Genetic analysis reveals different roles of Schizosaccharomyces pombe sfr1/dds20 in meiotic and mitotic DNA recombination and repair
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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. sfr1Δ 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 sfr1Δ 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.
KeywordsDNA repair Recombination UV tolerance S. pombe
We are grateful to C. Norbury, M. J. O’Connell, P. Russell, G. Smith, H. Shinagawa, K. Shiozaki, S. Waddell, E. Hartsuiker and S. Yasuhira for strains; and to W.-D. Heyer and K. Ehmsen for helpful comments on the manuscript. This work was supported by research grants from Swiss National Science Foundation to J.K., and Swiss SCOPES grants 7SUPJ062355 and IB73AO-110965, International Research Scholar’s grant 55000299 from the Howard Hughes Medical Institute to V.I.B. and research grant 06-04-48470 from the Russian Fund for Basic Research to F.K.K.
- Gutz H, Heslot H, Leupold U, Loprieno N (1974) Schizosaccharomyces pombe. In: King RC (ed) Handbook of genetics. Plenum Press, New York, pp 395–446Google Scholar
- Morikawa H, Morishita T, Kawane S, Iwasaki H, Carr AM, Shinagawa H (2004) 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 24:9401–9413PubMedCrossRefGoogle Scholar
- Savitsky K, Bar-Shira A, Gilad S, Rotman G, Ziv Y, Vanagaite L, Tagle DA, Smith S, Uziel T, Sfez S, Ashkenazi M, Pecker I, Frydman M, Harnik R, Patanjali SR, Simmons A, Clines GA, Sartiel A, Gatti RA, Chessa L, Sanal O, Lavin MF, Jaspers NGJ, Malcom A, Taylor R, Arlett CF, Miki T, Weissman SM, Lovett M, Collins FS, Shiloh Y (1995) A single Ataxia Telangiectasia gene with a product similar to PI-3 kinase. Science 268:1749–1753PubMedCrossRefGoogle Scholar
- Tomita K, Matsuura A, Caspari T, Carr AM, Akamatsu Y, Iwasaki H, Mizuno K, Ohta K, Uritani M, Ushimaru T, Yoshinaga K, Ueno M (2003) Competition between the Rad50 complex and the Ku heterodimer reveals a role for Exo1 in processing double-strand breaks but not telomeres. Mol Cell Biol 23:5186–5197PubMedCrossRefGoogle Scholar