title: Multiple interactions among the components of the recombinational DNA repair system in Schizosaccharomyces pombe.
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.
authors.affiliation: Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Tsutsui
authors.forename: F K
authors.initials: FK
authors.lastname: Khasanov
authors.forename: H
authors.initials: H
authors.lastname: Shinagawa
authors.forename: H
authors.initials: H
authors.lastname: Iwasaki
authors.forename: V I
authors.initials: VI
authors.lastname: Bashkirov
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics* / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000483:Alleles; D000818:Animals; D002875:Chromosomes / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D004265:DNA Helicases / Q000378:metabolism; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D019281:Dimerization; D019143:Evolution, Molecular; D005656:Fungal Proteins / Q000378:metabolism; D017353:Gene Deletion; D006868:Hydrolysis; D008741:Methyl Methanesulfonate; D051379:Mice; D008954:Models, Biological; D009153:Mutagens; D009154:Mutation; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D011485:Protein Binding; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D011817:Rabbits; D051135:Rad51 Recombinase; D011995:Recombination, Genetic; D012568:Schizosaccharomyces / Q000235:genetics*; D029702:Schizosaccharomyces pombe Proteins; D020798:Two-Hybrid System Techniques
chemical_list: D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D009153:Mutagens; C084232:RHP51 protein, S pombe; C121634:RHP55 protein, S pombe; D029702:Schizosaccharomyces pombe Proteins; D000255:Adenosine Triphosphate; D004247:DNA; D008741:Methyl Methanesulfonate; D051135:Rad51 Recombinase; D000251:Adenosine Triphosphatases; C442472:Rhp57 protein, S pombe; D004265:DNA Helicases; C099034:Rhp54 protein, S pombe