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Nasheuer HP, Meaney AM. Starting DNA Synthesis: Initiation Processes during the Replication of Chromosomal DNA in Humans. Genes (Basel) 2024; 15:360. [PMID: 38540419 PMCID: PMC10969946 DOI: 10.3390/genes15030360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 03/09/2024] [Accepted: 03/11/2024] [Indexed: 06/14/2024] Open
Abstract
The initiation reactions of DNA synthesis are central processes during human chromosomal DNA replication. They are separated into two main processes: the initiation events at replication origins, the start of the leading strand synthesis for each replicon, and the numerous initiation events taking place during lagging strand DNA synthesis. In addition, a third mechanism is the re-initiation of DNA synthesis after replication fork stalling, which takes place when DNA lesions hinder the progression of DNA synthesis. The initiation of leading strand synthesis at replication origins is regulated at multiple levels, from the origin recognition to the assembly and activation of replicative helicase, the Cdc45-MCM2-7-GINS (CMG) complex. In addition, the multiple interactions of the CMG complex with the eukaryotic replicative DNA polymerases, DNA polymerase α-primase, DNA polymerase δ and ε, at replication forks play pivotal roles in the mechanism of the initiation reactions of leading and lagging strand DNA synthesis. These interactions are also important for the initiation of signalling at unperturbed and stalled replication forks, "replication stress" events, via ATR (ATM-Rad 3-related protein kinase). These processes are essential for the accurate transfer of the cells' genetic information to their daughters. Thus, failures and dysfunctions in these processes give rise to genome instability causing genetic diseases, including cancer. In their influential review "Hallmarks of Cancer: New Dimensions", Hanahan and Weinberg (2022) therefore call genome instability a fundamental function in the development process of cancer cells. In recent years, the understanding of the initiation processes and mechanisms of human DNA replication has made substantial progress at all levels, which will be discussed in the review.
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Affiliation(s)
- Heinz Peter Nasheuer
- Centre for Chromosome Biology, School of Biological and Chemical Sciences, Biochemistry, University of Galway, H91 TK33 Galway, Ireland;
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2
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Siler J, Guo N, Liu Z, Qin Y, Bi X. γH2A/γH2AX Mediates DNA Damage-Specific Control of Checkpoint Signaling in Saccharomyces cerevisiae. Int J Mol Sci 2024; 25:2462. [PMID: 38473708 DOI: 10.3390/ijms25052462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2024] [Revised: 02/13/2024] [Accepted: 02/16/2024] [Indexed: 03/14/2024] Open
Abstract
DNA lesions trigger DNA damage checkpoint (DDC) signaling which arrests cell cycle progression and promotes DNA damage repair. In Saccharomyces cerevisiae, phosphorylation of histone H2A (γH2A, equivalent to γH2AX in mammals) is an early chromatin mark induced by DNA damage that is recognized by a group of DDC and DNA repair factors. We find that γH2A negatively regulates the G2/M checkpoint in response to the genotoxin camptothecin, which is a DNA topoisomerase I poison. γH2A also suppresses DDC signaling induced by the DNA alkylating agent methyl methanesulfonate. These results differ from prior findings, which demonstrate positive or no roles of γH2A in DDC in response to other DNA damaging agents such as phleomycin and ionizing radiation, which suggest that γH2A has DNA damage-specific effects on DDC signaling. We also find evidence supporting the notion that γH2A regulates DDC signaling by mediating the competitive recruitment of the DDC mediator Rad9 and the DNA repair factor Rtt107 to DNA lesions. We propose that γH2A/γH2AX serves to create a dynamic balance between DDC and DNA repair that is influenced by the nature of DNA damage.
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Affiliation(s)
- Jasmine Siler
- Department of Biology, University of Rochester, Rochester, NY 14627, USA
| | - Na Guo
- Department of Biology, University of Rochester, Rochester, NY 14627, USA
- College of Food Science and Engineering, Jilin University, Changchun 130012, China
| | - Zhengfeng Liu
- Department of Biology, University of Rochester, Rochester, NY 14627, USA
| | - Yuhua Qin
- Department of Biology, University of Rochester, Rochester, NY 14627, USA
| | - Xin Bi
- Department of Biology, University of Rochester, Rochester, NY 14627, USA
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3
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Saccharomyces cerevisiae as a Model System for Eukaryotic Cell Biology, from Cell Cycle Control to DNA Damage Response. Int J Mol Sci 2022; 23:ijms231911665. [PMID: 36232965 PMCID: PMC9570374 DOI: 10.3390/ijms231911665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 09/26/2022] [Accepted: 09/28/2022] [Indexed: 11/08/2022] Open
Abstract
The yeast Saccharomyces cerevisiae has been used for bread making and beer brewing for thousands of years. In addition, its ease of manipulation, well-annotated genome, expansive molecular toolbox, and its strong conservation of basic eukaryotic biology also make it a prime model for eukaryotic cell biology and genetics. In this review, we discuss the characteristics that made yeast such an extensively used model organism and specifically focus on the DNA damage response pathway as a prime example of how research in S. cerevisiae helped elucidate a highly conserved biological process. In addition, we also highlight differences in the DNA damage response of S. cerevisiae and humans and discuss the challenges of using S. cerevisiae as a model system.
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4
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A DNA Replication Fork-centric View of the Budding Yeast DNA Damage Response. DNA Repair (Amst) 2022; 119:103393. [DOI: 10.1016/j.dnarep.2022.103393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 08/25/2022] [Accepted: 08/26/2022] [Indexed: 11/23/2022]
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5
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Li L, Wang J, Yang Z, Zhao Y, Jiang H, Jiang L, Hou W, Ye R, He Q, Kupiec M, Luke B, Cao Q, Qi Z, Li Z, Lou H. Metabolic remodeling maintains a reducing environment for rapid activation of the yeast DNA replication checkpoint. EMBO J 2022; 41:e108290. [PMID: 35028974 PMCID: PMC8844976 DOI: 10.15252/embj.2021108290] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 11/04/2021] [Accepted: 12/09/2021] [Indexed: 12/31/2022] Open
Abstract
Nucleotide metabolism fuels normal DNA replication and is also primarily targeted by the DNA replication checkpoint when replication stalls. To reveal a comprehensive interconnection between genome maintenance and metabolism, we analyzed the metabolomic changes upon replication stress in the budding yeast S. cerevisiae. We found that upon treatment of cells with hydroxyurea, glucose is rapidly diverted to the oxidative pentose phosphate pathway (PPP). This effect is mediated by the AMP-dependent kinase, SNF1, which phosphorylates the transcription factor Mig1, thereby relieving repression of the gene encoding the rate-limiting enzyme of the PPP. Surprisingly, NADPH produced by the PPP is required for efficient recruitment of replication protein A (RPA) to single-stranded DNA, providing the signal for the activation of the Mec1/ATR-Rad53/CHK1 checkpoint signaling kinase cascade. Thus, SNF1, best known as a central energy controller, determines a fast mode of replication checkpoint activation through a redox mechanism. These findings establish that SNF1 provides a hub with direct links to cellular metabolism, redox, and surveillance of DNA replication in eukaryotes.
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Affiliation(s)
- Lili Li
- State Key Laboratory of AgrobiotechnologyCollege of Biological SciencesChina Agricultural UniversityBeijingChina
| | - Jie Wang
- State Key Laboratory of Plant Physiology and BiochemistryCollege of Biological SciencesChina Agricultural UniversityBeijingChina
| | - Zijia Yang
- State Key Laboratory of Plant Physiology and BiochemistryCollege of Biological SciencesChina Agricultural UniversityBeijingChina
| | - Yiling Zhao
- Center for Quantitative Biology and Peking‐Tsinghua Center for Life SciencesAcademy for Advanced Interdisciplinary StudiesPeking UniversityBeijingChina
| | - Hui Jiang
- State Key Laboratory of AgrobiotechnologyCollege of Biological SciencesChina Agricultural UniversityBeijingChina
| | - Luguang Jiang
- MOE Key Laboratory of Crop Heterosis and UtilizationNational Maize Improvement Center of ChinaCollege of Agronomy and BiotechnologyChina Agricultural UniversityBeijingChina
| | - Wenya Hou
- Shenzhen University General HospitalGuangdong Key Laboratory for Genome Stability and Disease PreventionShenzhen University School of MedicineShenzhenChina
| | - Risheng Ye
- Department of Medical EducationTexas Tech University Health Sciences Center Paul L. Foster School of MedicineEl PasoTXUSA
| | - Qun He
- State Key Laboratory of AgrobiotechnologyCollege of Biological SciencesChina Agricultural UniversityBeijingChina
| | - Martin Kupiec
- The Shmunis School of Biomedicine and Cancer ResearchTel Aviv UniversityRamat AvivIsrael
| | - Brian Luke
- Institute of Molecular Biology (IMB)MainzGermany,Institute of Developmental Biology and Neurobiology (IDN)Johannes Gutenberg UniversitätMainzGermany
| | - Qinhong Cao
- State Key Laboratory of AgrobiotechnologyCollege of Biological SciencesChina Agricultural UniversityBeijingChina
| | - Zhi Qi
- Center for Quantitative Biology and Peking‐Tsinghua Center for Life SciencesAcademy for Advanced Interdisciplinary StudiesPeking UniversityBeijingChina
| | - Zhen Li
- State Key Laboratory of Plant Physiology and BiochemistryCollege of Biological SciencesChina Agricultural UniversityBeijingChina
| | - Huiqiang Lou
- South China HospitalHealth Science CenterGuangdong Key Laboratory of Genome Instability and Disease PreventionShenzhen University School of MedicineShenzhenChina
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6
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Sahay O, Barik GK, Sharma T, Pillai AD, Rapole S, Santra MK. Damsel in distress calling on her knights: Illuminating the pioneering role of E3 ubiquitin ligases in guarding the genome integrity. DNA Repair (Amst) 2021; 109:103261. [PMID: 34920250 DOI: 10.1016/j.dnarep.2021.103261] [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: 08/19/2021] [Revised: 11/30/2021] [Accepted: 12/07/2021] [Indexed: 11/03/2022]
Abstract
The maintenance of genomic integrity is of utmost importance for the organisms to survive and to accurately inherit traits to their progenies. Any kind of DNA damage either due to defect in DNA duplication and/ or uncontrolled cell division or intracellular insults or environment radiation can result in gene mutation, chromosomal aberration and ultimately genomic instability, which may cause several diseases including cancers. Therefore, cells have evolved machineries for the surveillance of genomic integrity. Enormous exciting studies in the past indicate that ubiquitination (a posttranslational modification of proteins) plays a crucial role in maintaining the genomic integrity by diverse ways. In fact, various E3 ubiquitin ligases catalyse ubiquitination of key proteins to control their central role during cell cycle, DNA damage response (DDR) and DNA repair. Some E3 ligases promote genomic instability while others prevent it, deregulation of both of which leads to several malignancies. In this review, we consolidate the recent findings wherein the role of ubiquitination in conferring genome integrity is highlighted. We also discuss the latest discoveries on the mechanisms utilized by various E3 ligases to preserve genomic stability, with a focus on their actions during cell cycle progression and different types of DNA damage response as well as repair pathways.
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Affiliation(s)
- Osheen Sahay
- National Centre for Cell Science, Ganeshkhind Road, Pune, Maharashtra 411007, India; Department of Biotechnology, S.P. Pune University, Ganeshkhind Road, Pune, Maharashtra 411007, India
| | - Ganesh Kumar Barik
- National Centre for Cell Science, Ganeshkhind Road, Pune, Maharashtra 411007, India; Department of Biotechnology, S.P. Pune University, Ganeshkhind Road, Pune, Maharashtra 411007, India
| | - Tanisha Sharma
- National Centre for Cell Science, Ganeshkhind Road, Pune, Maharashtra 411007, India; Department of Biotechnology, S.P. Pune University, Ganeshkhind Road, Pune, Maharashtra 411007, India
| | - Ajay D Pillai
- National Centre for Cell Science, Ganeshkhind Road, Pune, Maharashtra 411007, India
| | - Srikanth Rapole
- National Centre for Cell Science, Ganeshkhind Road, Pune, Maharashtra 411007, India
| | - Manas Kumar Santra
- National Centre for Cell Science, Ganeshkhind Road, Pune, Maharashtra 411007, India.
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7
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Hurst V, Challa K, Jonas F, Forey R, Sack R, Seebacher J, Schmid CD, Barkai N, Shimada K, Gasser SM, Poli J. A regulatory phosphorylation site on Mec1 controls chromatin occupancy of RNA polymerases during replication stress. EMBO J 2021; 40:e108439. [PMID: 34569643 PMCID: PMC8561635 DOI: 10.15252/embj.2021108439] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 09/08/2021] [Accepted: 09/10/2021] [Indexed: 01/16/2023] Open
Abstract
Upon replication stress, budding yeast checkpoint kinase Mec1ATR triggers the downregulation of transcription, thereby reducing the level of RNA polymerase (RNAP) on chromatin to facilitate replication fork progression. Here, we identify a hydroxyurea-induced phosphorylation site on Mec1, Mec1-S1991, that contributes to the eviction of RNAPII and RNAPIII during replication stress. The expression of the non-phosphorylatable mec1-S1991A mutant reduces replication fork progression genome-wide and compromises survival on hydroxyurea. This defect can be suppressed by destabilizing chromatin-bound RNAPII through a TAP fusion to its Rpb3 subunit, suggesting that lethality in mec1-S1991A mutants arises from replication-transcription conflicts. Coincident with a failure to repress gene expression on hydroxyurea in mec1-S1991A cells, highly transcribed genes such as GAL1 remain bound at nuclear pores. Consistently, we find that nuclear pore proteins and factors controlling RNAPII and RNAPIII are phosphorylated in a Mec1-dependent manner on hydroxyurea. Moreover, we show that Mec1 kinase also contributes to reduced RNAPII occupancy on chromatin during an unperturbed S phase by promoting degradation of the Rpb1 subunit.
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Affiliation(s)
- Verena Hurst
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland.,Faculty of Natural Sciences, University of Basel, Basel, Switzerland
| | - Kiran Challa
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Felix Jonas
- Departments of Molecular Genetics and Physics of Complex Systems, Weizmann Institute of Science, Rehovot, Israel
| | - Romain Forey
- Institut de Génétique Humaine, CNRS, Université de Montpellier, Equipe labélisée Ligue contre le Cancer, Montpellier, France
| | - Ragna Sack
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Jan Seebacher
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Christoph D Schmid
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Naama Barkai
- Departments of Molecular Genetics and Physics of Complex Systems, Weizmann Institute of Science, Rehovot, Israel
| | - Kenji Shimada
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Susan M Gasser
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland.,Faculty of Natural Sciences, University of Basel, Basel, Switzerland
| | - Jérôme Poli
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland.,Institut de Génétique Humaine, CNRS, Université de Montpellier, Equipe labélisée Ligue contre le Cancer, Montpellier, France
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8
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Yin Y, Lee WTC, Gupta D, Xue H, Tonzi P, Borowiec JA, Huang TT, Modesti M, Rothenberg E. A basal-level activity of ATR links replication fork surveillance and stress response. Mol Cell 2021; 81:4243-4257.e6. [PMID: 34473946 DOI: 10.1016/j.molcel.2021.08.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 03/03/2021] [Accepted: 08/06/2021] [Indexed: 11/27/2022]
Abstract
Mammalian cells use diverse pathways to prevent deleterious consequences during DNA replication, yet the mechanism by which cells survey individual replisomes to detect spontaneous replication impediments at the basal level, and their accumulation during replication stress, remain undefined. Here, we used single-molecule localization microscopy coupled with high-order-correlation image-mining algorithms to quantify the composition of individual replisomes in single cells during unperturbed replication and under replicative stress. We identified a basal-level activity of ATR that monitors and regulates the amounts of RPA at forks during normal replication. Replication-stress amplifies the basal activity through the increased volume of ATR-RPA interaction and diffusion-driven enrichment of ATR at forks. This localized crowding of ATR enhances its collision probability, stimulating the activation of its replication-stress response. Finally, we provide a computational model describing how the basal activity of ATR is amplified to produce its canonical replication stress response.
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Affiliation(s)
- Yandong Yin
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016, USA.
| | - Wei Ting Chelsea Lee
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016, USA
| | - Dipika Gupta
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016, USA
| | - Huijun Xue
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016, USA
| | - Peter Tonzi
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016, USA
| | - James A Borowiec
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016, USA
| | - Tony T Huang
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016, USA
| | - Mauro Modesti
- Cancer Research Center of Marseille, CNRS UMR 7258, Inserm U1068, Institut Paoli-Calmettes, Aix-Marseille Université UM105, Marseille, France
| | - Eli Rothenberg
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016, USA.
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9
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Salas-Leiva DE, Tromer EC, Curtis BA, Jerlström-Hultqvist J, Kolisko M, Yi Z, Salas-Leiva JS, Gallot-Lavallée L, Williams SK, Kops GJPL, Archibald JM, Simpson AGB, Roger AJ. Genomic analysis finds no evidence of canonical eukaryotic DNA processing complexes in a free-living protist. Nat Commun 2021; 12:6003. [PMID: 34650064 PMCID: PMC8516963 DOI: 10.1038/s41467-021-26077-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 09/14/2021] [Indexed: 12/14/2022] Open
Abstract
Cells replicate and segregate their DNA with precision. Previous studies showed that these regulated cell-cycle processes were present in the last eukaryotic common ancestor and that their core molecular parts are conserved across eukaryotes. However, some metamonad parasites have secondarily lost components of the DNA processing and segregation apparatuses. To clarify the evolutionary history of these systems in these unusual eukaryotes, we generated a genome assembly for the free-living metamonad Carpediemonas membranifera and carried out a comparative genomics analysis. Here, we show that parasitic and free-living metamonads harbor an incomplete set of proteins for processing and segregating DNA. Unexpectedly, Carpediemonas species are further streamlined, lacking the origin recognition complex, Cdc6 and most structural kinetochore subunits. Carpediemonas species are thus the first known eukaryotes that appear to lack this suite of conserved complexes, suggesting that they likely rely on yet-to-be-discovered or alternative mechanisms to carry out these fundamental processes.
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Affiliation(s)
- Dayana E. Salas-Leiva
- grid.55602.340000 0004 1936 8200Institute for Comparative Genomics (ICG), Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2 Canada ,grid.5335.00000000121885934Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Eelco C. Tromer
- grid.5335.00000000121885934Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom ,grid.4830.f0000 0004 0407 1981Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, Netherlands
| | - Bruce A. Curtis
- grid.55602.340000 0004 1936 8200Institute for Comparative Genomics (ICG), Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2 Canada
| | - Jon Jerlström-Hultqvist
- grid.55602.340000 0004 1936 8200Institute for Comparative Genomics (ICG), Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2 Canada
| | - Martin Kolisko
- grid.418095.10000 0001 1015 3316Institute of Parasitology, Biology Centre, Czech Acad. Sci, České Budějovice, Czech Republic
| | - Zhenzhen Yi
- grid.263785.d0000 0004 0368 7397Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, School of Life Science, South China Normal University, Guangzhou, 510631 China
| | - Joan S. Salas-Leiva
- grid.466575.30000 0001 1835 194XCONACyT-Centro de Investigación en Materiales Avanzados, Departamento de medio ambiente y energía, Miguel de Cervantes 120, Complejo Industrial Chihuahua, 31136 Chihuahua, Chih. México
| | - Lucie Gallot-Lavallée
- grid.55602.340000 0004 1936 8200Institute for Comparative Genomics (ICG), Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2 Canada
| | - Shelby K. Williams
- grid.55602.340000 0004 1936 8200Institute for Comparative Genomics (ICG), Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2 Canada
| | - Geert J. P. L. Kops
- grid.7692.a0000000090126352Oncode Institute, Hubrecht Institute – KNAW (Royal Netherlands Academy of Arts and Sciences) and University Medical Centre Utrecht, Utrecht, The Netherlands
| | - John M. Archibald
- grid.55602.340000 0004 1936 8200Institute for Comparative Genomics (ICG), Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2 Canada
| | - Alastair G. B. Simpson
- grid.55602.340000 0004 1936 8200Institute for Comparative Genomics (ICG), Department of Biology, Dalhousie University, Halifax, NS B3H 4R2 Canada
| | - Andrew J. Roger
- grid.55602.340000 0004 1936 8200Institute for Comparative Genomics (ICG), Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2 Canada
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10
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Katerji M, Duerksen-Hughes PJ. DNA damage in cancer development: special implications in viral oncogenesis. Am J Cancer Res 2021; 11:3956-3979. [PMID: 34522461 PMCID: PMC8414375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 02/04/2021] [Indexed: 06/13/2023] Open
Abstract
DNA lesions arise from a combination of physiological/metabolic sources and exogenous environmental influences. When left unrepaired, these alterations accumulate in the cells and can give rise to mutations that change the function of important proteins (i.e. tumor suppressors, oncoproteins), or cause chromosomal rearrangements (i.e. gene fusions) that also result in the deregulation of key cellular molecules. Progressive acquisition of such genetic changes promotes uncontrolled cell proliferation and evasion of cell death, and hence plays a key role in carcinogenesis. Another less-studied consequence of DNA damage accumulating in the host genome is the integration of oncogenic DNA viruses such as Human papillomavirus, Merkel cell polyomavirus, and Hepatitis B virus. This critical step of viral-induced carcinogenesis is thought to be particularly facilitated by DNA breaks in both viral and host genomes. Therefore, the impact of DNA damage on carcinogenesis is magnified in the case of such oncoviruses via the additional effect of increasing integration frequency. In this review, we briefly present the various endogenous and exogenous factors that cause different types of DNA damage. Next, we discuss the contribution of these lesions in cancer development. Finally, we examine the amplified effect of DNA damage in viral-induced oncogenesis and summarize the limited data existing in the literature related to DNA damage-induced viral integration. To conclude, additional research is needed to assess the DNA damage pathways involved in the transition from viral infection to cancer. Discovering that a certain DNA damaging agent increases the likelihood of viral integration will enable the development of prophylactic and therapeutic strategies designed specifically to prevent such integration, with an ultimate goal of reducing or eliminating these viral-induced malignancies.
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Affiliation(s)
- Meghri Katerji
- Department of Basic Science, Loma Linda University School of Medicine Loma Linda, CA 92354, USA
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11
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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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12
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Abstract
The cell cycle is the sequence of events through which a cell duplicates its genome, grows, and divides. Key cell cycle transitions are driven by oscillators comprising of protein kinases and their regulators. Different cell cycle oscillators are inextricably linked to ensure orderly activation of oscillators. A recurring theme in their regulation is the abundance of autoamplifying loops that ensure switch-like and unidirectional cell cycle transitions. The periodicity of many cell cycle oscillators is choreographed by inherent mechanisms that promote automatic inactivation, often involving dephosphorylation and ubiquitin-mediated protein degradation. These inhibitory signals are subsequently suppressed to enable the next cell cycle to occur. Although the activation and inactivation of cell cycle oscillators are in essence autonomous during the unperturbed cell cycle, a number of checkpoint mechanisms are able to halt the cell cycle until preconditions or defects are addressed. Together, these mechanisms orchestrate orderly progression of the cell cycle to produce more cells and to safeguard genome stability.
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13
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Abstract
In order to preserve genome integrity, all cells must mount appropriate responses to DNA damage, including slowing down or arresting the cell cycle to give the cells time to repair the damage and changing gene expression, for example to induce genes involved in DNA repair. The Rad53 protein kinase is a conserved central mediator of these responses in eukaryotic cells, and its extensive phosphorylation upon DNA damage is necessary for its activation and subsequent activity. DNA damage checkpoints are key guardians of genome integrity. Eukaryotic cells respond to DNA damage by triggering extensive phosphorylation of Rad53/CHK2 effector kinase, whereupon activated Rad53/CHK2 mediates further aspects of checkpoint activation, including cell cycle arrest and transcriptional changes. Budding yeast Candida glabrata, closely related to model eukaryote Saccharomyces cerevisiae, is an opportunistic pathogen characterized by high genetic diversity and rapid emergence of drug-resistant mutants. However, the mechanisms underlying this genetic variability are unclear. We used Western blotting and mass spectrometry to show that, unlike S. cerevisiae, C. glabrata cells exposed to DNA damage did not induce C. glabrata Rad53 (CgRad53) phosphorylation. Furthermore, flow cytometry analysis showed that, unlike S. cerevisiae, C. glabrata cells did not accumulate in S phase upon DNA damage. Consistent with these observations, time-lapse microscopy showed C. glabrata cells continuing to divide in the presence of DNA damage, resulting in mitotic errors and cell death. Finally, transcriptome sequencing (RNAseq) analysis revealed transcriptional rewiring of the DNA damage response in C. glabrata and identified several key protectors of genome stability upregulated by DNA damage in S. cerevisiae but downregulated in C. glabrata, including proliferating cell nuclear antigen (PCNA). Together, our results reveal a noncanonical fungal DNA damage response in C. glabrata, which may contribute to rapidly generating genetic change and drug resistance.
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14
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Ruta LL, Farcasanu IC. Saccharomyces cerevisiae and Caffeine Implications on the Eukaryotic Cell. Nutrients 2020; 12:nu12082440. [PMID: 32823708 PMCID: PMC7468979 DOI: 10.3390/nu12082440] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 08/07/2020] [Accepted: 08/10/2020] [Indexed: 02/07/2023] Open
Abstract
Caffeine-a methylxanthine analogue of the purine bases adenine and guanine-is by far the most consumed neuro-stimulant, being the active principle of widely consumed beverages such as coffee, tea, hot chocolate, and cola. While the best-known action of caffeine is to prevent sleepiness by blocking the adenosine receptors, caffeine exerts a pleiotropic effect on cells, which lead to the activation or inhibition of various cell integrity pathways. The aim of this review is to present the main studies set to investigate the effects of caffeine on cells using the model eukaryotic microorganism Saccharomyces cerevisiae, highlighting the caffeine synergy with external cell stressors, such as irradiation or exposure to various chemical hazards, including cigarette smoke or chemical carcinogens. The review also focuses on the importance of caffeine-related yeast phenotypes used to resolve molecular mechanisms involved in cell signaling through conserved pathways, such as target of rapamycin (TOR) signaling, Pkc1-Mpk1 mitogen activated protein kinase (MAPK) cascade, or Ras/cAMP protein kinase A (PKA) pathway.
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15
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Park S, Karatayeva N, Demin AA, Munashingha PR, Seo YS. The secondary-structured DNA-binding activity of Dna2 endonuclease/helicase is critical to cell growth under replication stress. FEBS J 2020; 288:1224-1242. [PMID: 32638513 PMCID: PMC7984218 DOI: 10.1111/febs.15475] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Revised: 06/11/2020] [Accepted: 06/30/2020] [Indexed: 11/30/2022]
Abstract
Dna2 can efficiently process 5' flaps containing DNA secondary structure using coordinated action of the three biochemical activities: the N-terminally encoded DNA-binding activity and the C-terminally encoded endonuclease and helicase activities. In this study, we investigated the cross talk among the three functional domains using a variety of dna2 mutant alleles and enzymes derived thereof. We found that disruption of the catalytic activities of Dna2 activated Dna2-dependent checkpoint, residing in the N-terminal domain. This checkpoint activity contributed to growth defects of dna2 catalytic mutants, revealing the presence of an intramolecular functional cross talk in Dna2. The N-terminal domain of Dna2 bound specifically to substrates that mimic DNA replication fork intermediates, including Holliday junctions. Using site-directed mutagenesis of the N-terminal domain of Dna2, we discovered that five consecutive basic amino acid residues were essential for the ability of Dna2 to bind hairpin DNA in vitro. Mutant cells expressing the dna2 allele containing all five basic residues substituted with alanine displayed three distinct phenotypes: (i) temperature-sensitive growth defects, (ii) bypass of S-phase arrest, and (iii) increased sensitivity to DNA-damaging agents. Taken together, our results indicate that the interplay between the N-terminal regulatory and C-terminal catalytic domains of Dna2 plays an important role in vivo, especially when cells are placed under replication stress.
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Affiliation(s)
- Soyeong Park
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, Korea
| | - Nargis Karatayeva
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, Korea
| | - Annie Albert Demin
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, Korea
| | - Palinda Ruvan Munashingha
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, Korea
| | - Yeon-Soo Seo
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, Korea
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16
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Genetic investigation of formaldehyde-induced DNA damage response in Schizosaccharomyces pombe. Curr Genet 2020; 66:593-605. [DOI: 10.1007/s00294-020-01057-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 01/21/2020] [Accepted: 01/27/2020] [Indexed: 02/02/2023]
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17
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Urrutia G, Salmonson A, Toro-Zapata J, de Assuncao TM, Mathison A, Dusetti N, Iovanna J, Urrutia R, Lomberk G. Combined Targeting of G9a and Checkpoint Kinase 1 Synergistically Inhibits Pancreatic Cancer Cell Growth by Replication Fork Collapse. Mol Cancer Res 2019; 18:448-462. [PMID: 31822519 DOI: 10.1158/1541-7786.mcr-19-0490] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 10/31/2019] [Accepted: 12/06/2019] [Indexed: 12/11/2022]
Abstract
Because of its dismal outcome, pancreatic ductal adenocarcinoma (PDAC) remains a therapeutic challenge making the testing of new pharmacologic tools a goal of paramount importance. Here, we developed a rational approach for inhibiting PDAC growth based on leveraging cell-cycle arrest of malignant cells at a phase that shows increased sensitivity to distinct epigenomic inhibitors. Specifically, we simultaneously inhibited checkpoint kinase 1 (Chk1) by prexasertib and the G9a histone methyltransferase with BRD4770, thereby targeting two key pathways for replication fork stability. Methodologically, the antitumor effects and molecular mechanisms of the combination were assessed by an extensive battery of assays, utilizing cell lines and patient-derived cells as well as 3D spheroids and xenografts. We find that the prexasertib-BRD4770 combination displays a synergistic effect on replication-associated phenomena, including cell growth, DNA synthesis, cell-cycle progression at S phase, and DNA damage signaling, ultimately leading to a highly efficient induction of cell death. Moreover, cellular and molecular data reveal that the synergistic effect of these pathways can be explained, at least in large part, by the convergence of both Chk1 and G9a functions at the level of the ATR-RPA-checkpoint pathway, which is operational during replication stress. Thus, targeting the epigenetic regulator G9a, which is necessary for replication fork stability, combined with inhibition of the DNA damage checkpoint, offers a novel approach for controlling PDAC growth through replication catastrophe. IMPLICATIONS: This study offers an improved, context-dependent, paradigm for the use of epigenomic inhibitors and provides mechanistic insight into their potential therapeutic use against PDAC.
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Affiliation(s)
- Guillermo Urrutia
- Division of Research, Department of Surgery; Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Ann Salmonson
- Division of Research, Department of Surgery; Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Jorge Toro-Zapata
- Division of Research, Department of Surgery; Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Thiago M de Assuncao
- Division of Research, Department of Surgery; Medical College of Wisconsin, Milwaukee, Wisconsin.,Genomic Sciences and Precision Medicine Center (GSPMC), Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Angela Mathison
- Division of Research, Department of Surgery; Medical College of Wisconsin, Milwaukee, Wisconsin.,Genomic Sciences and Precision Medicine Center (GSPMC), Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Nelson Dusetti
- Centre de Recherche en Cancérologie de Marseille (CRCM), INSERM U1068, CNRS UMR 7258, Aix-Marseille Université and Institut Paoli-Calmettes, Parc Scientifique et Technologique de Luminy, Marseille, France
| | - Juan Iovanna
- Centre de Recherche en Cancérologie de Marseille (CRCM), INSERM U1068, CNRS UMR 7258, Aix-Marseille Université and Institut Paoli-Calmettes, Parc Scientifique et Technologique de Luminy, Marseille, France
| | - Raul Urrutia
- Division of Research, Department of Surgery; Medical College of Wisconsin, Milwaukee, Wisconsin.,Genomic Sciences and Precision Medicine Center (GSPMC), Medical College of Wisconsin, Milwaukee, Wisconsin.,Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Gwen Lomberk
- Division of Research, Department of Surgery; Medical College of Wisconsin, Milwaukee, Wisconsin. .,Genomic Sciences and Precision Medicine Center (GSPMC), Medical College of Wisconsin, Milwaukee, Wisconsin.,Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin
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18
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Investigation of the Possible Role of RAD9 in Post-Diapaused Embryonic Development of the Brine Shrimp Artemia sinica. Genes (Basel) 2019; 10:genes10100768. [PMID: 31574972 PMCID: PMC6826366 DOI: 10.3390/genes10100768] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 09/25/2019] [Accepted: 09/26/2019] [Indexed: 11/17/2022] Open
Abstract
Background: The cell cycle checkpoint protein RAD9 is a vital cell cycle regulator in eukaryotic cells. RAD9 is involved in diverse cellular functions by oligomer or monomer. However, the specific mechanism of its activity remains unknown in crustaceans, especially in embryonic diapause resumption of the brine shrimp Artemia sinica. Methods and Results: In the present article, a 1238 bp full-length cDNA of As–RAD9 gene, encoding 376 amino acids, was obtained from A. sinica. The expression pattern of As–RAD9 was analyzed by qPCR and Western blot. The mRNA expression level climbs to the top at the 10 h stage of embryo development, while the protein expression pattern is generally consistent with qPCR results. Moreover, the As–RADd9 related signaling proteins, As–RAD1, As–HUS1, As–RAD17, and As–CHK1, were also detected. Immunofluorescence assay showed that the location of As–RAD9 did not show tissue or organ specificity, and the intracellular expression was concentrated in the cytoplasm more than in the nucleus. We also explored the amount of As–RAD9 under the stresses of cold and high salinity, and the results indicate that As–RAD9 is a stress-related factor, though the mechanisms may be different in response to different stresses. Knocking down of the As–RAD9 gene led to embryonic development delay in A. sinica. Conclusions: All these results reveal that As–RAD9 is necessary for post-diapaused embryonic development in A. sinica.
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19
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Booth C, Romano R, Roncarolo MG, Thrasher AJ. Gene therapy for primary immunodeficiency. Hum Mol Genet 2019; 28:R15-R23. [DOI: 10.1093/hmg/ddz170] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 07/02/2019] [Accepted: 07/08/2019] [Indexed: 01/21/2023] Open
Abstract
Abstract
Gene therapy is now being trialled as a therapeutic option for an expanding number of conditions, based primarily on the successful treatment over the past two decades of patients with specific primary immunodeficiencies (PIDs) including severe combined immunodeficiency and Wiskott–Aldrich syndrome and metabolic conditions such as leukodystrophy. The field has evolved from the use of gammaretroviral vectors to more sophisticated lentiviral platforms that offer an improved biosafety profile alongside greater efficiency for hematopoietic stem cells gene transfer. Here we review more recent developments including licensing of gene therapies, use of gene corrected autologous T cells as an alternative strategy for some PIDs and the potential of targeted gene correction using various gene editing platforms. Given the promising results of recent clinical trials, it is likely that autologous gene therapies will become standard of care for a number of devastating diseases in the coming decade.
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Affiliation(s)
- Claire Booth
- Molecular and Cellular Immunology Section, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Rosa Romano
- Division of Stem Cell Transplantation and Regenerative Medicine, Department of Pediatrics, Stanford School of Medicine, Stanford, CA, USA
| | - Maria Grazia Roncarolo
- Division of Stem Cell Transplantation and Regenerative Medicine, Department of Pediatrics, Stanford School of Medicine, Stanford, CA, USA
- Institute for Stem Cell Biology and Regenerative Medicine (ISCBRM), Stanford School of Medicine, Stanford, CA, USA
| | - Adrian J Thrasher
- Molecular and Cellular Immunology Section, UCL Great Ormond Street Institute of Child Health, London, UK
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20
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Genome Instability Is Promoted by the Chromatin-Binding Protein Spn1 in Saccharomyces cerevisiae. Genetics 2018; 210:1227-1237. [PMID: 30301740 DOI: 10.1534/genetics.118.301600] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 10/02/2018] [Indexed: 02/06/2023] Open
Abstract
Cells expend a large amount of energy to maintain their DNA sequence. DNA repair pathways, cell cycle checkpoint activation, proofreading polymerases, and chromatin structure are ways in which the cell minimizes changes to the genome. During replication, the DNA-damage tolerance pathway allows the replication forks to bypass damage on the template strand. This avoids prolonged replication fork stalling, which can contribute to genome instability. The DNA-damage tolerance pathway includes two subpathways: translesion synthesis and template switch. Post-translational modification of PCNA and the histone tails, cell cycle phase, and local DNA structure have all been shown to influence subpathway choice. Chromatin architecture contributes to maintaining genome stability by providing physical protection of the DNA and by regulating DNA-processing pathways. As such, chromatin-binding factors have been implicated in maintaining genome stability. Using Saccharomyces cerevisiae, we examined the role of Spn1 (Suppresses postrecruitment gene number 1), a chromatin-binding and transcription elongation factor, in DNA-damage tolerance. Expression of a mutant allele of SPN1 results in increased resistance to the DNA-damaging agent methyl methanesulfonate, lower spontaneous and damage-induced mutation rates, along with increased chronological life span. We attribute these effects to an increased usage of the template switch branch of the DNA-damage tolerance pathway in the spn1 strain. This provides evidence for a role of wild-type Spn1 in promoting genome instability, as well as having ties to overcoming replication stress and contributing to chronological aging.
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21
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Fontana GA, Reinert JK, Thomä NH, Rass U. Shepherding DNA ends: Rif1 protects telomeres and chromosome breaks. MICROBIAL CELL 2018; 5:327-343. [PMID: 29992129 PMCID: PMC6035837 DOI: 10.15698/mic2018.07.639] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cells have evolved conserved mechanisms to protect DNA ends, such as those at the termini of linear chromosomes, or those at DNA double-strand breaks (DSBs). In eukaryotes, DNA ends at chromosomal termini are packaged into proteinaceous structures called telomeres. Telomeres protect chromosome ends from erosion, inadvertent activation of the cellular DNA damage response (DDR), and telomere fusion. In contrast, cells must respond to damage-induced DNA ends at DSBs by harnessing the DDR to restore chromosome integrity, avoiding genome instability and disease. Intriguingly, Rif1 (Rap1-interacting factor 1) has been implicated in telomere homeostasis as well as DSB repair. The protein was first identified in Saccharomyces cerevisiae as being part of the proteinaceous telosome. In mammals, RIF1 is not associated with intact telomeres, but was found at chromosome breaks, where RIF1 has emerged as a key mediator of pathway choice between the two evolutionary conserved DSB repair pathways of non-homologous end-joining (NHEJ) and homologous recombination (HR). While this functional dichotomy has long been a puzzle, recent findings link yeast Rif1 not only to telomeres, but also to DSB repair, and mechanistic parallels likely exist. In this review, we will provide an overview of the actions of Rif1 at DNA ends and explore how exclusion of end-processing factors might be the underlying principle allowing Rif1 to fulfill diverse biological roles at telomeres and chromosome breaks.
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Affiliation(s)
- Gabriele A Fontana
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058 Basel, Switzerland
| | - Julia K Reinert
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058 Basel, Switzerland.,University of Basel, Petersplatz 10, CH-4003 Basel, Switzerland
| | - Nicolas H Thomä
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058 Basel, Switzerland
| | - Ulrich Rass
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058 Basel, Switzerland
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22
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García-Rodríguez N, Morawska M, Wong RP, Daigaku Y, Ulrich HD. Spatial separation between replisome- and template-induced replication stress signaling. EMBO J 2018; 37:embj.201798369. [PMID: 29581097 PMCID: PMC5920239 DOI: 10.15252/embj.201798369] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 01/29/2018] [Accepted: 02/26/2018] [Indexed: 11/09/2022] Open
Abstract
Polymerase‐blocking DNA lesions are thought to elicit a checkpoint response via accumulation of single‐stranded DNA at stalled replication forks. However, as an alternative to persistent fork stalling, re‐priming downstream of lesions can give rise to daughter‐strand gaps behind replication forks. We show here that the processing of such structures by an exonuclease, Exo1, is required for timely checkpoint activation, which in turn prevents further gap erosion in S phase. This Rad9‐dependent mechanism of damage signaling is distinct from the Mrc1‐dependent, fork‐associated response to replication stress induced by conditions such as nucleotide depletion or replisome‐inherent problems, but reminiscent of replication‐independent checkpoint activation by single‐stranded DNA. Our results indicate that while replisome stalling triggers a checkpoint response directly at the stalled replication fork, the response to replication stress elicited by polymerase‐blocking lesions mainly emanates from Exo1‐processed, postreplicative daughter‐strand gaps, thus offering a mechanistic explanation for the dichotomy between replisome‐ versus template‐induced checkpoint signaling.
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Affiliation(s)
| | - Magdalena Morawska
- Institute of Molecular Biology (IMB), Mainz, Germany.,Cancer Research UK London Research Institute, Clare Hall Laboratories, Blanche Lane South Mimms, UK
| | - Ronald P Wong
- Institute of Molecular Biology (IMB), Mainz, Germany
| | - Yasukazu Daigaku
- Cancer Research UK London Research Institute, Clare Hall Laboratories, Blanche Lane South Mimms, UK
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23
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Rad52 phosphorylation by Ipl1 and Mps1 contributes to Mps1 kinetochore localization and spindle assembly checkpoint regulation. Proc Natl Acad Sci U S A 2017; 114:E9261-E9270. [PMID: 29078282 DOI: 10.1073/pnas.1705261114] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Rad52 is well known as a key factor in homologous recombination. Here, we report that Rad52 has functions unrelated to homologous recombination in Saccharomyces cerevisiae; it plays a role in the recruitment of Mps1 to the kinetochores and the maintenance of spindle assembly checkpoint (SAC) activity. Deletion of RAD52 causes various phenotypes related to the dysregulation of chromosome biorientation. Rad52 directly affects efficient operation of the SAC and accurate chromosome segregation. Remarkably, by using an in vitro kinase assay, we found that Rad52 is a substrate of Ipl1/Aurora and Mps1 in yeast and humans. Ipl1-dependent phosphorylation of Rad52 facilitates the kinetochore accumulation of Mps1, and Mps1-dependent phosphorylation of Rad52 is important for the accurate regulation of the SAC under spindle damage conditions. Taken together, our data provide detailed insights into the regulatory mechanism of chromosome biorientation by mitotic kinases.
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24
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Rangaswamy S, Pandey A, Mitra S, Hegde ML. Pre-Replicative Repair of Oxidized Bases Maintains Fidelity in Mammalian Genomes: The Cowcatcher Role of NEIL1 DNA Glycosylase. Genes (Basel) 2017; 8:E175. [PMID: 28665322 PMCID: PMC5541308 DOI: 10.3390/genes8070175] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 06/16/2017] [Accepted: 06/24/2017] [Indexed: 02/06/2023] Open
Abstract
Genomic fidelity in the humans is continuously challenged by genotoxic reactive oxygen species (ROS) generated both endogenously during metabolic processes, and by exogenous agents. Mispairing of most ROS-induced oxidized base lesions during DNA replication induces mutations. Although bulky base adducts induced by ultraviolet light and other environmental mutagens block replicative DNA polymerases, most oxidized base lesions do not block DNA synthesis. In 8-oxo-G:A mispairs generated by the incorporation of A opposite unrepaired 8-oxo-G, A is removed by MutYH (MYH) for post-replicative repair, and other oxidized base lesions must be repaired prior to replication in order to prevent mutation fixation. Our earlier studies documented S phase-specific overexpression of endonuclease VIII-like 1 (NEIL1) DNA glycosylase (DG), one of five oxidized base excision repair (BER)-initiating enzymes in mammalian cells, and its high affinity for replication fork-mimicking single-stranded (ss)DNA substrates. We recently provided experimental evidence for the role of NEIL1 in replicating-strand repair, and proposed the "cowcatcher" model of pre-replicative BER, where NEIL1's nonproductive binding to the lesion base in ssDNA template blocks DNA chain elongation, causing fork regression. Repair of the lesion in the then re-annealed duplex is carried out by NEIL1 in association with the DNA replication proteins. In this commentary, we highlight the critical role of pre-replicative BER in preventing mutagenesis, and discuss the distinction between pre-replicative vs. post-replicative BER.
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Affiliation(s)
- Suganya Rangaswamy
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX 77030, USA.
| | - Arvind Pandey
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX 77030, USA.
| | - Sankar Mitra
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX 77030, USA.
- Weill Cornell Medical College, Cornell University, New York, NY 10065, USA.
| | - Muralidhar L Hegde
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX 77030, USA.
- Weill Cornell Medical College, Cornell University, New York, NY 10065, USA.
- Houston Methodist Neurological Institute, Houston, TX 77030, USA.
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25
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Dmowski M, Fijałkowska IJ. Diverse roles of Dpb2, the non-catalytic subunit of DNA polymerase ε. Curr Genet 2017; 63:983-987. [PMID: 28516230 PMCID: PMC5668336 DOI: 10.1007/s00294-017-0706-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 05/09/2017] [Accepted: 05/10/2017] [Indexed: 12/18/2022]
Abstract
Timely progression of living cells through the cell cycle is precisely regulated. This involves a series of phosphorylation events which are regulated by various cyclins, activated in coordination with the cell cycle progression. Phosphorylated proteins govern cell growth, division as well as duplication of the genetic material and transcriptional activation of genes involved in these processes. A subset of these tightly regulated genes, which depend on the MBF transcription factor and are mainly involved in DNA replication and cell division, is transiently activated at the transition from G1 to S phase. A Saccharomyces cerevisiae mutant in the Dpb2 non-catalytic subunit of DNA polymerase ε (Polε) demonstrates abnormalities in transcription of MBF-dependent genes even in normal growth conditions. It is, therefore, tempting to speculate that Dpb2 which, as described previously, participates in the early stages of DNA replication initiation, has an impact on the regulation of replication-related genes expression with possible implications for genomic stability.
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Affiliation(s)
- Michał Dmowski
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106, Warsaw, Poland.
| | - Iwona J Fijałkowska
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106, Warsaw, Poland
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26
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Dmowski M, Rudzka J, Campbell JL, Jonczyk P, Fijałkowska IJ. Mutations in the Non-Catalytic Subunit Dpb2 of DNA Polymerase Epsilon Affect the Nrm1 Branch of the DNA Replication Checkpoint. PLoS Genet 2017; 13:e1006572. [PMID: 28107343 PMCID: PMC5291541 DOI: 10.1371/journal.pgen.1006572] [Citation(s) in RCA: 7] [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: 05/16/2016] [Revised: 02/03/2017] [Accepted: 01/05/2017] [Indexed: 12/14/2022] Open
Abstract
To preserve genome integrity, the S-phase checkpoint senses damaged DNA or nucleotide depletion and when necessary, arrests replication progression and delays cell division. Previous studies, based on two pol2 mutants have suggested the involvement of DNA polymerase epsilon (Pol ε) in sensing DNA replication accuracy in Saccharomyces cerevisiae. Here we have studied the involvement of Pol ε in sensing proper progression of DNA replication, using a mutant in DPB2, the gene coding for a non-catalytic subunit of Pol ε. Under genotoxic conditions, the dpb2-103 cells progress through S phase faster than wild-type cells. Moreover, the Nrm1-dependent branch of the checkpoint, which regulates the expression of many replication checkpoint genes, is impaired in dpb2-103 cells. Finally, deletion of DDC1 in the dpb2-103 mutant is lethal supporting a model of strand-specific activation of the replication checkpoint. This lethality is suppressed by NRM1 deletion. We postulate that improper activation of the Nrm1-branch may explain inefficient replication checkpoint activation in Pol ε mutants. The viability of living organisms depends on the integrity of their genomes. Each cell has to constantly monitor DNA replication and coordinate it with cell division to avoid genomic instability. This is achieved through pathways known as cell cycle checkpoints. Therefore, upon replication perturbation, DNA synthesis slows down and cell division is delayed. For that, a specific signal is induced and propagated through a mechanism that have already been identified but still need investigations. We have isolated a mutated form of Dpb2, the essential subunit of DNA polymerase epsilon (Pol ε) holoenzyme. This mutated form of Pol ε impairs proper activation of the cellular response to replication stress. We show that yeast cells with mutations in the DPB2 gene fail to activate the Nrm1-regulated branch of the checkpoint, which controls numerous genes expressed in response to replication stress. Moreover, our results support the model of parallel activation of replication checkpoint from the leading and lagging DNA strands. This strongly suggests that Pol ε, the leading strand replicase, is involved in replication checkpoint activation from this strand. Our results contribute to the understanding of mechanisms of cellular response to replication stress, which are necessary to preserve genome stability.
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Affiliation(s)
- Michał Dmowski
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences Pawińskiego 5a, Warsaw, POLAND
- * E-mail:
| | - Justyna Rudzka
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences Pawińskiego 5a, Warsaw, POLAND
| | - Judith L. Campbell
- Braun Laboratories, California Institute of Technology, Pasadena, CA, United States of America
| | - Piotr Jonczyk
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences Pawińskiego 5a, Warsaw, POLAND
| | - Iwona J. Fijałkowska
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences Pawińskiego 5a, Warsaw, POLAND
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27
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Siler J, Xia B, Wong C, Kath M, Bi X. Cell cycle-dependent positive and negative functions of Fun30 chromatin remodeler in DNA damage response. DNA Repair (Amst) 2017; 50:61-70. [PMID: 28089177 DOI: 10.1016/j.dnarep.2016.12.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 12/03/2016] [Accepted: 12/31/2016] [Indexed: 11/17/2022]
Abstract
The evolutionally conserved Fun30 chromatin remodeler in Saccharomyces cerevisiae has been shown to contribute to cellular resistance to genotoxic stress inflicted by camptothecin (CPT), methyl methanesulfonate (MMS) and hydroxyurea (HU). Fun30 aids in extensive DNA resection of DNA double stranded break (DSB) ends, which is thought to underlie its role in CPT-resistance. How Fun30 promotes MMS- or HU-resistance has not been resolved. Interestingly, we have recently found Fun30 to also play a negative role in cellular tolerance to MMS and HU in the absence of the Rad5-dependent DNA damage tolerance pathway. In this report, we show that Fun30 acts to down regulate Rad9-dependent DNA damage checkpoint triggered by CPT or MMS, but does not affect Rad9-independent intra-S phase replication checkpoint induced by MMS or HU. These results support the notion that Fun30 contributes to cellular response to DSBs by preventing excessive DNA damage checkpoint activation in addition to its role in facilitating DNA end resection. On the other hand, we present evidence suggesting that Fun30's negative function in MMS- and HU-tolerance in the absence of Rad5 is not related to its regulation of checkpoint activity. Moreover, we find Fun30 to be cell cycle regulated with its abundance peaking in G2/M phase of the cell cycle. Importantly, we demonstrate that artificially restricting Fun30 expression to G2/M does not affect its positive or negative function in genotoxin-resistance, but confining Fun30 to S phase abolishes its functions. These results indicate that both positive and negative functions of Fun30 in DNA damage response occur mainly in G2/M phase.
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Affiliation(s)
- Jasmine Siler
- Department of Biology, University of Rochester, Rochester, NY 14627, USA
| | - Bowen Xia
- Department of Biology, University of Rochester, Rochester, NY 14627, USA
| | - Carina Wong
- Department of Biology, University of Rochester, Rochester, NY 14627, USA
| | - Morgan Kath
- Department of Biology, University of Rochester, Rochester, NY 14627, USA
| | - Xin Bi
- Department of Biology, University of Rochester, Rochester, NY 14627, USA.
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28
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Seeber A, Hegnauer AM, Hustedt N, Deshpande I, Poli J, Eglinger J, Pasero P, Gut H, Shinohara M, Hopfner KP, Shimada K, Gasser SM. RPA Mediates Recruitment of MRX to Forks and Double-Strand Breaks to Hold Sister Chromatids Together. Mol Cell 2016; 64:951-966. [PMID: 27889450 DOI: 10.1016/j.molcel.2016.10.032] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 09/29/2016] [Accepted: 10/21/2016] [Indexed: 10/20/2022]
Abstract
The Mre11-Rad50-Xrs2 (MRX) complex is related to SMC complexes that form rings capable of holding two distinct DNA strands together. MRX functions at stalled replication forks and double-strand breaks (DSBs). A mutation in the N-terminal OB fold of the 70 kDa subunit of yeast replication protein A, rfa1-t11, abrogates MRX recruitment to both types of DNA damage. The rfa1 mutation is functionally epistatic with loss of any of the MRX subunits for survival of replication fork stress or DSB recovery, although it does not compromise end-resection. High-resolution imaging shows that either the rfa1-t11 or the rad50Δ mutation lets stalled replication forks collapse and allows the separation not only of opposing ends but of sister chromatids at breaks. Given that cohesin loss does not provoke visible sister separation as long as the RPA-MRX contacts are intact, we conclude that MRX also serves as a structural linchpin holding sister chromatids together at breaks.
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Affiliation(s)
- Andrew Seeber
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland; University of Basel, Faculty of Natural Sciences, Klingelbergstrasse 50, 4056 Basel, Switzerland
| | - Anna Maria Hegnauer
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Nicole Hustedt
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Ishan Deshpande
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland; University of Basel, Faculty of Natural Sciences, Klingelbergstrasse 50, 4056 Basel, Switzerland
| | - Jérôme Poli
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Jan Eglinger
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Philippe Pasero
- Institute of Human Genetics, CNRS UPR 1142, 34090 Montpellier, France
| | - Heinz Gut
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Miki Shinohara
- Institute for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan
| | | | - Kenji Shimada
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Susan M Gasser
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland; University of Basel, Faculty of Natural Sciences, Klingelbergstrasse 50, 4056 Basel, Switzerland.
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29
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Shyian M, Mattarocci S, Albert B, Hafner L, Lezaja A, Costanzo M, Boone C, Shore D. Budding Yeast Rif1 Controls Genome Integrity by Inhibiting rDNA Replication. PLoS Genet 2016; 12:e1006414. [PMID: 27820830 PMCID: PMC5098799 DOI: 10.1371/journal.pgen.1006414] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 10/10/2016] [Indexed: 12/27/2022] Open
Abstract
The Rif1 protein is a negative regulator of DNA replication initiation in eukaryotes. Here we show that budding yeast Rif1 inhibits DNA replication initiation at the rDNA locus. Absence of Rif1, or disruption of its interaction with PP1/Glc7 phosphatase, leads to more intensive rDNA replication. The effect of Rif1-Glc7 on rDNA replication is similar to that of the Sir2 deacetylase, and the two would appear to act in the same pathway, since the rif1Δ sir2Δ double mutant shows no further increase in rDNA replication. Loss of Rif1-Glc7 activity is also accompanied by an increase in rDNA repeat instability that again is not additive with the effect of sir2Δ. We find, in addition, that the viability of rif1Δ cells is severely compromised in combination with disruption of the MRX or Ctf4-Mms22 complexes, both of which are implicated in stabilization of stalled replication forks. Significantly, we show that removal of the rDNA replication fork barrier (RFB) protein Fob1, alleviation of replisome pausing by deletion of the Tof1/Csm3 complex, or a large deletion of the rDNA repeat array all rescue this synthetic growth defect of rif1Δ cells lacking in addition either MRX or Ctf4-Mms22 activity. These data suggest that the repression of origin activation by Rif1-Glc7 is important to avoid the deleterious accumulation of stalled replication forks at the rDNA RFB, which become lethal when fork stability is compromised. Finally, we show that Rif1-Glc7, unlike Sir2, has an important effect on origin firing outside of the rDNA locus that serves to prevent activation of the DNA replication checkpoint. Our results thus provide insights into a mechanism of replication control within a large repetitive chromosomal domain and its importance for the maintenance of genome stability. These findings may have important implications for metazoans, where large blocks of repetitive sequences are much more common.
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Affiliation(s)
- Maksym Shyian
- Department of Molecular Biology, University of Geneva, Geneva, Switzerland
- Institute of Genetics and Genomics in Geneva (iGE3), Geneva, Switzerland
| | - Stefano Mattarocci
- Department of Molecular Biology, University of Geneva, Geneva, Switzerland
- Institute of Genetics and Genomics in Geneva (iGE3), Geneva, Switzerland
| | - Benjamin Albert
- Department of Molecular Biology, University of Geneva, Geneva, Switzerland
- Institute of Genetics and Genomics in Geneva (iGE3), Geneva, Switzerland
| | - Lukas Hafner
- Department of Molecular Biology, University of Geneva, Geneva, Switzerland
- Institute of Genetics and Genomics in Geneva (iGE3), Geneva, Switzerland
| | - Aleksandra Lezaja
- Department of Molecular Biology, University of Geneva, Geneva, Switzerland
- Institute of Genetics and Genomics in Geneva (iGE3), Geneva, Switzerland
| | - Michael Costanzo
- University of Toronto, Donnelly Centre, Toronto, Ontario, Canada
| | - Charlie Boone
- University of Toronto, Donnelly Centre, Toronto, Ontario, Canada
| | - David Shore
- Department of Molecular Biology, University of Geneva, Geneva, Switzerland
- Institute of Genetics and Genomics in Geneva (iGE3), Geneva, Switzerland
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30
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Replication intermediates that escape Dna2 activity are processed by Holliday junction resolvase Yen1. Nat Commun 2016; 7:13157. [PMID: 27779184 PMCID: PMC5093310 DOI: 10.1038/ncomms13157] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 09/08/2016] [Indexed: 12/29/2022] Open
Abstract
Cells have evolved mechanisms to protect, restart and repair perturbed replication forks, allowing full genome duplication, even under replication stress. Interrogating the interplay between nuclease-helicase Dna2 and Holliday junction (HJ) resolvase Yen1, we find the Dna2 helicase activity acts parallel to homologous recombination (HR) in promoting DNA replication and chromosome detachment at mitosis after replication fork stalling. Yen1, but not the HJ resolvases Slx1-Slx4 and Mus81-Mms4, safeguards chromosome segregation by removing replication intermediates that escape Dna2. Post-replicative DNA damage checkpoint activation in Dna2 helicase-defective cells causes terminal G2/M arrest by precluding Yen1-dependent repair, whose activation requires progression into anaphase. These findings explain the exquisite replication stress sensitivity of Dna2 helicase-defective cells, and identify a non-canonical role for Yen1 in the processing of replication intermediates that is distinct from HJ resolution. The involvement of Dna2 helicase activity in completing replication may have implications for DNA2-associated pathologies, including cancer and Seckel syndrome.
DNA replication stress drives genome instability and cancer. Here, Ölmezer and colleagues show that the helicase activity of multifunctional enzyme Dna2 suppresses dead-end replication structures that impair chromosome segregation if not removed by Holliday junction resolvase Yen1 in yeast.
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31
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Chiker S, Pennaneach V, Loew D, Dingli F, Biard D, Cordelières FP, Gemble S, Vacher S, Bieche I, Hall J, Fernet M. Cdk5 promotes DNA replication stress checkpoint activation through RPA-32 phosphorylation, and impacts on metastasis free survival in breast cancer patients. Cell Cycle 2016; 14:3066-78. [PMID: 26237679 DOI: 10.1080/15384101.2015.1078020] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Cyclin dependent kinase 5 (Cdk5) is a determinant of PARP inhibitor and ionizing radiation (IR) sensitivity. Here we show that Cdk5-depleted (Cdk5-shRNA) HeLa cells show higher sensitivity to S-phase irradiation, chronic hydroxyurea exposure, and 5-fluorouracil and 6-thioguanine treatment, with hydroxyurea and IR sensitivity also seen in Cdk5-depleted U2OS cells. As Cdk5 is not directly implicated in DNA strand break repair we investigated in detail its proposed role in the intra-S checkpoint activation. While Cdk5-shRNA HeLa cells showed altered basal S-phase dynamics with slower replication velocity and fewer active origins per DNA megabase, checkpoint activation was impaired after a hydroxyurea block. Cdk5 depletion was associated with reduced priming phosphorylations of RPA32 serines 29 and 33 and SMC1-Serine 966 phosphorylation, lower levels of RPA serine 4 and 8 phosphorylation and DNA damage measured using the alkaline Comet assay, gamma-H2AX signal intensity, RPA and Rad51 foci, and sister chromatid exchanges resulting in impaired intra-S checkpoint activation and subsequently higher numbers of chromatin bridges. In vitro kinase assays coupled with mass spectrometry demonstrated that Cdk5 can carry out the RPA32 priming phosphorylations on serines 23, 29, and 33 necessary for this checkpoint activation. In addition we found an association between lower Cdk5 levels and longer metastasis free survival in breast cancer patients and survival in Cdk5-depleted breast tumor cells after treatment with IR and a PARP inhibitor. Taken together, these results show that Cdk5 is necessary for basal replication and replication stress checkpoint activation and highlight clinical opportunities to enhance tumor cell killing.
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Affiliation(s)
- Sara Chiker
- a Institut Curie; Centre de Recherche; Centre Universitaire ; Orsay Cedex , France.,b Inserm; U612; Centre Universitaire ; Orsay Cedex , France.,c Université Paris-XI; Faculté de Médecine ; Le Kremlin Bicêtre , France
| | - Vincent Pennaneach
- a Institut Curie; Centre de Recherche; Centre Universitaire ; Orsay Cedex , France.,b Inserm; U612; Centre Universitaire ; Orsay Cedex , France
| | - Damarys Loew
- d Institut Curie; Centre de Recherche; Laboratoire de Spectrométrie de Masse Protéomique ; Paris , France
| | - Florent Dingli
- d Institut Curie; Centre de Recherche; Laboratoire de Spectrométrie de Masse Protéomique ; Paris , France
| | - Denis Biard
- e Commissariat à l'Energie Atomique; DSV; iMETI; SEPIA; Team Cellular Engineering and Human Syndromes ; Fontenay aux Roses , France
| | - Fabrice P Cordelières
- a Institut Curie; Centre de Recherche; Centre Universitaire ; Orsay Cedex , France.,f CNRS; UMR3348; Centre Universitaire ; Orsay Cedex , France.,g Plateforme IBiSA d'Imagerie Cellulaire et Tissulaire; Institut Curie; Centre Universitaire ; Orsay , France
| | - Simon Gemble
- a Institut Curie; Centre de Recherche; Centre Universitaire ; Orsay Cedex , France.,f CNRS; UMR3348; Centre Universitaire ; Orsay Cedex , France
| | - Sophie Vacher
- h Pharmacogenetics Unit; Genetics Service ; Department of Tumour Biology ; Institut Curie ; Paris , France
| | - Ivan Bieche
- h Pharmacogenetics Unit; Genetics Service ; Department of Tumour Biology ; Institut Curie ; Paris , France
| | - Janet Hall
- a Institut Curie; Centre de Recherche; Centre Universitaire ; Orsay Cedex , France.,b Inserm; U612; Centre Universitaire ; Orsay Cedex , France.,i Centre de Recherche en Cancérologie de Lyon -UMR Inserm 1052 - CNRS 5286 ; Lyon , France
| | - Marie Fernet
- a Institut Curie; Centre de Recherche; Centre Universitaire ; Orsay Cedex , France.,b Inserm; U612; Centre Universitaire ; Orsay Cedex , France
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32
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Wan B, Hang LE, Zhao X. Multi-BRCT scaffolds use distinct strategies to support genome maintenance. Cell Cycle 2016; 15:2561-2570. [PMID: 27580271 DOI: 10.1080/15384101.2016.1218102] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Genome maintenance requires coordinated actions of diverse DNA metabolism processes. Scaffolding proteins, such as those containing multiple BRCT domains, can influence these processes by collaborating with numerous partners. The best-studied examples of multi-BRCT scaffolds are the budding yeast Dpb11 and its homologues in other organisms, which regulate DNA replication, repair, and damage checkpoints. Recent studies have shed light on another group of multi-BRCT scaffolds, including Rtt107 in budding yeast and related proteins in other organisms. These proteins also influence several DNA metabolism pathways, though they use strategies unlike those employed by the Dpb11 family of proteins. Yet, at the same time, these 2 classes of multi-BRCT proteins can collaborate under specific situations. This review summarizes recent advances in our understanding of how these multi-BRCT proteins function in distinct manners and how they collaborate, with a focus on Dpb11 and Rtt107.
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Affiliation(s)
- Bingbing Wan
- a Molecular Biology Program, Memorial Sloan Kettering Cancer Center , New York , NY , USA
| | - Lisa E Hang
- a Molecular Biology Program, Memorial Sloan Kettering Cancer Center , New York , NY , USA
| | - Xiaolan Zhao
- a Molecular Biology Program, Memorial Sloan Kettering Cancer Center , New York , NY , USA
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33
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Cussiol JR, Dibitetto D, Pellicioli A, Smolka MB. Slx4 scaffolding in homologous recombination and checkpoint control: lessons from yeast. Chromosoma 2016; 126:45-58. [PMID: 27165041 DOI: 10.1007/s00412-016-0600-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 04/27/2016] [Accepted: 04/29/2016] [Indexed: 01/07/2023]
Abstract
Homologous recombination-mediated DNA repair is essential for maintaining genome integrity. It is a multi-step process that involves resection of DNA ends, strand invasion, DNA synthesis and/or DNA end ligation, and finally, the processing of recombination intermediates such as Holliday junctions or other joint molecules. Over the last 15 years, it has been established that the Slx4 protein plays key roles in the processing of recombination intermediates, functioning as a scaffold to coordinate the action of structure-specific endonucleases. Recent work in budding yeast has uncovered unexpected roles for Slx4 in the initial step of DNA-end resection and in the modulation of DNA damage checkpoint signaling. Here we review these latest findings and discuss the emerging role of yeast Slx4 as an important coordinator of DNA damage signaling responses and a regulator of multiple steps in homologous recombination-mediated repair.
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Affiliation(s)
- José R Cussiol
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, 14853, USA
| | - Diego Dibitetto
- Department of Biosciences, University of Milan, 20133, Milan, Italy
| | | | - Marcus B Smolka
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, 14853, USA.
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34
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Gadaleta MC, González-Medina A, Noguchi E. Timeless protection of telomeres. Curr Genet 2016; 62:725-730. [PMID: 27068713 DOI: 10.1007/s00294-016-0599-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 03/28/2016] [Accepted: 03/30/2016] [Indexed: 11/30/2022]
Abstract
The DNA replication machinery encounters problems at numerous genomic regions that are inherently difficult to replicate. These genomic regions include telomeres, which contain repetitive DNA and telomere-binding proteins. If not properly regulated, replication of such genomic regions can result in DNA damage, leading to genomic instability. Studies implicated a role of Timeless-related proteins at difficult-to-replicate genomic regions, including telomeres. However, how these proteins maintain telomeres was elusive. In a recent report, we described the role of Swi1, a Timeless-related protein, in telomere maintenance in fission yeast. We demonstrated that Swi1 is required for proper replication of repeat DNA sequences at telomeres. We also showed that Swi1-deficient cells utilize recombination-based ALT (alternative lengthening of telomeres)-like mechanisms to maintain telomeres in the absence of telomerase. Here, we highlight these findings and present additional data to discuss the role of Swi1Timeless in telomere protection and ALT prevention.
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Affiliation(s)
- Mariana C Gadaleta
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, 245 N. 15th Street, Philadelphia, PA, 19102, USA.,The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Alberto González-Medina
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, 245 N. 15th Street, Philadelphia, PA, 19102, USA.,Universitat Pompeu Fabra, 08003, Barcelona, Spain
| | - Eishi Noguchi
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, 245 N. 15th Street, Philadelphia, PA, 19102, USA.
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35
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Gadaleta MC, Das MM, Tanizawa H, Chang YT, Noma KI, Nakamura TM, Noguchi E. Swi1Timeless Prevents Repeat Instability at Fission Yeast Telomeres. PLoS Genet 2016; 12:e1005943. [PMID: 26990647 PMCID: PMC4798670 DOI: 10.1371/journal.pgen.1005943] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 02/25/2016] [Indexed: 01/09/2023] Open
Abstract
Genomic instability associated with DNA replication stress is linked to cancer and genetic pathologies in humans. If not properly regulated, replication stress, such as fork stalling and collapse, can be induced at natural replication impediments present throughout the genome. The fork protection complex (FPC) is thought to play a critical role in stabilizing stalled replication forks at several known replication barriers including eukaryotic rDNA genes and the fission yeast mating-type locus. However, little is known about the role of the FPC at other natural impediments including telomeres. Telomeres are considered to be difficult to replicate due to the presence of repetitive GT-rich sequences and telomere-binding proteins. However, the regulatory mechanism that ensures telomere replication is not fully understood. Here, we report the role of the fission yeast Swi1Timeless, a subunit of the FPC, in telomere replication. Loss of Swi1 causes telomere shortening in a telomerase-independent manner. Our epistasis analyses suggest that heterochromatin and telomere-binding proteins are not major impediments for telomere replication in the absence of Swi1. Instead, repetitive DNA sequences impair telomere integrity in swi1Δ mutant cells, leading to the loss of repeat DNA. In the absence of Swi1, telomere shortening is accompanied with an increased recruitment of Rad52 recombinase and more frequent amplification of telomere/subtelomeres, reminiscent of tumor cells that utilize the alternative lengthening of telomeres pathway (ALT) to maintain telomeres. These results suggest that Swi1 ensures telomere replication by suppressing recombination and repeat instability at telomeres. Our studies may also be relevant in understanding the potential role of Swi1Timeless in regulation of telomere stability in cancer cells. In every round of the cell cycle, cells must accurately replicate their full genetic information. This process is highly regulated, as defects during DNA replication cause genomic instability, leading to various genetic disorders including cancers. To thwart these problems, cells carry an array of complex mechanisms to deal with various obstacles found across the genome that can hamper DNA replication and cause DNA damage. Understanding how these mechanisms are regulated and orchestrated is of paramount importance in the field. In this report, we describe how Swi1, a Timeless-related protein in fission yeast, regulates efficient replication of telomeres, which are considered to be difficult to replicate due to the presence of repetitive DNA and telomere-binding proteins. We show that Swi1 prevents telomere damage and maintains telomere length by protecting integrity of telomeric repeats. Swi1-mediated telomere maintenance is independent of telomerase activity, and loss of Swi1 causes hyper-activation of recombination-based telomere maintenance, which generates heterogeneous telomeres. Similar telomerase-independent and recombination-dependent mechanism is utilized by approximately 15% of human cancers, linking telomere replication defects with cancer development. Thus, our study may be relevant in understanding the role of telomere replication defects in the development of cancers in humans.
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Affiliation(s)
- Mariana C. Gadaleta
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Mukund M. Das
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Hideki Tanizawa
- Gene Expression and Regulation Program, The Wistar Institute, Philadelphia, Pennsylvania, United States of America
| | - Ya-Ting Chang
- Department of Biochemistry and Molecular Genetics, College of Medicine, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Ken-ichi Noma
- Gene Expression and Regulation Program, The Wistar Institute, Philadelphia, Pennsylvania, United States of America
| | - Toru M. Nakamura
- Department of Biochemistry and Molecular Genetics, College of Medicine, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Eishi Noguchi
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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36
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Poli J, Gerhold CB, Tosi A, Hustedt N, Seeber A, Sack R, Herzog F, Pasero P, Shimada K, Hopfner KP, Gasser SM. Mec1, INO80, and the PAF1 complex cooperate to limit transcription replication conflicts through RNAPII removal during replication stress. Genes Dev 2016; 30:337-54. [PMID: 26798134 PMCID: PMC4743062 DOI: 10.1101/gad.273813.115] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 12/21/2015] [Indexed: 12/11/2022]
Abstract
Poli et al. present genetic and proteomic analyses from budding yeast that uncover links between the DNA replication checkpoint sensor Mec1–Ddc2 (ATR–ATRIP), the chromatin remodeling complex INO80C, and the transcription complex PAF1C. A subset of chromatin-bound RNAPII is degraded in a manner dependent on Mec1, INO80, and PAF1 complexes in cells exposed to hydroxyurea. Little is known about how cells ensure DNA replication in the face of RNA polymerase II (RNAPII)-mediated transcription, especially under conditions of replicative stress. Here we present genetic and proteomic analyses from budding yeast that uncover links between the DNA replication checkpoint sensor Mec1–Ddc2 (ATR–ATRIP), the chromatin remodeling complex INO80C (INO80 complex), and the transcription complex PAF1C (PAF1 complex). We found that a subset of chromatin-bound RNAPII is degraded in a manner dependent on Mec1, INO80, and PAF1 complexes in cells exposed to hydroxyurea (HU). On HU, Mec1 triggers the efficient removal of PAF1C and RNAPII from transcribed genes near early firing origins. Failure to evict RNAPII correlates inversely with recovery from replication stress: paf1Δ cells, like ino80 and mec1 mutants, fail to restart forks efficiently after stalling. Our data reveal unexpected synergies between INO80C, Mec1, and PAF1C in the maintenance of genome integrity and suggest a mechanism of RNAPII degradation that reduces transcription–replication fork collision.
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Affiliation(s)
- Jérôme Poli
- Friedrich Miescher Institute for Biomedical Research, CH-4058 Basel, Switzerland
| | | | - Alessandro Tosi
- Gene Center, Ludwig Maximilian University of Munich, 81377 Munich, Germany
| | - Nicole Hustedt
- Friedrich Miescher Institute for Biomedical Research, CH-4058 Basel, Switzerland
| | - Andrew Seeber
- Friedrich Miescher Institute for Biomedical Research, CH-4058 Basel, Switzerland
| | - Ragna Sack
- Friedrich Miescher Institute for Biomedical Research, CH-4058 Basel, Switzerland
| | - Franz Herzog
- Gene Center, Ludwig Maximilian University of Munich, 81377 Munich, Germany
| | - Philippe Pasero
- UPR 1142, Institut de Génétique Humaine, Centre National de la Recherche Scientifique, 30396 Montpellier, France
| | - Kenji Shimada
- Friedrich Miescher Institute for Biomedical Research, CH-4058 Basel, Switzerland
| | - Karl-Peter Hopfner
- Gene Center, Ludwig Maximilian University of Munich, 81377 Munich, Germany
| | - Susan M Gasser
- Friedrich Miescher Institute for Biomedical Research, CH-4058 Basel, Switzerland; Faculty of Natural Sciences, University of Basel, CH-4056 Basel, Switzerland
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37
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Böhm S, Szakal B, Herken BW, Sullivan MR, Mihalevic MJ, Kabbinavar FF, Branzei D, Clark NL, Bernstein KA. The Budding Yeast Ubiquitin Protease Ubp7 Is a Novel Component Involved in S Phase Progression. J Biol Chem 2016; 291:4442-52. [PMID: 26740628 DOI: 10.1074/jbc.m115.671057] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Indexed: 11/06/2022] Open
Abstract
DNA damage must be repaired in an accurate and timely fashion to preserve genome stability. Cellular mechanisms preventing genome instability are crucial to human health because genome instability is considered a hallmark of cancer. Collectively referred to as the DNA damage response, conserved pathways ensure proper DNA damage recognition and repair. The function of numerous DNA damage response components is fine-tuned by posttranslational modifications, including ubiquitination. This not only involves the enzyme cascade responsible for conjugating ubiquitin to substrates but also requires enzymes that mediate directed removal of ubiquitin. Deubiquitinases remove ubiquitin from substrates to prevent degradation or to mediate signaling functions. The Saccharomyces cerevisiae deubiquitinase Ubp7 has been characterized previously as an endocytic factor. However, here we identify Ubp7 as a novel factor affecting S phase progression after hydroxyurea treatment and demonstrate an evolutionary and genetic interaction of Ubp7 with DNA damage repair pathways of homologous recombination and nucleotide excision repair. We find that deletion of UBP7 sensitizes cells to hydroxyurea and cisplatin and demonstrate that factors that stabilize replication forks are critical under these conditions. Furthermore, ubp7Δ cells exhibit an S phase progression defect upon checkpoint activation by hydroxyurea treatment. ubp7Δ mutants are epistatic to factors involved in histone maintenance and modification, and we find that a subset of Ubp7 is chromatin-associated. In summary, our results suggest that Ubp7 contributes to S phase progression by affecting the chromatin state at replication forks, and we propose histone H2B ubiquitination as a potential substrate of Ubp7.
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Affiliation(s)
- Stefanie Böhm
- From the Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania 15213
| | - Barnabas Szakal
- the Department of Molecular Oncology, Fondazione Istituto Fondazione Italiana per la Ricerca sul Cancro di Oncologia Molecolare, Milan 20139, Italy
| | - Benjamin W Herken
- From the Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania 15213
| | - Meghan R Sullivan
- From the Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania 15213
| | - Michael J Mihalevic
- From the Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania 15213
| | - Faiz F Kabbinavar
- From the Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania 15213
| | - Dana Branzei
- the Department of Molecular Oncology, Fondazione Istituto Fondazione Italiana per la Ricerca sul Cancro di Oncologia Molecolare, Milan 20139, Italy
| | - Nathan L Clark
- the Department of Computational and Systems Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, and
| | - Kara A Bernstein
- From the Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania 15213,
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Abstract
The DNA damage response (DDR) has been broadly defined as a complex network of cellular pathways that cooperate to sense and repair lesions in DNA. Multiple types of DNA damage, some natural DNA sequences, nucleotide pool deficiencies and collisions with transcription complexes can cause replication arrest to elicit the DDR. However, in practice, the term DDR as applied to eukaryotic/mammalian cells often refers more specifically to pathways involving the activation of the ATM (ataxia-telangiectasia mutated) and ATR (ATM-Rad3-related) kinases in response to double-strand breaks or arrested replication forks, respectively. Nevertheless, there are distinct responses to particular types of DNA damage that do not involve ATM or ATR. In addition, some of the aberrations that cause replication arrest and elicit the DDR cannot be categorized as direct DNA damage. These include nucleotide pool deficiencies, nucleotide sequences that can adopt non-canonical DNA structures, and collisions between replication forks and transcription complexes. The response to these aberrations can be called the genomic stress response (GSR), a term that is meant to encompass the sensing of all types of DNA aberrations together with the mechanisms involved in coping with them. In addition to fully functional cells, the consequences of processing genomic aberrations may include mutagenesis, genomic rearrangements and lethality.
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Affiliation(s)
- Philip C Hanawalt
- Department of Biology, Stanford University, Stanford, CA 94305-5020, USA.
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Liu F, Suryadi J, Bierbach U. Cellular Recognition and Repair of Monofunctional-Intercalative Platinum--DNA Adducts. Chem Res Toxicol 2015; 28:2170-8. [PMID: 26457537 DOI: 10.1021/acs.chemrestox.5b00327] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The cellular recognition and processing of monofunctional-intercalative DNA adducts formed by [PtCl(en)(L)](NO3)2 (P1-A1; en = ethane-1,2-diamine; L = N-[2-(acridin-9-ylamino)ethyl]-N-methylpropionamidine, acridinium cation), a cytotoxic hybrid agent with potent anticancer activity, was studied. Excision of these adducts and subsequent DNA repair synthesis were monitored in plasmids modified with platinum using incubations with mammalian cell-free extract. On the basis of the levels of [α-(32)P]-dCTP incorporation, P1-A1-DNA adducts were rapidly repaired with a rate approximately 8 times faster (t1/2 ≈ 18 min at 30 °C) than the adducts (cross-links) formed by the drug cisplatin. Cellular responses to P1-A1 and cisplatin were also studied in NCI-H460 lung cancer cells using immunocytochemistry in conjunction with confocal fluorescence microscopy. At the same dose, P1-A1, but not cisplatin, elicited a distinct requirement for DNA double-strand break repair and stalled replication fork repair, which caused nuclear fluorescent staining related to high levels of MUS81, a specialized repair endonuclease, and phosphorylated histone protein γ-H2AX. The results confirm previous observations in yeast-based chemical genomics assays. γ-H2AX fluorescence is observed as a large number of discrete foci signaling DNA double-strand breaks, pan-nuclear preapoptotic staining, and unique circularly shaped staining around the nucleoli and nuclear rim. DNA cleavage assays indicate that P1-A1 does not act as a typical topoisomerase poison, suggesting the high level of DNA double-strand breaks in cells is more likely a result of topoisomerase-independent replication fork collapse. Overall, the cellular response to platinum-acridines shares striking similarities with that reported for DNA adduct-forming derivatives of the drug doxorubicin. The results of this study are discussed in light of the cellular mechanism of action of platinum-acridines and their ability to overcome resistance to cisplatin.
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Affiliation(s)
- Fang Liu
- Department of Chemistry, Wake Forest University , Winston-Salem, North Carolina 27109, United States
| | - Jimmy Suryadi
- Department of Chemistry, Wake Forest University , Winston-Salem, North Carolina 27109, United States
| | - Ulrich Bierbach
- Department of Chemistry, Wake Forest University , Winston-Salem, North Carolina 27109, United States
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40
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Marcomini I, Gasser SM. Nuclear organization in DNA end processing: Telomeres vs double-strand breaks. DNA Repair (Amst) 2015; 32:134-140. [PMID: 26004856 DOI: 10.1016/j.dnarep.2015.04.024] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Many proteins ligands are shared between double-strand breaks and natural chromosomal ends or telomeres. The structural similarity of the 3' overhang, and the efficiency of cellular DNA end degradation machineries, highlight the need for mechanisms that resect selectively to promote or restrict recombination events. Here we examine the means used by eukaryotic cells to suppress resection at telomeres, target telomerase to short telomeres, and process broken ends for appropriate repair. Not only molecular ligands, but the spatial sequestration of telomeres and damage likely ensure that these two very similar structures have very distinct outcomes with respect to the DNA damage response and repair.
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Affiliation(s)
- Isabella Marcomini
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058 Basel, Switzerland; Faculty of Natural Sciences, University of Basel, Basel, Switzerland
| | - Susan M Gasser
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058 Basel, Switzerland; Faculty of Natural Sciences, University of Basel, Basel, Switzerland.
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41
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Abstract
To ensure duplication of the entire genome, eukaryotic DNA replication initiates from thousands of replication origins. The replication forks move through the chromatin until they encounter forks from neighboring origins. During replication fork termination forks converge, the replisomes disassemble and topoisomerase II resolves the daughter DNA molecules. If not resolved efficiently, terminating forks result in genomic instability through the formation of pathogenic structures. Our recent findings shed light onto the mechanism of replisome disassembly upon replication fork termination. We have shown that termination-specific polyubiquitylation of the replicative helicase component – Mcm7, leads to dissolution of the active helicase in a process dependent on the p97/VCP/Cdc48 segregase. The inhibition of terminating helicase disassembly resulted in a replication termination defect. In this extended view we present hypothetical models of replication fork termination and discuss remaining and emerging questions in the DNA replication termination field.
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Key Words
- CMG, Cdc45, Mcm2–7, GINS complex
- CRL, cullin-RING ligase
- D loop, displacement loop
- DDR, DNA damage response
- DNA replication
- DSB, double strand break
- DUB, deubiquitylating enzyme
- ER, endoplasmic reticulum
- ERAD, endoplasmic reticulum associated protein degradation
- GINS, Go-Ichi-Ni-San, complex made of Sld5, Psf1, Psf2, Psf3
- ICL, intra-strand crosslink
- MCM, Minichromosome maintenance
- Mcm2–7
- OriC, chromosomal replication origin
- R loop, RNA:DNA hybrid
- RING, really interesting gene
- RPC, Replisome Progression Complex
- Ter, termination site
- Tus-Ter, terminus utilisation substance - termination
- Xenopus
- p97 segregase
- replication termination
- replicative helicase
- replisome
- ubiquitin
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Affiliation(s)
- Rachael Bailey
- a School of Cancer Sciences; University of Birmingham ; Birmingham , UK
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42
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Chromatin remodeling factors Isw2 and Ino80 regulate checkpoint activity and chromatin structure in S phase. Genetics 2015; 199:1077-91. [PMID: 25701287 DOI: 10.1534/genetics.115.174730] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 02/13/2015] [Indexed: 12/19/2022] Open
Abstract
When cells undergo replication stress, proper checkpoint activation and deactivation are critical for genomic stability and cell survival and therefore must be highly regulated. Although mechanisms of checkpoint activation are well studied, mechanisms of checkpoint deactivation are far less understood. Previously, we reported that chromatin remodeling factors Isw2 and Ino80 attenuate the S-phase checkpoint activity in Saccharomyces cerevisiae, especially during recovery from hydroxyurea. In this study, we found that Isw2 and Ino80 have a more pronounced role in attenuating checkpoint activity during late S phase in the presence of methyl methanesulfonate (MMS). We therefore screened for checkpoint factors required for Isw2 and Ino80 checkpoint attenuation in the presence of MMS. Here we demonstrate that Isw2 and Ino80 antagonize checkpoint activators and attenuate checkpoint activity in S phase in MMS either through a currently unknown pathway or through RPA. Unexpectedly, we found that Isw2 and Ino80 increase chromatin accessibility around replicating regions in the presence of MMS through a novel mechanism. Furthermore, through growth assays, we provide additional evidence that Isw2 and Ino80 partially counteract checkpoint activators specifically in the presence of MMS. Based on these results, we propose that Isw2 and Ino80 attenuate S-phase checkpoint activity through a novel mechanism.
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43
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Hustedt N, Seeber A, Sack R, Tsai-Pflugfelder M, Bhullar B, Vlaming H, van Leeuwen F, Guénolé A, van Attikum H, Srivas R, Ideker T, Shimada K, Gasser SM. Yeast PP4 interacts with ATR homolog Ddc2-Mec1 and regulates checkpoint signaling. Mol Cell 2015; 57:273-89. [PMID: 25533186 PMCID: PMC5706562 DOI: 10.1016/j.molcel.2014.11.016] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 10/16/2014] [Accepted: 11/14/2014] [Indexed: 12/25/2022]
Abstract
Mec1-Ddc2 (ATR-ATRIP) controls the DNA damage checkpoint and shows differential cell-cycle regulation in yeast. To find regulators of Mec1-Ddc2, we exploited a mec1 mutant that retains catalytic activity in G2 and recruitment to stalled replication forks, but which is compromised for the intra-S phase checkpoint. Two screens, one for spontaneous survivors and an E-MAP screen for synthetic growth effects, identified loss of PP4 phosphatase, pph3Δ and psy2Δ, as the strongest suppressors of mec1-100 lethality on HU. Restored Rad53 phosphorylation accounts for part, but not all, of the pph3Δ-mediated survival. Phosphoproteomic analysis confirmed that 94% of the mec1-100-compromised targets on HU are PP4 regulated, including a phosphoacceptor site within Mec1 itself, mutation of which confers damage sensitivity. Physical interaction between Pph3 and Mec1, mediated by cofactors Psy2 and Ddc2, is shown biochemically and through FRET in subnuclear repair foci. This establishes a physical and functional Mec1-PP4 unit for regulating the checkpoint response.
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Affiliation(s)
- Nicole Hustedt
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland; Faculty of Sciences, University of Basel, 4056 Basel, Switzerland
| | - Andrew Seeber
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland; Faculty of Sciences, University of Basel, 4056 Basel, Switzerland
| | - Ragna Sack
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Monika Tsai-Pflugfelder
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Bhupinder Bhullar
- Novartis Institutes for Biomedical Research, Novartis Pharma AG, Fabrikstrasse 22, 4056 Basel, Switzerland
| | - Hanneke Vlaming
- Division of Gene Regulation, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, the Netherlands
| | - Fred van Leeuwen
- Division of Gene Regulation, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, the Netherlands
| | - Aude Guénolé
- Department of Toxicogenetics, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, the Netherlands
| | - Haico van Attikum
- Department of Toxicogenetics, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, the Netherlands
| | - Rohith Srivas
- Departments of Bioengineering and Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Trey Ideker
- Departments of Bioengineering and Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Kenji Shimada
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Susan M Gasser
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland; Faculty of Sciences, University of Basel, 4056 Basel, Switzerland.
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44
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Leman AR, Noguchi E. Chromatin immunoprecipitation to investigate origin association of replication factors in mammalian cells. Methods Mol Biol 2014; 1170:539-47. [PMID: 24906335 DOI: 10.1007/978-1-4939-0888-2_30] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
A variety of DNA-binding proteins regulate DNA transactions including DNA replication and DNA damage response. To initiate DNA replication in S phase of the cell cycle, numerous replication proteins must be recruited to the replication origin in order to unwind and synthesize DNA. Some replication factors stay at the origin, while replisome components move with the replication fork. When the replisome encounters DNA damage or other issues during DNA replication, the replication fork stalls and accumulates single-stranded DNA that triggers the ATR-dependent replication checkpoint, in order to slow down S phase and arrest the cell cycle at the G2-M transition. It is also possible that replication forks collapse, leading to double-strand breaks that recruit various DNA damage response proteins to activate cell cycle checkpoints and DNA repair pathways. Therefore, defining the localization of DNA transaction factors during the cell cycle should provide important insights into mechanistic understanding of DNA replication and its related processes. In this chapter, we describe a chromatin immunoprecipitation method to locate replisome components at replication origins in human cells.
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Affiliation(s)
- Adam R Leman
- Department of Biology, Duke University, Durham, NC, USA
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45
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Abstract
Checkpoints are conserved mechanisms that prevent progression into the next phase of the cell cycle when cells are unable to accomplish the previous event properly. Cells also possess a surveillance mechanism called the DNA replication checkpoint, which consists of a conserved kinase cascade that is provoked by insults that block or slow down replication fork progression. In the budding yeast Saccharomyces cerevisiae, the DNA replication checkpoint controls the timing of S-phase events such as origin firing and spindle elongation. This checkpoint also upregulates dNTP pools and maintains the replication fork structure in order to resume DNA replication after replication block. Many replication checkpoint factors have been found to be tumor suppressors, highlighting the importance of this checkpoint pathway in human health. Here we describe a series of protocols to analyze the DNA replication checkpoint in S. cerevisiae.
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Affiliation(s)
- Nicole Hustedt
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058, Basel, Switzerland
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