title: Involvement of Schizosaccharomyces pombe rrp1+ and rrp2+ in the Srs2- and Swi5/Sfr1-dependent pathway in response to DNA damage and replication inhibition.
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.
authors.affiliation: 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.
authors.forename: Dorota
authors.initials: D
authors.lastname: Dziadkowiec
authors.forename: Karol
authors.initials: K
authors.lastname: Kramarz
authors.forename: Karolina
authors.initials: K
authors.lastname: Kanik
authors.forename: Piotr
authors.initials: P
authors.lastname: Wisniewski
authors.forename: Antony M
authors.initials: AM
authors.lastname: Carr
mesh_terms: D004249:DNA Damage; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism*; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D017353:Gene Deletion; D051135:Rad51 Recombinase / Q000502:physiology; D059767:Recombinational DNA Repair; D025842:SUMO-1 Protein / Q000378:metabolism; D012568:Schizosaccharomyces / Q000235:genetics / Q000378:metabolism; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D015398:Signal Transduction; D058207:Sumoylation
chemical_list: D004268:DNA-Binding Proteins; C084232:RHP51 protein, S pombe; C542111:Rrp1 protein, S pombe; C542112:Rrp2 protein, S pombe; D025842:SUMO-1 Protein; D029702:Schizosaccharomyces pombe Proteins; C514357:Sfr1 protein, S pombe; C483769:Swi5 protein, S pombe; D051135:Rad51 Recombinase; D004265:DNA Helicases; C106462:Rqh1 protein, S pombe; C468289:Srs2 protein, S pombe