1
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Ito M, Fujita Y, Shinohara A. Positive and negative regulators of RAD51/DMC1 in homologous recombination and DNA replication. DNA Repair (Amst) 2024; 134:103613. [PMID: 38142595 DOI: 10.1016/j.dnarep.2023.103613] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 12/10/2023] [Accepted: 12/10/2023] [Indexed: 12/26/2023]
Abstract
RAD51 recombinase plays a central role in homologous recombination (HR) by forming a nucleoprotein filament on single-stranded DNA (ssDNA) to catalyze homology search and strand exchange between the ssDNA and a homologous double-stranded DNA (dsDNA). The catalytic activity of RAD51 assembled on ssDNA is critical for the DNA-homology-mediated repair of DNA double-strand breaks in somatic and meiotic cells and restarting stalled replication forks during DNA replication. The RAD51-ssDNA complex also plays a structural role in protecting the regressed/reversed replication fork. Two types of regulators control RAD51 filament formation, stability, and dynamics, namely positive regulators, including mediators, and negative regulators, so-called remodelers. The appropriate balance of action by the two regulators assures genome stability. This review describes the roles of positive and negative RAD51 regulators in HR and DNA replication and its meiosis-specific homolog DMC1 in meiotic recombination. We also provide future study directions for a comprehensive understanding of RAD51/DMC1-mediated regulation in maintaining and inheriting genome integrity.
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Affiliation(s)
- Masaru Ito
- Institute for Protein Research, Osaka University, Yamadaoka 3-2, Suita, Osaka 565-0871, Japan.
| | - Yurika Fujita
- Institute for Protein Research, Osaka University, Yamadaoka 3-2, Suita, Osaka 565-0871, Japan.
| | - Akira Shinohara
- Institute for Protein Research, Osaka University, Yamadaoka 3-2, Suita, Osaka 565-0871, Japan.
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2
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Genetic and Biochemical Characterizations of aLhr1 Helicase in the Thermophilic Crenarchaeon Sulfolobus acidocaldarius. Catalysts 2021. [DOI: 10.3390/catal12010034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Homologous recombination (HR) refers to the process of information exchange between homologous DNA duplexes and is composed of four main steps: end resection, strand invasion and formation of a Holliday junction (HJ), branch migration, and resolution of the HJ. Within each step of HR in Archaea, the helicase-promoting branch migration is not fully understood. Previous biochemical studies identified three candidates for archaeal helicase promoting branch migration in vitro: Hjm/Hel308, PINA, and archaeal long helicase related (aLhr) 2. However, there is no direct evidence of their involvement in HR in vivo. Here, we identified a novel helicase encoded by Saci_0814, isolated from the thermophilic crenarchaeon Sulfolobus acidocaldarius; the helicase dissociated a synthetic HJ. Notably, HR frequency in the Saci_0814-deleted strain was lower than that of the parent strain (5-fold decrease), indicating that Saci_0814 may be involved in HR in vivo. Saci_0814 is classified as an aLhr1 under superfamily 2 helicases; its homologs are conserved among Archaea. Purified protein produced in Escherichia coli showed branch migration activity in vitro. Based on both genetic and biochemical evidence, we suggest that aLhr1 is involved in HR and may function as a branch migration helicase in S. acidocaldarius.
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3
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Tsubouchi H, Argunhan B, Iwasaki H. Biochemical properties of fission yeast homologous recombination enzymes. Curr Opin Genet Dev 2021; 71:19-26. [PMID: 34246071 DOI: 10.1016/j.gde.2021.06.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 06/06/2021] [Accepted: 06/14/2021] [Indexed: 12/20/2022]
Abstract
Homologous recombination (HR) is a universal phenomenon conserved from viruses to humans. The mechanisms of HR are essentially the same in humans and simple unicellular eukaryotes like yeast. Two highly diverged yeast species, Saccharomyces cerevisiae and Schizosaccharomyces pombe, have proven exceptionally useful in understanding the fundamental mechanisms of eukaryotic HR by serving as a source for unique biological insights and also complementing each other. Here, we will review the features of S. pombe HR mechanisms in comparison to S. cerevisiae and other model organisms. Particular emphasis will be put on the biochemical characterization of HR mechanisms uncovered using S. pombe proteins.
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Affiliation(s)
- Hideo Tsubouchi
- Institute of Innovative Research, Tokyo Institute of Technology, Kanagawa, Japan; School of Life Science and Technology, Tokyo Institute of Technology, Kanagawa, Japan.
| | - Bilge Argunhan
- Institute of Innovative Research, Tokyo Institute of Technology, Kanagawa, Japan
| | - Hiroshi Iwasaki
- Institute of Innovative Research, Tokyo Institute of Technology, Kanagawa, Japan; School of Life Science and Technology, Tokyo Institute of Technology, Kanagawa, Japan.
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4
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Afshar N, Argunhan B, Palihati M, Taniguchi G, Tsubouchi H, Iwasaki H. A novel motif of Rad51 serves as an interaction hub for recombination auxiliary factors. eLife 2021; 10:64131. [PMID: 33493431 PMCID: PMC7837696 DOI: 10.7554/elife.64131] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Accepted: 12/26/2020] [Indexed: 12/14/2022] Open
Abstract
Homologous recombination (HR) is essential for maintaining genome stability. Although Rad51 is the key protein that drives HR, multiple auxiliary factors interact with Rad51 to potentiate its activity. Here, we present an interdisciplinary characterization of the interactions between Rad51 and these factors. Through structural analysis, we identified an evolutionarily conserved acidic patch of Rad51. The neutralization of this patch completely abolished recombinational DNA repair due to defects in the recruitment of Rad51 to DNA damage sites. This acidic patch was found to be important for the interaction with Rad55-Rad57 and essential for the interaction with Rad52. Furthermore, biochemical reconstitutions demonstrated that neutralization of this acidic patch also impaired the interaction with Rad54, indicating that a single motif is important for the interaction with multiple auxiliary factors. We propose that this patch is a fundamental motif that facilitates interactions with auxiliary factors and is therefore essential for recombinational DNA repair.
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Affiliation(s)
- Negar Afshar
- School of Life Science and Technology, Tokyo Institute of Technology, Tokyo, Japan.,Institute of Innovative Research, Tokyo Institute of Technology, Tokyo, Japan
| | - Bilge Argunhan
- Institute of Innovative Research, Tokyo Institute of Technology, Tokyo, Japan
| | - Maierdan Palihati
- School of Life Science and Technology, Tokyo Institute of Technology, Tokyo, Japan.,Institute of Innovative Research, Tokyo Institute of Technology, Tokyo, Japan
| | - Goki Taniguchi
- School of Life Science and Technology, Tokyo Institute of Technology, Tokyo, Japan.,Institute of Innovative Research, Tokyo Institute of Technology, Tokyo, Japan
| | - Hideo Tsubouchi
- School of Life Science and Technology, Tokyo Institute of Technology, Tokyo, Japan.,Institute of Innovative Research, Tokyo Institute of Technology, Tokyo, Japan
| | - Hiroshi Iwasaki
- School of Life Science and Technology, Tokyo Institute of Technology, Tokyo, Japan.,Institute of Innovative Research, Tokyo Institute of Technology, Tokyo, Japan
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5
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Andriuskevicius T, Kotenko O, Makovets S. Putting together and taking apart: assembly and disassembly of the Rad51 nucleoprotein filament in DNA repair and genome stability. Cell Stress 2018; 2:96-112. [PMID: 31225474 PMCID: PMC6551702 DOI: 10.15698/cst2018.05.134] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Homologous recombination is a key mechanism providing both genome stability and genetic diversity in all living organisms. Recombinases play a central role in this pathway: multiple protein subunits of Rad51 or its orthologues bind single-stranded DNA to form a nucleoprotein filament which is essential for initiating recombination events. Multiple factors are involved in the regulation of this step, both positively and negatively. In this review, we discuss Rad51 nucleoprotein assembly and disassembly, how it is regulated and what functional significance it has in genome maintenance.
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Affiliation(s)
| | - Oleksii Kotenko
- Institute of Cell Biology, School of Biological Sciences, University of Edinburgh
| | - Svetlana Makovets
- Institute of Cell Biology, School of Biological Sciences, University of Edinburgh
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6
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Argunhan B, Leung WK, Afshar N, Terentyev Y, Subramanian VV, Murayama Y, Hochwagen A, Iwasaki H, Tsubouchi T, Tsubouchi H. Fundamental cell cycle kinases collaborate to ensure timely destruction of the synaptonemal complex during meiosis. EMBO J 2017; 36:2488-2509. [PMID: 28694245 DOI: 10.15252/embj.201695895] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 05/31/2017] [Accepted: 06/02/2017] [Indexed: 01/07/2023] Open
Abstract
The synaptonemal complex (SC) is a proteinaceous macromolecular assembly that forms during meiotic prophase I and mediates adhesion of paired homologous chromosomes along their entire lengths. Although prompt disassembly of the SC during exit from prophase I is a landmark event of meiosis, the underlying mechanism regulating SC destruction has remained elusive. Here, we show that DDK (Dbf4-dependent Cdc7 kinase) is central to SC destruction. Upon exit from prophase I, Dbf4, the regulatory subunit of DDK, directly associates with and is phosphorylated by the Polo-like kinase Cdc5. In parallel, upregulated CDK1 activity also targets Dbf4. An enhanced Dbf4-Cdc5 interaction pronounced phosphorylation of Dbf4 and accelerated SC destruction, while reduced/abolished Dbf4 phosphorylation hampered destruction of SC proteins. SC destruction relieved meiotic inhibition of the ubiquitous recombinase Rad51, suggesting that the mitotic recombination machinery is reactivated following prophase I exit to repair any persisting meiotic DNA double-strand breaks. Taken together, we propose that the concerted action of DDK, Polo-like kinase, and CDK1 promotes efficient SC destruction at the end of prophase I to ensure faithful inheritance of the genome.
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Affiliation(s)
- Bilge Argunhan
- Genome Damage and Stability Centre, Life Sciences, University of Sussex, Brighton, East Sussex, UK.,Institute of Innovative Research, Tokyo Institute of Technology, Tokyo, Japan
| | - Wing-Kit Leung
- Genome Damage and Stability Centre, Life Sciences, University of Sussex, Brighton, East Sussex, UK
| | - Negar Afshar
- Genome Damage and Stability Centre, Life Sciences, University of Sussex, Brighton, East Sussex, UK.,Institute of Innovative Research, Tokyo Institute of Technology, Tokyo, Japan
| | - Yaroslav Terentyev
- Genome Damage and Stability Centre, Life Sciences, University of Sussex, Brighton, East Sussex, UK
| | | | - Yasuto Murayama
- Institute of Innovative Research, Tokyo Institute of Technology, Tokyo, Japan
| | | | - Hiroshi Iwasaki
- Institute of Innovative Research, Tokyo Institute of Technology, Tokyo, Japan
| | - Tomomi Tsubouchi
- Genome Damage and Stability Centre, Life Sciences, University of Sussex, Brighton, East Sussex, UK .,National Institute for Basic Biology, Okazaki, Japan
| | - Hideo Tsubouchi
- Genome Damage and Stability Centre, Life Sciences, University of Sussex, Brighton, East Sussex, UK .,National Institute for Basic Biology, Okazaki, Japan
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7
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Argunhan B, Murayama Y, Iwasaki H. The differentiated and conserved roles of Swi5-Sfr1 in homologous recombination. FEBS Lett 2017; 591:2035-2047. [PMID: 28423184 PMCID: PMC5573924 DOI: 10.1002/1873-3468.12656] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 04/10/2017] [Accepted: 04/12/2017] [Indexed: 11/13/2022]
Abstract
Homologous recombination (HR) is the process whereby two DNA molecules that share high sequence similarity are able to recombine to generate hybrid DNA molecules. Throughout evolution, the ability of HR to identify highly similar DNA sequences has been adopted for numerous biological phenomena including DNA repair, meiosis, telomere maintenance, ribosomal DNA amplification and immunological diversity. Although Rad51 and Dmc1 are the key proteins that promote HR in mitotic and meiotic cells, respectively, accessory proteins that allow Rad51 and Dmc1 to effectively fulfil their functions have been identified in all examined model systems. In this Review, we discuss the roles of the highly conserved Swi5‐Sfr1 accessory complex in yeast, mice and humans, and explore similarities and differences between these species.
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Affiliation(s)
- Bilge Argunhan
- Institute of Innovative Research, Tokyo Institute of Technology, Japan
| | - Yasuto Murayama
- Institute of Innovative Research, Tokyo Institute of Technology, Japan
| | - Hiroshi Iwasaki
- Institute of Innovative Research, Tokyo Institute of Technology, Japan
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8
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DNA repair pathways in trypanosomatids: from DNA repair to drug resistance. Microbiol Mol Biol Rev 2014; 78:40-73. [PMID: 24600040 DOI: 10.1128/mmbr.00045-13] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
All living organisms are continuously faced with endogenous or exogenous stress conditions affecting genome stability. DNA repair pathways act as a defense mechanism, which is essential to maintain DNA integrity. There is much to learn about the regulation and functions of these mechanisms, not only in human cells but also equally in divergent organisms. In trypanosomatids, DNA repair pathways protect the genome against mutations but also act as an adaptive mechanism to promote drug resistance. In this review, we scrutinize the molecular mechanisms and DNA repair pathways which are conserved in trypanosomatids. The recent advances made by the genome consortiums reveal the complete genomic sequences of several pathogens. Therefore, using bioinformatics and genomic sequences, we analyze the conservation of DNA repair proteins and their key protein motifs in trypanosomatids. We thus present a comprehensive view of DNA repair processes in trypanosomatids at the crossroads of DNA repair and drug resistance.
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9
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Dziadkowiec D, Kramarz K, Kanik K, Wisniewski P, Carr AM. Involvement of Schizosaccharomyces pombe rrp1+ and rrp2+ in the Srs2- and Swi5/Sfr1-dependent pathway in response to DNA damage and replication inhibition. Nucleic Acids Res 2013; 41:8196-209. [PMID: 23828040 PMCID: PMC3783160 DOI: 10.1093/nar/gkt564] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Previously we identified Rrp1 and Rrp2 as two proteins required for the Sfr1/Swi5-dependent branch of homologous recombination (HR) in Schizosaccharomyces pombe. Here we use a yeast two-hybrid approach to demonstrate that Rrp1 and Rrp2 can interact with each other and with Swi5, an HR mediator protein. Rrp1 and Rrp2 form co-localizing methyl methanesulphonate-induced foci in nuclei, further suggesting they function as a complex. To place the Rrp1/2 proteins more accurately within HR sub-pathways, we carried out extensive epistasis analysis between mutants defining Rrp1/2, Rad51 (recombinase), Swi5 and Rad57 (HR-mediators) plus the anti-recombinogenic helicases Srs2 and Rqh1. We confirm that Rrp1 and Rrp2 act together with Srs2 and Swi5 and independently of Rad57 and show that Rqh1 also acts independently of Rrp1/2. Mutants devoid of Srs2 are characterized by elevated recombination frequency with a concomitant increase in the percentage of conversion-type recombinants. Strains devoid of Rrp1 or Rrp2 did not show a change in HR frequency, but the number of conversion-type recombinants was increased, suggesting a possible function for Rrp1/2 with Srs2 in counteracting Rad51 activity. Our data allow us to propose a model placing Rrp1 and Rrp2 functioning together with Swi5 and Srs2 in a synthesis-dependent strand annealing HR repair pathway.
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Affiliation(s)
- Dorota Dziadkowiec
- Faculty of Biotechnology, Wrocław University, Przybyszewskiego 63-77, 51-148 Wrocław, Poland, Institute of Low Temperature and Structure Research, Polish Academy of Sciences, PO Box 1410, 50-950 Wrocław, Poland and Genome Damage and Stability Centre, University of Sussex, Falmer, Brighton, BN1 9RQ, UK
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10
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Khasanova OS, Vagin DA, Khasanov FK. Recombinational repair in Schizosaccharomyces pombe: The role of mediator proteins. Mol Biol 2012. [DOI: 10.1134/s0026893312050068] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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11
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Förster F, Beisser D, Grohme MA, Liang C, Mali B, Siegl AM, Engelmann JC, Shkumatov AV, Schokraie E, Müller T, Schnölzer M, Schill RO, Frohme M, Dandekar T. Transcriptome analysis in tardigrade species reveals specific molecular pathways for stress adaptations. Bioinform Biol Insights 2012; 6:69-96. [PMID: 22563243 PMCID: PMC3342025 DOI: 10.4137/bbi.s9150] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Tardigrades have unique stress-adaptations that allow them to survive extremes of cold, heat, radiation and vacuum. To study this, encoded protein clusters and pathways from an ongoing transcriptome study on the tardigrade Milnesium tardigradum were analyzed using bioinformatics tools and compared to expressed sequence tags (ESTs) from Hypsibius dujardini, revealing major pathways involved in resistance against extreme environmental conditions. ESTs are available on the Tardigrade Workbench along with software and databank updates. Our analysis reveals that RNA stability motifs for M. tardigradum are different from typical motifs known from higher animals. M. tardigradum and H. dujardini protein clusters and conserved domains imply metabolic storage pathways for glycogen, glycolipids and specific secondary metabolism as well as stress response pathways (including heat shock proteins, bmh2, and specific repair pathways). Redox-, DNA-, stress- and protein protection pathways complement specific repair capabilities to achieve the strong robustness of M. tardigradum. These pathways are partly conserved in other animals and their manipulation could boost stress adaptation even in human cells. However, the unique combination of resistance and repair pathways make tardigrades and M. tardigradum in particular so highly stress resistant.
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Affiliation(s)
- Frank Förster
- Dept. of Bioinformatics, Biocenter University of Würzburg, 97074 Würzburg, Germany
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12
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Amunugama R, Fishel R. Homologous Recombination in Eukaryotes. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2012; 110:155-206. [DOI: 10.1016/b978-0-12-387665-2.00007-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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13
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Hyppa RW, Smith GR. Crossover invariance determined by partner choice for meiotic DNA break repair. Cell 2010; 142:243-55. [PMID: 20655467 PMCID: PMC2911445 DOI: 10.1016/j.cell.2010.05.041] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2009] [Revised: 03/23/2010] [Accepted: 05/18/2010] [Indexed: 11/21/2022]
Abstract
Crossovers between meiotic homologs are crucial for their proper segregation, and crossover number and position are carefully controlled. Crossover homeostasis in budding yeast maintains crossovers at the expense of noncrossovers when double-strand DNA break (DSB) frequency is reduced. The mechanism of maintaining constant crossover levels in other species has been unknown. Here we investigate in fission yeast a different aspect of crossover control--the near invariance of crossover frequency per kb of DNA despite large variations in DSB intensity across the genome. Crossover invariance involves the choice of sister chromatid versus homolog for DSB repair. At strong DSB hotspots, intersister repair outnumbers interhomolog repair approximately 3:1, but our genetic and physical data indicate the converse in DSB-cold regions. This unanticipated mechanism of crossover control may operate in many species and explain, for example, the large excess of DSBs over crossovers and the repair of DSBs on unpaired chromosomes in diverse species.
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Affiliation(s)
- Randy W. Hyppa
- Fred Hutchinson Cancer Research Center Division of Basic Sciences Seattle, WA 98109 USA
| | - Gerald R. Smith
- Fred Hutchinson Cancer Research Center Division of Basic Sciences Seattle, WA 98109 USA
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14
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Deshpande GP, Hayles J, Hoe KL, Kim DU, Park HO, Hartsuiker E. Screening a genome-wide S. pombe deletion library identifies novel genes and pathways involved in genome stability maintenance. DNA Repair (Amst) 2009; 8:672-9. [PMID: 19264558 DOI: 10.1016/j.dnarep.2009.01.016] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2008] [Revised: 01/19/2009] [Accepted: 01/20/2009] [Indexed: 11/27/2022]
Abstract
The maintenance of genome stability is essential for an organism to avoid cell death and cancer. Based on screens for mutant sensitivity against DNA damaging agents a large number of DNA repair and DNA damage checkpoint genes have previously been identified in genetically amenable model organisms. These screens have however not been exhaustive and various genes have been, and remain to be, identified by other means. We therefore screened a genome-wide Schizosaccharomyces pombe deletion library for mutants sensitive against various DNA damaging agents. Screening the library on different concentrations of these genotoxins allowed us to assign a semi-quantitative score to each mutant expressing the degree of sensitivity. We isolated a total of 229 mutants which show sensitivity to one or more of the DNA damaging agents used. This set of mutants was significantly enriched for processes involved in DNA replication, DNA repair, DNA damage checkpoint, response to UV, mating type switching, telomere length maintenance and meiosis, and also for processes involved in the establishment and maintenance of chromatin architecture (notably members of the SAGA complex), transcription (members of the CCR4-Not complex) and microtubule related processes (members of the DASH complex). We also identified 23 sensitive mutants which had previously been classified as "sequence orphan" or as "conserved hypothetical". Among these, we identified genes showing extensive homology to CtIP, Stra13, Ybp1/Ybp2, Human Fragile X mental retardation interacting protein NUFIP1, and Aprataxin. The identification of these homologues will provide a basis for the further characterisation of the role of these conserved proteins in the genetically amenable model organism S. pombe.
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Affiliation(s)
- Gaurang P Deshpande
- Genome Damage and Stability Centre, University of Sussex, Brighton BN1 9RQ, UK
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15
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Dziadkowiec D, Petters E, Dyjankiewicz A, Karpiński P, Garcia V, Watson A, Carr AM. The role of novel genes rrp1(+) and rrp2(+) in the repair of DNA damage in Schizosaccharomyces pombe. DNA Repair (Amst) 2009; 8:627-36. [PMID: 19185548 DOI: 10.1016/j.dnarep.2008.12.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2008] [Revised: 12/08/2008] [Accepted: 12/16/2008] [Indexed: 10/21/2022]
Abstract
We identified two predicted proteins in Schizosaccharomyces pombe, Rrp1 (SPAC17A2.12) and Rrp2 (SPBC23E6.02) that share 34% and 36% similarity to Saccharomyces cerevisiae Ris1p, respectively. Ris1p is a DNA-dependent ATP-ase involved in gene silencing and DNA repair. Rrp1 and Rrp2 also share similarity with S. cerevisiae Rad5 and S. pombe Rad8, containing SNF2-N, RING finger and Helicase-C domains. To investigate the function of the Rrp proteins, we studied the DNA damage sensitivities and genetic interactions of null mutants with known DNA repair mutants. Single Deltarrp1 and Deltarrp2 mutants were not sensitive to CPT, 4NQO, CDPP, MMS, HU, UV or IR. The double mutants Deltarrp1 Deltarhp51 and Deltarrp2 Deltarhp51 plus the triple Deltarrp1 Deltarrp2 Deltarhp51 mutant did not display significant additional sensitivity. However, the double mutants Deltarrp1 Deltarhp57 and Deltarrp2 Deltarhp57 were significantly more sensitive to MMS, CPT, HU and IR than the Deltarhp57 single mutant. The checkpoint response in these strains was functional. In S. pombe, Rhp55/57 acts in parallel with a second mediator complex, Swi5/Sfr1, to facilitate Rhp51-dependent DNA repair. Deltarrp1 Deltasfr1 and Deltarrp2 Deltasfr1 double mutants did not show significant additional sensitivity, suggesting a function for Rrp proteins in the Swi5/Sfr1 pathway of DSB repair. Consistent with this, Deltarrp1 Deltarhp57 and Deltarrp2 Deltarhp57 mutants, but not Deltarrp1 Deltasfr1 or Deltarrp2 Deltasfr1 double mutants, exhibited slow growth and aberrations in cell and nuclear morphology that are typical of Deltarhp51.
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Affiliation(s)
- Dorota Dziadkowiec
- Faculty of Biotechnology, Wrocław University, Przybyszewskiego 63-77, 51-148 Wrocław, Poland.
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16
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Willis N, Rhind N. Mus81, Rhp51(Rad51), and Rqh1 form an epistatic pathway required for the S-phase DNA damage checkpoint. Mol Biol Cell 2008; 20:819-33. [PMID: 19037101 DOI: 10.1091/mbc.e08-08-0798] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The S-phase DNA damage checkpoint slows the rate of DNA synthesis in response to damage during replication. In the fission yeast Schizosaccharomyces pombe, Cds1, the S-phase-specific checkpoint effector kinase, is required for checkpoint signaling and replication slowing; upon treatment with the alkylating agent methyl methane sulfonate, cds1Delta mutants display a complete checkpoint defect. We have identified proteins downstream of Cds1 required for checkpoint-dependant slowing, including the structure-specific endonuclease Mus81 and the helicase Rqh1, which are implicated in replication fork stability and the negative regulation of recombination. Removing Rhp51, the Rad51 recombinase homologue, suppresses the slowing defect of rqh1Delta mutants, but not that of mus81Delta mutant, defining an epistatic pathway in which mus81 is epistatic to rhp51 and rhp51 is epistatic to rqh1. We propose that restraining recombination is required for the slowing of replication in response to DNA damage.
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Affiliation(s)
- Nicholas Willis
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA
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17
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Khasanov FK, Salakhova AF, Khasanova OS, Grishchuk AL, Chepurnaja OV, Korolev VG, Kohli J, Bashkirov VI. Genetic analysis reveals different roles of Schizosaccharomyces pombe sfr1/dds20 in meiotic and mitotic DNA recombination and repair. Curr Genet 2008; 54:197-211. [PMID: 18769921 DOI: 10.1007/s00294-008-0212-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2008] [Accepted: 08/15/2008] [Indexed: 11/26/2022]
Abstract
DNA double-strand break (DSB) repair mediated by the Rad51 pathway of homologous recombination is conserved in eukaryotes. In yeast, Rad51 paralogs, Saccharomyces cerevisiae Rad55-Rad57 and Schizosaccharomyces pombe Rhp55-Rhp57, are mediators of Rad51 nucleoprotein formation. The recently discovered S. pombe Sfr1/Dds20 protein has been shown to interact with Rad51 and to operate in the Rad51-dependent DSB repair pathway in parallel to the paralog-mediated pathway. Here we show that Sfr1 is a nuclear protein and acts downstream of Rad50 in DSB processing. sfr1Delta is epistatic to rad18 (-) and rad60 (-), and Sfr1 is a high-copy suppressor of the replication and repair defects of a rad60 mutant. Sfr1 functions in a Cds1-independent UV damage tolerance mechanism. In contrast to mitotic recombination, meiotic recombination is significantly reduced in sfr1Delta strains. Our data indicate that Sfr1 acts in DSB repair mainly outside of S-phase, and is required for wild-type levels of meiotic recombination. We suggest that Sfr1 acts early in recombination and has a specific role in Rad51 filament assembly, distinct from that of the Rad51 paralogs.
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Affiliation(s)
- Fuat K Khasanov
- Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia
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18
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Mus81 is essential for sister chromatid recombination at broken replication forks. EMBO J 2008; 27:1378-87. [PMID: 18388861 DOI: 10.1038/emboj.2008.65] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2007] [Accepted: 03/06/2008] [Indexed: 01/25/2023] Open
Abstract
Recombination is essential for the recovery of stalled/collapsed replication forks and therefore for the maintenance of genomic stability. The situation becomes critical when the replication fork collides with an unrepaired single-strand break and converts it into a one-ended double-strand break. We show in fission yeast that a unique broken replication fork requires the homologous recombination (HR) enzymes for cell viability. Two structure-specific heterodimeric endonucleases participate in two different resolution pathways. Mus81/Eme1 is essential when the sister chromatid is used for repair; conversely, Swi9/Swi10 is essential when an ectopic sequence is used for repair. Consequently, the utilization of these two HR modes of resolution mainly relies on the ratio of unique and repeated sequences present in various eukaryotic genomes. We also provide molecular evidence for sister recombination intermediates. These findings demonstrate that Mus81/Eme1 is the dedicated endonuclease that resolves sister chromatid recombination intermediates during the repair of broken replication forks.
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19
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Molecular characterization of the role of the Schizosaccharomyces pombe nip1+/ctp1+ gene in DNA double-strand break repair in association with the Mre11-Rad50-Nbs1 complex. Mol Cell Biol 2008; 28:3639-51. [PMID: 18378696 DOI: 10.1128/mcb.01828-07] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The Schizosaccharomyces pombe nip1(+)/ctp1(+) gene was previously identified as an slr (synthetically lethal with rad2) mutant. Epistasis analysis indicated that Nip1/Ctp1 functions in Rhp51-dependent recombinational repair, together with the Rad32 (spMre11)-Rad50-Nbs1 complex, which plays important roles in the early steps of DNA double-strand break repair. Nip1/Ctp1 was phosphorylated in asynchronous, exponentially growing cells and further phosphorylated in response to bleomycin treatment. Overproduction of Nip1/Ctp1 suppressed the DNA repair defect of an nbs1-s10 mutant, which carries a mutation in the FHA phosphopeptide-binding domain of Nbs1, but not of an nbs1 null mutant. Meiotic DNA double-strand breaks accumulated in the nip1/ctp1 mutant. The DNA repair phenotypes and epistasis relationships of nip1/ctp1 are very similar to those of the Saccharomyces cerevisiae sae2/com1 mutant, suggesting that Nip1/Ctp1 is a functional homologue of Sae2/Com1, although the sequence similarity between the proteins is limited to the C-terminal region containing the RHR motif. We found that the RxxL and CxxC motifs are conserved in Schizosaccharomyces species and in vertebrate CtIP, originally identified as a cofactor of the transcriptional corepressor CtBP. However, these two motifs are not found in other fungi, including Saccharomyces and Aspergillus species. We propose that Nip1/Ctp1 is a functional counterpart of Sae2/Com1 and CtIP.
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20
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Haruta N, Akamatsu Y, Tsutsui Y, Kurokawa Y, Murayama Y, Arcangioli B, Iwasaki H. Fission yeast Swi5 protein, a novel DNA recombination mediator. DNA Repair (Amst) 2007; 7:1-9. [PMID: 17716957 DOI: 10.1016/j.dnarep.2007.07.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2007] [Accepted: 07/09/2007] [Indexed: 11/26/2022]
Abstract
The Schizosaccharomyces pombe Swi5 protein forms two distinct protein complexes, Swi5-Sfr1 and Swi5-Swi2, each of which plays an important role in the related but functionally distinct processes of homologous recombination and mating-type switching, respectively. The Swi5-Sfr1 mediator complex has been shown to associate with the two RecA-like recombinases, Rhp51 (spRad51) and Dmc1, and to stimulate in vitro DNA strand exchange reactions mediated by these proteins. Genetic analysis indicates that Swi5-Sfr1 works independently of another mediator complex, Rhp55-Rhp57, during Rhp51-dependent recombinational repair. In addition, mutations affecting the two mediators generate distinct repair spectra of HO endonuclease-induced DNA double strand breaks, suggesting that these recombination mediators differently regulate recombination outcomes in an independent manner.
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Affiliation(s)
- Nami Haruta
- International Graduate School of Arts and Sciences, Yokohama City University, Tsurumi-ku, Yokohama 230-0045, Japan
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21
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Hope JC, Cruzata LD, Duvshani A, Mitsumoto J, Maftahi M, Freyer GA. Mus81-Eme1-dependent and -independent crossovers form in mitotic cells during double-strand break repair in Schizosaccharomyces pombe. Mol Cell Biol 2007; 27:3828-38. [PMID: 17353272 PMCID: PMC1900003 DOI: 10.1128/mcb.01596-06] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2006] [Revised: 09/18/2006] [Accepted: 03/02/2007] [Indexed: 11/20/2022] Open
Abstract
During meiosis, double-strand breaks (DSBs) lead to crossovers, thought to arise from the resolution of double Holliday junctions (HJs) by an HJ resolvase. In Schizosaccharomyces pombe, meiotic crossovers are produced primarily through a mechanism requiring the Mus81-Eme1 endonuclease complex. Less is known about the processes that produces crossovers during the repair of DSBs in mitotic cells. We employed an inducible DSB system to determine the role of Rqh1-Top3 and Mus81-Eme1 in mitotic DSB repair and crossover formation in S. pombe. In agreement with the meiotic data, crossovers are suppressed in cells lacking Mus81-Eme1. And relative to the wild type, rqh1Delta cells show a fourfold increase in crossover frequency. This suppression of crossover formation by Rqh1 is dependent on its helicase activity. We found that the synthetic lethality of cells lacking both Rqh1 and Eme1 is suppressed by loss of swi5(+), which allowed us to show that the excess crossovers formed in an rqh1Delta background are independent of Mus81-Eme1. This result suggests that a second process for crossover formation exists in S. pombe and is consistent with our finding that deletion of swi5(+) restored meiotic crossovers in eme1Delta cells. Evidence suggesting that Rqh1 also acts downstream of Swi5 in crossover formation was uncovered in these studies. Our results suggest that during Rhp51-dependent repair of DSBs, Rqh1-Top3 suppresses crossovers in the Rhp57-dependent pathway while Mus81-Eme1 and possibly Rqh1 promote crossovers in the Swi5-dependent pathway.
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Affiliation(s)
- Justin C Hope
- Graduate Program in Anatomy and Cell Biology, Columbia University, 722 W. 168th Street, New York, NY 10032, USA
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22
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Raji H, Hartsuiker E. Double-strand break repair and homologous recombination in Schizosaccharomyces pombe. Yeast 2007; 23:963-76. [PMID: 17072889 DOI: 10.1002/yea.1414] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The study of double-strand break repair and homologous recombination in Saccharomyces cerevisiae meiosis has provided important information about the mechanisms involved. However, it has become clear that the resulting recombination models are only partially applicable to repair in mitotic cells, where crossover formation is suppressed. In recent years our understanding of double-strand break repair and homologous recombination in Schizosaccharomyces pombe has increased significantly, and the identification of novel pathways and genes with homologues in higher eukaryotes has increased its value as a model organism for double-strand break repair. In this review we will focus on the involvement of homologous recombination and repair in different aspects of genome stability in Sz. pombe meiosis, replication and telomere maintenance. We will also discuss anti-recombination pathways (that suppress crossover formation), non-homologous end-joining, single-strand annealing and factors that influence the choice and prevalence of the different repair pathways in Sz. pombe.
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Affiliation(s)
- Hayatu Raji
- Genome Damage and Stability Centre, University of Sussex, Brighton BN1 9RQ, UK
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23
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Akamatsu Y, Tsutsui Y, Morishita T, Siddique MDSP, Kurokawa Y, Ikeguchi M, Yamao F, Arcangioli B, Iwasaki H. Fission yeast Swi5/Sfr1 and Rhp55/Rhp57 differentially regulate Rhp51-dependent recombination outcomes. EMBO J 2007; 26:1352-62. [PMID: 17304215 PMCID: PMC1817630 DOI: 10.1038/sj.emboj.7601582] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2006] [Accepted: 01/08/2007] [Indexed: 12/28/2022] Open
Abstract
Several accessory proteins referred to as mediators are required for the full activity of the Rad51 (Rhp51 in fission yeast) recombinase. In this study, we analyzed in vivo functions of the recently discovered Swi5/Sfr1 complex from fission yeast. In normally growing cells, the Swi5-GFP protein localizes to the nucleus, where it forms a diffuse nuclear staining pattern with a few distinct foci. These spontaneous foci do not form in swi2Delta mutants. Upon UV irradiation, Swi5 focus formation is induced in swi2Delta mutants, a response that depends on Sfr1 function, and Sfr1 also forms foci that colocalize with damage-induced Rhp51 foci. The number of UV-induced Rhp51 foci is partially reduced in swi5Delta and rhp57Delta mutants and completely abolished in an swi5Delta rhp57Delta double mutant. An assay for products generated by HO endonuclease-induced DNA double-strand breaks (DSBs) reveals that Rhp51 and Rhp57, but not Swi5/Sfr1, are essential for crossover production. These results suggest that Swi5/Sfr1 functions as an Rhp51 mediator but processes DSBs in a manner different from that of the Rhp55/57 mediator.
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Affiliation(s)
- Yufuko Akamatsu
- International Graduate School of Arts and Sciences, Yokohama City University, Yokohama, Kanagawa, Japan
| | - Yasuhiro Tsutsui
- Division of Mutagenesis, National Institute of Genetics, Mishima, Shizuoka, Japan
| | - Takashi Morishita
- International Graduate School of Arts and Sciences, Yokohama City University, Yokohama, Kanagawa, Japan
| | - MD Shahjahan P Siddique
- International Graduate School of Arts and Sciences, Yokohama City University, Yokohama, Kanagawa, Japan
| | - Yumiko Kurokawa
- International Graduate School of Arts and Sciences, Yokohama City University, Yokohama, Kanagawa, Japan
| | - Mitsunori Ikeguchi
- International Graduate School of Arts and Sciences, Yokohama City University, Yokohama, Kanagawa, Japan
| | - Fumiaki Yamao
- Division of Mutagenesis, National Institute of Genetics, Mishima, Shizuoka, Japan
| | - Benoit Arcangioli
- Departement de la Structure et Dynamique des Genomes, Institut Pasteur, Paris Cedex 15, France
| | - Hiroshi Iwasaki
- International Graduate School of Arts and Sciences, Yokohama City University, Yokohama, Kanagawa, Japan
- Division of Molecular and Cellular Biology, International Graduate School of Arts and Sciences, Yokohama City University, 1-7-29 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan. Tel.: +81 45 508 7238; Fax: +81 45 508 7269; E-mail:
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24
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Sultanova AN, Salakhova AF, Bashkirov VI, Khasanov FK. Cell phenotypes of a mutant in the gene encoding a Rad51 paralog in fission yeast. RUSS J GENET+ 2007. [DOI: 10.1134/s1022795407020056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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25
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Morishita T, Furukawa F, Sakaguchi C, Toda T, Carr AM, Iwasaki H, Shinagawa H. Role of the Schizosaccharomyces pombe F-Box DNA helicase in processing recombination intermediates. Mol Cell Biol 2005; 25:8074-83. [PMID: 16135799 PMCID: PMC1234317 DOI: 10.1128/mcb.25.18.8074-8083.2005] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In an effort to identify novel genes involved in recombination repair, we isolated fission yeast Schizosaccharomyces pombe mutants sensitive to methyl methanesulfonate (MMS) and a synthetic lethal with rad2. A gene that complements such mutations was isolated from the S. pombe genomic library, and subsequent analysis identified it as the fbh1 gene encoding the F-box DNA helicase, which is conserved in mammals but not conserved in Saccharomyces cerevisiae. An fbh1 deletion mutant is moderately sensitive to UV, MMS, and gamma rays. The rhp51 (RAD51 ortholog) mutation is epistatic to fbh1. fbh1 is essential for viability in stationary-phase cells and in the absence of either Srs2 or Rqh1 DNA helicase. In each case, lethality is suppressed by deletion of the recombination gene rhp57. These results suggested that fbh1 acts downstream of rhp51 and rhp57. Following UV irradiation or entry into the stationary phase, nuclear chromosomal domains of the fbh1Delta mutant shrank, and accumulation of some recombination intermediates was suggested by pulsed-field gel electrophoresis. Focus formation of Fbh1 protein was induced by treatment that damages DNA. Thus, the F-box DNA helicase appears to process toxic recombination intermediates, the formation of which is dependent on the function of Rhp51.
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Affiliation(s)
- Takashi Morishita
- Department of Molecular Microbiology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan
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26
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Osman F, Dixon J, Barr AR, Whitby MC. The F-Box DNA helicase Fbh1 prevents Rhp51-dependent recombination without mediator proteins. Mol Cell Biol 2005; 25:8084-96. [PMID: 16135800 PMCID: PMC1234329 DOI: 10.1128/mcb.25.18.8084-8096.2005] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
A key step in homologous recombination is the loading of Rad51 onto single-stranded DNA to form a nucleoprotein filament that promotes homologous DNA pairing and strand exchange. Mediator proteins, such as Rad52 and Rad55-Rad57, are thought to aid filament assembly by overcoming an inhibitory effect of the single-stranded-DNA-binding protein replication protein A. Here we show that mediator proteins are also required to enable fission yeast Rad51 (called Rhp51) to function in the presence of the F-box DNA helicase Fbh1. In particular, we show that the critical function of Rad22 (an orthologue of Rad52) in promoting Rhp51-dependent recombination and DNA repair can be mostly circumvented by deleting fbh1. Similarly, the reduced growth/viability and DNA damage sensitivity of an fbh1(-) mutant are variously suppressed by deletion of any one of the mediators Rad22, Rhp55, and Swi5. From these data we propose that Rhp51 action is controlled through an interplay between Fbh1 and the mediator proteins. Colocalization of Fbh1 with Rhp51 damage-induced foci suggests that this interplay occurs at the sites of nucleoprotein filament assembly. Furthermore, analysis of different fbh1 mutant alleles suggests that both the F-box and helicase activities of Fbh1 contribute to controlling Rhp51.
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Affiliation(s)
- Fekret Osman
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom
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27
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Sheedy DM, Dimitrova D, Rankin JK, Bass KL, Lee KM, Tapia-Alveal C, Harvey SH, Murray JM, O'Connell MJ. Brc1-mediated DNA repair and damage tolerance. Genetics 2005; 171:457-68. [PMID: 15972456 PMCID: PMC1456763 DOI: 10.1534/genetics.105.044966] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The structural maintenance of chromosome (SMC) proteins are key elements in controlling chromosome dynamics. In eukaryotic cells, three essential SMC complexes have been defined: cohesin, condensin, and the Smc5/6 complex. The latter is essential for DNA damage responses; in its absence both repair and checkpoint responses fail. In fission yeast, the UV-C and ionizing radiation (IR) sensitivity of a specific hypomorphic allele encoding the Smc6 subunit, rad18-74 (renamed smc6-74), is suppressed by mild overexpression of a six-BRCT-domain protein, Brc1. Deletion of brc1 does not result in a hypersensitivity to UV-C or IR, and thus the function of Brc1 relative to the Smc5/6 complex has remained unclear. Here we show that brc1Delta cells are hypersensitive to a range of radiomimetic drugs that share the feature of creating lesions that are an impediment to the completion of DNA replication. Through a genetic analysis of brc1Delta epistasis and by defining genes required for Brc1 to suppress smc6-74, we find that Brc1 functions to promote recombination through a novel postreplication repair pathway and the structure-specific nucleases Slx1 and Mus81. Activation of this pathway through overproduction of Brc1 bypasses a repair defect in smc6-74, reestablishing resolution of lesions by recombination.
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Affiliation(s)
- Daniel M Sheedy
- Department of Oncological Sciences, Mount Sinai School of Medicine, New York, NY 10029, USA
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28
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The dds20 + Gene Controls a Novel Rad51Sp-Dependent Pathway of Recombinational Repair in Schizosaccharomyces pombe. RUSS J GENET+ 2005. [DOI: 10.1007/s11177-005-0132-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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29
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Tsutsui Y, Morishita T, Natsume T, Yamashita K, Iwasaki H, Yamao F, Shinagawa H. Genetic and physical interactions between Schizosaccharomyces pombe Mcl1 and Rad2, Dna2 and DNA polymerase alpha: evidence for a multifunctional role of Mcl1 in DNA replication and repair. Curr Genet 2005; 48:34-43. [PMID: 15915339 DOI: 10.1007/s00294-005-0584-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2005] [Revised: 04/20/2005] [Accepted: 04/24/2005] [Indexed: 12/01/2022]
Abstract
Schizosaccharomyces pombe rad2 is involved in Okazaki fragments processing during lagging-strand DNA replication. Previous studies identified several slr mutants that are co-lethal with rad2Delta and sensitive to methyl methanesulfonate as single mutants. One of these mutants, slr3-1, is characterized here. Complementation and sequence analyses show that slr3-1 (mcl1-101) is allelic to mcl1(+), which is required for chromosome replication, cohesion and segregation. mcl1-101 is temperature-sensitive for growth and is highly sensitive to DNA damage. mcl1 cells arrest with 2C DNA content and chromosomal DNA double-strand breaks accumulate at the restrictive temperature. Mcl1p, which belongs to the Ctf4p/SepBp family, interacts both genetically and physically with DNA polymerase alpha. Mutations in rhp51 and dna2 enhance the growth defect of the mcl1-101 mutant. These results strongly suggest that Mcl1p is a functional homologue of Saccharomyces cerevisiae Ctf4p and plays a role in lagging-strand synthesis and Okazaki fragment processing, in addition to DNA repair.
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Affiliation(s)
- Yasuhiro Tsutsui
- Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan.
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30
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Khasanov FK, Salakhova AF, Chepurnaja OV, Korolev VG, Bashkirov VI. Identification and characterization of the rlp1+, the novel Rad51 paralog in the fission yeast Schizosaccharomyces pombe. DNA Repair (Amst) 2005; 3:1363-74. [PMID: 15336631 DOI: 10.1016/j.dnarep.2004.05.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2004] [Revised: 05/18/2004] [Accepted: 05/18/2004] [Indexed: 11/30/2022]
Abstract
A new DNA repair gene from fission yeast Schizosaccharomyces pombe rlp1+ (RecA-like protein) has been identified. Rlp1 shows homology to RecA-like proteins, and is the third S. pombe Rad51 paralog besides Rhp55 and Rhp57. The new gene encodes a 363 aa protein with predicted Mr of 41,700 and has NTP-binding motif. The rlp1Delta mutant is sensitive to methyl methanesulfonate (MMS), ionizing radiation (IR), and camptothecin (CPT), although to a lesser extent than the deletion mutants of rhp55+ and rhp51+ genes. In contrast to other recombinational repair mutants, the rlp1Delta mutant does not exhibit sensitivity to UV light and mitomycin C (MMC). Mitotic recombination is moderately reduced in rlp1 mutant. Epistatic analysis of MMS and IR-sensitivity of rlp1Delta mutant indicates that rlp1+ acts in the recombinational pathway of double-strand break (DSB) repair together with rhp51+, rhp55+, and rad22+ genes. Yeast two-hybrid analysis suggests that Rlp1 may interact with Rhp57 protein. We propose that Rlp1 have an accessory role in repair of a subset of DNA damage induced by MMS and IR, and is required for the full extent of DNA recombination and cell survival under condition of a replication fork collapse.
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Affiliation(s)
- Fuat K Khasanov
- Institute of Gene Biology, Russian Academy of Sciences, Molecular Biology of DNA Repair, Vavilov Street 34/5, 119334 Moscow, Russia
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31
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Hope JC, Maftahi M, Freyer GA. A postsynaptic role for Rhp55/57 that is responsible for cell death in Deltarqh1 mutants following replication arrest in Schizosaccharomyces pombe. Genetics 2005; 170:519-31. [PMID: 15802523 PMCID: PMC1450410 DOI: 10.1534/genetics.104.037598] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Following replication arrest, multiple cellular responses are triggered to maintain genomic integrity. In fission yeast, the RecQ helicase, Rqh1, plays a critical role in this process. This is demonstrated in Deltarqh1 cells that, following treatment with hydroxyurea (HU), undergo an aberrant mitosis leading to cell death. Previous data suggest that Rqh1 functions with homologous recombination (HR) in recovery from replication arrest. We have found that loss of the HR genes rhp55(+) or rhp57(+), but not rhp51(+) or rhp54(+), suppresses the HU sensitivity of Deltarqh1 cells. Much of this suppression requires Rhp51 and Rhp54. In addition, this suppression is partially dependent on swi5(+). In budding yeast, overexpressing Rad51 (the Rhp51 homolog) minimized the need for Rad55/57 (Rhp55/57) in nucleoprotein filament formation. We overexpressed Rhp51 in Schizosaccharomyces pombe and found that it greatly reduced the requirement for Rhp55/57 in recovery from DNA damage. However, overexpressing Rhp51 did not change the Deltarhp55 suppression of the HU sensitivity of Deltarqh1, supporting an Rhp55/57 function during HR independent of nucleoprotein filament formation. These results are consistent with Rqh1 playing a role late in HR following replication arrest and provide evidence for a postsynaptic function for Rhp55/57.
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Affiliation(s)
- Justin C Hope
- Graduate Program in Anatomy and Cell Biology, Department of Anatomy and Cell Biology, Columbia University, New York, NY 10032, USA
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32
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Morikawa H, Morishita T, Kawane S, Iwasaki H, Carr AM, Shinagawa H. Rad62 protein functionally and physically associates with the smc5/smc6 protein complex and is required for chromosome integrity and recombination repair in fission yeast. Mol Cell Biol 2004; 24:9401-13. [PMID: 15485909 PMCID: PMC522231 DOI: 10.1128/mcb.24.21.9401-9413.2004] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Smc5 and Smc6 proteins form a heterodimeric SMC (structural maintenance of chromosome) protein complex like SMC1-SMC3 cohesin and SMC2-SMC4 condensin, and they associate with non-SMC proteins Nse1 and Nse2 stably and Rad60 transiently. This multiprotein complex plays an essential role in maintaining chromosome integrity and repairing DNA double strand breaks (DSBs). This study characterizes a Schizosaccharomyces pombe mutant rad62-1, which is hypersensitive to methyl methanesulfonate (MMS) and synthetically lethal with rad2 (a feature of recombination mutants). rad62-1 is hypersensitive to UV and gamma rays, epistatic with rhp51, and defective in repair of DSBs. rad62 is essential for viability and genetically interacts with rad60, smc6, and brc1. Rad62 protein physically associates with the Smc5-6 complex. rad62-1 is synthetically lethal with mutations in the genes promoting recovery from stalled replication, such as rqh1, srs2, and mus81, and those involved in nucleotide excision repair like rad13 and rad16. These results suggest that Rad62, like Rad60, in conjunction with the Smc5-6 complex, plays an essential role in maintaining chromosome integrity and recovery from stalled replication by recombination.
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Affiliation(s)
- Hirofumi Morikawa
- Department of Molecular Microbiology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan
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33
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Ellermeier C, Schmidt H, Smith GR. Swi5 acts in meiotic DNA joint molecule formation in Schizosaccharomyces pombe. Genetics 2004; 168:1891-8. [PMID: 15466419 PMCID: PMC1448720 DOI: 10.1534/genetics.104.034280] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Previously isolated Schizosaccharomyces pombe swi5 mutants are defective in mitotic mating-type switching and in repair of meiotic recombination-related DNA double-strand breaks. Here, we identify the swi5 gene, which encodes an 85-amino-acid polypeptide, similar to Sae3 of Saccharomyces cerevisiae, with an N-terminal predicted coiled-coil domain. A swi5 complete deletion mutant had normal mitotic growth rate but was hypersensitive to DNA-damaging agents and defective in mating-type switching. In meiosis, recombinant frequencies were reduced by a factor of approximately 10. The swi5 deletion strongly reduced the viable spore yields of mutants lacking Rhp55 or Rhp57, proteins thought to aid joint molecule formation. Furthermore, the swi5 deletion strongly suppressed the low viable spore yield of mutants lacking Mus81*Eme1, which resolves joint molecules such as Holliday junctions. These and previous results indicate that the small Swi5 polypeptide acts in a branched pathway of joint molecule formation to repair meiotic DNA breaks.
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Affiliation(s)
- Chad Ellermeier
- Fred Hutchinson Research Cancer Center, Seattle, Washington 98109, USA
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34
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Ono Y, Tomita K, Matsuura A, Nakagawa T, Masukata H, Uritani M, Ushimaru T, Ueno M. A novel allele of fission yeast rad11 that causes defects in DNA repair and telomere length regulation. Nucleic Acids Res 2004; 31:7141-9. [PMID: 14654689 PMCID: PMC291861 DOI: 10.1093/nar/gkg917] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Replication protein A (RPA) is a heterotrimeric single-stranded DNA-binding protein involved in DNA replication, recombination and repair. In Saccharomyces cerevisiae, several mutants in the RFA1 gene encoding the large subunit of RPA have been isolated and one of the mutants with a missense allele, rfa1-D228Y, shows a synergistic reduction in telomere length when combined with a yku70 mutation. So far, only one mutant allele of the rad11(+) gene encoding the large subunit of RPA has been reported in Schizosaccharomyces pombe. To study the role of S.pombe RPA in DNA repair and possibly in telomere maintenance, we constructed a rad11-D223Y mutant, which corresponds to the S.cerevisiae rfa1-D228Y mutant. rad11-D223Y cells were methylmethane sulfonate, hydroxyurea, UV and gamma-ray sensitive, suggesting that rad11-D223Y cells have a defect in DNA repair activity. Unlike the S.cerevisiae rfa1-D228Y mutation, the rad11-D223Y mutation itself caused telomere shortening. Moreover, Rad11-Myc bound to telomere in a ChIP assay. These results strongly suggest that RPA is directly involved in telomere maintenance.
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Affiliation(s)
- Yuuki Ono
- Department of Chemistry, Shizuoka University, 836 OYA, Shizuoka 422-8529, Japan
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35
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Grishchuk AL, Kraehenbuehl R, Molnar M, Fleck O, Kohli J. Genetic and cytological characterization of the RecA-homologous proteins Rad51 and Dmc1 of Schizosaccharomyces pombe. Curr Genet 2004; 44:317-28. [PMID: 12955454 DOI: 10.1007/s00294-003-0439-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2003] [Revised: 07/27/2003] [Accepted: 07/29/2003] [Indexed: 10/26/2022]
Abstract
The Schizosaccharomyces pombe rad51(+) and dmc1(+) genes code for homologues of the Escherichia coli recombination protein RecA. Deletion of rad51(+) causes slow growth, retardation of cell division and a decrease in viability. rad51Delta cells have a defect in mating-type switching. The DNA modification at the mating-type locus required for mating-type switching contributes to slow growth in the rad51 mutant. Cell mating is reduced in crosses homozygous for rad51Delta. Ectopic expression of the dmc1(+) gene allowed us to demonstrate that the reduction in meiotic recombination in dmc1 mutants is not caused by a disturbance of rad24 expression from the dmc1- rad24 bicistronic RNA. We describe the functional defects of terminally epitope-tagged Dmc1 and Rad51 and discuss it in terms of protein interaction. Presumptive Rad51 and Dmc1 foci were detected on spreads of meiotic chromatin.
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Affiliation(s)
- Alexandra L Grishchuk
- Institute of Cell Biology, University of Bern, Baltzerstrasse 4, 3012 Bern, Switzerland
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36
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Akamatsu Y, Dziadkowiec D, Ikeguchi M, Shinagawa H, Iwasaki H. Two different Swi5-containing protein complexes are involved in mating-type switching and recombination repair in fission yeast. Proc Natl Acad Sci U S A 2003; 100:15770-5. [PMID: 14663140 PMCID: PMC307643 DOI: 10.1073/pnas.2632890100] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Homologous recombination is an important biological process that occurs in all organisms and facilitates genome rearrangements and repair of DNA double-strand breaks. Eukaryotic Rad51 proteins (Rad51sp or Rhp51 in fission yeast) are functional and structural homologs of bacterial RecA protein, an evolutionarily conserved protein that plays a key role in homologous pairing and strand exchange between homologous DNA molecules in vitro. Here we show that the fission yeast swi5+ gene, which was originally identified as a gene required for normal mating-type switching, encodes a protein conserved among eukaryotes and is involved in a previously uncharacterized Rhp51 (Rad51sp)-dependent recombination repair pathway that does not require the Rhp55/57 (Rad55/57sp) function. Protein interactions with both Swi5 and Rhp51 were found to be mediated by a domain common to Swi2 and Sfr1 (Swi five-dependent recombination repair protein 1, a previously uncharacterized protein with sequence similarity to the C-terminal part of Swi2). Genetic epistasis analyses suggest that the Swi5-Sfr1-Rhp51 interactions function specifically in DNA recombination repair, whereas the Swi5-Swi2-Rhp51 interactions may function, together with chromodomain protein Swi6 (HP1 homolog), in mating-type switching.
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Affiliation(s)
- Yufuko Akamatsu
- Graduate School of Integrated Science, Yokohama City University, 1-7-29, Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
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37
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Grishchuk AL, Kohli J. Five RecA-like Proteins of Schizosaccharomyces pombe Are Involved in Meiotic Recombination. Genetics 2003; 165:1031-43. [PMID: 14668362 PMCID: PMC1462848 DOI: 10.1093/genetics/165.3.1031] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
The genome of Schizosaccharomyces pombe contains five genes that code for proteins with sequence similarity to the Escherichia coli recombination protein RecA: rad51+, rhp55+, rhp57+, rlp1+, and dmc1+. We analyzed the effect of deletion of each of these genes on meiotic recombination and viability of spores. Meiotic recombination levels were different from wild type in all recA-related mutants in several genetic intervals, suggesting that all five RecA homologs of S. pombe are required for normal levels of meiotic recombination. Spore viability was reduced in rad51, rhp55, and rhp57 mutants, but not in rlp1 and dmc1. It is argued that reduction of crossover is not the only cause for the observed reduction of spore viability. Analysis of double and triple mutants revealed that Rad51 and Dmc1 play major and partially overlapping roles in meiotic recombination, while Rhp55, Rhp57, and Rlp1 play accessory roles. Remarkably, deletion of Rlp1 decreases the frequency of intergenic recombination (crossovers), but increases intragenic recombination (gene conversion). On the basis of our results, we present a model for the involvement of five RecA-like proteins of S. pombe in meiotic recombination and discuss their respective roles.
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Affiliation(s)
- A L Grishchuk
- Institute of Cell Biology, University of Bern, CH-3012 Bern, Switzerland
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38
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Ueno M, Nakazaki T, Akamatsu Y, Watanabe K, Tomita K, Lindsay HD, Shinagawa H, Iwasaki H. Molecular characterization of the Schizosaccharomyces pombe nbs1+ gene involved in DNA repair and telomere maintenance. Mol Cell Biol 2003; 23:6553-63. [PMID: 12944481 PMCID: PMC193704 DOI: 10.1128/mcb.23.18.6553-6563.2003] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The human MRN complex is a multisubunit nuclease that is composed of Mre11, Rad50, and Nbs1 and is involved in homologous recombination and DNA damage checkpoints. Mutations of the MRN genes cause genetic disorders such as Nijmegen breakage syndrome. Here we identified a Schizosaccharomyces pombe nbs1(+) homologue by screening for mutants with mutations that caused methyl methanesulfonate (MMS) sensitivity and were synthetically lethal with the rad2Delta mutation. Nbs1 physically interacts with the C-terminal half of Rad32, the Schizosaccharomyces pombe Mre11 homologue, in a yeast two-hybrid assay. nbs1 mutants showed sensitivities to gamma-rays, UV, MMS, and hydroxyurea and displayed telomere shortening similar to the characteristics of rad32 and rad50 mutants. nbs1, rad32, and rad50 mutant cells were elongated and exhibited abnormal nuclear morphology. These findings indicate that S. pombe Nbs1 forms a complex with Rad32-Rad50 and is required for homologous recombination repair, telomere length regulation, and the maintenance of chromatin structure. Amino acid sequence features and some characteristics of the DNA repair function suggest that the S. pombe Rad32-Rad50-Nbs1 complex has functional similarity to the corresponding MRN complexes of higher eukaryotes. Therefore, S. pombe Nbs1 will provide an additional model system for studying the molecular function of the MRN complex associated with genetic diseases.
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Affiliation(s)
- Masaru Ueno
- Department of Chemistry, Faculty of Science, Shizuoka University, 836 Oya, Shizuoka 422-8529, Japan.
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39
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Henry-Mowatt J, Jackson D, Masson JY, Johnson PA, Clements PM, Benson FE, Thompson LH, Takeda S, West SC, Caldecott KW. XRCC3 and Rad51 modulate replication fork progression on damaged vertebrate chromosomes. Mol Cell 2003; 11:1109-17. [PMID: 12718895 DOI: 10.1016/s1097-2765(03)00132-1] [Citation(s) in RCA: 128] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The mechanisms by which the progression of eukaryotic replication forks is controlled after DNA damage are unclear. We have found that fork progression is slowed by cisplatin or UV treatment in intact vertebrate cells and in replication assays in vitro. Fork slowing is reduced or absent in irs1SF CHO cells and XRCC3(-/-) chicken DT40 cells, indicating that fork slowing is an active process that requires the homologous recombination protein XRCC3. The addition of purified human Rad51C-XRCC3 complex restores fork slowing in permeabilized XRCC3(-/-) cells. Moreover, the requirement for XRCC3 for fork slowing can be circumvented by addition of human Rad51. These data demonstrate that the recombination proteins XRCC3 and Rad51 cooperatively modulate the progression of replication forks on damaged vertebrate chromosomes.
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Affiliation(s)
- Judith Henry-Mowatt
- School of Biological Sciences, University of Manchester, Stopford Building, Oxford Road, United Kingdom
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40
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Symington LS. Role of RAD52 epistasis group genes in homologous recombination and double-strand break repair. Microbiol Mol Biol Rev 2002; 66:630-70, table of contents. [PMID: 12456786 PMCID: PMC134659 DOI: 10.1128/mmbr.66.4.630-670.2002] [Citation(s) in RCA: 790] [Impact Index Per Article: 35.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The process of homologous recombination is a major DNA repair pathway that operates on DNA double-strand breaks, and possibly other kinds of DNA lesions, to promote error-free repair. Central to the process of homologous recombination are the RAD52 group genes (RAD50, RAD51, RAD52, RAD54, RDH54/TID1, RAD55, RAD57, RAD59, MRE11, and XRS2), most of which were identified by their requirement for the repair of ionizing-radiation-induced DNA damage in Saccharomyces cerevisiae. The Rad52 group proteins are highly conserved among eukaryotes, and Rad51, Mre11, and Rad50 are also conserved in prokaryotes and archaea. Recent studies showing defects in homologous recombination and double-strand break repair in several human cancer-prone syndromes have emphasized the importance of this repair pathway in maintaining genome integrity. Although sensitivity to ionizing radiation is a universal feature of rad52 group mutants, the mutants show considerable heterogeneity in different assays for recombinational repair of double-strand breaks and spontaneous mitotic recombination. Herein, I provide an overview of recent biochemical and structural analyses of the Rad52 group proteins and discuss how this information can be incorporated into genetic studies of recombination.
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Affiliation(s)
- Lorraine S Symington
- Department of Microbiology and Institute of Cancer Research, Columbia University College of Physicians and Surgeons, New York, New York 10032, USA.
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41
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Maftahi M, Hope JC, Delgado-Cruzata L, Han CS, Freyer GA. The severe slow growth of Deltasrs2 Deltarqh1 in Schizosaccharomyces pombe is suppressed by loss of recombination and checkpoint genes. Nucleic Acids Res 2002; 30:4781-92. [PMID: 12409469 PMCID: PMC135788 DOI: 10.1093/nar/gkf581] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Our interest in the Schizosaccharomyces pombe RecQ helicase, rqh1+, led us to investigate the function of a related putative DNA helicase, srs2+. We identified the srs2+ homolog in S.pombe, and found that srs2+ is not essential for cell viability. A Deltasrs2 Deltarqh1 double mutant grows extremely slowly with aberrant shaped cells and low viability. This slow growth does not appear to be related to stalled replication, as Deltasrs2 Deltarqh1 cells showed higher survival rates, compared with Deltarqh1, when stalled forks were increased by UV irradiation or hydroxy urea treatment. Consistent with this result, we found that Deltasrs2 Deltarqh1 cells progress through S-phase with a slight delay, but undergo a checkpoint-dependent arrest presumably at G2/M. Further, we found that Deltasrs2 Deltarqh1 slow growth is related to recombination, as loss of either the rhp51+ or rhp57+ recombination genes improves cell growth in the double mutant. Deltasrs2 is also synthetic lethal with Deltarhp54, another homologous recombination gene. This lethality is suppressed in a Deltarhp51 background. Together, these results demonstrate a clear genetic interaction between rqh1+, srs2+ and the genes of the homologous recombination pathway.
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Affiliation(s)
- Mohamed Maftahi
- Department of Environmental Health Sciences, Columbia University, Mailman School of Public Health and College of Physicians and Surgeons, Kolb Building, Room 114, 722 West 168th Street, New York, NY 10032, USA
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42
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Kim WJ, Park EJ, Lee H, Seong RH, Park SD. Physical interaction between recombinational proteins Rhp51 and Rad22 in Schizosaccharomyces pombe. J Biol Chem 2002; 277:30264-70. [PMID: 12050150 DOI: 10.1074/jbc.m202517200] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In eukaryotes, Rad51 and Rad52 are two key components of homologous recombination and recombinational repair. These two proteins interact with each other. Here we investigated the role of interaction between Rhp51 and Rad22, the fission yeast homologs of Rad51 and Rad52, respectively, on the function of each protein. We identified a direct association between the two proteins and their self-interactions both in vivo and in vitro. We also determined the binding domains of each protein that mediate these interactions. To characterize the role of Rhp51-Rad22 interaction, we used random mutagenesis to identify the mutants Rhp51 and Rad22, which cannot interact each other. Interestingly, we found that mutant Rhp51 protein, which cannot interact with either Rad22 or Rti1 (G282D), lost its DNA repair ability. In contrast, mutant Rad22 proteins, which cannot specifically bind to Rhp51 (S379L and P381L), maintained their DNA repair ability. These results suggest that the interaction between Rhp51 and Rad22 is crucial for the recombinational repair function of Rhp51. However, the significance of this interaction on the function of Rad22 remains to be characterized further.
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Affiliation(s)
- Woo Jae Kim
- School of Biological Sciences and Institute for Molecular Biology and Genetics, Seoul National University, Seoul 151-742, Republic of Korea
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43
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van den Bosch M, Lohman PHM, Pastink A. DNA double-strand break repair by homologous recombination. Biol Chem 2002; 383:873-92. [PMID: 12222678 DOI: 10.1515/bc.2002.095] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The induction of double-strand breaks (DSBs) in DNA by exposure to DNA damaging agents, or as intermediates in normal cellular processes, constitutes a severe threat for the integrity of the genome. If not properly repaired, DSBs may result in chromosomal aberrations, which, in turn, can lead to cell death or to uncontrolled cell growth. To maintain the integrity of the genome, multiple pathways for the repair of DSBs have evolved during evolution: homologous recombination (HR), non-homologous end joining (NHEJ) and single-strand annealing (SSA). HR has the potential to lead to accurate repair of DSBs, whereas NHEJ and SSA are essentially mutagenic. In yeast, DSBs are primarily repaired via high-fidelity repair of DSBs mediated by HR, whereas in higher eukaryotes, both HR and NHEJ are important. In this review, we focus on the functional conservation of HR from fungi to mammals and on the role of the individual proteins in this process.
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Affiliation(s)
- Michael van den Bosch
- Department of Radiation Genetics and Chemical Mutagenesis, Leiden University Medical Center, The Netherlands
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44
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Morishita T, Tsutsui Y, Iwasaki H, Shinagawa H. The Schizosaccharomyces pombe rad60 gene is essential for repairing double-strand DNA breaks spontaneously occurring during replication and induced by DNA-damaging agents. Mol Cell Biol 2002; 22:3537-48. [PMID: 11971984 PMCID: PMC133806 DOI: 10.1128/mcb.22.10.3537-3548.2002] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
To identify novel genes involved in DNA double-strand break (DSB) repair, we previously isolated Schizosaccharomyces pombe mutants which are hypersensitive to methyl methanesulfonate (MMS) and synthetic lethals with rad2. This study characterizes one of these mutants, rad60-1. The gene that complements the MMS sensitivity of this mutant was cloned and designated rad60. rad60 encodes a protein with 406 amino acids which has the conserved ubiquitin-2 motif found in ubiquitin family proteins. rad60-1 is hypersensitive to UV and gamma rays, epistatic to rhp51, and defective in the repair of DSBs caused by gamma-irradiation. The rad60-1 mutant is also temperature sensitive for growth. At the restrictive temperature (37 degrees C), rad60-1 cells grow for several divisions and then arrest with 2C DNA content; the arrested cells accumulate DSBs and have a diffuse and often aberrantly shaped nuclear chromosomal domain. The rad60-1 mutant is a synthetic lethal with rad18-X, and expression of wild-type rad60 from a multicopy plasmid partially suppresses the MMS sensitivity of rad18-X cells. rad18 encodes a conserved protein of the structural maintenance of chromosomes (SMC) family (A. R. Lehmann, M. Walicka, D. J. Griffiths, J. M. Murray, F. Z. Watts, S. McCready, and A. M. Carr, Mol. Cell. Biol. 15:7067-7080, 1995). These results suggest that S. pombe Rad60 is required to repair DSBs, which accumulate during replication, by recombination between sister chromatids. Rad60 may perform this function in concert with the SMC protein Rad18.
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Affiliation(s)
- Takashi Morishita
- Department of Molecular Microbiology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan
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45
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Masson JY, Tarsounas MC, Stasiak AZ, Stasiak A, Shah R, McIlwraith MJ, Benson FE, West SC. Identification and purification of two distinct complexes containing the five RAD51 paralogs. Genes Dev 2001; 15:3296-307. [PMID: 11751635 PMCID: PMC312846 DOI: 10.1101/gad.947001] [Citation(s) in RCA: 285] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2001] [Accepted: 10/31/2001] [Indexed: 12/29/2022]
Abstract
Cells defective in any of the RAD51 paralogs (RAD51B, RAD51C, RAD51D, XRCC2, and XRCC3) are sensitive to DNA cross-linking agents and to ionizing radiation. Because the paralogs are required for the assembly of DNA damage-induced RAD51 foci, and mutant cell lines are defective in homologous recombination and show genomic instability, their defect is thought to be caused by an inability to promote efficient recombinational repair. Here, we show that the five paralogs exist in two distinct complexes in human cells: one contains RAD51B, RAD51C, RAD51D, and XRCC2 (defined as BCDX2), whereas the other consists of RAD51C with XRCC3. Both protein complexes have been purified to homogeneity and their biochemical properties investigated. BCDX2 binds single-stranded DNA and single-stranded gaps in duplex DNA, in accord with the proposal that the paralogs play an early (pre-RAD51) role in recombinational repair. Moreover, BCDX2 complex binds specifically to nicks in duplex DNA. We suggest that the extreme sensitivity of paralog-defective cell lines to cross-linking agents is owing to defects in the processing of incised cross links and the consequential failure to initiate recombinational repair at these sites.
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Affiliation(s)
- J Y Masson
- Imperial Cancer Research Fund, Clare Hall Laboratories, South Mimms, Hertfordshire EN6 3LD, UK
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46
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Tsutsui Y, Khasanov FK, Shinagawa H, Iwasaki H, Bashkirov VI. Multiple interactions among the components of the recombinational DNA repair system in Schizosaccharomyces pombe. Genetics 2001; 159:91-105. [PMID: 11560889 PMCID: PMC1461803 DOI: 10.1093/genetics/159.1.91] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Schizosaccharomyces pombe Rhp55 and Rhp57 are RecA-like proteins involved in double-strand break (DSB) repair. Here we demonstrate that Rhp55 and Rhp57 proteins strongly interact in vivo, similar to Saccharomyces cerevisiae Rad55p and Rad57p. Mutations in the conserved ATP-binding/hydrolysis folds of both the Rhp55 and Rhp57 proteins impaired their function in DNA repair but not in cell proliferation. However, when combined, ATPase fold mutations in Rhp55p and Rhp57p resulted in severe defects of both functions, characteristic of the deletion mutants. Yeast two-hybrid analysis also revealed other multiple in vivo interactions among S. pombe proteins involved in recombinational DNA repair. Similar to S. cerevisiae Rad51p-Rad54p, S. pombe Rhp51p and Rhp54p were found to interact. Both putative Rad52 homologs in S. pombe, Rad22p and Rti1p, were found to interact with the C-terminal region of Rhp51 protein. Moreover, Rad22p and Rti1p exhibited mutual, as well as self-, interactions. In contrast to the S. cerevisiae interacting pair Rad51p-Rad55p, S. pombe Rhp51 protein strongly interacted with Rhp57 but not with Rhp55 protein. In addition, the Rti1 and Rad22 proteins were found to form a complex with the large subunit of S. pombe RPA. Our data provide compelling evidence that most, but not all, of the protein-protein interactions found in S. cerevisiae DSB repair are evolutionarily conserved.
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Affiliation(s)
- Y Tsutsui
- Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan
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47
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Abstract
The induction of double-strand breaks (DSBs) in DNA by exposure to DNA damaging agents or as intermediates in normal cellular processes, creates a severe threat for the integrity of the genome. Unrepaired or incorrectly repaired DSBs lead to broken chromosomes and/or gross chromosomal rearrangements which are frequently associated with tumor formation in mammals. To maintain the integrity of the genome and to prevent the formation of chromosomal aberrations, several pathways exist in eukaryotes: homologous recombination (HR), non-homologous end joining (NHEJ) and single-strand annealing (SSA). These mechanisms are conserved in evolution, but the relative contribution depends on the organism, cell type and stage of the cell cycle. In yeast, DSBs are primarily repaired via HR while in higher eukaryotes, both HR and NHEJ are important. In mammals, defects in both HR or NHEJ lead to a predisposition to cancer and at the cellular level, the frequency of chromosomal aberrations is increased. This review summarizes our current knowledge about DSB-repair with emphasis on recent progress in understanding the precise biochemical activities of individual proteins involved.
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Affiliation(s)
- A Pastink
- Sylvius Laboratory, Department of Radiation Genetics and Chemical Mutagenesis, Wassenaarseweg 72, 2333 AL Leiden, The Netherlands.
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48
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Gasior SL, Olivares H, Ear U, Hari DM, Weichselbaum R, Bishop DK. Assembly of RecA-like recombinases: distinct roles for mediator proteins in mitosis and meiosis. Proc Natl Acad Sci U S A 2001; 98:8411-8. [PMID: 11459983 PMCID: PMC37451 DOI: 10.1073/pnas.121046198] [Citation(s) in RCA: 132] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Members of the RecA family of recombinases from bacteriophage T4, Escherichia coli, yeast, and higher eukaryotes function in recombination as higher-order oligomers assembled on tracts of single-strand DNA (ssDNA). Biochemical studies have shown that assembly of recombinase involves accessory factors. These studies have identified a class of proteins, called recombination mediator proteins, that act by promoting assembly of recombinase on ssDNA tracts that are bound by ssDNA-binding protein (ssb). In the absence of mediators, ssb inhibits recombination reactions by competing with recombinase for DNA-binding sites. Here we briefly review mediated recombinase assembly and present results of new in vivo experiments. Immuno-double-staining experiments in Saccharomyces cerevisiae suggest that Rad51, the eukaryotic recombinase, can assemble at or near sites containing ssb (replication protein A, RPA) during the response to DNA damage, consistent with a need for mediator activity. Correspondingly, mediator gene mutants display defects in Rad51 assembly after DNA damage and during meiosis, although the requirements for assembly are distinct in the two cases. In meiosis, both Rad52 and Rad55/57 are required, whereas either Rad52 or Rad55/57 is sufficient to promote assembly of Rad51 in irradiated mitotic cells. Rad52 promotes normal amounts of Rad51 assembly in the absence of Rad55 at 30 degrees C but not 20 degrees C, accounting for the cold sensitivity of rad55 null mutants. Finally, we show that assembly of Rad51 is induced by radiation during S phase but not during G(1), consistent with the role of Rad51 in repairing the spontaneous damage that occurs during DNA replication.
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Affiliation(s)
- S L Gasior
- Department of Radiation and Cellular Oncology, University of Chicago, Chicago, IL 60637, USA
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49
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Masson JY, Stasiak AZ, Stasiak A, Benson FE, West SC. Complex formation by the human RAD51C and XRCC3 recombination repair proteins. Proc Natl Acad Sci U S A 2001; 98:8440-6. [PMID: 11459987 PMCID: PMC37455 DOI: 10.1073/pnas.111005698] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
In vertebrates, the RAD51 protein is required for genetic recombination, DNA repair, and cellular proliferation. Five paralogs of RAD51, known as RAD51B, RAD51C, RAD51D, XRCC2, and XRCC3, have been identified and also shown to be required for recombination and genome stability. At the present time, however, very little is known about their biochemical properties or precise biological functions. As a first step toward understanding the roles of the RAD51 paralogs in recombination, the human RAD51C and XRCC3 proteins were overexpressed and purified from baculovirus-infected insect cells. The two proteins copurify as a complex, a property that reflects their endogenous association observed in HeLa cells. Purified RAD51C--XRCC3 complex binds single-stranded, but not duplex DNA, to form protein--DNA networks that have been visualized by electron microscopy.
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Affiliation(s)
- J Y Masson
- Imperial Cancer Research Fund, Clare Hall Laboratories, South Mimms, Hertfordshire EN6 3LD, United Kingdom
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50
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Kurumizaka H, Ikawa S, Nakada M, Eda K, Kagawa W, Takata M, Takeda S, Yokoyama S, Shibata T. Homologous-pairing activity of the human DNA-repair proteins Xrcc3.Rad51C. Proc Natl Acad Sci U S A 2001; 98:5538-43. [PMID: 11331762 PMCID: PMC33248 DOI: 10.1073/pnas.091603098] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The human Xrcc3 protein is involved in the repair of damaged DNA through homologous recombination, in which homologous pairing is a key step. The Rad51 protein is believed to be the only protein factor that promotes homologous pairing in recombinational DNA repair in mitotic cells. In the brain, however, Rad51 expression is extremely low, whereas XRCC3, a human homologue of Saccharomyces cerevisiae RAD57 that activates the Rad51-dependent homologous pairing with the yeast Rad55 protein, is expressed. In this study, a two-hybrid analysis conducted with the use of a human brain cDNA library revealed that the major Xrcc3-interacting protein is a Rad51 paralog, Rad51C/Rad51L2. The purified Xrcc3.Rad51C complex, which shows apparent 1:1 stoichiometry, was found to catalyze the homologous pairing. Although the activity is reduced, the Rad51C protein alone also catalyzed homologous pairing, suggesting that Rad51C is a catalytic subunit for homologous pairing. The DNA-binding activity of Xrcc3.Rad51C was drastically decreased in the absence of Xrcc3, indicating that Xrcc3 is important for the DNA binding of Xrcc3.Rad51C. Electron microscopic observations revealed that Xrcc3.Rad51C and Rad51C formed similar filamentous structures with circular single-stranded DNA.
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Affiliation(s)
- H Kurumizaka
- Genomic Sciences Center, RIKEN, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama-shi, Kanagawa 230-0045, Japan
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