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Kang S, Yoo J, Myung K. PCNA cycling dynamics during DNA replication and repair in mammals. Trends Genet 2024; 40:526-539. [PMID: 38485608 DOI: 10.1016/j.tig.2024.02.006] [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: 01/17/2024] [Revised: 02/18/2024] [Accepted: 02/20/2024] [Indexed: 06/06/2024]
Abstract
Proliferating cell nuclear antigen (PCNA) is a eukaryotic replicative DNA clamp. Furthermore, DNA-loaded PCNA functions as a molecular hub during DNA replication and repair. PCNA forms a closed homotrimeric ring that encircles the DNA, and association and dissociation of PCNA from DNA are mediated by clamp-loader complexes. PCNA must be actively released from DNA after completion of its function. If it is not released, abnormal accumulation of PCNA on chromatin will interfere with DNA metabolism. ATAD5 containing replication factor C-like complex (RLC) is a PCNA-unloading clamp-loader complex. ATAD5 deficiency causes various DNA replication and repair problems, leading to genome instability. Here, we review recent progress regarding the understanding of the action mechanisms of PCNA unloading complex in DNA replication/repair pathways.
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Affiliation(s)
- Sukhyun Kang
- Center for Genomic Integrity, Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
| | - Juyeong Yoo
- Center for Genomic Integrity, Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea; Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
| | - Kyungjae Myung
- Center for Genomic Integrity, Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea; Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea.
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2
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Zhang ZY, Xu JH, Zhang JL, Lin YX, Ou-Yang J. CD276 enhances sunitinib resistance in clear cell renal cell carcinoma by promoting DNA damage repair and activation of FAK-MAPK signaling pathway. BMC Cancer 2024; 24:650. [PMID: 38802739 PMCID: PMC11131182 DOI: 10.1186/s12885-024-12402-7] [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: 11/09/2023] [Accepted: 05/20/2024] [Indexed: 05/29/2024] Open
Abstract
OBJECTIVE This study aimed to explore the effect of CD276 expression on the sunitinib sensitivity of clear cell renal cell carcinoma (ccRCC) cell and animal models and the potential mechanisms involved. METHODS CD276 expression levels of ccRCC and normal samples were analyzed via online databases and real-time quantitative PCR (RT-qPCR). CD276 was knocked down in ccRCC cell models (sunitinib-resistant 786-O/R cells and sunitinib-sensitive 786-O cells) using shRNA transfection, and the cells were exposed to a sunitinib (2 µM) environment. Cells proliferation was then analyzed using MTT assay and colony formation experiment. Alkaline comet assay, immunofluorescent staining, and western blot experiments were conducted to assess the DNA damage repair ability of the cells. Western blot was also used to observe the activation of FAK-MAPK pathway within the cells. Finally, a nude mouse xenograft model was established and the nude mice were orally administered sunitinib (40 mg/kg/d) to evaluate the in vivo effects of CD276 knockdown on the therapeutic efficacy of sunitinib against ccRCC. RESULTS CD276 was significantly upregulated in both ccRCC clinical tissue samples and cell models. In vitro experiments showed that knocking down CD276 reduced the survival rate, IC50 value, and colony-forming ability of ccRCC cells. Knocking down CD276 increased the comet tail moment (TM) values and γH2AX foci number, and reduced BRCA1 and RAD51 protein levels. Knocking down CD276 also decreased the levels of p-FAK, p-MEK, and p-ERK proteins. CONCLUSION Knocking down CD276 effectively improved the sensitivity of ccRCC cell and animal models to sunitinib treatment.
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Affiliation(s)
- Zhi-Yu Zhang
- Department of Urology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, 215000, China
| | - Jian-Hao Xu
- Department of Pathology, The First People's Hospital of Kunshan, Suzhou, Jiangsu, 215300, China
| | - Jiang-Lei Zhang
- Department of Urology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, 215000, China
| | - Yu-Xin Lin
- Department of Urology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, 215000, China
| | - Jun Ou-Yang
- Department of Urology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, 215000, China.
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3
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Schreuder A, Wendel TJ, Dorresteijn CGV, Noordermeer SM. (Single-stranded DNA) gaps in understanding BRCAness. Trends Genet 2024:S0168-9525(24)00100-8. [PMID: 38789375 DOI: 10.1016/j.tig.2024.04.013] [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: 02/02/2024] [Revised: 04/22/2024] [Accepted: 04/23/2024] [Indexed: 05/26/2024]
Abstract
The tumour-suppressive roles of BRCA1 and 2 have been attributed to three seemingly distinct functions - homologous recombination, replication fork protection, and single-stranded (ss)DNA gap suppression - and their relative importance is under debate. In this review, we examine the origin and resolution of ssDNA gaps and discuss the recent advances in understanding the role of BRCA1/2 in gap suppression. There are ample data showing that gap accumulation in BRCA1/2-deficient cells is linked to genomic instability and chemosensitivity. However, it remains unclear whether there is a causative role and the function of BRCA1/2 in gap suppression cannot unambiguously be dissected from their other functions. We therefore conclude that the three functions of BRCA1 and 2 are closely intertwined and not mutually exclusive.
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Affiliation(s)
- Anne Schreuder
- Leiden University Medical Center, Department of Human Genetics, Leiden, The Netherlands; Oncode Institute, Utrecht, The Netherlands
| | - Tiemen J Wendel
- Leiden University Medical Center, Department of Human Genetics, Leiden, The Netherlands; Oncode Institute, Utrecht, The Netherlands
| | - Carlo G V Dorresteijn
- Leiden University Medical Center, Department of Human Genetics, Leiden, The Netherlands
| | - Sylvie M Noordermeer
- Leiden University Medical Center, Department of Human Genetics, Leiden, The Netherlands; Oncode Institute, Utrecht, The Netherlands.
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4
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Uhrig ME, Sharma N, Maxwell P, Selemenakis P, Mazin AV, Wiese C. Disparate requirements for RAD54L in replication fork reversal. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.07.26.550704. [PMID: 37546955 PMCID: PMC10402051 DOI: 10.1101/2023.07.26.550704] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
RAD54L is a DNA motor protein with multiple roles in homologous recombination DNA repair (HR). In vitro , RAD54L was shown to also catalyze the reversal and restoration of model replication forks. In cells, however, little is known about how RAD54L may regulate the dynamics of DNA replication. Here, we show that RAD54L restrains the progression of replication forks and functions as a fork remodeler in human cells. Analogous to HLTF, SMARCAL1, and FBH1, and consistent with a role in fork reversal, RAD54L decelerates fork progression in response to replication stress and suppresses the formation of replication-associated ssDNA gaps. Interestingly, loss of RAD54L prevents nascent strand DNA degradation in both BRCA1/2- and 53BP1-deficient cells, suggesting that RAD54L functions in both pathways of RAD51-mediated replication fork reversal. In the HLTF/SMARCAL1 pathway, RAD54L is critical, but its ability to catalyze branch migration is dispensable, indicative of its function downstream of HLTF/SMARCAL1. Conversely, in the FBH1 pathway, branch migration activity of RAD54L is essential, and FBH1 engagement is dependent on its concerted action with RAD54L. Collectively, our results reveal disparate requirements for RAD54L in two distinct RAD51-mediated fork reversal pathways, positing its potential as a future therapeutic target.
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5
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Son MY, Belan O, Spirek M, Cibulka J, Nikulenkov F, Kim YY, Hwang S, Myung K, Montagna C, Kim TM, Krejci L, Hasty P. RAD51 separation of function mutation disables replication fork maintenance but preserves DSB repair. iScience 2024; 27:109524. [PMID: 38577109 PMCID: PMC10993188 DOI: 10.1016/j.isci.2024.109524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 03/01/2023] [Accepted: 03/14/2024] [Indexed: 04/06/2024] Open
Abstract
Homologous recombination (HR) protects replication forks (RFs) and repairs DNA double-strand breaks (DSBs). Within HR, BRCA2 regulates RAD51 via two interaction regions: the BRC repeats to form filaments on single-stranded DNA and exon 27 (Ex27) to stabilize the filament. Here, we identified a RAD51 S181P mutant that selectively disrupted the RAD51-Ex27 association while maintaining interaction with BRC repeat and proficiently forming filaments capable of DNA binding and strand invasion. Interestingly, RAD51 S181P was defective for RF protection/restart but proficient for DSB repair. Our data suggest that Ex27-mediated stabilization of RAD51 filaments is required for the protection of RFs, while it seems dispensable for the repair of DSBs.
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Affiliation(s)
- Mi Young Son
- Department of Molecular Medicine, The Barshop Institute for Longevity and Aging Studies, The Cancer Therapy Research Center, UT Health San Antonio, San Antonio, TX 78229, USA
| | - Ondrej Belan
- Department of Biology, Masaryk University, 625 00 Brno, Czech Republic
| | - Mario Spirek
- Department of Biology, Masaryk University, 625 00 Brno, Czech Republic
- National Centre for Biomolecular Research, Masaryk University, 625 00 Brno, Czech Republic
| | - Jakub Cibulka
- Department of Biology, Masaryk University, 625 00 Brno, Czech Republic
| | - Fedor Nikulenkov
- Department of Biology, Masaryk University, 625 00 Brno, Czech Republic
| | - You Young Kim
- Center for Genomic Integrity Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
| | - Sunyoung Hwang
- Center for Genomic Integrity Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
| | - Kyungjae Myung
- Center for Genomic Integrity Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
| | - Cristina Montagna
- Department of Genetics, Albert Einstein College of Medicine of Yeshiva University, Bronx, NY 10461, USA
| | - Tae Moon Kim
- Department of Molecular Medicine, The Barshop Institute for Longevity and Aging Studies, The Cancer Therapy Research Center, UT Health San Antonio, San Antonio, TX 78229, USA
- Center for Genomic Integrity Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
| | - Lumir Krejci
- Department of Biology, Masaryk University, 625 00 Brno, Czech Republic
- National Centre for Biomolecular Research, Masaryk University, 625 00 Brno, Czech Republic
| | - Paul Hasty
- Department of Molecular Medicine, The Barshop Institute for Longevity and Aging Studies, The Cancer Therapy Research Center, UT Health San Antonio, San Antonio, TX 78229, USA
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6
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Rageul J, Lo N, Phi AL, Patel JA, Park JJ, Kim H. Poly(ADP-ribosyl)ation of TIMELESS limits DNA replication stress and promotes stalled fork protection. Cell Rep 2024; 43:113845. [PMID: 38393943 PMCID: PMC11029348 DOI: 10.1016/j.celrep.2024.113845] [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: 10/04/2023] [Revised: 01/16/2024] [Accepted: 02/06/2024] [Indexed: 02/25/2024] Open
Abstract
Poly(ADP-ribosyl)ation (PARylation), catalyzed mainly by poly(ADP-ribose) polymerase (PARP)1, is a key posttranslational modification involved in DNA replication and repair. Here, we report that TIMELESS (TIM), an essential scaffold of the replisome, is PARylated, which is linked to its proteolysis. TIM PARylation requires recognition of auto-modified PARP1 via two poly(ADP-ribose)-binding motifs, which primes TIM for proteasome-dependent degradation. Cells expressing the PARylation-refractory TIM mutant or under PARP inhibition accumulate TIM at DNA replication forks, causing replication stress and hyper-resection of stalled forks. Mechanistically, aberrant engagement of TIM with the replicative helicase impedes RAD51 loading and protection of reversed forks. Accordingly, defective TIM degradation hypersensitizes BRCA2-deficient cells to replication damage. Our study defines TIM as a substrate of PARP1 and elucidates how the control of replisome remodeling by PARylation is linked to stalled fork protection. Therefore, we propose a mechanism of PARP inhibition that impinges on the DNA replication fork instability caused by defective TIM turnover.
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Affiliation(s)
- Julie Rageul
- Department of Pharmacological Sciences, State University of New York at Stony Brook, Stony Brook, NY 11794, USA.
| | - Natalie Lo
- Department of Pharmacological Sciences, State University of New York at Stony Brook, Stony Brook, NY 11794, USA
| | - Amy L Phi
- Department of Pharmacological Sciences, State University of New York at Stony Brook, Stony Brook, NY 11794, USA
| | - Jinal A Patel
- Department of Pharmacological Sciences, State University of New York at Stony Brook, Stony Brook, NY 11794, USA
| | - Jennifer J Park
- Department of Pharmacological Sciences, State University of New York at Stony Brook, Stony Brook, NY 11794, USA
| | - Hyungjin Kim
- Department of Pharmacological Sciences, State University of New York at Stony Brook, Stony Brook, NY 11794, USA; Stony Brook Cancer Center, Renaissance School of Medicine at Stony Brook University, Stony Brook, NY 11794, USA.
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7
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Ubhi T, Zaslaver O, Quaile AT, Plenker D, Cao P, Pham NA, Békési A, Jang GH, O'Kane GM, Notta F, Moffat J, Wilson JM, Gallinger S, Vértessy BG, Tuveson DA, Röst HL, Brown GW. Cytidine deaminases APOBEC3C and APOBEC3D promote DNA replication stress resistance in pancreatic cancer cells. NATURE CANCER 2024:10.1038/s43018-024-00742-z. [PMID: 38448522 DOI: 10.1038/s43018-024-00742-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 02/09/2024] [Indexed: 03/08/2024]
Abstract
Gemcitabine is a potent inhibitor of DNA replication and is a mainstay therapeutic for diverse cancers, particularly pancreatic ductal adenocarcinoma (PDAC). However, most tumors remain refractory to gemcitabine therapies. Here, to define the cancer cell response to gemcitabine, we performed genome-scale CRISPR-Cas9 chemical-genetic screens in PDAC cells and found selective loss of cell fitness upon disruption of the cytidine deaminases APOBEC3C and APOBEC3D. Following gemcitabine treatment, APOBEC3C and APOBEC3D promote DNA replication stress resistance and cell survival by deaminating cytidines in the nuclear genome to ensure DNA replication fork restart and repair in PDAC cells. We provide evidence that the chemical-genetic interaction between APOBEC3C or APOBEC3D and gemcitabine is absent in nontransformed cells but is recapitulated across different PDAC cell lines, in PDAC organoids and in PDAC xenografts. Thus, we uncover roles for APOBEC3C and APOBEC3D in DNA replication stress resistance and offer plausible targets for improving gemcitabine-based therapies for PDAC.
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Affiliation(s)
- Tajinder Ubhi
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada
| | - Olga Zaslaver
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada
| | - Andrew T Quaile
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada
| | - Dennis Plenker
- Lustgarten Foundation Pancreatic Cancer Research Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
- Xilis Inc., Durham, NC, USA
| | - Pinjiang Cao
- Living Biobank, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - Nhu-An Pham
- Living Biobank, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - Angéla Békési
- Department of Applied Biotechnology and Food Science, Faculty of Chemical Technology and Biotechnology, BME Budapest University of Technology and Economics, Budapest, Hungary
- Genome Metabolism Research Group, Institute of Molecular Life Sciences, Research Centre for Natural Sciences, Hungarian Research Network, Budapest, Hungary
| | - Gun-Ho Jang
- Ontario Institute for Cancer Research, Toronto, Ontario, Canada
| | - Grainne M O'Kane
- Ontario Institute for Cancer Research, Toronto, Ontario, Canada
- Wallace McCain Centre for Pancreatic Cancer, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - Faiyaz Notta
- Ontario Institute for Cancer Research, Toronto, Ontario, Canada
- Division of Research, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - Jason Moffat
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Julie M Wilson
- Ontario Institute for Cancer Research, Toronto, Ontario, Canada
| | - Steven Gallinger
- Ontario Institute for Cancer Research, Toronto, Ontario, Canada
- Wallace McCain Centre for Pancreatic Cancer, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
- Lunenfeld Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
- Hepatobiliary/Pancreatic Surgical Oncology Program, University Health Network, Toronto, Ontario, Canada
| | - Beáta G Vértessy
- Department of Applied Biotechnology and Food Science, Faculty of Chemical Technology and Biotechnology, BME Budapest University of Technology and Economics, Budapest, Hungary
- Genome Metabolism Research Group, Institute of Molecular Life Sciences, Research Centre for Natural Sciences, Hungarian Research Network, Budapest, Hungary
| | - David A Tuveson
- Lustgarten Foundation Pancreatic Cancer Research Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Hannes L Röst
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Grant W Brown
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada.
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada.
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8
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Khodaverdian V, Sano T, Maggs L, Tomarchio G, Dias A, Clairmont C, Tran M, McVey M. REV1 Coordinates a Multi-Faceted Tolerance Response to DNA Alkylation Damage and Prevents Chromosome Shattering in Drosophila melanogaster. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.13.580051. [PMID: 38405884 PMCID: PMC10888836 DOI: 10.1101/2024.02.13.580051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
When replication forks encounter damaged DNA, cells utilize DNA damage tolerance mechanisms to allow replication to proceed. These include translesion synthesis at the fork, postreplication gap filling, and template switching via fork reversal or homologous recombination. The extent to which these different damage tolerance mechanisms are utilized depends on cell, tissue, and developmental context-specific cues, the last two of which are poorly understood. To address this gap, we have investigated damage tolerance responses following alkylation damage in Drosophila melanogaster. We report that translesion synthesis, rather than template switching, is the preferred response to alkylation-induced damage in diploid larval tissues. Furthermore, we show that the REV1 protein plays a multi-faceted role in damage tolerance in Drosophila. Drosophila larvae lacking REV1 are hypersensitive to methyl methanesulfonate (MMS) and have highly elevated levels of γ-H2Av foci and chromosome aberrations in MMS-treated tissues. Loss of the REV1 C-terminal domain (CTD), which recruits multiple translesion polymerases to damage sites, sensitizes flies to MMS. In the absence of the REV1 CTD, DNA polymerases eta and zeta become critical for MMS tolerance. In addition, flies lacking REV3, the catalytic subunit of polymerase zeta, require the deoxycytidyl transferase activity of REV1 to tolerate MMS. Together, our results demonstrate that Drosophila prioritize the use of multiple translesion polymerases to tolerate alkylation damage and highlight the critical role of REV1 in the coordination of this response to prevent genome instability.
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Affiliation(s)
- Varandt Khodaverdian
- Department of Biology, Tufts University, Medford, MA 02155
- Current address: Yarrow Biotechnology, New York, NY
| | - Tokio Sano
- Department of Biology, Tufts University, Medford, MA 02155
| | - Lara Maggs
- Department of Biology, Tufts University, Medford, MA 02155
| | - Gina Tomarchio
- Current address: Molecular Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY
| | - Ana Dias
- Department of Biology, Tufts University, Medford, MA 02155
| | - Connor Clairmont
- Department of Biology, Tufts University, Medford, MA 02155
- Current address: Vertex Pharmaceuticals, Boston, MA
| | - Mai Tran
- Department of Biology, Tufts University, Medford, MA 02155
| | - Mitch McVey
- Department of Biology, Tufts University, Medford, MA 02155
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9
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Lim PX, Zaman M, Feng W, Jasin M. BRCA2 promotes genomic integrity and therapy resistance primarily through its role in homology-directed repair. Mol Cell 2024; 84:447-462.e10. [PMID: 38244544 DOI: 10.1016/j.molcel.2023.12.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 10/10/2023] [Accepted: 12/15/2023] [Indexed: 01/22/2024]
Abstract
Tumor suppressor BRCA2 functions in homology-directed repair (HDR), the protection of stalled replication forks, and the suppression of replicative gaps, but their relative contributions to genome integrity and chemotherapy response are under scrutiny. Here, we report that mouse and human cells require a RAD51 filament stabilization motif in BRCA2 for fork protection and gap suppression but not HDR. In mice, the loss of fork protection/gap suppression does not compromise genome stability or shorten tumor latency. By contrast, HDR deficiency increases spontaneous and replication stress-induced chromosome aberrations and tumor predisposition. Unlike with HDR, fork protection/gap suppression defects are also observed in Brca2 heterozygous cells, likely due to reduced RAD51 stabilization at stalled forks/gaps. Gaps arise from PRIMPOL activity, which is associated with 5-hydroxymethyl-2'-deoxyuridine sensitivity due to the formation of SMUG1-generated abasic sites and is exacerbated by poly(ADP-ribose) polymerase (PARP) inhibition. However, HDR proficiency has the major role in mitigating sensitivity to chemotherapeutics, including PARP inhibitors.
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Affiliation(s)
- Pei Xin Lim
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Mahdia Zaman
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Weiran Feng
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; Louis V. Gerstner Jr. Graduate School of Biomedical Sciences, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Maria Jasin
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; Louis V. Gerstner Jr. Graduate School of Biomedical Sciences, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA.
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10
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Ito M, Fujita Y, Shinohara A. Positive and negative regulators of RAD51/DMC1 in homologous recombination and DNA replication. DNA Repair (Amst) 2024; 134:103613. [PMID: 38142595 DOI: 10.1016/j.dnarep.2023.103613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 12/10/2023] [Accepted: 12/10/2023] [Indexed: 12/26/2023]
Abstract
RAD51 recombinase plays a central role in homologous recombination (HR) by forming a nucleoprotein filament on single-stranded DNA (ssDNA) to catalyze homology search and strand exchange between the ssDNA and a homologous double-stranded DNA (dsDNA). The catalytic activity of RAD51 assembled on ssDNA is critical for the DNA-homology-mediated repair of DNA double-strand breaks in somatic and meiotic cells and restarting stalled replication forks during DNA replication. The RAD51-ssDNA complex also plays a structural role in protecting the regressed/reversed replication fork. Two types of regulators control RAD51 filament formation, stability, and dynamics, namely positive regulators, including mediators, and negative regulators, so-called remodelers. The appropriate balance of action by the two regulators assures genome stability. This review describes the roles of positive and negative RAD51 regulators in HR and DNA replication and its meiosis-specific homolog DMC1 in meiotic recombination. We also provide future study directions for a comprehensive understanding of RAD51/DMC1-mediated regulation in maintaining and inheriting genome integrity.
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Affiliation(s)
- Masaru Ito
- Institute for Protein Research, Osaka University, Yamadaoka 3-2, Suita, Osaka 565-0871, Japan.
| | - Yurika Fujita
- Institute for Protein Research, Osaka University, Yamadaoka 3-2, Suita, Osaka 565-0871, Japan.
| | - Akira Shinohara
- Institute for Protein Research, Osaka University, Yamadaoka 3-2, Suita, Osaka 565-0871, Japan.
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11
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Kumar C, Remus D. Looping out of control: R-loops in transcription-replication conflict. Chromosoma 2024; 133:37-56. [PMID: 37419963 PMCID: PMC10771546 DOI: 10.1007/s00412-023-00804-8] [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: 04/18/2023] [Revised: 06/27/2023] [Accepted: 06/28/2023] [Indexed: 07/09/2023]
Abstract
Transcription-replication conflict is a major cause of replication stress that arises when replication forks collide with the transcription machinery. Replication fork stalling at sites of transcription compromises chromosome replication fidelity and can induce DNA damage with potentially deleterious consequences for genome stability and organismal health. The block to DNA replication by the transcription machinery is complex and can involve stalled or elongating RNA polymerases, promoter-bound transcription factor complexes, or DNA topology constraints. In addition, studies over the past two decades have identified co-transcriptional R-loops as a major source for impairment of DNA replication forks at active genes. However, how R-loops impede DNA replication at the molecular level is incompletely understood. Current evidence suggests that RNA:DNA hybrids, DNA secondary structures, stalled RNA polymerases, and condensed chromatin states associated with R-loops contribute to the of fork progression. Moreover, since both R-loops and replication forks are intrinsically asymmetric structures, the outcome of R-loop-replisome collisions is influenced by collision orientation. Collectively, the data suggest that the impact of R-loops on DNA replication is highly dependent on their specific structural composition. Here, we will summarize our current understanding of the molecular basis for R-loop-induced replication fork progression defects.
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Affiliation(s)
- Charanya Kumar
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York, 10065, USA
| | - Dirk Remus
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York, 10065, USA.
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12
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González-Acosta D, Lopes M. DNA replication and replication stress response in the context of nuclear architecture. Chromosoma 2024; 133:57-75. [PMID: 38055079 PMCID: PMC10904558 DOI: 10.1007/s00412-023-00813-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 10/23/2023] [Accepted: 10/24/2023] [Indexed: 12/07/2023]
Abstract
The DNA replication process needs to be coordinated with other DNA metabolism transactions and must eventually extend to the full genome, regardless of chromatin status, gene expression, secondary structures and DNA lesions. Completeness and accuracy of DNA replication are crucial to maintain genome integrity, limiting transformation in normal cells and offering targeting opportunities for proliferating cancer cells. DNA replication is thus tightly coordinated with chromatin dynamics and 3D genome architecture, and we are only beginning to understand the underlying molecular mechanisms. While much has recently been discovered on how DNA replication initiation is organised and modulated in different genomic regions and nuclear territories-the so-called "DNA replication program"-we know much less on how the elongation of ongoing replication forks and particularly the response to replication obstacles is affected by the local nuclear organisation. Also, it is still elusive how specific components of nuclear architecture participate in the replication stress response. Here, we review known mechanisms and factors orchestrating replication initiation, and replication fork progression upon stress, focusing on recent evidence linking genome organisation and nuclear architecture with the cellular responses to replication interference, and highlighting open questions and future challenges to explore this exciting new avenue of research.
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Affiliation(s)
| | - Massimo Lopes
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland.
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13
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Han J, Mu Y, Huang J. Preserving genome integrity: The vital role of SUMO-targeted ubiquitin ligases. CELL INSIGHT 2023; 2:100128. [PMID: 38047137 PMCID: PMC10692494 DOI: 10.1016/j.cellin.2023.100128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 10/09/2023] [Accepted: 10/09/2023] [Indexed: 12/05/2023]
Abstract
Various post-translational modifications (PTMs) collaboratively fine-tune protein activities. SUMO-targeted ubiquitin E3 ligases (STUbLs) emerge as specialized enzymes that recognize SUMO-modified substrates through SUMO-interaction motifs and subsequently ubiquitinate them via the RING domain, thereby bridging the SUMO and ubiquitin signaling pathways. STUbLs participate in a wide array of molecular processes, including cell cycle regulation, DNA repair, replication, and mitosis, operating under both normal conditions and in response to challenges such as genotoxic stress. Their ability to catalyze various types of ubiquitin chains results in diverse proteolytic and non-proteolytic outcomes for target substrates. Importantly, STUbLs are strategically positioned in close proximity to SUMO proteases and deubiquitinases (DUBs), ensuring precise and dynamic control over their target proteins. In this review, we provide insights into the unique properties and indispensable roles of STUbLs, with a particular emphasis on their significance in preserving genome integrity in humans.
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Affiliation(s)
- Jinhua Han
- Institute of Geriatrics, Affiliated Zhejiang Hospital, Zhejiang University School of Medicine, Hangzhou, 310030, Zhejiang, China
- The MOE Key Laboratory of Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network, Life Sciences Institute, Zhejiang University, Hangzhou, 310058, Zhejiang, China
| | - Yanhua Mu
- National-Local Joint Engineering Research Center of Biodiagnosis & Biotherapy, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710004, Shaanxi, China
| | - Jun Huang
- Institute of Geriatrics, Affiliated Zhejiang Hospital, Zhejiang University School of Medicine, Hangzhou, 310030, Zhejiang, China
- The MOE Key Laboratory of Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network, Life Sciences Institute, Zhejiang University, Hangzhou, 310058, Zhejiang, China
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14
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Heuzé J, Kemiha S, Barthe A, Vilarrubias AT, Aouadi E, Aiello U, Libri D, Lin Y, Lengronne A, Poli J, Pasero P. RNase H2 degrades toxic RNA:DNA hybrids behind stalled forks to promote replication restart. EMBO J 2023; 42:e113104. [PMID: 37855233 PMCID: PMC10690446 DOI: 10.15252/embj.2022113104] [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: 11/20/2022] [Revised: 09/27/2023] [Accepted: 10/04/2023] [Indexed: 10/20/2023] Open
Abstract
R-loops represent a major source of replication stress, but the mechanism by which these structures impede fork progression remains unclear. To address this question, we monitored fork progression, arrest, and restart in Saccharomyces cerevisiae cells lacking RNase H1 and H2, two enzymes responsible for degrading RNA:DNA hybrids. We found that while RNase H-deficient cells could replicate their chromosomes normally under unchallenged growth conditions, their replication was impaired when exposed to hydroxyurea (HU) or methyl methanesulfonate (MMS). Treated cells exhibited increased levels of RNA:DNA hybrids at stalled forks and were unable to generate RPA-coated single-stranded (ssDNA), an important postreplicative intermediate in resuming replication. Similar impairments in nascent DNA resection and ssDNA formation at HU-arrested forks were observed in human cells lacking RNase H2. However, fork resection was fully restored by addition of triptolide, an inhibitor of transcription that induces RNA polymerase degradation. Taken together, these data indicate that RNA:DNA hybrids not only act as barriers to replication forks, but also interfere with postreplicative fork repair mechanisms if not promptly degraded by RNase H.
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Affiliation(s)
- Jonathan Heuzé
- Institut de Génétique HumaineUniversité de Montpellier, CNRS, Equipe labélisée Ligue contre le CancerMontpellierFrance
| | - Samira Kemiha
- Institut de Génétique HumaineUniversité de Montpellier, CNRS, Equipe labélisée Ligue contre le CancerMontpellierFrance
| | - Antoine Barthe
- Institut de Génétique HumaineUniversité de Montpellier, CNRS, Equipe labélisée Ligue contre le CancerMontpellierFrance
| | - Alba Torán Vilarrubias
- Institut de Génétique HumaineUniversité de Montpellier, CNRS, Equipe labélisée Ligue contre le CancerMontpellierFrance
| | - Elyès Aouadi
- Institut de Génétique HumaineUniversité de Montpellier, CNRS, Equipe labélisée Ligue contre le CancerMontpellierFrance
| | - Umberto Aiello
- Université Paris Cité, CNRS, Institut Jacques MonodParisFrance
- Department of GeneticsStanford UniversityStanfordCAUSA
| | - Domenico Libri
- Université Paris Cité, CNRS, Institut Jacques MonodParisFrance
- Present address:
Institut de Génétique Moléculaire de MontpellierUniversité de Montpellier, CNRSMontpellierFrance
| | - Yea‐Lih Lin
- Institut de Génétique HumaineUniversité de Montpellier, CNRS, Equipe labélisée Ligue contre le CancerMontpellierFrance
| | - Armelle Lengronne
- Institut de Génétique HumaineUniversité de Montpellier, CNRS, Equipe labélisée Ligue contre le CancerMontpellierFrance
| | - Jérôme Poli
- Institut de Génétique HumaineUniversité de Montpellier, CNRS, Equipe labélisée Ligue contre le CancerMontpellierFrance
- Institut Universitaire de France (IUF)ParisFrance
| | - Philippe Pasero
- Institut de Génétique HumaineUniversité de Montpellier, CNRS, Equipe labélisée Ligue contre le CancerMontpellierFrance
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15
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Palumbieri MD, Merigliano C, González-Acosta D, Kuster D, Krietsch J, Stoy H, von Känel T, Ulferts S, Welter B, Frey J, Doerdelmann C, Sanchi A, Grosse R, Chiolo I, Lopes M. Nuclear actin polymerization rapidly mediates replication fork remodeling upon stress by limiting PrimPol activity. Nat Commun 2023; 14:7819. [PMID: 38016948 PMCID: PMC10684888 DOI: 10.1038/s41467-023-43183-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 11/02/2023] [Indexed: 11/30/2023] Open
Abstract
Cells rapidly respond to replication stress actively slowing fork progression and inducing fork reversal. How replication fork plasticity is achieved in the context of nuclear organization is currently unknown. Using nuclear actin probes in living and fixed cells, we visualized nuclear actin filaments in unperturbed S phase and observed their rapid extension in number and length upon genotoxic treatments, frequently taking contact with replication factories. Chemically or genetically impairing nuclear actin polymerization shortly before these treatments prevents active fork slowing and abolishes fork reversal. Defective fork remodeling is linked to deregulated chromatin loading of PrimPol, which promotes unrestrained and discontinuous DNA synthesis and limits the recruitment of RAD51 and SMARCAL1 to nascent DNA. Moreover, defective nuclear actin polymerization upon mild replication interference induces chromosomal instability in a PRIMPOL-dependent manner. Hence, by limiting PrimPol activity, nuclear F-actin orchestrates replication fork plasticity and is a key molecular determinant in the rapid cellular response to genotoxic treatments.
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Affiliation(s)
| | - Chiara Merigliano
- Molecular and Computational Biology Department, University of Southern California, Los Angeles, CA, USA
| | | | - Danina Kuster
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Jana Krietsch
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Henriette Stoy
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
- Department of Cellular and Molecular Medicine, Copenhagen University, Copenhagen, Denmark
| | - Thomas von Känel
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Svenja Ulferts
- Institute of Experimental and Clinical Pharmacology and Toxicology, Medical Faculty, University of Freiburg, Freiburg im Breisgau, Germany
| | - Bettina Welter
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Joël Frey
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Cyril Doerdelmann
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Andrea Sanchi
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Robert Grosse
- Institute of Experimental and Clinical Pharmacology and Toxicology, Medical Faculty, University of Freiburg, Freiburg im Breisgau, Germany
- CIBSS - Centre for Integrative Biological Signaling Studies, University of Freiburg, Freiburg im Breisgau, Germany
| | - Irene Chiolo
- Molecular and Computational Biology Department, University of Southern California, Los Angeles, CA, USA.
| | - Massimo Lopes
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland.
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16
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Guh CL, Lei KH, Chen YA, Jiang YZ, Chang HY, Liaw H, Li HW, Yen HY, Chi P. RAD51 paralogs synergize with RAD51 to protect reversed forks from cellular nucleases. Nucleic Acids Res 2023; 51:11717-11731. [PMID: 37843130 PMCID: PMC10681713 DOI: 10.1093/nar/gkad856] [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: 04/14/2023] [Revised: 09/12/2023] [Accepted: 09/23/2023] [Indexed: 10/17/2023] Open
Abstract
Fork reversal is a conserved mechanism to prevent stalled replication forks from collapsing. Formation and protection of reversed forks are two crucial steps in ensuring fork integrity and stability. Five RAD51 paralogs, namely, RAD51B, RAD51C, RAD51D, XRCC2 and XRCC3, which share sequence and structural similarity to the recombinase RAD51, play poorly defined mechanistic roles in these processes. Here, using purified BCDX2 (RAD51BCD-XRCC2) and CX3 (RAD51C-XRCC3) complexes and in vitro reconstituted biochemical systems, we mechanistically dissect their functions in forming and protecting reversed forks. We show that both RAD51 paralog complexes lack fork reversal activities. Whereas CX3 exhibits modest fork protection activity, BCDX2 significantly synergizes with RAD51 to protect DNA against attack by the nucleases MRE11 and EXO1. DNA protection is contingent upon the ability of RAD51 to form a functional nucleoprotein filament on DNA. Collectively, our results provide evidence for a hitherto unknown function of RAD51 paralogs in synergizing with RAD51 nucleoprotein filament to prevent degradation of stressed replication forks.
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Affiliation(s)
- Chia-Lun Guh
- Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan
| | - Kai-Hang Lei
- Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan
| | - Yi-An Chen
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Yi-Zhen Jiang
- Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan
| | - Hao-Yen Chang
- Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Hungjiun Liaw
- Department of Life Sciences, National Cheng Kung University, Tainan, Taiwan
| | - Hung-Wen Li
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Hsin-Yung Yen
- Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Peter Chi
- Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
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17
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Bellani MA, Shaik A, Majumdar I, Ling C, Seidman MM. The Response of the Replication Apparatus to Leading Template Strand Blocks. Cells 2023; 12:2607. [PMID: 37998342 PMCID: PMC10670059 DOI: 10.3390/cells12222607] [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: 10/23/2023] [Revised: 11/07/2023] [Accepted: 11/08/2023] [Indexed: 11/25/2023] Open
Abstract
Duplication of the genome requires the replication apparatus to overcome a variety of impediments, including covalent DNA adducts, the most challenging of which is on the leading template strand. Replisomes consist of two functional units, a helicase to unwind DNA and polymerases to synthesize it. The helicase is a multi-protein complex that encircles the leading template strand and makes the first contact with a leading strand adduct. The size of the channel in the helicase would appear to preclude transit by large adducts such as DNA: protein complexes (DPC). Here we discuss some of the extensively studied pathways that support replication restart after replisome encounters with leading template strand adducts. We also call attention to recent work that highlights the tolerance of the helicase for adducts ostensibly too large to pass through the central channel.
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Affiliation(s)
| | | | | | | | - Michael M. Seidman
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA; (M.A.B.)
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18
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Appleby R, Joudeh L, Cobbett K, Pellegrini L. Structural basis for stabilisation of the RAD51 nucleoprotein filament by BRCA2. Nat Commun 2023; 14:7003. [PMID: 37919288 PMCID: PMC10622577 DOI: 10.1038/s41467-023-42830-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 10/23/2023] [Indexed: 11/04/2023] Open
Abstract
The BRCA2 tumour suppressor protein preserves genomic integrity via interactions with the DNA-strand exchange RAD51 protein in homology-directed repair. The RAD51-binding TR2 motif at the BRCA2 C-terminus is essential for protection and restart of stalled replication forks. Biochemical evidence shows that TR2 recognises filamentous RAD51, but existing models of TR2 binding to RAD51 lack a structural basis. Here we used cryo-electron microscopy and structure-guided mutagenesis to elucidate the mechanism of TR2 binding to nucleoprotein filaments of human RAD51. We find that TR2 binds across the protomer interface in the filament, acting as a brace for adjacent RAD51 molecules. TR2 targets an acidic-patch motif on human RAD51 that serves as a recruitment hub in fission yeast Rad51 for recombination mediators Rad52 and Rad55-Rad57. Our findings provide a structural rationale for RAD51 filament stabilisation by BRCA2 and reveal a common recruitment mechanism of recombination mediators to the RAD51 filament.
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Affiliation(s)
- Robert Appleby
- Department of Biochemistry, University of Cambridge, Cambridge, CB2 1GA, UK
| | - Luay Joudeh
- Department of Biochemistry, University of Cambridge, Cambridge, CB2 1GA, UK
| | - Katie Cobbett
- Department of Biochemistry, University of Cambridge, Cambridge, CB2 1GA, UK
| | - Luca Pellegrini
- Department of Biochemistry, University of Cambridge, Cambridge, CB2 1GA, UK.
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19
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Bhowmick R, Hickson ID, Liu Y. Completing genome replication outside of S phase. Mol Cell 2023; 83:3596-3607. [PMID: 37716351 DOI: 10.1016/j.molcel.2023.08.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 08/03/2023] [Accepted: 08/17/2023] [Indexed: 09/18/2023]
Abstract
Mitotic DNA synthesis (MiDAS) is an unusual form of DNA replication that occurs during mitosis. Initially, MiDAS was characterized as a process associated with intrinsically unstable loci known as common fragile sites that occurs after cells experience DNA replication stress (RS). However, it is now believed to be a more widespread "salvage" mechanism that is called upon to complete the duplication of any under-replicated genomic region. Emerging data suggest that MiDAS is a DNA repair process potentially involving two or more pathways working in parallel or sequentially. In this review, we introduce the causes of RS, regions of the human genome known to be especially vulnerable to RS, and the strategies used to complete DNA replication outside of S phase. Additionally, because MiDAS is a prominent feature of aneuploid cancer cells, we will discuss how targeting MiDAS might potentially lead to improvements in cancer therapy.
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Affiliation(s)
- Rahul Bhowmick
- Center for Chromosome Stability and Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, Panum Institute, Blegdamsvej 3B, 2200 Copenhagen N, Denmark; Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Ian D Hickson
- Center for Chromosome Stability and Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, Panum Institute, Blegdamsvej 3B, 2200 Copenhagen N, Denmark.
| | - Ying Liu
- Center for Chromosome Stability and Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, Panum Institute, Blegdamsvej 3B, 2200 Copenhagen N, Denmark.
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20
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Adolph MB, Garje AS, Balakrishnan S, Morati F, Modesti M, Chazin WJ, Cortez D. CRISPR-dependent Base Editing Screens Identify Separation of Function Mutants of RADX with Altered RAD51 Regulatory Activity. J Mol Biol 2023; 435:168236. [PMID: 37572935 PMCID: PMC10530557 DOI: 10.1016/j.jmb.2023.168236] [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: 06/19/2023] [Revised: 08/01/2023] [Accepted: 08/04/2023] [Indexed: 08/14/2023]
Abstract
RAD51 forms nucleoprotein filaments to promote homologous recombination, replication fork reversal, and fork protection. Numerous factors regulate the stability of these filaments and improper regulation leads to genomic instability and ultimately disease including cancer. RADX is a single stranded DNA binding protein that modulates RAD51 filament stability. Here, we utilize a CRISPR-dependent base editing screen to tile mutations across RADX to delineate motifs required for RADX function. We identified separation of function mutants of RADX that bind DNA and RAD51 but have a reduced ability to stimulate its ATP hydrolysis activity. Cells expressing these RADX mutants accumulate RAD51 on chromatin, exhibit replication defects, have reduced growth, accumulate DNA damage, and are hypersensitive to DNA damage and replication stress. These results indicate that RADX must promote RAD51 ATP turnover to regulate RAD51 and genome stability during DNA replication.
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Affiliation(s)
- Madison B Adolph
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Atharv S Garje
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Swati Balakrishnan
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, USA; Center for Structural Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Florian Morati
- Cancer Research Center of Marseille, Department of Genome Integrity, CNRS UMR7258, Inserm U1068, Institut Paoli-Calmettes, Aix Marseille Univ, Marseille, France
| | - Mauro Modesti
- Cancer Research Center of Marseille, Department of Genome Integrity, CNRS UMR7258, Inserm U1068, Institut Paoli-Calmettes, Aix Marseille Univ, Marseille, France
| | - Walter J Chazin
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, USA; Center for Structural Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - David Cortez
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, USA.
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21
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Liu W, Polaczek P, Roubal I, Meng Y, Choe WC, Caron MC, Sedgeman C, Xi Y, Liu C, Wu Q, Zheng L, Masson JY, Shen B, Campbell J. FANCD2 and RAD51 recombinase directly inhibit DNA2 nuclease at stalled replication forks and FANCD2 acts as a novel RAD51 mediator in strand exchange to promote genome stability. Nucleic Acids Res 2023; 51:9144-9165. [PMID: 37526271 PMCID: PMC10516637 DOI: 10.1093/nar/gkad624] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 06/17/2023] [Accepted: 07/28/2023] [Indexed: 08/02/2023] Open
Abstract
FANCD2 protein, a key coordinator and effector of the interstrand crosslink repair pathway, is also required to prevent excessive nascent strand degradation at hydroxyurea-induced stalled forks. The RAD51 recombinase has also been implicated in regulation of resection at stalled replication forks. The mechanistic contributions of these proteins to fork protection are not well understood. Here, we used purified FANCD2 and RAD51 to study how each protein regulates DNA resection at stalled forks. We characterized three mechanisms of FANCD2-mediated fork protection: (1) The N-terminal domain of FANCD2 inhibits the essential DNA2 nuclease activity by directly binding to DNA2 accounting for over-resection in FANCD2 defective cells. (2) Independent of dimerization with FANCI, FANCD2 itself stabilizes RAD51 filaments to inhibit multiple nucleases, including DNA2, MRE11 and EXO1. (3) Unexpectedly, we uncovered a new FANCD2 function: by stabilizing RAD51 filaments, FANCD2 acts to stimulate the strand exchange activity of RAD51. Our work biochemically explains non-canonical mechanisms by which FANCD2 and RAD51 protect stalled forks. We propose a model in which the strand exchange activity of FANCD2 provides a simple molecular explanation for genetic interactions between FANCD2 and BRCA2 in the FA/BRCA fork protection pathway.
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Affiliation(s)
- Wenpeng Liu
- Braun Laboratories, California Institute of Technology, Pasadena, CA 91125, USA
- Colleges of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Piotr Polaczek
- Braun Laboratories, California Institute of Technology, Pasadena, CA 91125, USA
| | - Ivan Roubal
- Braun Laboratories, California Institute of Technology, Pasadena, CA 91125, USA
| | - Yuan Meng
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, 1500 East Duarte Road, Duarte, CA 91010-3000, USA
- Colleges of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Won-chae Choe
- Braun Laboratories, California Institute of Technology, Pasadena, CA 91125, USA
| | - Marie-Christine Caron
- Genome Stability Laboratory, CHU de Québec Research Center, HDQ Pavilion, Oncology Division, 9 McMahon, Québec City, QC G1R 3S3, Canada
| | - Carl A Sedgeman
- Braun Laboratories, California Institute of Technology, Pasadena, CA 91125, USA
| | - Yu Xi
- Colleges of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Changwei Liu
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, 1500 East Duarte Road, Duarte, CA 91010-3000, USA
- Colleges of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Qiong Wu
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, 1500 East Duarte Road, Duarte, CA 91010-3000, USA
| | - Li Zheng
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, 1500 East Duarte Road, Duarte, CA 91010-3000, USA
| | - Jean-Yves Masson
- Genome Stability Laboratory, CHU de Québec Research Center, HDQ Pavilion, Oncology Division, 9 McMahon, Québec City, QC G1R 3S3, Canada
- Department of Molecular Biology, Medical Biochemistry and Pathology; Laval University Cancer Research Center, Québec City, QC G1V 0A6, Canada
| | - Binghui Shen
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, 1500 East Duarte Road, Duarte, CA 91010-3000, USA
| | - Judith L Campbell
- Braun Laboratories, California Institute of Technology, Pasadena, CA 91125, USA
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22
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Chakraborty S, Schirmeisen K, Lambert SA. The multifaceted functions of homologous recombination in dealing with replication-associated DNA damages. DNA Repair (Amst) 2023; 129:103548. [PMID: 37541027 DOI: 10.1016/j.dnarep.2023.103548] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 07/26/2023] [Accepted: 07/27/2023] [Indexed: 08/06/2023]
Abstract
The perturbation of DNA replication, a phenomena termed "replication stress", is a driving force of genome instability and a hallmark of cancer cells. Among the DNA repair mechanisms that contribute to tolerating replication stress, the homologous recombination pathway is central to the alteration of replication fork progression. In many organisms, defects in the homologous recombination machinery result in increased cell sensitivity to replication-blocking agents and a higher risk of cancer in humans. Moreover, the status of homologous recombination in cancer cells often correlates with the efficacy of anti-cancer treatment. In this review, we discuss our current understanding of the different functions of homologous recombination in fixing replication-associated DNA damage and contributing to complete genome duplication. We also examine which functions are pivotal in preventing cancer and genome instability.
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Affiliation(s)
- Shrena Chakraborty
- Institut Curie, Université PSL, CNRS UMR3348, 91400 Orsay, France; Université Paris-Saclay, CNRS UMR3348, 91400 Orsay, France; Equipe Labelisée Ligue Nationale Contre le Cancer, France
| | - Kamila Schirmeisen
- Institut Curie, Université PSL, CNRS UMR3348, 91400 Orsay, France; Université Paris-Saclay, CNRS UMR3348, 91400 Orsay, France; Equipe Labelisée Ligue Nationale Contre le Cancer, France
| | - Sarah Ae Lambert
- Institut Curie, Université PSL, CNRS UMR3348, 91400 Orsay, France; Université Paris-Saclay, CNRS UMR3348, 91400 Orsay, France; Equipe Labelisée Ligue Nationale Contre le Cancer, France.
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23
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Saldanha J, Rageul J, Patel JA, Kim H. The Adaptive Mechanisms and Checkpoint Responses to a Stressed DNA Replication Fork. Int J Mol Sci 2023; 24:10488. [PMID: 37445667 PMCID: PMC10341514 DOI: 10.3390/ijms241310488] [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: 05/26/2023] [Revised: 06/13/2023] [Accepted: 06/20/2023] [Indexed: 07/15/2023] Open
Abstract
DNA replication is a tightly controlled process that ensures the faithful duplication of the genome. However, DNA damage arising from both endogenous and exogenous assaults gives rise to DNA replication stress associated with replication fork slowing or stalling. Therefore, protecting the stressed fork while prompting its recovery to complete DNA replication is critical for safeguarding genomic integrity and cell survival. Specifically, the plasticity of the replication fork in engaging distinct DNA damage tolerance mechanisms, including fork reversal, repriming, and translesion DNA synthesis, enables cells to overcome a variety of replication obstacles. Furthermore, stretches of single-stranded DNA generated upon fork stalling trigger the activation of the ATR kinase, which coordinates the cellular responses to replication stress by stabilizing the replication fork, promoting DNA repair, and controlling cell cycle and replication origin firing. Deregulation of the ATR checkpoint and aberrant levels of chronic replication stress is a common characteristic of cancer and a point of vulnerability being exploited in cancer therapy. Here, we discuss the various adaptive responses of a replication fork to replication stress and the roles of ATR signaling that bring fork stabilization mechanisms together. We also review how this knowledge is being harnessed for the development of checkpoint inhibitors to trigger the replication catastrophe of cancer cells.
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Affiliation(s)
- Joanne Saldanha
- The Graduate Program in Genetics, Stony Brook University, Stony Brook, NY 11794, USA
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794, USA
| | - Julie Rageul
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794, USA
| | - Jinal A Patel
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794, USA
| | - Hyungjin Kim
- The Graduate Program in Genetics, Stony Brook University, Stony Brook, NY 11794, USA
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794, USA
- Stony Brook Cancer Center, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY 11794, USA
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