second primase‐polymerase identified in mammalian cells after Polα/Primase. The recruitment of PrimPol to the vicinity of ICLs depends on its interaction with RPA, but not on FANCM translocase or the BLM/TOP3A/RMI1‐2 (BTR) complex that also participate in ICL traverse. Genetic ablation of PRIMPOL makes cells more dependent on the fork convergence mechanism to initiate ICL repair, and PRIMPOL KO cells and mice display hypersensitivity to ICL‐inducing drugs. These results open the possibility of targeting PrimPol activity to enhance the efficacy of chemotherapy based on DNA crosslinking agents.
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Affiliation(s)
- Daniel González-Acosta
- DNA Replication Group, Molecular Oncology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Elena Blanco-Romero
- DNA Replication Group, Molecular Oncology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Patricia Ubieto-Capella
- DNA Replication Group, Molecular Oncology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Karun Mutreja
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Samuel Míguez
- DNA Replication Group, Molecular Oncology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Susana Llanos
- DNA Replication Group, Molecular Oncology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Fernando García
- Proteomics Unit-ProteoRed-ISCIII, Biotechnology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Javier Muñoz
- Proteomics Unit-ProteoRed-ISCIII, Biotechnology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Luis Blanco
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Madrid, Spain
| | - Massimo Lopes
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Juan Méndez
- DNA Replication Group, Molecular Oncology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
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15
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Mouse Models for Deciphering the Impact of Homologous Recombination on Tumorigenesis. Cancers (Basel) 2021; 13:cancers13092083. [PMID: 33923105 PMCID: PMC8123484 DOI: 10.3390/cancers13092083] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 04/19/2021] [Accepted: 04/20/2021] [Indexed: 12/15/2022] Open
Abstract
Homologous recombination (HR) is a fundamental evolutionarily conserved process that plays prime role(s) in genome stability maintenance through DNA repair and through the protection and resumption of arrested replication forks. Many HR genes are deregulated in cancer cells. Notably, the breast cancer genes BRCA1 and BRCA2, two important HR players, are the most frequently mutated genes in familial breast and ovarian cancer. Transgenic mice constitute powerful tools to unravel the intricate mechanisms controlling tumorigenesis in vivo. However, the genes central to HR are essential in mammals, and their knockout leads to early embryonic lethality in mice. Elaborated strategies have been developed to overcome this difficulty, enabling one to analyze the consequences of HR disruption in vivo. In this review, we first briefly present the molecular mechanisms of HR in mammalian cells to introduce each factor in the HR process. Then, we present the different mouse models of HR invalidation and the consequences of HR inactivation on tumorigenesis. Finally, we discuss the use of mouse models for the development of targeted cancer therapies as well as perspectives on the future potential for understanding the mechanisms of HR inactivation-driven tumorigenesis in vivo.
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Young SJ, West SC. Coordinated roles of SLX4 and MutSβ in DNA repair and the maintenance of genome stability. Crit Rev Biochem Mol Biol 2021; 56:157-177. [PMID: 33596761 PMCID: PMC7610648 DOI: 10.1080/10409238.2021.1881433] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 01/06/2021] [Accepted: 01/22/2021] [Indexed: 12/14/2022]
Abstract
SLX4 provides a molecular scaffold for the assembly of multiple protein complexes required for the maintenance of genome stability. It is involved in the repair of DNA crosslinks, the resolution of recombination intermediates, the response to replication stress and the maintenance of telomere length. To carry out these diverse functions, SLX4 interacts with three structure-selective endonucleases, MUS81-EME1, SLX1 and XPF-ERCC1, as well as the telomere binding proteins TRF2, RTEL1 and SLX4IP. Recently, SLX4 was shown to interact with MutSβ, a heterodimeric protein involved in DNA mismatch repair, trinucleotide repeat instability, crosslink repair and recombination. Importantly, MutSβ promotes the pathogenic expansion of CAG/CTG trinucleotide repeats, which is causative of myotonic dystrophy and Huntington's disease. The colocalization and specific interaction of MutSβ with SLX4, together with their apparently overlapping functions, are suggestive of a common role in reactions that promote DNA maintenance and genome stability. This review will focus on the role of SLX4 in DNA repair, the interplay between MutSβ and SLX4, and detail how they cooperate to promote recombinational repair and DNA crosslink repair. Furthermore, we speculate that MutSβ and SLX4 may provide an alternative cellular mechanism that modulates trinucleotide instability.
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Affiliation(s)
- Sarah J Young
- DNA Recombination and Repair Laboratory, The Francis Crick Institute, London, UK
| | - Stephen C West
- DNA Recombination and Repair Laboratory, The Francis Crick Institute, London, UK
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17
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Chen S, Geng X, Syeda MZ, Huang Z, Zhang C, Ying S. Human MUS81: A Fence-Sitter in Cancer. Front Cell Dev Biol 2021; 9:657305. [PMID: 33791310 PMCID: PMC8005573 DOI: 10.3389/fcell.2021.657305] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 02/10/2021] [Indexed: 12/21/2022] Open
Abstract
MUS81 complex, exhibiting endonuclease activity on specific DNA structures, plays an influential part in DNA repair. Research has proved that MUS81 is dispensable for embryonic development and cell viability in mammals. However, an intricate picture has emerged from studies in which discrepant gene mutations completely alter the role of MUS81 in human cancers. Here, we review the recent understanding of how MUS81 functions in tumors with distinct genetic backgrounds and discuss the potential therapeutic strategies targeting MUS81 in cancer.
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Affiliation(s)
- Sisi Chen
- International Institutes of Medicine, The Fourth Affiliated Hospital of Zhejiang University School of Medicine, Yiwu, China.,Key Laboratory of Respiratory Disease of Zhejiang Province, Department of Pharmacology and Department of Respiratory and Critical Care Medicine of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Xinwei Geng
- Key Laboratory of Respiratory Disease of Zhejiang Province, Department of Pharmacology and Department of Respiratory and Critical Care Medicine of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Madiha Zahra Syeda
- Key Laboratory of Respiratory Disease of Zhejiang Province, Department of Pharmacology and Department of Respiratory and Critical Care Medicine of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Zhengming Huang
- Key Laboratory of Respiratory Disease of Zhejiang Province, Department of Pharmacology and Department of Respiratory and Critical Care Medicine of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Chao Zhang
- Key Laboratory of Respiratory Disease of Zhejiang Province, Department of Pharmacology and Department of Respiratory and Critical Care Medicine of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Songmin Ying
- International Institutes of Medicine, The Fourth Affiliated Hospital of Zhejiang University School of Medicine, Yiwu, China.,Key Laboratory of Respiratory Disease of Zhejiang Province, Department of Pharmacology and Department of Respiratory and Critical Care Medicine of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
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18
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Han Y, Zhao Y, Wang H, Zhang Y, Ding Q, Ma L. Identification of ceRNA and candidate genes related to fertility conversion of TCMS line YS3038 in wheat. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2021; 158:190-207. [PMID: 33214039 DOI: 10.1016/j.plaphy.2020.10.037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 10/28/2020] [Indexed: 06/11/2023]
Abstract
Previous studies have indicated that noncoding RNAs are important factors in gene functions. To explore the mechanism of male sterility of YS3038, the sterile genes were mapped, and based on previous work, the expression of long noncoding RNAs (lncRNAs), circular RNAs (circRNAs), and their target genes was studied. Weighted gene coexpression network analysis (WGCNA) and competitive endogenous RNA (ceRNA) analysis were further performed for differentially expressed noncoding RNAs and target genes. At last, the candidate genes were silenced by barley stripe mosaic virus-induced gene silencing (BSMV-VIGS) to prove their function. The sterile genes were mapped on chromosomes 1B and 6B based on chip mix pool analysis, and one major effect QTL (27.3190% variation) was found based on SSR primers. The WGCNA analysis revealed that the dark turquoise and steel blue modules were highly correlated with anther development and fertility conversion, respectively. The ceRNA analysis showed that a total of 184 RNAs interacted with each other, including 115 mRNAs, 55 microRNAs (miRNAs), eight circRNAs, and six lncRNAs. Finally, the seed setting rate of the plant was significantly decreased after fatty acyl-CoA reductase 5 silencing. This study provides breeders with a new option for the development of thermosensitive cytoplasmic male-sterile (TCMS) wheat lines, which will favor the sustainable development of two-line hybrid wheat.
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Affiliation(s)
- Yucui Han
- College of Agronomy, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Yue Zhao
- College of Agronomy, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Hairong Wang
- College of Agronomy, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Yiyang Zhang
- College of Agronomy, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Qin Ding
- College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China.
| | - Lingjian Ma
- College of Agronomy, Northwest A&F University, Yangling, Shaanxi, 712100, China.
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19
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Rickman KA, Noonan RJ, Lach FP, Sridhar S, Wang AT, Abhyankar A, Huang A, Kelly M, Auerbach AD, Smogorzewska A. Distinct roles of BRCA2 in replication fork protection in response to hydroxyurea and DNA interstrand cross-links. Genes Dev 2020; 34:832-846. [PMID: 32354836 PMCID: PMC7263144 DOI: 10.1101/gad.336446.120] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 04/01/2020] [Indexed: 02/07/2023]
Abstract
DNA interstrand cross-links (ICLs) are a form of DNA damage that requires the interplay of a number of repair proteins including those of the Fanconi anemia (FA) and the homologous recombination (HR) pathways. Pathogenic variants in the essential gene BRCA2/FANCD1, when monoallelic, predispose to breast and ovarian cancer, and when biallelic, result in a severe subtype of Fanconi anemia. BRCA2 function in the FA pathway is attributed to its role as a mediator of the RAD51 recombinase in HR repair of programmed DNA double-strand breaks (DSB). BRCA2 and RAD51 functions are also required to protect stalled replication forks from nucleolytic degradation during response to hydroxyurea (HU). While RAD51 has been shown to be necessary in the early steps of ICL repair to prevent aberrant nuclease resection, the role of BRCA2 in this process has not been described. Here, based on the analysis of BRCA2 DNA-binding domain (DBD) mutants (c.8488-1G>A and c.8524C>T) discovered in FA patients presenting with atypical FA-like phenotypes, we establish that BRCA2 is necessary for the protection of DNA at ICLs. Cells carrying BRCA2 DBD mutations are sensitive to ICL-inducing agents but resistant to HU treatment consistent with relatively high HR repair in these cells. BRCA2 function at an ICL protects against DNA2-WRN nuclease-helicase complex and not the MRE11 nuclease that is implicated in the resection of HU-induced stalled replication forks. Our results also indicate that unlike the processing at HU-induced stalled forks, the function of the SNF2 translocases (SMARCAL1, ZRANB3, or HLTF), implicated in fork reversal, are not an integral component of the ICL repair, pointing to a different mechanism of fork protection at different DNA lesions.
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Affiliation(s)
- Kimberly A Rickman
- Laboratory of Genome Maintenance, The Rockefeller University, New York, New York 10065, USA
| | - Raymond J Noonan
- Laboratory of Genome Maintenance, The Rockefeller University, New York, New York 10065, USA
| | - Francis P Lach
- Laboratory of Genome Maintenance, The Rockefeller University, New York, New York 10065, USA
| | - Sunandini Sridhar
- Laboratory of Genome Maintenance, The Rockefeller University, New York, New York 10065, USA
| | - Anderson T Wang
- Laboratory of Genome Maintenance, The Rockefeller University, New York, New York 10065, USA
| | | | - Athena Huang
- Laboratory of Genome Maintenance, The Rockefeller University, New York, New York 10065, USA
| | - Michael Kelly
- Tufts Medical Center, Boston, Massachusetts 02111, USA
| | - Arleen D Auerbach
- Human Genetics and Hematology, The Rockefeller University, New York, New York 10065, USA
| | - Agata Smogorzewska
- Laboratory of Genome Maintenance, The Rockefeller University, New York, New York 10065, USA
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20
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Saccharomyces cerevisiae Mus81-Mms4 prevents accelerated senescence in telomerase-deficient cells. PLoS Genet 2020; 16:e1008816. [PMID: 32469862 PMCID: PMC7286520 DOI: 10.1371/journal.pgen.1008816] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 06/10/2020] [Accepted: 04/30/2020] [Indexed: 01/31/2023] Open
Abstract
Alternative lengthening of telomeres (ALT) in human cells is a conserved process that is often activated in telomerase-deficient human cancers. This process exploits components of the recombination machinery to extend telomere ends, thus allowing for increased proliferative potential. Human MUS81 (Mus81 in Saccharomyces cerevisiae) is the catalytic subunit of structure-selective endonucleases involved in recombination and has been implicated in the ALT mechanism. However, it is unclear whether MUS81 activity at the telomere is specific to ALT cells or if it is required for more general aspects of telomere stability. In this study, we use S. cerevisiae to evaluate the contribution of the conserved Mus81-Mms4 endonuclease in telomerase-deficient yeast cells that maintain their telomeres by mechanisms akin to human ALT. Similar to human cells, we find that yeast Mus81 readily localizes to telomeres and its activity is important for viability after initial loss of telomerase. Interestingly, our analysis reveals that yeast Mus81 is not required for the survival of cells undergoing recombination-mediated telomere lengthening, i.e. for ALT itself. Rather we infer from genetic analysis that Mus81-Mms4 facilitates telomere replication during times of telomere instability. Furthermore, combining mus81 mutants with mutants of a yeast telomere replication factor, Rrm3, reveals that the two proteins function in parallel to promote normal growth during times of telomere stress. Combined with previous reports, our data can be interpreted in a consistent model in which both yeast and human MUS81-dependent nucleases participate in the recovery of stalled replication forks within telomeric DNA. Furthermore, this process becomes crucial under conditions of additional replication stress, such as telomere replication in telomerase-deficient cells. Cancer cell divisions require active chromosome lengthening through extension of their highly repetitive ends, called telomeres. This process is accomplished through two main mechanisms: the activity of an RNA-protein complex, telomerase, or through a telomerase-independent process termed alternative lengthening of telomeres (ALT). Human MUS81, the catalytic subunit of a set of structure-selective endonucleases, was found to be essential in human cells undergoing ALT and proposed to be directly involved in telomere lengthening. Using telomerase-deficient Saccharomyces cerevisiae cells as a model for ALT, we tested the hypothesis that Mus81-Mms4, the budding yeast homolog of human MUS81-dependent nucleases, is essential for telomere lengthening as proposed for human cells. Using genetic and molecular assays we confirm that Mus81-Mms4 is involved in telomere metabolism in yeast. However, to our surprise, we find that Mus81-Mms4 is not directly involved in recombination-based mechanisms of telomere lengthening. Rather it appears that Mus81-Mms4 is involved in resolving replication stress at telomeres, which is augmented in cells undergoing telomere instability. This model is consistent with observations in mammalian cells and suggest that cells undergoing telomere shortening experience replication stress at telomeres.
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21
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Yin Y, Liu W, Shen Q, Zhang P, Wang L, Tao R, Li H, Ma X, Zeng X, Cheong JH, Song S, Ajani JA, Mills GB, Tao K, Peng G. The DNA Endonuclease Mus81 Regulates ZEB1 Expression and Serves as a Target of BET4 Inhibitors in Gastric Cancer. Mol Cancer Ther 2019; 18:1439-1450. [PMID: 31142662 DOI: 10.1158/1535-7163.mct-18-0833] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 01/09/2019] [Accepted: 05/16/2019] [Indexed: 02/07/2023]
Abstract
DNA replication and repair proteins play an important role in cancer initiation and progression by affecting genomic instability. The DNA endonuclease Mus81 is a DNA structure-specific endonuclease, which has been implicated in DNA replication and repair. In this study, we found that Mus81 promotes gastric metastasis by controlling the transcription of ZEB1, a master regulator of the epithelial-mesenchymal transition (EMT). Our results revealed that Mus81 is highly expressed in gastric cancer samples from patients and cell lines compared with their normal counterparts. Particularly, Mus81 expression positively correlated with ZEB1 expression and Mus81 overexpression was significantly associated with higher incidence of lymph node metastasis in patients. Furthermore, Mus81 promoted migration of gastric cancer cells both in vitro and in vivo We conducted a drug screen using a collection of preclinical and FDA-approved drugs and found that the BRD4 inhibitor AZD5153 inhibited the expression of Mus81 and ZEB1 by regulating the epigenetic factor Sirt5. As expected, AZD5153 treatment significantly reduced the migration of gastric cancer cells overexpressing Mus81 in vitro and in vivo Collectively, we show that Mus81 is a regulator of ZEB1 and promotes metastasis in gastric cancer. Importantly, we demonstrate that the BRD4 inhibitor AZD5153 can potentially be used as an effective antimetastasis drug because of its effect on Mus81.
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Affiliation(s)
- Yuping Yin
- Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Weizhen Liu
- Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Qian Shen
- Department of Oncology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Peng Zhang
- Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Lulu Wang
- Department of Clinical Cancer Prevention, the University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Ruikang Tao
- Center for Biomolecular Science and Engineering, University of California Santa Cruz, Santa Cruz, California
| | - Hang Li
- Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xianxiong Ma
- Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiangyu Zeng
- Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jae-Ho Cheong
- Institute for Personalized Cancer Therapy, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, South Korea
| | - Shumei Song
- Department of Gastrointestinal Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Jaffer A Ajani
- Department of Gastrointestinal Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Gordon B Mills
- Department of Precision Oncology, Oregon Health & Science University Knight Cancer Institute, Portland, Oregon
| | - Kaixiong Tao
- Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| | - Guang Peng
- Department of Clinical Cancer Prevention, the University of Texas MD Anderson Cancer Center, Houston, Texas.
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Abstract
The SLX4/FANCP tumor suppressor has emerged as a key player in the maintenance of genome stability, making pivotal contributions to the repair of interstrand cross-links, homologous recombination, and in response to replication stress genome-wide as well as at specific loci such as common fragile sites and telomeres. SLX4 does so in part by acting as a scaffold that controls and coordinates the XPF-ERCC1, MUS81-EME1, and SLX1 structure-specific endonucleases in different DNA repair and recombination mechanisms. It also interacts with other important DNA repair and cell cycle control factors including MSH2, PLK1, TRF2, and TOPBP1 as well as with ubiquitin and SUMO. This review aims at providing an up-to-date and comprehensive view on the key functions that SLX4 fulfills to maintain genome stability as well as to highlight and discuss areas of uncertainty and emerging concepts.
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Affiliation(s)
- Jean-Hugues Guervilly
- a CRCM, CNRS, INSERM, Aix Marseille Univ, Institut Paoli-Calmettes , Marseille , France
| | - Pierre Henri Gaillard
- a CRCM, CNRS, INSERM, Aix Marseille Univ, Institut Paoli-Calmettes , Marseille , France
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23
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Fujii N. Potential Strategies to Target Protein-Protein Interactions in the DNA Damage Response and Repair Pathways. J Med Chem 2017; 60:9932-9959. [PMID: 28654754 DOI: 10.1021/acs.jmedchem.7b00358] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This review article discusses some insights about generating novel mechanistic inhibitors of the DNA damage response and repair (DDR) pathways by focusing on protein-protein interactions (PPIs) of the key DDR components. General requirements for PPI strategies, such as selecting the target PPI site on the basis of its functionality, are discussed first. Next, on the basis of functional rationale and biochemical feasibility to identify a PPI inhibitor, 26 PPIs in DDR pathways (BER, MMR, NER, NHEJ, HR, TLS, and ICL repair) are specifically discussed for inhibitor discovery to benefit cancer therapies using a DNA-damaging agent.
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Affiliation(s)
- Naoaki Fujii
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital , 262 Danny Thomas Place, MS1000, Memphis, Tennessee 38105, United States
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24
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Bellendir SP, Rognstad DJ, Morris LP, Zapotoczny G, Walton WG, Redinbo MR, Ramsden DA, Sekelsky J, Erie DA. Substrate preference of Gen endonucleases highlights the importance of branched structures as DNA damage repair intermediates. Nucleic Acids Res 2017; 45:5333-5348. [PMID: 28369583 PMCID: PMC5435919 DOI: 10.1093/nar/gkx214] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 02/16/2017] [Accepted: 03/21/2017] [Indexed: 11/20/2022] Open
Abstract
Human GEN1 and yeast Yen1 are endonucleases with the ability to cleave Holliday junctions (HJs), which are proposed intermediates in recombination. In vivo, GEN1 and Yen1 function secondarily to Mus81, which has weak activity on intact HJs. We show that the genetic relationship is reversed in Drosophila, with Gen mutants having more severe defects than mus81 mutants. In vitro, DmGen, like HsGEN1, efficiently cleaves HJs, 5΄ flaps, splayed arms, and replication fork structures. We find that the cleavage rates for 5΄ flaps are significantly higher than those for HJs for both DmGen and HsGEN1, even in vast excess of enzyme over substrate. Kinetic studies suggest that the difference in cleavage rates results from a slow, rate-limiting conformational change prior to HJ cleavage: formation of a productive dimer on the HJ. Despite the stark difference in vivo that Drosophila uses Gen over Mus81 and humans use MUS81 over GEN1, we find the in vitro activities of DmGen and HsGEN1 to be strikingly similar. These findings suggest that simpler branched structures may be more important substrates for Gen orthologs in vivo, and highlight the utility of using the Drosophila model system to further understand these enzymes.
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Affiliation(s)
| | | | - Lydia P. Morris
- Lineberger Comprehensive Cancer Center, Chapel Hill, NC 27599, USA
| | | | | | - Matthew R. Redinbo
- Department of Chemistry, Chapel Hill, NC 27599, USA
- Integrative Program for Biological and Genome Sciences, Chapel Hill, NC 27599, USA
| | - Dale A. Ramsden
- Curriculum in Genetics and Molecular Biology, Chapel Hill, NC 27599, USA
- Lineberger Comprehensive Cancer Center, Chapel Hill, NC 27599, USA
- Department of Biochemistry and Biophysics, Chapel Hill, NC 27599, USA
| | - Jeff Sekelsky
- Curriculum in Genetics and Molecular Biology, Chapel Hill, NC 27599, USA
- Lineberger Comprehensive Cancer Center, Chapel Hill, NC 27599, USA
- Integrative Program for Biological and Genome Sciences, Chapel Hill, NC 27599, USA
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Dorothy A. Erie
- Department of Chemistry, Chapel Hill, NC 27599, USA
- Integrative Program for Biological and Genome Sciences, Chapel Hill, NC 27599, USA
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25
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Dehé PM, Gaillard PHL. Control of structure-specific endonucleases to maintain genome stability. Nat Rev Mol Cell Biol 2017; 18:315-330. [PMID: 28327556 DOI: 10.1038/nrm.2016.177] [Citation(s) in RCA: 116] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Structure-specific endonucleases (SSEs) have key roles in DNA replication, recombination and repair, and emerging roles in transcription. These enzymes have specificity for DNA secondary structure rather than for sequence, and therefore their activity must be precisely controlled to ensure genome stability. In this Review, we discuss how SSEs are controlled as part of genome maintenance pathways in eukaryotes, with an emphasis on the elaborate mechanisms that regulate the members of the major SSE families - including the xeroderma pigmentosum group F-complementing protein (XPF) and MMS and UV-sensitive protein 81 (MUS81)-dependent nucleases, and the flap endonuclease 1 (FEN1), XPG and XPG-like endonuclease 1 (GEN1) enzymes - during processes such as DNA adduct repair, Holliday junction processing and replication stress. We also discuss newly characterized connections between SSEs and other classes of DNA-remodelling enzymes and cell cycle control machineries, which reveal the importance of SSE scaffolds such as the synthetic lethal of unknown function 4 (SLX4) tumour suppressor for the maintenance of genome stability.
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Affiliation(s)
- Pierre-Marie Dehé
- Centre de Recherche en Cancérologie de Marseille, CRCM, CNRS, Aix Marseille Université, INSERM, Institut Paoli-Calmettes, 27 Boulevard Leï Roure, 13009 Marseille, France
| | - Pierre-Henri L Gaillard
- Centre de Recherche en Cancérologie de Marseille, CRCM, CNRS, Aix Marseille Université, INSERM, Institut Paoli-Calmettes, 27 Boulevard Leï Roure, 13009 Marseille, France
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26
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Wyatt HDM, Laister RC, Martin SR, Arrowsmith CH, West SC. The SMX DNA Repair Tri-nuclease. Mol Cell 2017; 65:848-860.e11. [PMID: 28257701 PMCID: PMC5344696 DOI: 10.1016/j.molcel.2017.01.031] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Revised: 01/17/2017] [Accepted: 01/25/2017] [Indexed: 01/13/2023]
Abstract
The efficient removal of replication and recombination intermediates is essential for the maintenance of genome stability. Resolution of these potentially toxic structures requires the MUS81-EME1 endonuclease, which is activated at prometaphase by formation of the SMX tri-nuclease containing three DNA repair structure-selective endonucleases: SLX1-SLX4, MUS81-EME1, and XPF-ERCC1. Here we show that SMX tri-nuclease is more active than the three individual nucleases, efficiently cleaving replication forks and recombination intermediates. Within SMX, SLX4 co-ordinates the SLX1 and MUS81-EME1 nucleases for Holliday junction resolution, in a reaction stimulated by XPF-ERCC1. SMX formation activates MUS81-EME1 for replication fork and flap structure cleavage by relaxing substrate specificity. Activation involves MUS81's conserved N-terminal HhH domain, which mediates incision site selection and SLX4 binding. Cell cycle-dependent formation and activation of this tri-nuclease complex provides a unique mechanism by which cells ensure chromosome segregation and preserve genome integrity.
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Affiliation(s)
- Haley D M Wyatt
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Rob C Laister
- Princess Margaret Cancer Centre and Department of Medical Biophysics, University of Toronto, 101 College Street, Toronto, ON M5G 1L7, Canada
| | - Stephen R Martin
- Structural Biology Science Technology Platform, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Cheryl H Arrowsmith
- Princess Margaret Cancer Centre and Department of Medical Biophysics, University of Toronto, 101 College Street, Toronto, ON M5G 1L7, Canada
| | - Stephen C West
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK.
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27
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Onaka AT, Toyofuku N, Inoue T, Okita AK, Sagawa M, Su J, Shitanda T, Matsuyama R, Zafar F, Takahashi TS, Masukata H, Nakagawa T. Rad51 and Rad54 promote noncrossover recombination between centromere repeats on the same chromatid to prevent isochromosome formation. Nucleic Acids Res 2016; 44:10744-10757. [PMID: 27697832 PMCID: PMC5159554 DOI: 10.1093/nar/gkw874] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 09/06/2016] [Accepted: 09/21/2016] [Indexed: 12/14/2022] Open
Abstract
Centromeres consist of DNA repeats in many eukaryotes. Non-allelic homologous recombination (HR) between them can result in gross chromosomal rearrangements (GCRs). In fission yeast, Rad51 suppresses isochromosome formation that occurs between inverted repeats in the centromere. However, how the HR enzyme prevents homology-mediated GCRs remains unclear. Here, we provide evidence that Rad51 with the aid of the Swi/Snf-type motor protein Rad54 promotes non-crossover recombination between centromere repeats to prevent isochromosome formation. Mutations in Rad51 and Rad54 epistatically increased the rates of isochromosome formation and chromosome loss. In sharp contrast, these mutations decreased gene conversion between inverted repeats in the centromere. Remarkably, analysis of recombinant DNAs revealed that rad51 and rad54 increase the proportion of crossovers. In the absence of Rad51, deletion of the structure-specific endonuclease Mus81 decreased both crossovers and isochromosomes, while the cdc27/pol32-D1 mutation, which impairs break-induced replication, did not. We propose that Rad51 and Rad54 promote non-crossover recombination between centromere repeats on the same chromatid, thereby suppressing crossover between non-allelic repeats on sister chromatids that leads to chromosomal rearrangements. Furthermore, we found that Rad51 and Rad54 are required for gene silencing in centromeres, suggesting that HR also plays a role in the structure and function of centromeres.
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Affiliation(s)
- Atsushi T Onaka
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Naoko Toyofuku
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Takahiro Inoue
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Akiko K Okita
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Minami Sagawa
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Jie Su
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Takeshi Shitanda
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Rei Matsuyama
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Faria Zafar
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Tatsuro S Takahashi
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Hisao Masukata
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Takuro Nakagawa
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
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28
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Xing M, Wang X, Palmai-Pallag T, Shen H, Helleday T, Hickson ID, Ying S. Acute MUS81 depletion leads to replication fork slowing and a constitutive DNA damage response. Oncotarget 2016; 6:37638-46. [PMID: 26415217 PMCID: PMC4741954 DOI: 10.18632/oncotarget.5497] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2015] [Accepted: 09/11/2015] [Indexed: 11/25/2022] Open
Abstract
The MUS81 protein belongs to a conserved family of DNA structure-specific nucleases that play important roles in DNA replication and repair. Inactivation of the Mus81 gene in mice has no major deleterious consequences for embryonic development, although cancer susceptibility has been reported. We have investigated the role of MUS81 in human cells by acutely depleting the protein using shRNAs. We found that MUS81 depletion from human fibroblasts leads to accumulation of ssDNA and a constitutive DNA damage response that ultimately activates cellular senescence. Moreover, we show that MUS81 is required for efficient replication fork progression during an unperturbed S-phase, and for recovery of productive replication following replication stalling. These results demonstrate essential roles for the MUS81 nuclease in maintenance of replication fork integrity.
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Affiliation(s)
- Meichun Xing
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou, China
| | - Xiaohui Wang
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou, China
| | | | - Huahao Shen
- Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital, Institute of Respiratory Diseases, Zhejiang University School of Medicine, Hangzhou, China.,State Key Laboratory For Respiratory Diseases, Guangzhou, China
| | - Thomas Helleday
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Ian D Hickson
- Center for Chromosome Stability and Nordea Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Songmin Ying
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou, China.,Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital, Institute of Respiratory Diseases, Zhejiang University School of Medicine, Hangzhou, China
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29
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Xie S, Zheng H, Wen X, Sun J, Wang Y, Gao X, Guo L, Lu R. MUS81 is associated with cell proliferation and cisplatin sensitivity in serous ovarian cancer. Biochem Biophys Res Commun 2016; 476:493-500. [DOI: 10.1016/j.bbrc.2016.05.152] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 05/28/2016] [Indexed: 01/10/2023]
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30
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Thongthip S, Bellani M, Gregg SQ, Sridhar S, Conti BA, Chen Y, Seidman MM, Smogorzewska A. Fan1 deficiency results in DNA interstrand cross-link repair defects, enhanced tissue karyomegaly, and organ dysfunction. Genes Dev 2016; 30:645-59. [PMID: 26980189 PMCID: PMC4803051 DOI: 10.1101/gad.276261.115] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Thongthip et al. describe a FANCD2/FANCI-associated nuclease 1 (Fan1)-deficient mouse and show that FAN1 is required for cellular and organismal resistance to DNA interstrand cross-links. Karyomegaly becomes prominent in the kidneys and livers of Fan1-deficient mice with age, and mice develop liver dysfunction. Deficiency of FANCD2/FANCI-associated nuclease 1 (FAN1) in humans leads to karyomegalic interstitial nephritis (KIN), a rare hereditary kidney disease characterized by chronic renal fibrosis, tubular degeneration, and characteristic polyploid nuclei in multiple tissues. The mechanism of how FAN1 protects cells is largely unknown but is thought to involve FAN1's function in DNA interstrand cross-link (ICL) repair. Here, we describe a Fan1-deficient mouse and show that FAN1 is required for cellular and organismal resistance to ICLs. We show that the ubiquitin-binding zinc finger (UBZ) domain of FAN1, which is needed for interaction with FANCD2, is not required for the initial rapid recruitment of FAN1 to ICLs or for its role in DNA ICL resistance. Epistasis analyses reveal that FAN1 has cross-link repair activities that are independent of the Fanconi anemia proteins and that this activity is redundant with the 5′–3′ exonuclease SNM1A. Karyomegaly becomes prominent in kidneys and livers of Fan1-deficient mice with age, and mice develop liver dysfunction. Treatment of Fan1-deficient mice with ICL-inducing agents results in pronounced thymic and bone marrow hypocellularity and the disappearance of c-kit+ cells. Our results provide insight into the mechanism of FAN1 in ICL repair and demonstrate that the Fan1 mouse model effectively recapitulates the pathological features of human FAN1 deficiency.
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Affiliation(s)
- Supawat Thongthip
- Laboratory of Genome Maintenance, The Rockefeller University, New York, New York 10065, USA
| | - Marina Bellani
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, Maryland 21224, USA
| | - Siobhan Q Gregg
- Laboratory of Genome Maintenance, The Rockefeller University, New York, New York 10065, USA
| | - Sunandini Sridhar
- Laboratory of Genome Maintenance, The Rockefeller University, New York, New York 10065, USA
| | - Brooke A Conti
- Laboratory of Genome Maintenance, The Rockefeller University, New York, New York 10065, USA
| | - Yanglu Chen
- Laboratory of Genome Maintenance, The Rockefeller University, New York, New York 10065, USA
| | - Michael M Seidman
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, Maryland 21224, USA
| | - Agata Smogorzewska
- Laboratory of Genome Maintenance, The Rockefeller University, New York, New York 10065, USA
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31
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Zhou X, DeLucia M, Ahn J. SLX4-SLX1 Protein-independent Down-regulation of MUS81-EME1 Protein by HIV-1 Viral Protein R (Vpr). J Biol Chem 2016; 291:16936-16947. [PMID: 27354282 DOI: 10.1074/jbc.m116.721183] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Indexed: 12/22/2022] Open
Abstract
Evolutionarily conserved structure-selective endonuclease MUS81 forms a complex with EME1 and further associates with another endonuclease SLX4-SLX1 to form a four-subunit complex of MUS81-EME1-SLX4-SLX1, coordinating distinctive biochemical activities of both endonucleases in DNA repair. Viral protein R (Vpr), a highly conserved accessory protein in primate lentiviruses, was previously reported to bind SLX4 to mediate down-regulation of MUS81. However, the detailed mechanism underlying MUS81 down-regulation is unclear. Here, we report that HIV-1 Vpr down-regulates both MUS81 and its cofactor EME1 by hijacking the host CRL4-DCAF1 E3 ubiquitin ligase. Multiple Vpr variants, from HIV-1 and SIV, down-regulate both MUS81 and EME1. Furthermore, a C-terminally truncated Vpr mutant and point mutants R80A and Q65R, all of which lack G2 arrest activity, are able to down-regulate MUS81-EME1, suggesting that Vpr-induced G2 arrest is not correlated with MUS81-EME1 down-regulation. We also show that neither the interaction of MUS81-EME1 with Vpr nor their down-regulation is dependent on SLX4-SLX1. Together, these data provide new insight on a conserved function of Vpr in a host endonuclease down-regulation.
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Affiliation(s)
- Xiaohong Zhou
- From the Department of Structural Biology and Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15260
| | - Maria DeLucia
- From the Department of Structural Biology and Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15260
| | - Jinwoo Ahn
- From the Department of Structural Biology and Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15260
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32
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Braun J, Meixner A, Brachner A, Foisner R. The GIY-YIG Type Endonuclease Ankyrin Repeat and LEM Domain-Containing Protein 1 (ANKLE1) Is Dispensable for Mouse Hematopoiesis. PLoS One 2016; 11:e0152278. [PMID: 27010503 PMCID: PMC4807109 DOI: 10.1371/journal.pone.0152278] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 03/12/2016] [Indexed: 01/01/2023] Open
Abstract
Ankyrin repeat and LEM-domain containing protein 1 (ANKLE1) is a GIY-YIG endonuclease with unknown functions, mainly expressed in mouse hematopoietic tissues. To test its potential role in hematopoiesis we generated Ankle1-deficient mice. Ankle1Δ/Δ mice are viable without any detectable phenotype in hematopoiesis. Neither hematopoietic progenitor cells, myeloid and lymphoid progenitors, nor B and T cell development in bone marrow, spleen and thymus, are affected in Ankle1Δ/Δ-mice. Similarly embryonic stress erythropoiesis in liver and adult erythropoiesis in bone marrow and spleen appear normal. To test whether ANKLE1, like the only other known GIY-YIG endonuclease in mammals, SLX1, may contribute to Holliday junction resolution during DNA repair, Ankle1-deficient cells were exposed to various DNA-damage inducing agents. However, lack of Ankle1 did not affect cell viability and, unlike depletion of Slx1, Ankle1-deficiency did not increase sister chromatid exchange in Bloom helicase-depleted cells. Altogether, we show that lack of Ankle1 does neither affect mouse hematopoiesis nor DNA damage repair in mouse embryonic fibroblasts, indicating a redundant or non-essential function of ANKLE1 in mouse.
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Affiliation(s)
- Juliane Braun
- Max F. Perutz Laboratories (MFPL), Department of Medical Biochemistry, Medical University of Vienna, Vienna Biocenter (VBC), Vienna, Austria
| | - Arabella Meixner
- IMBA-Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria
| | - Andreas Brachner
- Max F. Perutz Laboratories (MFPL), Department of Medical Biochemistry, Medical University of Vienna, Vienna Biocenter (VBC), Vienna, Austria
| | - Roland Foisner
- Max F. Perutz Laboratories (MFPL), Department of Medical Biochemistry, Medical University of Vienna, Vienna Biocenter (VBC), Vienna, Austria
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33
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Ghamrasni SE, Cardoso R, Li L, Guturi KKN, Bjerregaard VA, Liu Y, Venkatesan S, Hande MP, Henderson JT, Sanchez O, Hickson ID, Hakem A, Hakem R. Rad54 and Mus81 cooperation promotes DNA damage repair and restrains chromosome missegregation. Oncogene 2016; 35:4836-45. [PMID: 26876210 DOI: 10.1038/onc.2016.16] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Revised: 11/03/2015] [Accepted: 11/10/2015] [Indexed: 12/18/2022]
Abstract
Rad54 and Mus81 mammalian proteins physically interact and are important for the homologous recombination DNA repair pathway; however, their functional interactions in vivo are poorly defined. Here, we show that combinatorial loss of Rad54 and Mus81 results in hypersensitivity to DNA-damaging agents, defects on both the homologous recombination and non-homologous DNA end joining repair pathways and reduced fertility. We also observed that while Mus81 deficiency diminished the cleavage of common fragile sites, very strikingly, Rad54 loss impaired this cleavage to even a greater extent. The inefficient repair of DNA double-strand breaks (DSBs) in Rad54(-/-)Mus81(-/-) cells was accompanied by elevated levels of chromosome missegregation and cell death. Perhaps as a consequence, tumor incidence in Rad54(-/-)Mus81(-/-) mice remained comparable to that in Mus81(-/-) mice. Our study highlights the importance of the cooperation between Rad54 and Mus81 for mediating DNA DSB repair and restraining chromosome missegregation.
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Affiliation(s)
- S El Ghamrasni
- Department of Medical Biophysics, University of Toronto and Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - R Cardoso
- Department of Medical Biophysics, University of Toronto and Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - L Li
- Department of Medical Biophysics, University of Toronto and Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - K K N Guturi
- Department of Medical Biophysics, University of Toronto and Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - V A Bjerregaard
- Department of Cellular and Molecular Medicine, Center for Chromosome Stability and Center for Healthy Ageing, University of Copenhagen, Panum Institute, Copenhagen, Denmark
| | - Y Liu
- Department of Cellular and Molecular Medicine, Center for Chromosome Stability and Center for Healthy Ageing, University of Copenhagen, Panum Institute, Copenhagen, Denmark
| | - S Venkatesan
- Department of Physiology, Yong Loo Lin School of Medicine and Tembusu College, National University of Singapore, Singapore
| | - M P Hande
- Department of Physiology, Yong Loo Lin School of Medicine and Tembusu College, National University of Singapore, Singapore
| | - J T Henderson
- Department of Pharmaceutical Sciences, Division of Biomolecular Science, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - O Sanchez
- Department of pathology, University of Ontario Institute of Technology, Oshawa, Ontario, Canada
| | - I D Hickson
- Department of Cellular and Molecular Medicine, Center for Chromosome Stability and Center for Healthy Ageing, University of Copenhagen, Panum Institute, Copenhagen, Denmark
| | - A Hakem
- Department of Medical Biophysics, University of Toronto and Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - R Hakem
- Department of Medical Biophysics, University of Toronto and Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
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34
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Liu Q, Underwood TSA, Kung J, Wang M, Lu HM, Paganetti H, Held KD, Hong TS, Efstathiou JA, Willers H. Disruption of SLX4-MUS81 Function Increases the Relative Biological Effectiveness of Proton Radiation. Int J Radiat Oncol Biol Phys 2016; 95:78-85. [PMID: 27084631 DOI: 10.1016/j.ijrobp.2016.01.046] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Revised: 11/20/2015] [Accepted: 01/25/2016] [Indexed: 12/25/2022]
Abstract
PURPOSE Clinical proton beam therapy has been based on the use of a generic relative biological effectiveness (RBE) of ∼1.1. However, emerging data have suggested that Fanconi anemia (FA) and homologous recombination pathway defects can lead to a variable RBE, at least in vitro. We investigated the role of SLX4 (FANCP), which acts as a docking platform for the assembly of multiple structure-specific endonucleases, in the response to proton irradiation. METHODS AND MATERIALS Isogenic cell pairs for the study of SLX4, XPF/ERCC1, MUS81, and SLX1 were irradiated at the mid-spread-out Bragg peak of a clinical proton beam (linear energy transfer 2.5 keV/μm) or with 250 kVp x-rays, and the clonogenic survival fractions were determined. To estimate the RBE of the protons relative to cobalt-60 photons (Co60Eq), we assigned a RBE(Co60Eq) of 1.1 to x-rays to correct the physical dose measured. Standard DNA repair foci assays were used to monitor the damage responses, and the cell cycle distributions were assessed by flow cytometry. The poly(ADP-ribose) polymerase inhibitor olaparib was used for comparison. RESULTS Loss of SLX4 function resulted in an enhanced proton RBE(Co60Eq) of 1.42 compared with 1.11 for wild-type cells (at a survival fraction of 0.1; P<.05), which correlated with increased persistent DNA double-strand breaks in cells in the S/G2 phase. Genetic analysis identified the SLX4-binding partner MUS81 as a mediator of resistance to proton radiation. Both proton irradiation and olaparib treatment resulted in a similar prolonged accumulation of RAD51 foci in SLX4/MUS81-deficient cells, suggesting a common defect in the repair of DNA replication fork-associated damage. CONCLUSIONS A defect in the FA pathway at the level of SLX4 results in hypersensitivity to proton radiation, which is, at least in part, due to impaired MUS81-mediated processing of replication forks that stall at clustered DNA damage. In vivo and clinical studies are needed to confirm these findings in human cancers.
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Affiliation(s)
- Qi Liu
- Laboratory of Cellular and Molecular Radiation Oncology, Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts
| | - Tracy S A Underwood
- Division of Radiation Physics, Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts
| | - Jong Kung
- Division of Radiation Physics, Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts
| | - Meng Wang
- Laboratory of Cellular and Molecular Radiation Oncology, Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts
| | - Hsiao-Ming Lu
- Division of Radiation Physics, Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts
| | - Harald Paganetti
- Division of Radiation Physics, Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts
| | - Kathryn D Held
- Laboratory of Cellular and Molecular Radiation Oncology, Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts
| | - Theodore S Hong
- Laboratory of Cellular and Molecular Radiation Oncology, Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts
| | - Jason A Efstathiou
- Laboratory of Cellular and Molecular Radiation Oncology, Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts
| | - Henning Willers
- Laboratory of Cellular and Molecular Radiation Oncology, Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts.
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35
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Wu F, Chen WJ, Yan L, Tan GQ, Li WT, Zhu XJ, Ge XC, Liu JW, Wang BL. Mus81 knockdown improves chemosensitivity of hepatocellular carcinoma cells by inducing S-phase arrest and promoting apoptosis through CHK1 pathway. Cancer Med 2015; 5:370-85. [PMID: 26714930 PMCID: PMC4735774 DOI: 10.1002/cam4.588] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2015] [Revised: 10/18/2015] [Accepted: 10/20/2015] [Indexed: 11/10/2022] Open
Abstract
As a critical endonuclease in DNA repair, Mus81 is traditionally regarded as a tumor suppressor, but recently correlated with the sensitivity of mitomycin C and 5-fluorouracil in colon cancer and breast cancer cells. However, its role in chemosensitivity of other human malignancies still remains unknown. This study therefore aims to investigate the effects of Mus81 knockdown on the chemosensitivity of hepatocellular carcinoma (HCC), a usually chemorefractory tumor, and explore the underlying mechanisms. Mus81 expression in HepG2 and Bel-7402 HCC cell lines was depleted by lentivirus-mediated short hairpin RNA and the elevated sensitivity of these Mus81-inhibited HCC cells to therapeutic agents, especially to epirubicin (EPI), was evidenced by MTT assay and an HCC chemotherapy mouse model. Flow cytometric analysis also showed that Mus81 knockdown lead to an obvious S-phase arrest and an elevated apoptosis in EPI-treated HepG2 and Bel-7402 cells, which could be rescued by CHK1 inhibition. The activation of CHK1/CDC25A/CDK2 pathway was also demonstrated in Mus81-inhibited HepG2 cells and xenograft mouse tumors under EPI treatment. Meanwhile, the apoptosis of HepG2 cells in response to EPI was remarkably promoted by Mus81 knockdown through activating p53/Bax/Caspase-3 pathway under the controlling of CHK1. In addition, CHK2 inhibition slightly raised CHK1 activity, thereby enhancing the S-phase arrest and apoptosis induced by EPI in Mus81-suppressed HCC cells. In conclusion, Mus81 knockdown improves the chemosensitivity of HCC cells by inducing S-phase arrest and promoting apoptosis through CHK1 pathway, suggesting Mus81 as a novel therapeutic target for HCC.
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Affiliation(s)
- Fan Wu
- Department of Hepatobiliary Surgery, Guangzhou Red Cross Hospital /Fourth Affiliated Hospital of Jinan University, Tongfu Roud 396, Guangzhou, 510220, China
| | - Wei-Jia Chen
- Department of Hepatobiliary Surgery, Guangzhou Red Cross Hospital /Fourth Affiliated Hospital of Jinan University, Tongfu Roud 396, Guangzhou, 510220, China
| | - Lun Yan
- Department of Hepatobiliary Surgery, Guangzhou Red Cross Hospital /Fourth Affiliated Hospital of Jinan University, Tongfu Roud 396, Guangzhou, 510220, China
| | - Guo-Qian Tan
- Department of Hepatobiliary Surgery, Guangzhou Red Cross Hospital /Fourth Affiliated Hospital of Jinan University, Tongfu Roud 396, Guangzhou, 510220, China
| | - Wei-Tao Li
- Department of Hepatobiliary Surgery, Guangzhou Red Cross Hospital /Fourth Affiliated Hospital of Jinan University, Tongfu Roud 396, Guangzhou, 510220, China
| | - Xuan-Jin Zhu
- Department of Hepatobiliary Surgery, Guangzhou Red Cross Hospital /Fourth Affiliated Hospital of Jinan University, Tongfu Roud 396, Guangzhou, 510220, China
| | - Xiao-Chuan Ge
- Department of Hepatobiliary Surgery, Guangzhou Red Cross Hospital /Fourth Affiliated Hospital of Jinan University, Tongfu Roud 396, Guangzhou, 510220, China
| | - Jian-Wei Liu
- Department of Hepatobiliary Surgery, Guangzhou Red Cross Hospital /Fourth Affiliated Hospital of Jinan University, Tongfu Roud 396, Guangzhou, 510220, China
| | - Bai-Lin Wang
- Department of Hepatobiliary Surgery, Guangzhou Red Cross Hospital /Fourth Affiliated Hospital of Jinan University, Tongfu Roud 396, Guangzhou, 510220, China
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Qian Y, Liu Y, Yan Q, Lv J, Ni X, Wu Y, Dong X. Inhibition of Mus81 by siRNA enhances sensitivity to 5-FU in breast carcinoma cell lines. Onco Targets Ther 2014; 7:1883-90. [PMID: 25364260 PMCID: PMC4211853 DOI: 10.2147/ott.s64339] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
PURPOSE One of the most challenging aspects of breast carcinoma chemotherapy is the rapid acquirement of drug resistance. Improving the sensitivity to chemotherapeutic drugs is very important for successful treatment. Mus81 plays an important role in maintaining the stability of the genome and DNA repair. However, recent studies suggested that Mus81 expression levels correlate well with resistance to DNA-damaging drugs. The present study aimed to investigate the role of Mus81 on the chemosensitivity of breast carcinoma cells in response to 5-fluorouracil (5-FU), a chemotherapeutic drug that is widely used for treatment of breast malignancies. METHODS The expression of Mus81 in MCF-7 and T47D cells was suppressed by small interfering RNA (siRNA). mRNA and protein levels of Mus81 were analyzed by quantitative real-time polymerase chain reaction and Western blot. Cell viability and colony survival were determined by Cell Counting Kit-8 and plate colony formation assay, respectively. Cell cycle and apoptosis were detected by flow cytometry. RESULTS 5-FU inhibited the cell viability of MCF-7 and T47D cells in a concentration-dependent manner. We found that the Mus81-silenced MCF-7 and T47D cells exhibited decreased cell viability and clonogenic survival, but increased G2 accumulation, in response to 5-FU. In addition, Mus81 deficiency resulted in increased apoptosis and p53 expression in MCF-7 after 5-FU treatment. However, Mus81 deficiency did not affect the apoptosis of T47D cells with 5-FU. CONCLUSION Taken together, our data suggest that Mus81 inhibition significantly increased the chemosensitivity of MCF-7 and T47D cells in response to 5-FU. Thus, Mus81 siRNA is potentially a useful adjuvant strategy for breast cancer chemotherapy.
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Affiliation(s)
- Ying Qian
- The Key Laboratory of Laboratory Medicine, Ministry of Education of China; School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, Zhejiang, People's Republic of China ; Shaoxing People's Hospital, Shaoxing Hospital of Zhejiang University, Shaoxing, Zhejiang, People's Republic of China
| | - Yanning Liu
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, Zhejiang, People's Republic of China
| | - Qiuyue Yan
- The Key Laboratory of Laboratory Medicine, Ministry of Education of China; School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, Zhejiang, People's Republic of China ; Shaoxing People's Hospital, Shaoxing Hospital of Zhejiang University, Shaoxing, Zhejiang, People's Republic of China
| | - Juan Lv
- Shaoxing People's Hospital, Shaoxing Hospital of Zhejiang University, Shaoxing, Zhejiang, People's Republic of China
| | - Xiaoyan Ni
- Shaoxing People's Hospital, Shaoxing Hospital of Zhejiang University, Shaoxing, Zhejiang, People's Republic of China
| | - Yunlu Wu
- The Key Laboratory of Laboratory Medicine, Ministry of Education of China; School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, Zhejiang, People's Republic of China ; Shaoxing People's Hospital, Shaoxing Hospital of Zhejiang University, Shaoxing, Zhejiang, People's Republic of China
| | - Xuejun Dong
- The Key Laboratory of Laboratory Medicine, Ministry of Education of China; School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, Zhejiang, People's Republic of China ; Shaoxing People's Hospital, Shaoxing Hospital of Zhejiang University, Shaoxing, Zhejiang, People's Republic of China
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Extracellular matrix defects in aneurysmal Fibulin-4 mice predispose to lung emphysema. PLoS One 2014; 9:e106054. [PMID: 25255451 PMCID: PMC4177830 DOI: 10.1371/journal.pone.0106054] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Accepted: 07/28/2014] [Indexed: 12/19/2022] Open
Abstract
Background In this study we set out to investigate the clinically observed relationship between chronic obstructive pulmonary disease (COPD) and aortic aneurysms. We tested the hypothesis that an inherited deficiency of connective tissue might play a role in the combined development of pulmonary emphysema and vascular disease. Methods We first determined the prevalence of chronic obstructive pulmonary disease in a clinical cohort of aortic aneurysms patients and arterial occlusive disease patients. Subsequently, we used a combined approach comprising pathological, functional, molecular imaging, immunological and gene expression analysis to reveal the sequence of events that culminates in pulmonary emphysema in aneurysmal Fibulin-4 deficient (Fibulin-4R) mice. Results Here we show that COPD is significantly more prevalent in aneurysm patients compared to arterial occlusive disease patients, independent of smoking, other clinical risk factors and inflammation. In addition, we demonstrate that aneurysmal Fibulin-4R/R mice display severe developmental lung emphysema, whereas Fibulin-4+/R mice acquire alveolar breakdown with age and upon infectious stress. This vicious circle is further exacerbated by the diminished antiprotease capacity of the lungs and ultimately results in the development of pulmonary emphysema. Conclusions Our experimental data identify genetic susceptibility to extracellular matrix degradation and secondary inflammation as the common mechanisms in both COPD and aneurysm formation.
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Nair N, Castor D, Macartney T, Rouse J. Identification and characterization of MUS81 point mutations that abolish interaction with the SLX4 scaffold protein. DNA Repair (Amst) 2014; 24:131-137. [PMID: 25224045 PMCID: PMC4251979 DOI: 10.1016/j.dnarep.2014.08.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2014] [Revised: 08/16/2014] [Accepted: 08/22/2014] [Indexed: 12/02/2022]
Abstract
MUS81-EME1 is a conserved structure-selective endonuclease with a preference for branched DNA substrates in vitro that correspond to intermediates of DNA repair. Cells lacking MUS81 or EME1 show defects in the repair of DNA interstrand crosslinks (ICL) resulting in hypersensitivity to agents such as mitomycin C. In metazoans, a proportion of cellular MUS81-EME1 binds the SLX4 scaffold protein, which is itself instrumental for ICL repair. It was previously reported that mutations in SLX4 that abolished interaction with MUS81 affected ICL repair in human cells but not in murine cells. In this study we looked the other way around by pinpointing amino acid residues in MUS81 that when mutated abolish the interaction with SLX4. These mutations fully rescued the mitomycin C hypersensitivity of MUS81 knockout murine cells, but they were unable to rescue the sensitivity of two different human cell lines defective in MUS81. These data support an SLX4-dependent role for MUS81 in the repair, but not the induction of ICL-induced double-strand breaks. This study sheds light on the extent to which MUS81 function in ICL repair requires interaction with SLX4.
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Affiliation(s)
- Nidhi Nair
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK
| | - Dennis Castor
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK
| | - Thomas Macartney
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK
| | - John Rouse
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK.
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Abstract
Four-way DNA intermediates, called Holliday junctions (HJs), can form during meiotic and mitotic recombination, and their removal is crucial for chromosome segregation. A group of ubiquitous and highly specialized structure-selective endonucleases catalyze the cleavage of HJs into two disconnected DNA duplexes in a reaction called HJ resolution. These enzymes, called HJ resolvases, have been identified in bacteria and their bacteriophages, archaea, and eukaryotes. In this review, we discuss fundamental aspects of the HJ structure and their interaction with junction-resolving enzymes. This is followed by a brief discussion of the eubacterial RuvABC enzymes, which provide the paradigm for HJ resolvases in other organisms. Finally, we review the biochemical and structural properties of some well-characterized resolvases from archaea, bacteriophage, and eukaryotes.
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Affiliation(s)
- Haley D M Wyatt
- London Research Institute, Cancer Research UK, Clare Hall Laboratories, South Mimms, Herts EN6 3LD, United Kingdom
| | - Stephen C West
- London Research Institute, Cancer Research UK, Clare Hall Laboratories, South Mimms, Herts EN6 3LD, United Kingdom
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40
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Kim Y. Nuclease delivery: versatile functions of SLX4/FANCP in genome maintenance. Mol Cells 2014; 37:569-74. [PMID: 24938228 PMCID: PMC4145367 DOI: 10.14348/molcells.2014.0118] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Revised: 05/27/2014] [Accepted: 05/28/2014] [Indexed: 11/27/2022] Open
Abstract
As a scaffold, SLX4/FANCP interacts with multiple proteins involved in genome integrity. Although not having recognizable catalytic domains, SLX4 participates in diverse genome maintenance pathways by delivering nucleases where they are needed, and promoting their cooperative execution to prevent genomic instabilities. Physiological importance of SLX4 is emphasized by the identification of causative mutations of SLX4 genes in patients diagnosed with Fanconi anemia (FA), a rare recessive genetic disorder characterized by genomic instability and predisposition to cancers. Recent progress in understanding functional roles of SLX4 has greatly expanded our knowledge in the repair of DNA interstrand crosslinks (ICLs), Holliday junction (HJ) resolution, telomere homeostasis and regulation of DNA damage response induced by replication stress. Here, these diverse functions of SLX4 are reviewed in detail.
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Affiliation(s)
- Yonghwan Kim
- Department of Life Systems, Sookmyung Women’s University, Seoul 140-742,
Korea
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41
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Nucleases in homologous recombination as targets for cancer therapy. FEBS Lett 2014; 588:2446-56. [DOI: 10.1016/j.febslet.2014.06.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Revised: 06/02/2014] [Accepted: 06/02/2014] [Indexed: 11/21/2022]
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42
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Cooperation of Blm and Mus81 in development, fertility, genomic integrity and cancer suppression. Oncogene 2014; 34:1780-9. [DOI: 10.1038/onc.2014.121] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Revised: 02/10/2014] [Accepted: 03/26/2014] [Indexed: 01/16/2023]
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Hodskinson MRG, Silhan J, Crossan GP, Garaycoechea JI, Mukherjee S, Johnson CM, Schärer OD, Patel KJ. Mouse SLX4 is a tumor suppressor that stimulates the activity of the nuclease XPF-ERCC1 in DNA crosslink repair. Mol Cell 2014; 54:472-84. [PMID: 24726326 PMCID: PMC4017094 DOI: 10.1016/j.molcel.2014.03.014] [Citation(s) in RCA: 115] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Revised: 01/21/2014] [Accepted: 02/28/2014] [Indexed: 11/18/2022]
Abstract
SLX4 binds to three nucleases (XPF-ERCC1, MUS81-EME1, and SLX1), and its deficiency leads to genomic instability, sensitivity to DNA crosslinking agents, and Fanconi anemia. However, it is not understood how SLX4 and its associated nucleases act in DNA crosslink repair. Here, we uncover consequences of mouse Slx4 deficiency and reveal its function in DNA crosslink repair. Slx4-deficient mice develop epithelial cancers and have a contracted hematopoietic stem cell pool. The N-terminal domain of SLX4 (mini-SLX4) that only binds to XPF-ERCC1 is sufficient to confer resistance to DNA crosslinking agents. Recombinant mini-SLX4 enhances XPF-ERCC1 nuclease activity up to 100-fold, directing specificity toward DNA forks. Mini-SLX4-XPF-ERCC1 also vigorously stimulates dual incisions around a DNA crosslink embedded in a synthetic replication fork, an essential step in the repair of this lesion. These observations define vertebrate SLX4 as a tumor suppressor, which activates XPF-ERCC1 nuclease specificity in DNA crosslink repair.
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Affiliation(s)
| | - Jan Silhan
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Gerry P Crossan
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Juan I Garaycoechea
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Shivam Mukherjee
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400, USA
| | | | - Orlando D Schärer
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400, USA; Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794-8651, USA
| | - Ketan J Patel
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK; Department of Medicine, Level 5, Addenbrooke's Hospital, University of Cambridge, Cambridge CB2 0QQ, UK.
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Mukherjee S, Wright WD, Ehmsen KT, Heyer WD. The Mus81-Mms4 structure-selective endonuclease requires nicked DNA junctions to undergo conformational changes and bend its DNA substrates for cleavage. Nucleic Acids Res 2014; 42:6511-22. [PMID: 24744239 PMCID: PMC4041439 DOI: 10.1093/nar/gku265] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Mus81-Mms4/EME1 is a DNA structure-selective endonuclease that cleaves joint DNA molecules that form during homologous recombination in mitotic and meiotic cells. Here, we demonstrate by kinetic analysis using physically tethered DNA substrates that budding yeast Mus81-Mms4 requires inherent rotational flexibility in DNA junctions for optimal catalysis. Förster Resonance Energy Transfer experiments further reveal that recognition of 3′-flap and nicked Holliday junction substrates by Mus81-Mms4 involves induction of a sharp bend with a 100° angle between two duplex DNA arms. In addition, thiol crosslinking of Mus81-Mms4 bound to DNA junctions demonstrates that the heterodimer undergoes a conformational change induced by joint DNA molecules with preferred structural properties. The results from all three approaches suggest a model for catalysis by Mus81-Mms4 in which initial DNA binding is based on minimal structural requirements followed by a rate-limiting conformational transition of the substrate and protein. This leads to a sharply kinked DNA molecule that may fray the DNA four base pairs away from the junction point to position the nuclease for cleavage between the fourth and fifth nucleotide. These data suggest that mutually compatible conformational changes of Mus81-Mms4 and its substrates tailor its incision activity to nicked junction molecules.
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Affiliation(s)
- Sucheta Mukherjee
- Department of Microbiology & Molecular Genetics, University of California, One Shields Ave., Davis, Davis CA 95616-8665, USA
| | - William Douglass Wright
- Department of Microbiology & Molecular Genetics, University of California, One Shields Ave., Davis, Davis CA 95616-8665, USA
| | - Kirk Tevebaugh Ehmsen
- Department of Microbiology & Molecular Genetics, University of California, One Shields Ave., Davis, Davis CA 95616-8665, USA
| | - Wolf-Dietrich Heyer
- Department of Microbiology & Molecular Genetics, University of California, One Shields Ave., Davis, Davis CA 95616-8665, USA Department of Molecular & Cellular Biology, University of California, One Shields Ave., Davis, Davis CA 95616-8665, USA
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45
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Gwon GH, Jo A, Baek K, Jin KS, Fu Y, Lee JB, Kim Y, Cho Y. Crystal structures of the structure-selective nuclease Mus81-Eme1 bound to flap DNA substrates. EMBO J 2014; 33:1061-72. [PMID: 24733841 DOI: 10.1002/embj.201487820] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The Mus81-Eme1 complex is a structure-selective endonuclease with a critical role in the resolution of recombination intermediates during DNA repair after interstrand cross-links, replication fork collapse, or double-strand breaks. To explain the molecular basis of 3' flap substrate recognition and cleavage mechanism by Mus81-Eme1, we determined crystal structures of human Mus81-Eme1 bound to various flap DNA substrates. Mus81-Eme1 undergoes gross substrate-induced conformational changes that reveal two key features: (i) a hydrophobic wedge of Mus81 that separates pre- and post-nick duplex DNA and (ii) a "5' end binding pocket" that hosts the 5' nicked end of post-nick DNA. These features are crucial for comprehensive protein-DNA interaction, sharp bending of the 3' flap DNA substrate, and incision strand placement at the active site. While Mus81-Eme1 unexpectedly shares several common features with members of the 5' flap nuclease family, the combined structural, biochemical, and biophysical analyses explain why Mus81-Eme1 preferentially cleaves 3' flap DNA substrates with 5' nicked ends.
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Affiliation(s)
- Gwang Hyeon Gwon
- Department of Life Science, Pohang University of Science and Technology, Pohang, South Korea
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46
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Pepe A, West SC. Substrate specificity of the MUS81-EME2 structure selective endonuclease. Nucleic Acids Res 2014; 42:3833-45. [PMID: 24371268 PMCID: PMC3973302 DOI: 10.1093/nar/gkt1333] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Revised: 11/16/2013] [Accepted: 11/29/2013] [Indexed: 11/13/2022] Open
Abstract
MUS81 plays important cellular roles in the restart of stalled replication forks, the resolution of recombination intermediates and in telomere length maintenance. Although the actions of MUS81-EME1 have been extensively investigated, MUS81 is the catalytic subunit of two human structure-selective endonucleases, MUS81-EME1 and MUS81-EME2. Little is presently known about the activities of MUS81-EME2. Here, we have purified MUS81-EME2 and compared its activities with MUS81-EME1. We find that MUS81-EME2 is a more active endonuclease than MUS81-EME1 and exhibits broader substrate specificity. Like MUS81-EME1, MUS81-EME2 cleaves 3'-flaps, replication forks and nicked Holliday junctions, and exhibits limited endonuclease activity with intact Holliday junctions. In contrast to MUS81-EME1, however, MUS81-EME2 cuts D-loop recombination intermediates and in so doing disengages the D-loop structure by cleaving the 3'-invading strand. Additionally, MUS81-EME2 acts on 5'-flap structures to cleave off a duplex arm, in reactions that cannot be promoted by MUS81-EME1. These studies suggest that MUS81-EME1 and MUS81-EME2 exhibit similar and yet distinct DNA structure selectivity, indicating that the two MUS81 complexes may promote different nucleolytic cleavage reactions in vivo.
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Affiliation(s)
- Alessandra Pepe
- London Research Institute, Cancer Research UK, Clare Hall Laboratories, South Mimms, Herts EN6 3LD, UK
| | - Stephen C. West
- London Research Institute, Cancer Research UK, Clare Hall Laboratories, South Mimms, Herts EN6 3LD, UK
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47
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Abstract
Two papers in this issue, Castor et al. (2013) and Wyatt et al. (2013), and a third in Cell Reports, Garner et al. (2013), demonstrate that the scaffold protein SLX4 coordinates multiple nucleases in order to effectively resolve Holliday junctions and repair interstrand crosslinks (ICLs) in mammalian cells.
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Affiliation(s)
- Steven J Brill
- Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, NJ 08854, USA.
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48
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Minocherhomji S, Hickson ID. Structure-specific endonucleases: guardians of fragile site stability. Trends Cell Biol 2013; 24:321-7. [PMID: 24361091 DOI: 10.1016/j.tcb.2013.11.007] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Revised: 11/14/2013] [Accepted: 11/15/2013] [Indexed: 12/26/2022]
Abstract
Fragile sites are conserved loci predisposed to form breaks in metaphase chromosomes. The inherent instability of these loci is associated with chromosomal rearrangements in cancers and is a feature of cells from patients with chromosomal instability syndromes. One class of fragile sites, the common fragile sites (CFSs), have previously been shown to recruit several DNA repair proteins after the completion of bulk DNA synthesis in the cell, probably indicative of their inability to complete timely DNA replication. CFS loci are also prone to trigger mitotic non-disjunction of sister chromatids, leading to the formation of ultra-fine anaphase bridges (UFBs) and micronuclei. We discuss recent developments in the CFS field; in particular, the role of DNA structure-specific endonucleases in promoting cleavage at CFSs.
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Affiliation(s)
- Sheroy Minocherhomji
- Nordea Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, Denmark
| | - Ian D Hickson
- Nordea Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, Denmark.
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49
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Rass U. Resolving branched DNA intermediates with structure-specific nucleases during replication in eukaryotes. Chromosoma 2013; 122:499-515. [PMID: 24008669 PMCID: PMC3827899 DOI: 10.1007/s00412-013-0431-z] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 08/03/2013] [Accepted: 08/08/2013] [Indexed: 11/29/2022]
Abstract
Genome duplication requires that replication forks track the entire length of every chromosome. When complications occur, homologous recombination-mediated repair supports replication fork movement and recovery. This leads to physical connections between the nascent sister chromatids in the form of Holliday junctions and other branched DNA intermediates. A key role in the removal of these recombination intermediates falls to structure-specific nucleases such as the Holliday junction resolvase RuvC in Escherichia coli. RuvC is also known to cut branched DNA intermediates that originate directly from blocked replication forks, targeting them for origin-independent replication restart. In eukaryotes, multiple structure-specific nucleases, including Mus81-Mms4/MUS81-EME1, Yen1/GEN1, and Slx1-Slx4/SLX1-SLX4 (FANCP) have been implicated in the resolution of branched DNA intermediates. It is becoming increasingly clear that, as a group, they reflect the dual function of RuvC in cleaving recombination intermediates and failing replication forks to assist the DNA replication process.
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Affiliation(s)
- Ulrich Rass
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058, Basel, Switzerland,
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50
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Wyatt HDM, Sarbajna S, Matos J, West SC. Coordinated actions of SLX1-SLX4 and MUS81-EME1 for Holliday junction resolution in human cells. Mol Cell 2013; 52:234-47. [PMID: 24076221 DOI: 10.1016/j.molcel.2013.08.035] [Citation(s) in RCA: 223] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 07/18/2013] [Accepted: 08/14/2013] [Indexed: 10/26/2022]
Abstract
Holliday junctions (HJs) are four-way DNA intermediates that form during homologous recombination, and their efficient resolution is essential for chromosome segregation. Here, we show that three structure-selective endonucleases, namely SLX1-SLX4, MUS81-EME1, and GEN1, define two pathways of HJ resolution in human cells. One pathway is mediated by GEN1, whereas SLX1-SLX4 and MUS81-EME1 provide a second and genetically distinct pathway (SLX-MUS). Cells depleted for SLX-MUS or GEN1 pathway proteins exhibit severe defects in chromosome segregation and reduced survival. In response to CDK-mediated phosphorylation, SLX1-SLX4 and MUS81-EME1 associate at the G2/M transition to form a stable SLX-MUS holoenzyme, which can be reconstituted in vitro. Biochemical studies show that SLX-MUS is a HJ resolvase that coordinates the active sites of two distinct endonucleases during HJ resolution. This cleavage reaction is more efficient and orchestrated than that mediated by SLX1-SLX4 alone, which exhibits a potent nickase activity that acts promiscuously upon DNA secondary structures.
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Affiliation(s)
- Haley D M Wyatt
- London Research Institute, Cancer Research UK, Clare Hall Laboratories, South Mimms, Herts EN6 3LD, UK
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