1
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Guan Y, He H, Guo Y, Zhang L. Essential roles of Rad6 in conidial property, stress tolerance, and pathogenicity of Beauveria bassiana. Virulence 2024; 15:2362748. [PMID: 38860453 PMCID: PMC11174126 DOI: 10.1080/21505594.2024.2362748] [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: 01/12/2024] [Accepted: 05/28/2024] [Indexed: 06/12/2024] Open
Abstract
Rad6 functions as a ubiquitin-conjugating protein that regulates cellular processes in many fungal species. However, its role in filamentous entomopathogenic fungi remains poorly understood. This study characterizes Rad6 in Beauveria bassiana, a filamentous fungus widely employed as a critical fungicide globally. The results demonstrate a significant association between Rad6 and conidial properties, heat shock response, and UV-B tolerance. Concurrently, the mutant strain exhibited heightened sensitivity to oxidative stress, cell wall interfering agents, DNA damage stress, and prolonged heat shock. Furthermore, the absence of Rad6 significantly extended the median lethal time (LT50) of Galleria mellonella infected by B. bassiana. This delay could be attributed to reduced Pr1 proteases and extracellular cuticle-degrading enzymes, diminished dimorphic transition rates, and dysregulated antioxidant enzymes. Additionally, the absence of Rad6 had a more pronounced effect on genetic information processing, metabolism, and cellular processes under normal conditions. However, its impact was limited to metabolism in oxidative stress. This study offers a comprehensive understanding of the pivotal roles of Rad6 in conidial and hyphal stress tolerance, environmental adaptation, and the pathogenesis of Beauveria bassiana.
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Affiliation(s)
- Yi Guan
- Fujian Key Laboratory of Marine Enzyme Engineering, Fuzhou University, Fuzhou, Fujian, China
| | - Haomin He
- Fujian Key Laboratory of Marine Enzyme Engineering, Fuzhou University, Fuzhou, Fujian, China
| | - Yuhan Guo
- Fujian Key Laboratory of Marine Enzyme Engineering, Fuzhou University, Fuzhou, Fujian, China
| | - Longbin Zhang
- Fujian Key Laboratory of Marine Enzyme Engineering, Fuzhou University, Fuzhou, Fujian, China
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2
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García-Rodríguez N, Domínguez-García I, Domínguez-Pérez MD, Huertas P. EXO1 and DNA2-mediated ssDNA gap expansion is essential for ATR activation and to maintain viability in BRCA1-deficient cells. Nucleic Acids Res 2024; 52:6376-6391. [PMID: 38721777 PMCID: PMC11194085 DOI: 10.1093/nar/gkae317] [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: 10/06/2023] [Revised: 03/25/2024] [Accepted: 05/02/2024] [Indexed: 06/25/2024] Open
Abstract
DNA replication faces challenges from DNA lesions originated from endogenous or exogenous sources of stress, leading to the accumulation of single-stranded DNA (ssDNA) that triggers the activation of the ATR checkpoint response. To complete genome replication in the presence of damaged DNA, cells employ DNA damage tolerance mechanisms that operate not only at stalled replication forks but also at ssDNA gaps originated by repriming of DNA synthesis downstream of lesions. Here, we demonstrate that human cells accumulate post-replicative ssDNA gaps following replicative stress induction. These gaps, initiated by PrimPol repriming and expanded by the long-range resection factors EXO1 and DNA2, constitute the principal origin of the ssDNA signal responsible for ATR activation upon replication stress, in contrast to stalled forks. Strikingly, the loss of EXO1 or DNA2 results in synthetic lethality when combined with BRCA1 deficiency, but not BRCA2. This phenomenon aligns with the observation that BRCA1 alone contributes to the expansion of ssDNA gaps. Remarkably, BRCA1-deficient cells become addicted to the overexpression of EXO1, DNA2 or BLM. This dependence on long-range resection unveils a new vulnerability of BRCA1-mutant tumors, shedding light on potential therapeutic targets for these cancers.
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Affiliation(s)
- Néstor García-Rodríguez
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Sevilla, Spain
- Departamento de Genética, Universidad de Sevilla, Sevilla, Spain
| | - Iria Domínguez-García
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Sevilla, Spain
- Departamento de Genética, Universidad de Sevilla, Sevilla, Spain
| | - María del Carmen Domínguez-Pérez
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Sevilla, Spain
- Departamento de Genética, Universidad de Sevilla, Sevilla, Spain
| | - Pablo Huertas
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Sevilla, Spain
- Departamento de Genética, Universidad de Sevilla, Sevilla, Spain
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3
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Meyer D, Ceballos SJ, Gore S, Liu J, Reginato G, Cano-Linares MI, Maslowska KH, Villafañez F, Ede C, Pagès V, Prado F, Cejka P, Heyer WD. Rad51 determines pathway usage in post-replication repair. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.14.599120. [PMID: 38915629 PMCID: PMC11195247 DOI: 10.1101/2024.06.14.599120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
Stalled replication forks can be processed by several distinct mechanisms collectively called post-replication repair which includes homologous recombination, fork regression, and translesion DNA synthesis. However, the regulation of the usage between these pathways is not fully understood. The Rad51 protein plays a pivotal role in maintaining genomic stability through its roles in HR and in protecting stalled replication forks from degradation. We report the isolation of separation-of-function mutations in Saccharomyces cerevisiae Rad51 that retain their recombination function but display a defect in fork protection leading to a shift in post-replication repair pathway usage from HR to alternate pathways including mutagenic translesion synthesis. Rad51-E135D and Rad51-K305N show normal in vivo and in vitro recombination despite changes in their DNA binding profiles, in particular to dsDNA, with a resulting effect on their ATPase activities. The mutants lead to a defect in Rad51 recruitment to stalled forks in vivo as well as a defect in the protection of dsDNA from degradation by Dna2-Sgs1 and Exo1 in vitro . A high-resolution cryo-electron microscopy structure of the Rad51-ssDNA filament at 2.4 Å resolution provides a structural basis for a mechanistic understanding of the mutant phenotypes. Together, the evidence suggests a model in which Rad51 binding to duplex DNA is critical to control pathway usage at stalled replication forks.
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4
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Khatib JB, Nicolae CM, Moldovan GL. Role of Translesion DNA Synthesis in the Metabolism of Replication-associated Nascent Strand Gaps. J Mol Biol 2024; 436:168275. [PMID: 37714300 PMCID: PMC10842951 DOI: 10.1016/j.jmb.2023.168275] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 08/11/2023] [Accepted: 09/08/2023] [Indexed: 09/17/2023]
Abstract
Translesion DNA synthesis (TLS) is a DNA damage tolerance pathway utilized by cells to overcome lesions encountered throughout DNA replication. During replication stress, cancer cells show increased dependency on TLS proteins for cellular survival and chemoresistance. TLS proteins have been described to be involved in various DNA repair pathways. One of the major emerging roles of TLS is single-stranded DNA (ssDNA) gap-filling, primarily after the repriming activity of PrimPol upon encountering a lesion. Conversely, suppression of ssDNA gap accumulation by TLS is considered to represent a mechanism for cancer cells to evade the toxicity of chemotherapeutic agents, specifically in BRCA-deficient cells. Thus, TLS inhibition is emerging as a potential treatment regimen for DNA repair-deficient tumors.
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Affiliation(s)
- Jude B Khatib
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA. https://twitter.com/JudeBKhatib
| | - Claudia M Nicolae
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - George-Lucian Moldovan
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA.
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5
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Capece M, Tessari A, Mills J, Vinciguerra GLR, Louke D, Lin C, McElwain BK, Miles WO, Coppola V, Davies AE, Palmieri D, Croce CM. A novel auxin-inducible degron system for rapid, cell cycle-specific targeted proteolysis. Cell Death Differ 2023; 30:2078-2091. [PMID: 37537305 PMCID: PMC10482871 DOI: 10.1038/s41418-023-01191-4] [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: 11/22/2022] [Revised: 06/02/2023] [Accepted: 07/03/2023] [Indexed: 08/05/2023] Open
Abstract
The discrimination of protein biological functions in different phases of the cell cycle is limited by the lack of experimental approaches that do not require pre-treatment with compounds affecting the cell cycle progression. Therefore, potential cycle-specific biological functions of a protein of interest could be biased by the effects of cell treatments. The OsTIR1/auxin-inducible degron (AID) system allows "on demand" selective and reversible protein degradation upon exposure to the phytohormone auxin. In the current format, this technology does not allow to study the effect of acute protein depletion selectively in one phase of the cell cycle, as auxin similarly affects all the treated cells irrespectively of their proliferation status. Therefore, the AID system requires coupling with cell synchronization techniques, which can alter the basal biological status of the studied cell population, as with previously available approaches. Here, we introduce a new AID system to Regulate OsTIR1 Levels based on the Cell Cycle Status (ROLECCS system), which induces proteolysis of both exogenously transfected and endogenous gene-edited targets in specific phases of the cell cycle. We validated the ROLECCS technology by down regulating the protein levels of TP53, one of the most studied tumor suppressor genes, with a widely known role in cell cycle progression. By using our novel tool, we observed that TP53 degradation is associated with increased number of micronuclei, and this phenotype is specifically achieved when TP53 is lost in S/G2/M phases of the cell cycle, but not in G1. Therefore, we propose the use of the ROLECCS system as a new improved way of studying the differential roles that target proteins may have in specific phases of the cell cycle.
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Affiliation(s)
- Marina Capece
- Department of Cancer Biology and Genetics, College of Medicine, The Ohio State University, 43210, Columbus, OH, USA
- The Ohio State University Wexner Medical Center and Comprehensive Cancer Center, 43210, Columbus, OH, USA
| | - Anna Tessari
- Department of Cancer Biology and Genetics, College of Medicine, The Ohio State University, 43210, Columbus, OH, USA
- The Ohio State University Wexner Medical Center and Comprehensive Cancer Center, 43210, Columbus, OH, USA
| | - Joseph Mills
- Department of Cancer Biology and Genetics, College of Medicine, The Ohio State University, 43210, Columbus, OH, USA
- The Ohio State University Wexner Medical Center and Comprehensive Cancer Center, 43210, Columbus, OH, USA
| | - Gian Luca Rampioni Vinciguerra
- Department of Cancer Biology and Genetics, College of Medicine, The Ohio State University, 43210, Columbus, OH, USA
- The Ohio State University Wexner Medical Center and Comprehensive Cancer Center, 43210, Columbus, OH, USA
| | - Darian Louke
- The Ohio State University Wexner Medical Center and Comprehensive Cancer Center, 43210, Columbus, OH, USA
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, 43210, Columbus, OH, USA
| | - Chenyu Lin
- Department of Cancer Biology and Genetics, College of Medicine, The Ohio State University, 43210, Columbus, OH, USA
- The Ohio State University Wexner Medical Center and Comprehensive Cancer Center, 43210, Columbus, OH, USA
| | - Bryan K McElwain
- Department of Cancer Biology and Genetics, College of Medicine, The Ohio State University, 43210, Columbus, OH, USA
- The Ohio State University Wexner Medical Center and Comprehensive Cancer Center, 43210, Columbus, OH, USA
| | - Wayne O Miles
- Department of Cancer Biology and Genetics, College of Medicine, The Ohio State University, 43210, Columbus, OH, USA
- The Ohio State University Wexner Medical Center and Comprehensive Cancer Center, 43210, Columbus, OH, USA
| | - Vincenzo Coppola
- Department of Cancer Biology and Genetics, College of Medicine, The Ohio State University, 43210, Columbus, OH, USA
- The Ohio State University Wexner Medical Center and Comprehensive Cancer Center, 43210, Columbus, OH, USA
| | - Alexander E Davies
- The Ohio State University Wexner Medical Center and Comprehensive Cancer Center, 43210, Columbus, OH, USA
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, 43210, Columbus, OH, USA
| | - Dario Palmieri
- Department of Cancer Biology and Genetics, College of Medicine, The Ohio State University, 43210, Columbus, OH, USA.
- The Ohio State University Wexner Medical Center and Comprehensive Cancer Center, 43210, Columbus, OH, USA.
- Gene Editing Shared Resource, The Ohio State University Wexner Medical Center and Comprehensive Cancer Center, 43210, Columbus, OH, USA.
| | - Carlo M Croce
- Department of Cancer Biology and Genetics, College of Medicine, The Ohio State University, 43210, Columbus, OH, USA.
- The Ohio State University Wexner Medical Center and Comprehensive Cancer Center, 43210, Columbus, OH, USA.
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6
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Egger T, Aze A, Maiorano D. Detection of endogenous translesion DNA synthesis in single mammalian cells. CELL REPORTS METHODS 2023; 3:100501. [PMID: 37426760 PMCID: PMC10326377 DOI: 10.1016/j.crmeth.2023.100501] [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: 07/18/2022] [Revised: 02/07/2023] [Accepted: 05/18/2023] [Indexed: 07/11/2023]
Abstract
Translesion DNA synthesis (TLS) is an evolutionarily conserved process that cells activate to tolerate DNA damage. TLS facilitates proliferation under DNA damage conditions and is exploited by cancer cells to gain therapy resistance. It has been so far challenging to analyze endogenous TLS factors such as PCNAmUb and TLS DNA polymerases in single mammalian cells due to a lack of suitable detection tools. We have adapted a flow cytometry-based quantitative method allowing detection of endogenous, chromatin-bound TLS factors in single mammalian cells, either untreated or exposed to DNA-damaging agents. This high-throughput procedure is quantitative, accurate, and allows unbiased analysis of TLS factors' recruitment to chromatin, as well as occurrence of DNA lesions with respect to the cell cycle. We also demonstrate detection of endogenous TLS factors by immunofluorescence microscopy and provide insights into TLS dynamics upon DNA replication forks stalled by UV-C-induced DNA damage.
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Affiliation(s)
- Tom Egger
- Institut de Génétique Humaine (IGH) CNRS UMR9002, Université de Montpellier, Molecular Bases of Human Pathologies Department, “Genome Surveillance and Stability” Laboratory, 34396 Cedex 5 Montpellier, France
| | - Antoine Aze
- Institut de Génétique Humaine (IGH) CNRS UMR9002, Université de Montpellier, Molecular Bases of Human Pathologies Department, “Genome Surveillance and Stability” Laboratory, 34396 Cedex 5 Montpellier, France
| | - Domenico Maiorano
- Institut de Génétique Humaine (IGH) CNRS UMR9002, Université de Montpellier, Molecular Bases of Human Pathologies Department, “Genome Surveillance and Stability” Laboratory, 34396 Cedex 5 Montpellier, France
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7
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El-Sawy SA, Amin YA, El-Naggar SA, Abdelsadik A. Artemisia annua L. (Sweet wormwood) leaf extract attenuates high-fat diet-induced testicular dysfunctions and improves spermatogenesis in obese rats. JOURNAL OF ETHNOPHARMACOLOGY 2023; 313:116528. [PMID: 37127141 DOI: 10.1016/j.jep.2023.116528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 04/15/2023] [Accepted: 04/18/2023] [Indexed: 05/03/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Artemisia annua L., known as "sweet wormwood," is widely used in Egyptian folk medicine. Egyptians implement the aerial parts in the treatment of respiratory, digestive and sexual dysfunctions. However, the mechanism by which Artemisia annua improves testicular function is still being discovered. AIM OF THE STUDY This study aimed to evaluate the modulatory effects of the crude leaf extract of Artemisia annua (AAE) on a high-fat diet induced testicular dysfunction in rats and compare it with the antilipolytic drug Orlistat. MATERIAL AND METHODS Forty adult rats were randomly classified and assigned to four groups. The first group typically consumed a balanced diet and served as a negative control (GP1). A high-fat diet-induced obesity was applied to the other three groups for 12 weeks. A positive control remained on HFD for another 8 weeks, which is GP2. Other groups were administered for 8 consecutive weeks either with Orlistat (50 mg/kg body weight) or AAE (100 mg/kg body weight), which have been defined as GP3 and GP4, respectively. Testosterone (TST), follicle-stimulating hormone (FSH) and luteinizing hormone (LH) were determined in the sera of all groups. In addition, the oxidant/antioxidant biomarkers such as protein carbonyl, malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) activities, lactate dehydrogenase (LDH) and creatine kinase isoenzyme-B (CK-MB) were determined. An immunohistochemical stain with the apoptotic marker caspase-3 and the proliferating cell nuclear antigen (PCNA) were also investigated. RESULTS In the testes of the obese group, the results showed hormonal imbalance, an increase in oxidative stress biomarkers and apoptosis. In the group treated with orlistat (GP3), noticeably more perturbations were noted. The obese rats that had been treated with AAE (GP4) showed a significantly reduced level of oxidative stress, hormonal balance restoration and reduced apoptosis. CONCLUSIONS The crude leaf extract of A. annua is a potential herbal therapeutic for the treatment of obesity-related testicular dysfunction and the restoration of hormonal imbalance in obese rats.
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Affiliation(s)
- Samer A El-Sawy
- Biochemistry Department, Faculty of Medicine, Sohag University, Sohag, Egypt
| | - Yahia A Amin
- Theriogenology Department, Faculty of Veterinary Medicine, Aswan University, Aswan, Egypt.
| | - Sabry A El-Naggar
- Zoology Department, Faculty of Science, Tanta University, Tanta, Egypt
| | - Ahmed Abdelsadik
- Zoology Department, Faculty of Science, Aswan University, Aswan, Egypt; Laboratory of Immunometabolism, Aswan University, Egypt
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8
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Tosato V, Rossi B, Sims J, Bruschi CV. Timing of Chromosome DNA Integration throughout the Yeast Cell Cycle. Biomolecules 2023; 13:biom13040614. [PMID: 37189362 DOI: 10.3390/biom13040614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 03/22/2023] [Accepted: 03/23/2023] [Indexed: 03/31/2023] Open
Abstract
The dynamic mechanism of cell uptake and genomic integration of exogenous linear DNA still has to be completely clarified, especially within each phase of the cell cycle. We present a study of integration events of double-stranded linear DNA molecules harboring at their ends sequence homologies to the host’s genome, all throughout the cell cycle of the model organism Saccharomyces cerevisiae, comparing the efficiency of chromosomal integration of two types of DNA cassettes tailored for site-specific integration and bridge-induced translocation. Transformability increases in S phase regardless of the sequence homologies, while the efficiency of chromosomal integration during a specific cycle phase depends upon the genomic targets. Moreover, the frequency of a specific translocation between chromosomes XV and VIII strongly increased during DNA synthesis under the control of Pol32 polymerase. Finally, in the null POL32 double mutant, different pathways drove the integration in the various phases of the cell cycle and bridge-induced translocation was possible outside the S phase even without Pol32. The discovery of this cell-cycle dependent regulation of specific pathways of DNA integration, associated with an increase of ROS levels following translocation events, is a further demonstration of a sensing ability of the yeast cell in determining a cell-cycle-related choice of DNA repair pathways under stress.
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9
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Anand J, Chiou L, Sciandra C, Zhang X, Hong J, Wu D, Zhou P, Vaziri C. Roles of trans-lesion synthesis (TLS) DNA polymerases in tumorigenesis and cancer therapy. NAR Cancer 2023; 5:zcad005. [PMID: 36755961 PMCID: PMC9900426 DOI: 10.1093/narcan/zcad005] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 12/10/2022] [Accepted: 01/30/2023] [Indexed: 02/08/2023] Open
Abstract
DNA damage tolerance and mutagenesis are hallmarks and enabling characteristics of neoplastic cells that drive tumorigenesis and allow cancer cells to resist therapy. The 'Y-family' trans-lesion synthesis (TLS) DNA polymerases enable cells to replicate damaged genomes, thereby conferring DNA damage tolerance. Moreover, Y-family DNA polymerases are inherently error-prone and cause mutations. Therefore, TLS DNA polymerases are potential mediators of important tumorigenic phenotypes. The skin cancer-propensity syndrome xeroderma pigmentosum-variant (XPV) results from defects in the Y-family DNA Polymerase Pol eta (Polη) and compensatory deployment of alternative inappropriate DNA polymerases. However, the extent to which dysregulated TLS contributes to the underlying etiology of other human cancers is unclear. Here we consider the broad impact of TLS polymerases on tumorigenesis and cancer therapy. We survey the ways in which TLS DNA polymerases are pathologically altered in cancer. We summarize evidence that TLS polymerases shape cancer genomes, and review studies implicating dysregulated TLS as a driver of carcinogenesis. Because many cancer treatment regimens comprise DNA-damaging agents, pharmacological inhibition of TLS is an attractive strategy for sensitizing tumors to genotoxic therapies. Therefore, we discuss the pharmacological tractability of the TLS pathway and summarize recent progress on development of TLS inhibitors for therapeutic purposes.
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Affiliation(s)
- Jay Anand
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, 614 Brinkhous-Bullitt Building, Chapel Hill, NC 27599, USA
| | - Lilly Chiou
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, 614 Brinkhous-Bullitt Building, Chapel Hill, NC 27599, USA
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Carly Sciandra
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Xingyuan Zhang
- Department of Biostatistics, University of North Carolina at Chapel Hill, 135 Dauer Drive, 3101 McGavran-Greenberg Hall, Chapel Hill, NC 27599, USA
| | - Jiyong Hong
- Department of Chemistry, Duke University, Durham, NC 27708, USA
| | - Di Wu
- Department of Biostatistics, University of North Carolina at Chapel Hill, 135 Dauer Drive, 3101 McGavran-Greenberg Hall, Chapel Hill, NC 27599, USA
| | - Pei Zhou
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Cyrus Vaziri
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, 614 Brinkhous-Bullitt Building, Chapel Hill, NC 27599, USA
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10
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González-Garrido C, Prado F. Parental histone distribution and location of the replication obstacle at nascent strands control homologous recombination. Cell Rep 2023; 42:112174. [PMID: 36862554 DOI: 10.1016/j.celrep.2023.112174] [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: 06/20/2022] [Revised: 12/09/2022] [Accepted: 02/10/2023] [Indexed: 03/03/2023] Open
Abstract
The advance and stability of replication forks rely on a tight co-regulation of DNA synthesis and nucleosome assembly. We show that mutants affected in parental histone recycling are impaired in the recombinational repair of the single-stranded DNA gaps generated in response to DNA adducts that hamper replication, which are then filled in by translesion synthesis. These recombination defects are in part due to an excess of parental nucleosomes at the invaded strand that destabilizes the sister chromatid junction formed after strand invasion through a Srs2-dependent mechanism. In addition, we show that a dCas9∗/R-loop is more recombinogenic when the dCas9∗/DNA-RNA hybrid interferes with the lagging than with the leading strand, and this recombination is particularly sensitive to problems in the deposition of parental histones at the strand that contains the hindrance. Therefore, parental histone distribution and location of the replication obstacle at the lagging or leading strand regulate homologous recombination.
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Affiliation(s)
- Cristina González-Garrido
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Consejo Superior de Investigaciones Científicas, Universidad de Sevilla, Universidad Pablo de Olavide, Seville, Spain
| | - Félix Prado
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Consejo Superior de Investigaciones Científicas, Universidad de Sevilla, Universidad Pablo de Olavide, Seville, Spain.
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11
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Jackson LM, Moldovan GL. Mechanisms of PARP1 inhibitor resistance and their implications for cancer treatment. NAR Cancer 2022; 4:zcac042. [PMID: 36568963 PMCID: PMC9773381 DOI: 10.1093/narcan/zcac042] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 11/28/2022] [Accepted: 12/06/2022] [Indexed: 12/24/2022] Open
Abstract
The discovery of synthetic lethality as a result of the combined loss of PARP1 and BRCA has revolutionized the treatment of DNA repair-deficient cancers. With the development of PARP inhibitors, patients displaying germline or somatic mutations in BRCA1 or BRCA2 were presented with a novel therapeutic strategy. However, a large subset of patients do not respond to PARP inhibitors. Furthermore, many of those who do respond eventually acquire resistance. As such, combating de novo and acquired resistance to PARP inhibitors remains an obstacle in achieving durable responses in patients. In this review, we touch on some of the key mechanisms of PARP inhibitor resistance, including restoration of homologous recombination, replication fork stabilization and suppression of single-stranded DNA gap accumulation, as well as address novel approaches for overcoming PARP inhibitor resistance.
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Affiliation(s)
- Lindsey M Jackson
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - George-Lucian Moldovan
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
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12
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Benureau Y, Pouvelle C, Dupaigne P, Baconnais S, Moreira Tavares E, Mazón G, Despras E, Le Cam E, Kannouche P. Changes in the architecture and abundance of replication intermediates delineate the chronology of DNA damage tolerance pathways at UV-stalled replication forks in human cells. Nucleic Acids Res 2022; 50:9909-9929. [PMID: 36107774 PMCID: PMC9508826 DOI: 10.1093/nar/gkac746] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 08/09/2022] [Accepted: 08/23/2022] [Indexed: 11/21/2022] Open
Abstract
DNA lesions in S phase threaten genome stability. The DNA damage tolerance (DDT) pathways overcome these obstacles and allow completion of DNA synthesis by the use of specialised translesion (TLS) DNA polymerases or through recombination-related processes. However, how these mechanisms coordinate with each other and with bulk replication remains elusive. To address these issues, we monitored the variation of replication intermediate architecture in response to ultraviolet irradiation using transmission electron microscopy. We show that the TLS polymerase η, able to accurately bypass the major UV lesion and mutated in the skin cancer-prone xeroderma pigmentosum variant (XPV) syndrome, acts at the replication fork to resolve uncoupling and prevent post-replicative gap accumulation. Repriming occurs as a compensatory mechanism when this on-the-fly mechanism cannot operate, and is therefore predominant in XPV cells. Interestingly, our data support a recombination-independent function of RAD51 at the replication fork to sustain repriming. Finally, we provide evidence for the post-replicative commitment of recombination in gap repair and for pioneering observations of in vivo recombination intermediates. Altogether, we propose a chronology of UV damage tolerance in human cells that highlights the key role of polη in shaping this response and ensuring the continuity of DNA synthesis.
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Affiliation(s)
- Yann Benureau
- UMR9019 CNRS, Genome Integrity and Cancers, Laboratory Genome Integrity , Immune Response and Cancers, Equipe Labellisée La Ligue Contre Le Cancer, Gustave Roussy 94805 , Villejuif , France
- UMR9019 CNRS, Genome Integrity and Cancers, Laboratory DSB Repair , Replication stress and Genome Integrity, Gustave Roussy 94805 , Villejuif, France
- Université Paris-Saclay , France
| | - Caroline Pouvelle
- UMR9019 CNRS, Genome Integrity and Cancers, Laboratory Genome Integrity , Immune Response and Cancers, Equipe Labellisée La Ligue Contre Le Cancer, Gustave Roussy 94805 , Villejuif , France
- Université Paris-Saclay , France
| | - Pauline Dupaigne
- UMR9019 CNRS, Genome Integrity and Cancers, Laboratory DSB Repair , Replication stress and Genome Integrity, Gustave Roussy 94805 , Villejuif, France
- Université Paris-Saclay , France
| | - Sonia Baconnais
- UMR9019 CNRS, Genome Integrity and Cancers, Laboratory DSB Repair , Replication stress and Genome Integrity, Gustave Roussy 94805 , Villejuif, France
- Université Paris-Saclay , France
| | - Eliana Moreira Tavares
- UMR9019 CNRS, Genome Integrity and Cancers, Laboratory DSB Repair , Replication stress and Genome Integrity, Gustave Roussy 94805 , Villejuif, France
- Université Paris-Saclay , France
| | - Gerard Mazón
- UMR9019 CNRS, Genome Integrity and Cancers, Laboratory DSB Repair , Replication stress and Genome Integrity, Gustave Roussy 94805 , Villejuif, France
- Université Paris-Saclay , France
| | - Emmanuelle Despras
- UMR9019 CNRS, Genome Integrity and Cancers, Laboratory Genome Integrity , Immune Response and Cancers, Equipe Labellisée La Ligue Contre Le Cancer, Gustave Roussy 94805 , Villejuif , France
- Université Paris-Saclay , France
| | - Eric Le Cam
- UMR9019 CNRS, Genome Integrity and Cancers, Laboratory DSB Repair , Replication stress and Genome Integrity, Gustave Roussy 94805 , Villejuif, France
- Université Paris-Saclay , France
| | - Patricia L Kannouche
- UMR9019 CNRS, Genome Integrity and Cancers, Laboratory Genome Integrity , Immune Response and Cancers, Equipe Labellisée La Ligue Contre Le Cancer, Gustave Roussy 94805 , Villejuif , France
- Université Paris-Saclay , France
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13
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Thakar T, Dhoonmoon A, Straka J, Schleicher EM, Nicolae CM, Moldovan GL. Lagging strand gap suppression connects BRCA-mediated fork protection to nucleosome assembly through PCNA-dependent CAF-1 recycling. Nat Commun 2022; 13:5323. [PMID: 36085347 PMCID: PMC9463168 DOI: 10.1038/s41467-022-33028-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 08/29/2022] [Indexed: 11/17/2022] Open
Abstract
The inability to protect stalled replication forks from nucleolytic degradation drives genome instability and underlies chemosensitivity in BRCA-deficient tumors. An emerging hallmark of BRCA-deficiency is the inability to suppress replication-associated single-stranded DNA (ssDNA) gaps. Here, we report that lagging strand ssDNA gaps interfere with the ASF1-CAF-1 nucleosome assembly pathway, and drive fork degradation in BRCA-deficient cells. We show that CAF-1 function at replication forks is lost in BRCA-deficient cells, due to defects in its recycling during replication stress. This CAF-1 recycling defect is caused by lagging strand gaps which preclude PCNA unloading, causing sequestration of PCNA-CAF-1 complexes on chromatin. Importantly, correcting PCNA unloading defects in BRCA-deficient cells restores CAF-1-dependent fork stability. We further show that the activation of a HIRA-dependent compensatory histone deposition pathway restores fork stability to BRCA-deficient cells. We thus define lagging strand gap suppression and nucleosome assembly as critical enablers of BRCA-mediated fork stability. Efficient DNA replication is crucial for genome stability. Here, Thakar et al. report that accumulation of lagging strand ssDNA gaps during replication interferes with nucleosome assembly and drives replication fork degradation in BRCA-deficient cells.
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Affiliation(s)
- Tanay Thakar
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA
| | - Ashna Dhoonmoon
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA
| | - Joshua Straka
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA
| | - Emily M Schleicher
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA
| | - Claudia M Nicolae
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA
| | - George-Lucian Moldovan
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA.
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14
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Lv Q, Han S, Wang L, Xia J, Li P, Hu R, Wang J, Gao L, Chen Y, Wang Y, Du J, Bao F, Hu Y, Xu X, Xiao W, He Y. TEB/POLQ plays dual roles in protecting Arabidopsis from NO-induced DNA damage. Nucleic Acids Res 2022; 50:6820-6836. [PMID: 35736216 PMCID: PMC9262624 DOI: 10.1093/nar/gkac469] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Revised: 05/07/2022] [Accepted: 06/10/2022] [Indexed: 12/24/2022] Open
Abstract
Nitric oxide (NO) is a key player in numerous physiological processes. Excessive NO induces DNA damage, but how plants respond to this damage remains unclear. We screened and identified an Arabidopsis NO hypersensitive mutant and found it to be allelic to TEBICHI/POLQ, encoding DNA polymerase θ. The teb mutant plants were preferentially sensitive to NO- and its derivative peroxynitrite-induced DNA damage and subsequent double-strand breaks (DSBs). Inactivation of TEB caused the accumulation of spontaneous DSBs largely attributed to endogenous NO and was synergistic to DSB repair pathway mutations with respect to growth. These effects were manifested in the presence of NO-inducing agents and relieved by NO scavengers. NO induced G2/M cell cycle arrest in the teb mutant, indicative of stalled replication forks. Genetic analyses indicate that Polθ is required for translesion DNA synthesis across NO-induced lesions, but not oxidation-induced lesions. Whole-genome sequencing revealed that Polθ bypasses NO-induced base adducts in an error-free manner and generates mutations characteristic of Polθ-mediated end joining. Our experimental data collectively suggests that Polθ plays dual roles in protecting plants from NO-induced DNA damage. Since Polθ is conserved in higher eukaryotes, mammalian Polθ may also be required for balancing NO physiological signaling and genotoxicity.
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Affiliation(s)
- Qiang Lv
- College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Shuang Han
- College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Lei Wang
- College of Life Sciences, Capital Normal University, Beijing 100048, China
- Department of Biological Sciences, Mississippi State University, Mississippi State, MS 39762, USA
| | - Jinchan Xia
- College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Peng Li
- College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Ruoyang Hu
- College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Jinzheng Wang
- College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Lei Gao
- College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Yuli Chen
- College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Yu Wang
- College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Jing Du
- College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Fang Bao
- College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Yong Hu
- College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Xingzhi Xu
- College of Life Sciences, Capital Normal University, Beijing 100048, China
- Guangdong Key Laboratory for Genome Stability & Disease Prevention and Carson International Cancer Center, Shenzhen University School of Medicine, Shenzhen, Guangdong 518060, China
| | - Wei Xiao
- College of Life Sciences, Capital Normal University, Beijing 100048, China
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
| | - Yikun He
- College of Life Sciences, Capital Normal University, Beijing 100048, China
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15
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Post-Translational Modifications of PCNA: Guiding for the Best DNA Damage Tolerance Choice. J Fungi (Basel) 2022; 8:jof8060621. [PMID: 35736104 PMCID: PMC9225081 DOI: 10.3390/jof8060621] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 06/01/2022] [Accepted: 06/07/2022] [Indexed: 02/01/2023] Open
Abstract
The sliding clamp PCNA is a multifunctional homotrimer mainly linked to DNA replication. During this process, cells must ensure an accurate and complete genome replication when constantly challenged by the presence of DNA lesions. Post-translational modifications of PCNA play a crucial role in channeling DNA damage tolerance (DDT) and repair mechanisms to bypass unrepaired lesions and promote optimal fork replication restart. PCNA ubiquitination processes trigger the following two main DDT sub-pathways: Rad6/Rad18-dependent PCNA monoubiquitination and Ubc13-Mms2/Rad5-mediated PCNA polyubiquitination, promoting error-prone translation synthesis (TLS) or error-free template switch (TS) pathways, respectively. However, the fork protection mechanism leading to TS during fork reversal is still poorly understood. In contrast, PCNA sumoylation impedes the homologous recombination (HR)-mediated salvage recombination (SR) repair pathway. Focusing on Saccharomyces cerevisiae budding yeast, we summarized PCNA related-DDT and repair mechanisms that coordinately sustain genome stability and cell survival. In addition, we compared PCNA sequences from various fungal pathogens, considering recent advances in structural features. Importantly, the identification of PCNA epitopes may lead to potential fungal targets for antifungal drug development.
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16
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Wegmann S, Meister C, Renz C, Yakoub G, Wollscheid HP, Takahashi DT, Mikicic I, Beli P, Ulrich HD. Linkage reprogramming by tailor-made E3s reveals polyubiquitin chain requirements in DNA-damage bypass. Mol Cell 2022; 82:1589-1602.e5. [PMID: 35263628 PMCID: PMC9098123 DOI: 10.1016/j.molcel.2022.02.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 01/05/2022] [Accepted: 02/08/2022] [Indexed: 12/22/2022]
Abstract
A polyubiquitin chain can adopt a variety of shapes, depending on how the ubiquitin monomers are joined. However, the relevance of linkage for the signaling functions of polyubiquitin chains is often poorly understood because of our inability to control or manipulate this parameter in vivo. Here, we present a strategy for reprogramming polyubiquitin chain linkage by means of tailor-made, linkage- and substrate-selective ubiquitin ligases. Using the polyubiquitylation of the budding yeast replication factor PCNA in response to DNA damage as a model case, we show that altering the features of a polyubiquitin chain in vivo can change the fate of the modified substrate. We also provide evidence for redundancy between distinct but structurally similar linkages, and we demonstrate by proof-of-principle experiments that the method can be generalized to targets beyond PCNA. Our study illustrates a promising approach toward the in vivo analysis of polyubiquitin signaling.
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Affiliation(s)
- Sabrina Wegmann
- Institute of Molecular Biology gGmbH (IMB), Ackermannweg 4, 55128 Mainz, Germany
| | - Cindy Meister
- Institute of Molecular Biology gGmbH (IMB), Ackermannweg 4, 55128 Mainz, Germany
| | - Christian Renz
- Institute of Molecular Biology gGmbH (IMB), Ackermannweg 4, 55128 Mainz, Germany
| | - George Yakoub
- Institute of Molecular Biology gGmbH (IMB), Ackermannweg 4, 55128 Mainz, Germany
| | | | - Diane T Takahashi
- Université de Strasbourg, UMR7242 Biotechnologie et Signalisation Cellulaire, Ecole Supérieure de Biotechnologie de Strasbourg, 10413 Illkirch, Strasbourg, France
| | - Ivan Mikicic
- Institute of Molecular Biology gGmbH (IMB), Ackermannweg 4, 55128 Mainz, Germany
| | - Petra Beli
- Institute of Molecular Biology gGmbH (IMB), Ackermannweg 4, 55128 Mainz, Germany; Institute for Developmental Biology and Neurobiology, Johannes Gutenberg-Universität, 55128 Mainz, Germany
| | - Helle D Ulrich
- Institute of Molecular Biology gGmbH (IMB), Ackermannweg 4, 55128 Mainz, Germany.
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17
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Che J, Hong X, Rao H. PCNA Ubiquitylation: Instructive or Permissive to DNA Damage Tolerance Pathways? Biomolecules 2021; 11:biom11101543. [PMID: 34680175 PMCID: PMC8533919 DOI: 10.3390/biom11101543] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 10/12/2021] [Accepted: 10/15/2021] [Indexed: 11/16/2022] Open
Abstract
DNA lesions escaping from repair often block the DNA replicative polymerases required for DNA replication and are handled during the S/G2 phases by the DNA damage tolerance (DDT) mechanisms, which include the error-prone translesion synthesis (TLS) and the error-free template switching (TS) pathways. Where the mono-ubiquitylation of PCNA K164 is critical for TLS, the poly-ubiquitylation of the same residue is obligatory for TS. However, it is not known how cells divide the labor between TLS and TS. Due to the fact that the type of DNA lesion significantly influences the TLS and TS choice, we propose that, instead of altering the ratio between the mono- and poly-Ub forms of PCNA, the competition between TLS and TS would automatically determine the selection between the two pathways. Future studies, especially the single integrated lesion “i-Damage” system, would elucidate detailed mechanisms governing the choices of specific DDT pathways.
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Affiliation(s)
- Jun Che
- Correspondence: (J.C.); (H.R.)
| | | | - Hai Rao
- Correspondence: (J.C.); (H.R.)
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18
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Temporally distinct post-replicative repair mechanisms fill PRIMPOL-dependent ssDNA gaps in human cells. Mol Cell 2021; 81:4026-4040.e8. [PMID: 34624216 DOI: 10.1016/j.molcel.2021.09.013] [Citation(s) in RCA: 92] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 07/20/2021] [Accepted: 09/10/2021] [Indexed: 12/11/2022]
Abstract
PRIMPOL repriming allows DNA replication to skip DNA lesions, leading to ssDNA gaps. These gaps must be filled to preserve genome stability. Using a DNA fiber approach to directly monitor gap filling, we studied the post-replicative mechanisms that fill the ssDNA gaps generated in cisplatin-treated cells upon increased PRIMPOL expression or when replication fork reversal is defective because of SMARCAL1 inactivation or PARP inhibition. We found that a mechanism dependent on the E3 ubiquitin ligase RAD18, PCNA monoubiquitination, and the REV1 and POLζ translesion synthesis polymerases promotes gap filling in G2. The E2-conjugating enzyme UBC13, the RAD51 recombinase, and REV1-POLζ are instead responsible for gap filling in S, suggesting that temporally distinct pathways of gap filling operate throughout the cell cycle. Furthermore, we found that BRCA1 and BRCA2 promote gap filling by limiting MRE11 activity and that simultaneously targeting fork reversal and gap filling enhances chemosensitivity in BRCA-deficient cells.
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19
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Arbel M, Liefshitz B, Kupiec M. DNA damage bypass pathways and their effect on mutagenesis in yeast. FEMS Microbiol Rev 2021; 45:5896953. [PMID: 32840566 DOI: 10.1093/femsre/fuaa038] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 08/23/2020] [Indexed: 12/11/2022] Open
Abstract
What is the origin of mutations? In contrast to the naïve notion that mutations are unfortunate accidents, genetic research in microorganisms has demonstrated that most mutations are created by genetically encoded error-prone repair mechanisms. However, error-free repair pathways also exist, and it is still unclear how cells decide when to use one repair method or the other. Here, we summarize what is known about the DNA damage tolerance mechanisms (also known as post-replication repair) for perhaps the best-studied organism, the yeast Saccharomyces cerevisiae. We describe the latest research, which has established the existence of at least two error-free and two error-prone inter-related mechanisms of damage tolerance that compete for the handling of spontaneous DNA damage. We explore what is known about the induction of mutations by DNA damage. We point to potential paradoxes and to open questions that still remain unanswered.
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Affiliation(s)
- Matan Arbel
- The Shmunis School of Biomedicine and Cancer Research, Tel Aviv University, Ramat Aviv 69978, Israel
| | - Batia Liefshitz
- The Shmunis School of Biomedicine and Cancer Research, Tel Aviv University, Ramat Aviv 69978, Israel
| | - Martin Kupiec
- The Shmunis School of Biomedicine and Cancer Research, Tel Aviv University, Ramat Aviv 69978, Israel
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20
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McPherson KS, Korzhnev DM. Targeting protein-protein interactions in the DNA damage response pathways for cancer chemotherapy. RSC Chem Biol 2021; 2:1167-1195. [PMID: 34458830 PMCID: PMC8342002 DOI: 10.1039/d1cb00101a] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Accepted: 06/20/2021] [Indexed: 12/11/2022] Open
Abstract
Cellular DNA damage response (DDR) is an extensive signaling network that orchestrates DNA damage recognition, repair and avoidance, cell cycle progression and cell death. DDR alteration is a hallmark of cancer, with the deficiency in one DDR capability often compensated by a dependency on alternative pathways endowing cancer cells with survival and growth advantage. Targeting these DDR pathways has provided multiple opportunities for the development of cancer therapies. Traditional drug discovery has mainly focused on catalytic inhibitors that block enzyme active sites, which limits the number of potential drug targets within the DDR pathways. This review article describes the emerging approach to the development of cancer therapeutics targeting essential protein-protein interactions (PPIs) in the DDR network. The overall strategy for the structure-based design of small molecule PPI inhibitors is discussed, followed by an overview of the major DNA damage sensing, DNA repair, and DNA damage tolerance pathways with a specific focus on PPI targets for anti-cancer drug design. The existing small molecule inhibitors of DDR PPIs are summarized that selectively kill cancer cells and/or sensitize cancers to front-line genotoxic therapies, and a range of new PPI targets are proposed that may lead to the development of novel chemotherapeutics.
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Affiliation(s)
- Kerry Silva McPherson
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center Farmington CT 06030 USA +1 860 679 3408 +1 860 679 2849
| | - Dmitry M Korzhnev
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center Farmington CT 06030 USA +1 860 679 3408 +1 860 679 2849
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21
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Guilliam TA. Mechanisms for Maintaining Eukaryotic Replisome Progression in the Presence of DNA Damage. Front Mol Biosci 2021; 8:712971. [PMID: 34295925 PMCID: PMC8290200 DOI: 10.3389/fmolb.2021.712971] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 06/25/2021] [Indexed: 12/04/2022] Open
Abstract
The eukaryotic replisome coordinates template unwinding and nascent-strand synthesis to drive DNA replication fork progression and complete efficient genome duplication. During its advancement along the parental template, each replisome may encounter an array of obstacles including damaged and structured DNA that impede its progression and threaten genome stability. A number of mechanisms exist to permit replisomes to overcome such obstacles, maintain their progression, and prevent fork collapse. A combination of recent advances in structural, biochemical, and single-molecule approaches have illuminated the architecture of the replisome during unperturbed replication, rationalised the impact of impediments to fork progression, and enhanced our understanding of DNA damage tolerance mechanisms and their regulation. This review focusses on these studies to provide an updated overview of the mechanisms that support replisomes to maintain their progression on an imperfect template.
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Affiliation(s)
- Thomas A. Guilliam
- Division of Protein and Nucleic Acid Chemistry, Medical Research Council Laboratory of Molecular Biology, Cambridge, United Kingdom
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22
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Shimada K, Tsai-Pflugfelder M, Vijeh Motlagh ND, Delgoshaie N, Fuchs J, Gut H, Gasser SM. The stabilized Pol31-Pol3 interface counteracts Pol32 ablation with differential effects on repair. Life Sci Alliance 2021; 4:4/9/e202101138. [PMID: 34226278 PMCID: PMC8321694 DOI: 10.26508/lsa.202101138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 06/23/2021] [Accepted: 06/24/2021] [Indexed: 11/24/2022] Open
Abstract
DNA polymerase δ, which contains the catalytic subunit, Pol3, Pol31, and Pol32, contributes both to DNA replication and repair. The deletion of pol31 is lethal, and compromising the Pol3-Pol31 interaction domains confers hypersensitivity to cold, hydroxyurea (HU), and methyl methanesulfonate, phenocopying pol32Δ. We have identified alanine-substitutions in pol31 that suppress these deficiencies in pol32Δ cells. We characterize two mutants, pol31-T415A and pol31-W417A, which map to a solvent-exposed loop that mediates Pol31-Pol3 and Pol31-Rev3 interactions. The pol31-T415A substitution compromises binding to the Pol3 CysB domain, whereas Pol31-W417A improves it. Importantly, loss of Pol32, such as pol31-T415A, leads to reduced Pol3 and Pol31 protein levels, which are restored by pol31-W417A. The mutations have differential effects on recovery from acute HU, break-induced replication and trans-lesion synthesis repair pathways. Unlike trans-lesion synthesis and growth on HU, the loss of break-induced replication in pol32Δ cells is not restored by pol31-W417A, highlighting pathway-specific roles for Pol32 in fork-related repair. Intriguingly, CHIP analyses of replication forks on HU showed that pol32Δ and pol31-T415A indirectly destabilize DNA pol α and pol ε at stalled forks.
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Affiliation(s)
- Kenji Shimada
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | | | | | - Neda Delgoshaie
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Jeannette Fuchs
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Heinz Gut
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Susan M Gasser
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
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23
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Wong RP, Petriukov K, Ulrich HD. Daughter-strand gaps in DNA replication - substrates of lesion processing and initiators of distress signalling. DNA Repair (Amst) 2021; 105:103163. [PMID: 34186497 DOI: 10.1016/j.dnarep.2021.103163] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 06/18/2021] [Accepted: 06/19/2021] [Indexed: 10/21/2022]
Abstract
Dealing with DNA lesions during genome replication is particularly challenging because damaged replication templates interfere with the progression of the replicative DNA polymerases and thereby endanger the stability of the replisome. A variety of mechanisms for the recovery of replication forks exist, but both bacteria and eukaryotic cells also have the option of continuing replication downstream of the lesion, leaving behind a daughter-strand gap in the newly synthesized DNA. In this review, we address the significance of these single-stranded DNA structures as sites of DNA damage sensing and processing at a distance from ongoing genome replication. We describe the factors controlling the emergence of daughter-strand gaps from stalled replication intermediates, the benefits and risks of their expansion and repair via translesion synthesis or recombination-mediated template switching, and the mechanisms by which they activate local as well as global replication stress signals. Our growing understanding of daughter-strand gaps not only identifies them as targets of fundamental genome maintenance mechanisms, but also suggests that proper control over their activities has important practical implications for treatment strategies and resistance mechanisms in cancer therapy.
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Affiliation(s)
- Ronald P Wong
- Institute of Molecular Biology (IMB) gGmbH, Ackermannweg 4, D - 55128 Mainz, Germany
| | - Kirill Petriukov
- Institute of Molecular Biology (IMB) gGmbH, Ackermannweg 4, D - 55128 Mainz, Germany
| | - Helle D Ulrich
- Institute of Molecular Biology (IMB) gGmbH, Ackermannweg 4, D - 55128 Mainz, Germany.
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24
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Alekseeva EA, Korolev VG. DNA Damage Tolerance in the Yeast Saccharomyces cerevisiae. RUSS J GENET+ 2021. [DOI: 10.1134/s1022795421040025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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25
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Quinet A, Tirman S, Cybulla E, Meroni A, Vindigni A. To skip or not to skip: choosing repriming to tolerate DNA damage. Mol Cell 2021; 81:649-658. [PMID: 33515486 PMCID: PMC7935405 DOI: 10.1016/j.molcel.2021.01.012] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 11/21/2020] [Accepted: 01/06/2021] [Indexed: 12/14/2022]
Abstract
Accurate DNA replication is constantly threatened by DNA lesions arising from endogenous and exogenous sources. Specialized DNA replication stress response pathways ensure replication fork progression in the presence of DNA lesions with minimal delay in fork elongation. These pathways broadly include translesion DNA synthesis, template switching, and replication fork repriming. Here, we discuss recent advances toward our understanding of the mechanisms that regulate the fine-tuned balance between these different replication stress response pathways. We also discuss the molecular pathways required to fill single-stranded DNA gaps that accumulate throughout the genome after repriming and the biological consequences of using repriming instead of other DNA damage tolerance pathways on genome integrity and cell fitness.
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Affiliation(s)
- Annabel Quinet
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Stephanie Tirman
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA; Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO 63104, USA
| | - Emily Cybulla
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA; Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO 63104, USA
| | - Alice Meroni
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Alessandro Vindigni
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA.
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26
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DNA-damage tolerance through PCNA ubiquitination and sumoylation. Biochem J 2021; 477:2655-2677. [PMID: 32726436 DOI: 10.1042/bcj20190579] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 07/08/2020] [Accepted: 07/10/2020] [Indexed: 12/12/2022]
Abstract
DNA-damage tolerance (DDT) is employed by eukaryotic cells to bypass replication-blocking lesions induced by DNA-damaging agents. In budding yeast Saccharomyces cerevisiae, DDT is mediated by RAD6 epistatic group genes and the central event for DDT is sequential ubiquitination of proliferating cell nuclear antigen (PCNA), a DNA clamp required for replication and DNA repair. DDT consists of two parallel pathways: error-prone DDT is mediated by PCNA monoubiquitination, which recruits translesion synthesis DNA polymerases to bypass lesions with decreased fidelity; and error-free DDT is mediated by K63-linked polyubiquitination of PCNA at the same residue of monoubiquitination, which facilitates homologous recombination-mediated template switch. Interestingly, the same PCNA residue is also subjected to sumoylation, which leads to inhibition of unwanted recombination at replication forks. All three types of PCNA posttranslational modifications require dedicated conjugating and ligation enzymes, and these enzymes are highly conserved in eukaryotes, from yeast to human.
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27
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Tirman S, Cybulla E, Quinet A, Meroni A, Vindigni A. PRIMPOL ready, set, reprime! Crit Rev Biochem Mol Biol 2021; 56:17-30. [PMID: 33179522 PMCID: PMC7906090 DOI: 10.1080/10409238.2020.1841089] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 09/15/2020] [Accepted: 10/20/2020] [Indexed: 12/14/2022]
Abstract
DNA replication forks are constantly challenged by DNA lesions induced by endogenous and exogenous sources. DNA damage tolerance mechanisms ensure that DNA replication continues with minimal effects on replication fork elongation either by using specialized DNA polymerases, which have the ability to replicate through the damaged template, or by skipping the damaged DNA, leaving it to be repaired after replication. These mechanisms are evolutionarily conserved in bacteria, yeast, and higher eukaryotes, and are paramount to ensure timely and faithful duplication of the genome. The Primase and DNA-directed Polymerase (PRIMPOL) is a recently discovered enzyme that possesses both primase and polymerase activities. PRIMPOL is emerging as a key player in DNA damage tolerance, particularly in vertebrate and human cells. Here, we review our current understanding of the function of PRIMPOL in DNA damage tolerance by focusing on the structural aspects that define its dual enzymatic activity, as well as on the mechanisms that control its chromatin recruitment and expression levels. We also focus on the latest findings on the mitochondrial and nuclear functions of PRIMPOL and on the impact of loss of these functions on genome stability and cell survival. Defining the function of PRIMPOL in DNA damage tolerance is becoming increasingly important in the context of human disease. In particular, we discuss recent evidence pointing at the PRIMPOL pathway as a novel molecular target to improve cancer cell response to DNA-damaging chemotherapy and as a predictive parameter to stratify patients in personalized cancer therapy.
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Affiliation(s)
- Stephanie Tirman
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis MO, 63110, USA
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO 63104, USA
| | - Emily Cybulla
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis MO, 63110, USA
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO 63104, USA
| | - Annabel Quinet
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis MO, 63110, USA
| | - Alice Meroni
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis MO, 63110, USA
| | - Alessandro Vindigni
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis MO, 63110, USA
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28
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Cano‐Linares MI, Yáñez‐Vilches A, García‐Rodríguez N, Barrientos‐Moreno M, González‐Prieto R, San‐Segundo P, Ulrich HD, Prado F. Non-recombinogenic roles for Rad52 in translesion synthesis during DNA damage tolerance. EMBO Rep 2021; 22:e50410. [PMID: 33289333 PMCID: PMC7788459 DOI: 10.15252/embr.202050410] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 10/09/2020] [Accepted: 10/15/2020] [Indexed: 01/09/2023] Open
Abstract
DNA damage tolerance relies on homologous recombination (HR) and translesion synthesis (TLS) mechanisms to fill in the ssDNA gaps generated during passing of the replication fork over DNA lesions in the template. Whereas TLS requires specialized polymerases able to incorporate a dNTP opposite the lesion and is error-prone, HR uses the sister chromatid and is mostly error-free. We report that the HR protein Rad52-but not Rad51 and Rad57-acts in concert with the TLS machinery (Rad6/Rad18-mediated PCNA ubiquitylation and polymerases Rev1/Pol ζ) to repair MMS and UV light-induced ssDNA gaps through a non-recombinogenic mechanism, as inferred from the different phenotypes displayed in the absence of Rad52 and Rad54 (essential for MMS- and UV-induced HR); accordingly, Rad52 is required for efficient DNA damage-induced mutagenesis. In addition, Rad52, Rad51, and Rad57, but not Rad54, facilitate Rad6/Rad18 binding to chromatin and subsequent DNA damage-induced PCNA ubiquitylation. Therefore, Rad52 facilitates the tolerance process not only by HR but also by TLS through Rad51/Rad57-dependent and -independent processes, providing a novel role for the recombination proteins in maintaining genome integrity.
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Affiliation(s)
- María I Cano‐Linares
- Department of Genome BiologyAndalusian Molecular Biology and Regenerative Medicine Center (CABIMER)CSIC‐University of Seville‐University Pablo de OlavideSevilleSpain
| | - Aurora Yáñez‐Vilches
- Department of Genome BiologyAndalusian Molecular Biology and Regenerative Medicine Center (CABIMER)CSIC‐University of Seville‐University Pablo de OlavideSevilleSpain
| | - Néstor García‐Rodríguez
- Institute of Molecular Biology (IMB)MainzGermany
- Present address:
Department of Genome BiologyAndalusian Molecular Biology and Regenerative Medicine Center (CABIMER)CSIC‐University of Seville‐University Pablo de OlavideSevilleSpain
| | - Marta Barrientos‐Moreno
- Department of Genome BiologyAndalusian Molecular Biology and Regenerative Medicine Center (CABIMER)CSIC‐University of Seville‐University Pablo de OlavideSevilleSpain
| | - Román González‐Prieto
- Department of Genome BiologyAndalusian Molecular Biology and Regenerative Medicine Center (CABIMER)CSIC‐University of Seville‐University Pablo de OlavideSevilleSpain
- Present address:
Department of Cell and Chemical BiologyLeiden University Medical CenterLeidenThe Netherlands
| | - Pedro San‐Segundo
- Institute of Functional Biology and Genomics (IBFG)CSIC‐University of SalamancaSalamancaSpain
| | | | - Félix Prado
- Department of Genome BiologyAndalusian Molecular Biology and Regenerative Medicine Center (CABIMER)CSIC‐University of Seville‐University Pablo de OlavideSevilleSpain
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29
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Denkiewicz-Kruk M, Jedrychowska M, Endo S, Araki H, Jonczyk P, Dmowski M, Fijalkowska IJ. Recombination and Pol ζ Rescue Defective DNA Replication upon Impaired CMG Helicase-Pol ε Interaction. Int J Mol Sci 2020; 21:ijms21249484. [PMID: 33322195 PMCID: PMC7762974 DOI: 10.3390/ijms21249484] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 12/06/2020] [Accepted: 12/09/2020] [Indexed: 11/22/2022] Open
Abstract
The CMG complex (Cdc45, Mcm2–7, GINS (Psf1, 2, 3, and Sld5)) is crucial for both DNA replication initiation and fork progression. The CMG helicase interaction with the leading strand DNA polymerase epsilon (Pol ε) is essential for the preferential loading of Pol ε onto the leading strand, the stimulation of the polymerase, and the modulation of helicase activity. Here, we analyze the consequences of impaired interaction between Pol ε and GINS in Saccharomyces cerevisiae cells with the psf1-100 mutation. This significantly affects DNA replication activity measured in vitro, while in vivo, the psf1-100 mutation reduces replication fidelity by increasing slippage of Pol ε, which manifests as an elevated number of frameshifts. It also increases the occurrence of single-stranded DNA (ssDNA) gaps and the demand for homologous recombination. The psf1-100 mutant shows elevated recombination rates and synthetic lethality with rad52Δ. Additionally, we observe increased participation of DNA polymerase zeta (Pol ζ) in DNA synthesis. We conclude that the impaired interaction between GINS and Pol ε requires enhanced involvement of error-prone Pol ζ, and increased participation of recombination as a rescue mechanism for recovery of impaired replication forks.
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Affiliation(s)
- Milena Denkiewicz-Kruk
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106 Warsaw, Poland; (M.D.-K.); (M.J.); (P.J.)
| | - Malgorzata Jedrychowska
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106 Warsaw, Poland; (M.D.-K.); (M.J.); (P.J.)
| | - Shizuko Endo
- National Institute of Genetics, 1111 Yata, Mishima, Shizuoka 411-8540, Japan; (S.E.); (H.A.)
| | - Hiroyuki Araki
- National Institute of Genetics, 1111 Yata, Mishima, Shizuoka 411-8540, Japan; (S.E.); (H.A.)
| | - Piotr Jonczyk
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106 Warsaw, Poland; (M.D.-K.); (M.J.); (P.J.)
| | - Michal Dmowski
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106 Warsaw, Poland; (M.D.-K.); (M.J.); (P.J.)
- Correspondence: (M.D.); (I.J.F.); Tel.: +48-22-5921128 (M.D.); +48-22-5921113 (I.J.F.)
| | - Iwona J. Fijalkowska
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106 Warsaw, Poland; (M.D.-K.); (M.J.); (P.J.)
- Correspondence: (M.D.); (I.J.F.); Tel.: +48-22-5921128 (M.D.); +48-22-5921113 (I.J.F.)
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30
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Álvarez V, Frattini C, Sacristán MP, Gallego-Sánchez A, Bermejo R, Bueno A. PCNA Deubiquitylases Control DNA Damage Bypass at Replication Forks. Cell Rep 2020; 29:1323-1335.e5. [PMID: 31665643 DOI: 10.1016/j.celrep.2019.09.054] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 08/01/2019] [Accepted: 09/17/2019] [Indexed: 01/06/2023] Open
Abstract
DNA damage tolerance plays a key role in protecting cell viability through translesion synthesis and template switching-mediated bypass of genotoxic polymerase-blocking base lesions. Both tolerance pathways critically rely on ubiquitylation of the proliferating-cell nuclear antigen (PCNA) on lysine 164 and have been proposed to operate uncoupled from replication. We report that Ubp10 and Ubp12 ubiquitin proteases differentially cooperate in PCNA deubiquitylation, owing to distinct activities on PCNA-linked ubiquitin chains. Ubp10 and Ubp12 associate with replication forks in a fashion determined by Ubp10 dependency on lagging-strand PCNA residence, and they downregulate translesion polymerase recruitment and template switch events engaging nascent strands. These findings reveal PCNAK164 deubiquitylation as a key mechanism for the modulation of lesion bypass during replication, which might set a framework for establishing strand-differential pathway choices. We propose that damage tolerance is tempered at replication forks to limit the extension of bypass events and sustain chromosome replication rates.
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Affiliation(s)
- Vanesa Álvarez
- Instituto de Biología Molecular y Celular del Cáncer (USAL/CSIC), Salamanca, Spain
| | | | - María P Sacristán
- Instituto de Biología Molecular y Celular del Cáncer (USAL/CSIC), Salamanca, Spain; Departamento de Microbiología y Genética, Universidad de Salamanca, Salamanca, Spain
| | | | | | - Avelino Bueno
- Instituto de Biología Molecular y Celular del Cáncer (USAL/CSIC), Salamanca, Spain; Departamento de Microbiología y Genética, Universidad de Salamanca, Salamanca, Spain.
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31
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Ma Y, Song Y, Shen R, Li P, Ding H, Guo Z, Liu X, Wang D. Loss of RAD6B induces degeneration of the cochlea in mice. Biochem Biophys Res Commun 2020; 531:402-408. [PMID: 32868078 DOI: 10.1016/j.bbrc.2020.08.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 08/08/2020] [Indexed: 01/11/2023]
Abstract
Presbycusis is a form of age-related hearing loss (AHL). Many studies have shown that the degeneration of various structures in the cochlea of the inner ear is related to AHL, and DNA damage is an important factor leading to the above process. As an E2 ubiquitin-conjugated enzyme, RAD6B plays an important role in DNA damage repair (DDR) through histone ubiquitination. However, the molecular mechanism is still unclear. In this study, we investigated the role of RAD6B in the morphological changes and DDR mechanisms in aging-related degeneration of the cochlea of mice. We observed that the hair cells, stria vascularis and spiral ganglion in the cochlea of the RAD6B knockout mice showed significant degenerative changes and abnormal expression of proteins associated with DDR mechanisms compared with those of the littermate wild-type mice. In conclusion, our results suggest that the deletion of RAD6B may lead to abnormalities in DDR, thereby accelerating the degeneration of various structures in the cochlea and senescence and apoptosis of cochlea cells.
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Affiliation(s)
- Yangping Ma
- Department of Anatomy and Histology, School of Basic Medical Sciences, Lanzhou University, Lanzhou, China
| | - Yanfeng Song
- Department of Anatomy and Histology, School of Basic Medical Sciences, Lanzhou University, Lanzhou, China
| | - Rong Shen
- Department of Anatomy and Histology, School of Basic Medical Sciences, Lanzhou University, Lanzhou, China
| | - Panpan Li
- Department of Anatomy and Histology, School of Basic Medical Sciences, Lanzhou University, Lanzhou, China
| | - Han Ding
- Department of Anatomy and Histology, School of Basic Medical Sciences, Lanzhou University, Lanzhou, China
| | - Zhao Guo
- Department of Anatomy and Histology, School of Basic Medical Sciences, Lanzhou University, Lanzhou, China
| | - Xiangwen Liu
- Department of Anatomy and Histology, School of Basic Medical Sciences, Lanzhou University, Lanzhou, China
| | - Degui Wang
- Department of Anatomy and Histology, School of Basic Medical Sciences, Lanzhou University, Lanzhou, China.
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32
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Lehmann CP, Jiménez-Martín A, Branzei D, Tercero JA. Prevention of unwanted recombination at damaged replication forks. Curr Genet 2020; 66:1045-1051. [PMID: 32671464 PMCID: PMC7599154 DOI: 10.1007/s00294-020-01095-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 07/01/2020] [Accepted: 07/08/2020] [Indexed: 02/07/2023]
Abstract
Homologous recombination is essential for the maintenance of genome integrity but must be strictly controlled to avoid dangerous outcomes that produce the opposite effect, genomic instability. During unperturbed chromosome replication, recombination is globally inhibited at ongoing DNA replication forks, which helps to prevent deleterious genomic rearrangements. This inhibition is carried out by Srs2, a helicase that binds to SUMOylated PCNA and has an anti-recombinogenic function at replication forks. However, at damaged stalled forks, Srs2 is counteracted and DNA lesion bypass can be achieved by recombination-mediated template switching. In budding yeast, template switching is dependent on Rad5. In the absence of this protein, replication forks stall in the presence of DNA lesions and cells die. Recently, we showed that in cells lacking Rad5 that are exposed to DNA damage or replicative stress, elimination of the conserved Mgs1/WRNIP1 ATPase allows an alternative mode of DNA damage bypass that is driven by recombination and facilitates completion of chromosome replication and cell viability. We have proposed that Mgs1 is important to prevent a potentially harmful salvage pathway of recombination at damaged stalled forks. In this review, we summarize our current understanding of how unwanted recombination is prevented at damaged stalled replication forks.
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Affiliation(s)
- Carl P Lehmann
- Centro de Biología Molecular Severo Ochoa (CSIC/UAM), Cantoblanco, 28049, Madrid, Spain
| | - Alberto Jiménez-Martín
- Centro de Biología Molecular Severo Ochoa (CSIC/UAM), Cantoblanco, 28049, Madrid, Spain.,Centro Andaluz de Biología del Desarrollo (CSIC/UPO), 41013, Seville, Spain
| | - Dana Branzei
- IFOM, The FIRC Institute of Molecular Oncology, Via Adamello 16, 20139, Milan, Italy.,Istituto di Genetica Molecolare, Consiglio Nazionale delle Ricerche (IGM-CNR), Via Abbiategrasso 207, 27100, Pavia, Italy
| | - José Antonio Tercero
- Centro de Biología Molecular Severo Ochoa (CSIC/UAM), Cantoblanco, 28049, Madrid, Spain.
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33
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Wang Z, Xiao W. Distinct requirements for budding yeast Rev1 and Polη in translesion DNA synthesis across different types of DNA damage. Curr Genet 2020; 66:1019-1028. [PMID: 32623695 DOI: 10.1007/s00294-020-01092-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 06/24/2020] [Accepted: 06/26/2020] [Indexed: 02/04/2023]
Abstract
Certain replication-blocking lesions can escape DNA repair and must be bypassed to prevent fork collapse and cell death. Budding yeast DNA-damage tolerance consists of translesion DNA synthesis (TLS) and template switch. TLS utilizes specialized DNA polymerases to insert nucleotides opposite the damage site, followed by extension, allowing continual replication in the presence of lesions on the template DNA. Meanwhile, Rev1 is additionally required for the subsequent extension step of TLS regardless of the initial insertion polymerase utilized. Here we assess relative contributions of two Y-family TLS polymerases, Rev1 and Polη, in bypassing lesions induced by various types of DNA-damaging agents. Our experimental results collectively indicate that yeast cells preferentially utilize relatively error-free TLS polymerase(s) to bypass given lesions, and that the mutagenic TLS polymerase may serve as a backup. Interestingly, if Polη is unable to serve as a TLS polymerase under certain circumstances, it may be counter-active. The cooperation among TLS polymerases may strike a balance between survival and stress-induced mutagenesis. These observations indicate that specialized Y-family DNA polymerases have evolved to deal with different types of environmental genotoxic stresses.
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Affiliation(s)
- Zihao Wang
- Beijing Key Laboratory of DNA Damage Responses and College of Life Sciences, Capital Normal University, Beijing, 100048, China
| | - Wei Xiao
- Beijing Key Laboratory of DNA Damage Responses and College of Life Sciences, Capital Normal University, Beijing, 100048, China. .,Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, SK, S7N 5E5, Canada.
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34
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Pardo B, Moriel‐Carretero M, Vicat T, Aguilera A, Pasero P. Homologous recombination and Mus81 promote replication completion in response to replication fork blockage. EMBO Rep 2020; 21:e49367. [PMID: 32419301 PMCID: PMC7332989 DOI: 10.15252/embr.201949367] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 04/16/2020] [Accepted: 04/20/2020] [Indexed: 12/19/2022] Open
Abstract
Impediments to DNA replication threaten genome stability. The homologous recombination (HR) pathway has been involved in the restart of blocked replication forks. Here, we used a method to increase yeast cell permeability in order to study at the molecular level the fate of replication forks blocked by DNA topoisomerase I poisoning by camptothecin (CPT). Our results indicate that Rad52 and Rad51 HR factors are required to complete DNA replication in response to CPT. Recombination events occurring during S phase do not generally lead to the restart of DNA synthesis but rather protect blocked forks until they merge with convergent forks. This fusion generates structures requiring their resolution by the Mus81 endonuclease in G2 /M. At the global genome level, the multiplicity of replication origins in eukaryotic genomes and the fork protection mechanism provided by HR appear therefore to be essential to complete DNA replication in response to fork blockage.
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Affiliation(s)
- Benjamin Pardo
- Institut de Génétique HumaineUniversité de Montpellier‐CNRSMontpellierFrance
- Centro Andaluz de Biología Molecular y Medicina Regenerativa CABIMERUniversidad de Sevilla‐CSIC‐Universidad Pablo de OlavideSevilleSpain
| | - María Moriel‐Carretero
- Institut de Génétique HumaineUniversité de Montpellier‐CNRSMontpellierFrance
- Centro Andaluz de Biología Molecular y Medicina Regenerativa CABIMERUniversidad de Sevilla‐CSIC‐Universidad Pablo de OlavideSevilleSpain
- Present address:
Centre de Recherche en Biologie cellulaire de MontpellierUniversité de Montpellier‐CNRSMontpellierFrance
| | - Thibaud Vicat
- Institut de Génétique HumaineUniversité de Montpellier‐CNRSMontpellierFrance
| | - Andrés Aguilera
- Centro Andaluz de Biología Molecular y Medicina Regenerativa CABIMERUniversidad de Sevilla‐CSIC‐Universidad Pablo de OlavideSevilleSpain
| | - Philippe Pasero
- Institut de Génétique HumaineUniversité de Montpellier‐CNRSMontpellierFrance
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35
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Arbel M, Liefshitz B, Kupiec M. How yeast cells deal with stalled replication forks. Curr Genet 2020; 66:911-915. [PMID: 32394094 DOI: 10.1007/s00294-020-01082-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 04/24/2020] [Accepted: 04/29/2020] [Indexed: 12/27/2022]
Abstract
DNA polymerases sometimes stall during DNA replication at sites where DNA is damaged, or upon encounter with proteins or secondary structures of DNA. When that happens, the polymerase clamp PCNA can become modified with a single ubiquitin moiety at lysine 164, opening DNA Damage Tolerance (DDT) mechanisms that either repair or bypass the lesions. An alternative repair mechanism is the salvage recombination (SR) pathway, which copies information from the sister chromatid. SUMOylation of PCNA at the same lysine, or at lysine 127, can recruit the Srs2 helicase, which negatively controls SR. Recently, we have dissected the relationship between SR and the DDT pathways, and showed that overexpression of either the PCNA unloader Elg1, or the Rad52 homologous recombination protein, can bypass the repression by Srs2. Our results shed light on the interactions between different DNA damage repair/bypass proteins, and underscore the importance of PCNA modifications in organizing the complex task of dealing with DNA damage during replication of the genetic material.
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Affiliation(s)
- Matan Arbel
- School of Molecular Cell Biology and Biotechnology, Tel Aviv University, 69978, Ramat, Aviv, Israel
| | - Batia Liefshitz
- School of Molecular Cell Biology and Biotechnology, Tel Aviv University, 69978, Ramat, Aviv, Israel
| | - Martin Kupiec
- School of Molecular Cell Biology and Biotechnology, Tel Aviv University, 69978, Ramat, Aviv, Israel.
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36
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Access to PCNA by Srs2 and Elg1 Controls the Choice between Alternative Repair Pathways in Saccharomyces cerevisiae. mBio 2020; 11:mBio.00705-20. [PMID: 32371600 PMCID: PMC7403780 DOI: 10.1128/mbio.00705-20] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
PCNA, the ring that encircles DNA maintaining the processivity of DNA polymerases, is modified by ubiquitin and SUMO. Whereas ubiquitin is required for bypassing lesions through the DNA damage tolerance (DDT) pathways, we show here that SUMOylation represses another pathway, salvage recombination. The Srs2 helicase is recruited to SUMOylated PCNA and prevents the salvage pathway from acting. The pathway can be induced by overexpressing the PCNA unloader Elg1, or the homologous recombination protein Rad52. Our results underscore the role of PCNA modifications in controlling the various bypass and DNA repair mechanisms. During DNA replication, stalling can occur when the replicative DNA polymerases encounter lesions or hard-to replicate regions. Under these circumstances, the processivity factor PCNA gets ubiquitylated at lysine 164, inducing the DNA damage tolerance (DDT) mechanisms that can bypass lesions encountered during DNA replication. PCNA can also be SUMOylated at the same residue or at lysine 127. Surprisingly, pol30-K164R mutants display a higher degree of sensitivity to DNA-damaging agents than pol30-KK127,164RR strains, unable to modify any of the lysines. Here, we show that in addition to translesion synthesis and strand-transfer DDT mechanisms, an alternative repair mechanism (“salvage recombination”) that copies information from the sister chromatid is repressed by the recruitment of Srs2 to SUMOylated PCNA. Overexpression of Elg1, the PCNA unloader, or of the recombination protein Rad52 allows its activation. We dissect the genetic requirements for this pathway, as well as the interactions between Srs2 and Elg1.
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37
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Bittmann J, Grigaitis R, Galanti L, Amarell S, Wilfling F, Matos J, Pfander B. An advanced cell cycle tag toolbox reveals principles underlying temporal control of structure-selective nucleases. eLife 2020; 9:e52459. [PMID: 32352375 PMCID: PMC7220381 DOI: 10.7554/elife.52459] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 04/29/2020] [Indexed: 12/26/2022] Open
Abstract
Cell cycle tags allow to restrict target protein expression to specific cell cycle phases. Here, we present an advanced toolbox of cell cycle tag constructs in budding yeast with defined and compatible peak expression that allow comparison of protein functionality at different cell cycle phases. We apply this technology to the question of how and when Mus81-Mms4 and Yen1 nucleases act on DNA replication or recombination structures. Restriction of Mus81-Mms4 to M phase but not S phase allows a wildtype response to various forms of replication perturbation and DNA damage in S phase, suggesting it acts as a post-replicative resolvase. Moreover, we use cell cycle tags to reinstall cell cycle control to a deregulated version of Yen1, showing that its premature activation interferes with the response to perturbed replication. Curbing resolvase activity and establishing a hierarchy of resolution mechanisms are therefore the principal reasons underlying resolvase cell cycle regulation.
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Affiliation(s)
- Julia Bittmann
- Max Planck Institute of Biochemistry, DNA Replication and Genome IntegrityMartinsriedGermany
| | - Rokas Grigaitis
- Institute of Biochemistry, Eidgenössische Technische Hochschule, ZürichZürichSwitzerland
| | - Lorenzo Galanti
- Max Planck Institute of Biochemistry, DNA Replication and Genome IntegrityMartinsriedGermany
| | - Silas Amarell
- Max Planck Institute of Biochemistry, DNA Replication and Genome IntegrityMartinsriedGermany
| | - Florian Wilfling
- Max Planck Institute of Biochemistry, Molecular Cell BiologyMartinsriedGermany
| | - Joao Matos
- Institute of Biochemistry, Eidgenössische Technische Hochschule, ZürichZürichSwitzerland
| | - Boris Pfander
- Max Planck Institute of Biochemistry, DNA Replication and Genome IntegrityMartinsriedGermany
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38
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Guilliam TA, Yeeles JTP. Reconstitution of translesion synthesis reveals a mechanism of eukaryotic DNA replication restart. Nat Struct Mol Biol 2020; 27:450-460. [PMID: 32341533 DOI: 10.1038/s41594-020-0418-4] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 03/16/2020] [Indexed: 12/23/2022]
Abstract
Leading-strand template aberrations cause helicase-polymerase uncoupling and impede replication fork progression, but the details of how uncoupled forks are restarted remain uncertain. Using purified proteins from Saccharomyces cerevisiae, we have reconstituted translesion synthesis (TLS)-mediated restart of a eukaryotic replisome following collision with a cyclobutane pyrimidine dimer. We find that TLS functions 'on the fly' to promote resumption of rapid replication fork rates, despite lesion bypass occurring uncoupled from the Cdc45-MCM-GINS (CMG) helicase. Surprisingly, the main lagging-strand polymerase, Pol δ, binds the leading strand upon uncoupling and inhibits TLS. Pol δ is also crucial for efficient recoupling of leading-strand synthesis to CMG following lesion bypass. Proliferating cell nuclear antigen monoubiquitination positively regulates TLS to overcome Pol δ inhibition. We reveal that these mechanisms of negative and positive regulation also operate on the lagging strand. Our observations have implications for both fork restart and the division of labor during leading-strand synthesis generally.
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Affiliation(s)
- Thomas A Guilliam
- Division of Protein and Nucleic Acid Chemistry, Medical Research Council Laboratory of Molecular Biology, Cambridge, UK
| | - Joseph T P Yeeles
- Division of Protein and Nucleic Acid Chemistry, Medical Research Council Laboratory of Molecular Biology, Cambridge, UK.
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Takahashi TS, Wollscheid HP, Lowther J, Ulrich HD. Effects of chain length and geometry on the activation of DNA damage bypass by polyubiquitylated PCNA. Nucleic Acids Res 2020; 48:3042-3052. [PMID: 32009145 PMCID: PMC7102961 DOI: 10.1093/nar/gkaa053] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 01/15/2020] [Accepted: 01/30/2020] [Indexed: 01/06/2023] Open
Abstract
Ubiquitylation of the eukaryotic sliding clamp, PCNA, activates a pathway of DNA damage bypass that facilitates the replication of damaged DNA. In its monoubiquitylated form, PCNA recruits a set of damage-tolerant DNA polymerases for translesion synthesis. Alternatively, modification by K63-linked polyubiquitylation triggers a recombinogenic process involving template switching. Despite the identification of proteins interacting preferentially with polyubiquitylated PCNA, the molecular function of the chain and the relevance of its K63-linkage are poorly understood. Using genetically engineered mimics of polyubiquitylated PCNA, we have now examined the properties of the ubiquitin chain required for damage bypass in budding yeast. By varying key parameters such as the geometry of the junction, cleavability and capacity for branching, we demonstrate that either the structure of the ubiquitin-ubiquitin junction or its dynamic assembly or disassembly at the site of action exert a critical impact on damage bypass, even though known effectors of polyubiquitylated PCNA are not strictly linkage-selective. Moreover, we found that a single K63-junction supports substantial template switching activity, irrespective of its attachment site on PCNA. Our findings provide insight into the interrelationship between the two branches of damage bypass and suggest the existence of a yet unidentified, highly linkage-selective receptor of polyubiquitylated PCNA.
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Affiliation(s)
- Tomio S Takahashi
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | | | | | - Helle D Ulrich
- Institute of Molecular Biology gGmbH (IMB), Ackermannweg 4, D-55128 Mainz, Germany
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40
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Jiménez-Martín A, Saugar I, Joseph CR, Mayer A, Lehmann CP, Szakal B, Branzei D, Tercero JA. The Mgs1/WRNIP1 ATPase is required to prevent a recombination salvage pathway at damaged replication forks. SCIENCE ADVANCES 2020; 6:eaaz3327. [PMID: 32285001 PMCID: PMC7141828 DOI: 10.1126/sciadv.aaz3327] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 01/14/2020] [Indexed: 06/11/2023]
Abstract
DNA damage tolerance (DDT) is crucial for genome integrity maintenance. DDT is mainly carried out by template switch recombination, an error-free mode of overcoming DNA lesions, or translesion DNA synthesis, which is error-prone. Here, we investigated the role of Mgs1/WRNIP1 in modulating DDT. Using budding yeast, we found that elimination of Mgs1 in cells lacking Rad5, an essential protein for DDT, activates an alternative mode of DNA damage bypass, driven by recombination, which allows chromosome replication and cell viability under stress conditions that block DNA replication forks. This salvage pathway is RAD52 and RAD59 dependent, requires the DNA polymerase δ and PCNA modification at K164, and is enabled by Esc2 and the PCNA unloader Elg1, being inhibited when Mgs1 is present. We propose that Mgs1 is necessary to prevent a potentially toxic recombination salvage pathway at sites of perturbed replication, which, in turn, favors Rad5-dependent template switching, thus helping to preserve genome stability.
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Affiliation(s)
| | - Irene Saugar
- Centro de Biología Molecular Severo Ochoa (CSIC/UAM), Cantoblanco, 28049 Madrid, Spain
| | - Chinnu Rose Joseph
- IFOM, The FIRC Institute of Molecular Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Alexandra Mayer
- IFOM, The FIRC Institute of Molecular Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Carl P. Lehmann
- Centro de Biología Molecular Severo Ochoa (CSIC/UAM), Cantoblanco, 28049 Madrid, Spain
| | - Barnabas Szakal
- IFOM, The FIRC Institute of Molecular Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Dana Branzei
- IFOM, The FIRC Institute of Molecular Oncology, Via Adamello 16, 20139 Milan, Italy
- Istituto di Genetica Molecolare, Consiglio Nazionale delle Ricerche (IGM-CNR), Via Abbiategrasso 207, 27100 Pavia, Italy
| | - José Antonio Tercero
- Centro de Biología Molecular Severo Ochoa (CSIC/UAM), Cantoblanco, 28049 Madrid, Spain
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41
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Ovejero S, Bueno A, Sacristán MP. Working on Genomic Stability: From the S-Phase to Mitosis. Genes (Basel) 2020; 11:E225. [PMID: 32093406 PMCID: PMC7074175 DOI: 10.3390/genes11020225] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 02/17/2020] [Accepted: 02/18/2020] [Indexed: 12/15/2022] Open
Abstract
Fidelity in chromosome duplication and segregation is indispensable for maintaining genomic stability and the perpetuation of life. Challenges to genome integrity jeopardize cell survival and are at the root of different types of pathologies, such as cancer. The following three main sources of genomic instability exist: DNA damage, replicative stress, and chromosome segregation defects. In response to these challenges, eukaryotic cells have evolved control mechanisms, also known as checkpoint systems, which sense under-replicated or damaged DNA and activate specialized DNA repair machineries. Cells make use of these checkpoints throughout interphase to shield genome integrity before mitosis. Later on, when the cells enter into mitosis, the spindle assembly checkpoint (SAC) is activated and remains active until the chromosomes are properly attached to the spindle apparatus to ensure an equal segregation among daughter cells. All of these processes are tightly interconnected and under strict regulation in the context of the cell division cycle. The chromosomal instability underlying cancer pathogenesis has recently emerged as a major source for understanding the mitotic processes that helps to safeguard genome integrity. Here, we review the special interconnection between the S-phase and mitosis in the presence of under-replicated DNA regions. Furthermore, we discuss what is known about the DNA damage response activated in mitosis that preserves chromosomal integrity.
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Affiliation(s)
- Sara Ovejero
- Instituto de Biología Molecular y Celular del Cáncer (IBMCC), Universidad de Salamanca-CSIC, Campus Miguel de Unamuno, 37007 Salamanca, Spain
- Institute of Human Genetics, CNRS, University of Montpellier, 34000 Montpellier, France
- Department of Biological Hematology, CHU Montpellier, 34295 Montpellier, France
| | - Avelino Bueno
- Instituto de Biología Molecular y Celular del Cáncer (IBMCC), Universidad de Salamanca-CSIC, Campus Miguel de Unamuno, 37007 Salamanca, Spain
- Departamento de Microbiología y Genética, Universidad de Salamanca, Campus Miguel de Unamuno, 37007 Salamanca, Spain
| | - María P. Sacristán
- Instituto de Biología Molecular y Celular del Cáncer (IBMCC), Universidad de Salamanca-CSIC, Campus Miguel de Unamuno, 37007 Salamanca, Spain
- Departamento de Microbiología y Genética, Universidad de Salamanca, Campus Miguel de Unamuno, 37007 Salamanca, Spain
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42
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Gupta SV, Schmidt KH. Maintenance of Yeast Genome Integrity by RecQ Family DNA Helicases. Genes (Basel) 2020; 11:E205. [PMID: 32085395 PMCID: PMC7074392 DOI: 10.3390/genes11020205] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 02/11/2020] [Accepted: 02/14/2020] [Indexed: 12/28/2022] Open
Abstract
With roles in DNA repair, recombination, replication and transcription, members of the RecQ DNA helicase family maintain genome integrity from bacteria to mammals. Mutations in human RecQ helicases BLM, WRN and RecQL4 cause incurable disorders characterized by genome instability, increased cancer predisposition and premature adult-onset aging. Yeast cells lacking the RecQ helicase Sgs1 share many of the cellular defects of human cells lacking BLM, including hypersensitivity to DNA damaging agents and replication stress, shortened lifespan, genome instability and mitotic hyper-recombination, making them invaluable model systems for elucidating eukaryotic RecQ helicase function. Yeast and human RecQ helicases have common DNA substrates and domain structures and share similar physical interaction partners. Here, we review the major cellular functions of the yeast RecQ helicases Sgs1 of Saccharomyces cerevisiae and Rqh1 of Schizosaccharomyces pombe and provide an outlook on some of the outstanding questions in the field.
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Affiliation(s)
- Sonia Vidushi Gupta
- Department of Cell Biology, Microbiology and Molecular Biology, University of South, Florida, Tampa, FL 33620, USA;
| | - Kristina Hildegard Schmidt
- Department of Cell Biology, Microbiology and Molecular Biology, University of South, Florida, Tampa, FL 33620, USA;
- Cancer Biology and Evolution Program, H. Lee Moffitt Cancer Center and Research, Institute, Tampa, FL 33612, USA
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43
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Determinants of Replication-Fork Pausing at tRNA Genes in Saccharomyces cerevisiae. Genetics 2020; 214:825-838. [PMID: 32071194 DOI: 10.1534/genetics.120.303092] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Accepted: 02/12/2020] [Indexed: 12/21/2022] Open
Abstract
Transfer RNA (tRNA) genes are widely studied sites of replication-fork pausing and genome instability in the budding yeast Saccharomyces cerevisiae tRNAs are extremely highly transcribed and serve as constitutive condensin binding sites. tRNA transcription by RNA polymerase III has previously been identified as stimulating replication-fork pausing at tRNA genes, but the nature of the block to replication has not been incontrovertibly demonstrated. Here, we describe a systematic, genome-wide analysis of the contributions of candidates to replication-fork progression at tDNAs in yeast: transcription factor binding, transcription, topoisomerase activity, condensin-mediated clustering, and Rad18-dependent DNA repair. We show that an asymmetric block to replication is maintained even when tRNA transcription is abolished by depletion of one or more subunits of RNA polymerase III. By contrast, analogous depletion of the essential transcription factor TFIIIB removes the obstacle to replication. Therefore, our data suggest that the RNA polymerase III transcription complex itself represents an asymmetric obstacle to replication even in the absence of RNA synthesis. We additionally demonstrate that replication-fork progression past tRNA genes is unaffected by the global depletion of condensin from the nucleus, and can be stimulated by the removal of topoisomerases or Rad18-dependent DNA repair pathways.
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Kellner V, Luke B. Molecular and physiological consequences of faulty eukaryotic ribonucleotide excision repair. EMBO J 2020; 39:e102309. [PMID: 31833079 PMCID: PMC6996501 DOI: 10.15252/embj.2019102309] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 10/22/2019] [Accepted: 11/26/2019] [Indexed: 01/11/2023] Open
Abstract
The duplication of the eukaryotic genome is an intricate process that has to be tightly safe-guarded. One of the most frequently occurring errors during DNA synthesis is the mis-insertion of a ribonucleotide instead of a deoxyribonucleotide. Ribonucleotide excision repair (RER) is initiated by RNase H2 and results in error-free removal of such mis-incorporated ribonucleotides. If left unrepaired, DNA-embedded ribonucleotides result in a variety of alterations within chromosomal DNA, which ultimately lead to genome instability. Here, we review how genomic ribonucleotides lead to chromosomal aberrations and discuss how the tight regulation of RER timing may be important for preventing unwanted DNA damage. We describe the structural impact of unrepaired ribonucleotides on DNA and chromatin and comment on the potential consequences for cellular fitness. In the context of the molecular mechanisms associated with faulty RER, we have placed an emphasis on how and why increased levels of genomic ribonucleotides are associated with severe autoimmune syndromes, neuropathology, and cancer. In addition, we discuss therapeutic directions that could be followed for pathologies associated with defective removal of ribonucleotides from double-stranded DNA.
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Affiliation(s)
- Vanessa Kellner
- Institute of Molecular Biology (IMB)MainzGermany
- Present address:
Department of BiologyNew York UniversityNew YorkNYUSA
| | - Brian Luke
- Institute of Molecular Biology (IMB)MainzGermany
- Institute of Developmental Biology and Neurobiology (IDN)Johannes Gutenberg UniversitätMainzGermany
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45
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Dovrat D, Dahan D, Sherman S, Tsirkas I, Elia N, Aharoni A. A Live-Cell Imaging Approach for Measuring DNA Replication Rates. Cell Rep 2019; 24:252-258. [PMID: 29972785 DOI: 10.1016/j.celrep.2018.06.018] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 04/02/2018] [Accepted: 06/01/2018] [Indexed: 10/28/2022] Open
Abstract
We describe a simple and direct approach to measure the progression of single DNA replication forks in living cells by monitoring two fluorescently labeled loci downstream of an origin of replication. We employ this approach to investigate the roles of several leading and lagging strand factors in overall replisome function and show that fork progression is strongly dependent on proper maturation of Okazaki fragments. We also demonstrate how related cellular phenotypes, such as cell-cycle progression and the dynamics of sister chromatid cohesion, may be simultaneously monitored and correlated to DNA replication at the single-cell level.
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Affiliation(s)
- Daniel Dovrat
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Be'er Sheva 8410501, Israel
| | - Danielle Dahan
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Be'er Sheva 8410501, Israel
| | - Shachar Sherman
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Be'er Sheva 8410501, Israel
| | - Ioannis Tsirkas
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Be'er Sheva 8410501, Israel
| | - Natalie Elia
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Be'er Sheva 8410501, Israel.
| | - Amir Aharoni
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Be'er Sheva 8410501, Israel.
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46
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Defects in the GINS complex increase the instability of repetitive sequences via a recombination-dependent mechanism. PLoS Genet 2019; 15:e1008494. [PMID: 31815930 PMCID: PMC6922473 DOI: 10.1371/journal.pgen.1008494] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 12/19/2019] [Accepted: 10/25/2019] [Indexed: 12/16/2022] Open
Abstract
Faithful replication and repair of DNA lesions ensure genome maintenance. During replication in eukaryotic cells, DNA is unwound by the CMG helicase complex, which is composed of three major components: the Cdc45 protein, Mcm2-7, and the GINS complex. The CMG in complex with DNA polymerase epsilon (CMG-E) participates in the establishment and progression of the replisome. Impaired functioning of the CMG-E was shown to induce genomic instability and promote the development of various diseases. Therefore, CMG-E components play important roles as caretakers of the genome. In Saccharomyces cerevisiae, the GINS complex is composed of the Psf1, Psf2, Psf3, and Sld5 essential subunits. The Psf1-1 mutant form fails to interact with Psf3, resulting in impaired replisome assembly and chromosome replication. Here, we show increased instability of repeat tracts (mononucleotide, dinucleotide, trinucleotide and longer) in yeast psf1-1 mutants. To identify the mechanisms underlying this effect, we analyzed repeated sequence instability using derivatives of psf1-1 strains lacking genes involved in translesion synthesis, recombination, or mismatch repair. Among these derivatives, deletion of RAD52, RAD51, MMS2, POL32, or PIF1 significantly decreased DNA repeat instability. These results, together with the observed increased amounts of single-stranded DNA regions and Rfa1 foci suggest that recombinational mechanisms make important contributions to repeat tract instability in psf1-1 cells. We propose that defective functioning of the CMG-E complex in psf1-1 cells impairs the progression of DNA replication what increases the contribution of repair mechanisms such as template switch and break-induced replication. These processes require sequence homology search which in case of a repeated DNA tract may result in misalignment leading to its expansion or contraction. Processes that ensure genome stability are crucial for all organisms to avoid mutations and decrease the risk of diseases. The coordinated activity of mechanisms underlying the maintenance of high-fidelity DNA duplication and repair is critical to deal with the malfunction of replication forks or DNA damage. Repeated sequences in DNA are particularly prone to instability; these sequences undergo expansions or contractions, leading in humans to various neurological, neurodegenerative, and neuromuscular disorders. A mutant form of one of the noncatalytic subunits of active DNA helicase complex impairs DNA replication. Here, we show that this form also significantly increases the instability of mononucleotide, dinucleotide, trinucleotide and longer repeat tracts. Our results suggest that in cells that harbor a mutated variant of the helicase complex, continuation of DNA replication is facilitated by recombination processes, and this mechanism can be highly mutagenic during repair synthesis through repetitive regions, especially regions that form secondary structures. Our results indicate that proper functioning of the DNA helicase complex is crucial for maintenance of the stability of repeated DNA sequences, especially in the context of recently described disorders in which mutations or deregulation of the human homologs of genes encoding DNA helicase subunits were observed.
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47
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Pol V-Mediated Translesion Synthesis Elicits Localized Untargeted Mutagenesis during Post-replicative Gap Repair. Cell Rep 2019; 24:1290-1300. [PMID: 30067983 DOI: 10.1016/j.celrep.2018.06.120] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 05/14/2018] [Accepted: 06/28/2018] [Indexed: 11/23/2022] Open
Abstract
In vivo, replication forks proceed beyond replication-blocking lesions by way of downstream repriming, generating daughter strand gaps that are subsequently processed by post-replicative repair pathways such as homologous recombination and translesion synthesis (TLS). The way these gaps are filled during TLS is presently unknown. The structure of gap repair synthesis was assessed by sequencing large collections of single DNA molecules that underwent specific TLS events in vivo. The higher error frequency of specialized relative to replicative polymerases allowed us to visualize gap-filling events at high resolution. Unexpectedly, the data reveal that a specialized polymerase, Pol V, synthesizes stretches of DNA both upstream and downstream of a site-specific DNA lesion. Pol V-mediated untargeted mutations are thus spread over several hundred nucleotides, strongly eliciting genetic instability on either side of a given lesion. Consequently, post-replicative gap repair may be a source of untargeted mutations critical for gene diversification in adaptation and evolution.
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48
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Zapatka M, Pociño-Merino I, Heluani-Gahete H, Bermúdez-López M, Tarrés M, Ibars E, Solé-Soler R, Gutiérrez-Escribano P, Apostolova S, Casas C, Aragon L, Wellinger R, Colomina N, Torres-Rosell J. Sumoylation of Smc5 Promotes Error-free Bypass at Damaged Replication Forks. Cell Rep 2019; 29:3160-3172.e4. [DOI: 10.1016/j.celrep.2019.10.123] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 09/25/2019] [Accepted: 10/29/2019] [Indexed: 12/15/2022] Open
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49
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Masuda Y, Masutani C. Spatiotemporal regulation of PCNA ubiquitination in damage tolerance pathways. Crit Rev Biochem Mol Biol 2019; 54:418-442. [PMID: 31736364 DOI: 10.1080/10409238.2019.1687420] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
DNA is constantly exposed to a wide variety of exogenous and endogenous agents, and most DNA lesions inhibit DNA synthesis. To cope with such problems during replication, cells have molecular mechanisms to resume DNA synthesis in the presence of DNA lesions, which are known as DNA damage tolerance (DDT) pathways. The concept of ubiquitination-mediated regulation of DDT pathways in eukaryotes was established via genetic studies in the yeast Saccharomyces cerevisiae, in which two branches of the DDT pathway are regulated via ubiquitination of proliferating cell nuclear antigen (PCNA): translesion DNA synthesis (TLS) and homology-dependent repair (HDR), which are stimulated by mono- and polyubiquitination of PCNA, respectively. Over the subsequent nearly two decades, significant progress has been made in understanding the mechanisms that regulate DDT pathways in other eukaryotes. Importantly, TLS is intrinsically error-prone because of the miscoding nature of most damaged nucleotides and inaccurate replication of undamaged templates by TLS polymerases (pols), whereas HDR is theoretically error-free because the DNA synthesis is thought to be predominantly performed by pol δ, an accurate replicative DNA pol, using the undamaged sister chromatid as its template. Thus, the regulation of the choice between the TLS and HDR pathways is critical to determine the appropriate biological outcomes caused by DNA damage. In this review, we summarize our current understanding of the species-specific regulatory mechanisms of PCNA ubiquitination and how cells choose between TLS and HDR. We then provide a hypothetical model for the spatiotemporal regulation of DDT pathways in human cells.
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Affiliation(s)
- Yuji Masuda
- Department of Genome Dynamics, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan.,Graduate School of Medicine, Nagoya University, Nagoya, Japan
| | - Chikahide Masutani
- Department of Genome Dynamics, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan.,Graduate School of Medicine, Nagoya University, Nagoya, Japan
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50
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Winczura A, Appanah R, Tatham MH, Hay RT, De Piccoli G. The S phase checkpoint promotes the Smc5/6 complex dependent SUMOylation of Pol2, the catalytic subunit of DNA polymerase ε. PLoS Genet 2019; 15:e1008427. [PMID: 31765407 PMCID: PMC6876773 DOI: 10.1371/journal.pgen.1008427] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 09/16/2019] [Indexed: 12/31/2022] Open
Abstract
Replication fork stalling and accumulation of single-stranded DNA trigger the S phase checkpoint, a signalling cascade that, in budding yeast, leads to the activation of the Rad53 kinase. Rad53 is essential in maintaining cell viability, but its targets of regulation are still partially unknown. Here we show that Rad53 drives the hyper-SUMOylation of Pol2, the catalytic subunit of DNA polymerase ε, principally following replication forks stalling induced by nucleotide depletion. Pol2 is the main target of SUMOylation within the replisome and its modification requires the SUMO-ligase Mms21, a subunit of the Smc5/6 complex. Moreover, the Smc5/6 complex co-purifies with Pol ε, independently of other replisome components. Finally, we map Pol2 SUMOylation to a single site within the N-terminal catalytic domain and identify a SUMO-interacting motif at the C-terminus of Pol2. These data suggest that the S phase checkpoint regulate Pol ε during replication stress through Pol2 SUMOylation and SUMO-binding ability.
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Affiliation(s)
- Alicja Winczura
- Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | - Rowin Appanah
- Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | - Michael H. Tatham
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, United Kingdom
| | - Ronald T. Hay
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, United Kingdom
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