Multiple Interactions Among the Components of the Recombinational DNA Repair System in Schizosaccharomyces pombe

Corresponding author: Vladimir I. Bashkirov, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., Moscow 117334, Russia., vibashkirov{at}mail.ru (E-mail)

Communicating editor: L. S. SYMINGTON

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.

This article has been cited by other articles:

				T. Morishita, F. Furukawa, C. Sakaguchi, T. Toda, A. M. Carr, H. Iwasaki, and H. Shinagawa Role of the Schizosaccharomyces pombe F-Box DNA Helicase in Processing Recombination Intermediates Mol. Cell. Biol., September 15, 2005; 25(18): 8074 - 8083. [Abstract] [Full Text] [PDF]

				F. Osman, J. Dixon, A. R. Barr, and M. C. Whitby The F-Box DNA Helicase Fbh1 Prevents Rhp51-Dependent Recombination without Mediator Proteins Mol. Cell. Biol., September 15, 2005; 25(18): 8084 - 8096. [Abstract] [Full Text] [PDF]

				C. L. Doe, F. Osman, J. Dixon, and M. C. Whitby DNA repair by a Rad22-Mus81-dependent pathway that is independent of Rhp51 Nucleic Acids Res., October 14, 2004; 32(18): 5570 - 5581. [Abstract] [Full Text] [PDF]

				Y. Akamatsu, D. Dziadkowiec, M. Ikeguchi, H. Shinagawa, and H. Iwasaki Two different Swi5-containing protein complexes are involved in mating-type switching and recombination repair in fission yeast PNAS, December 23, 2003; 100(26): 15770 - 15775. [Abstract] [Full Text] [PDF]

				A. L. Grishchuk and J. Kohli Five RecA-like Proteins of Schizosaccharomyces pombe Are Involved in Meiotic Recombination Genetics, November 1, 2003; 165(3): 1031 - 1043. [Abstract] [Full Text] [PDF]

				M. G. Catlett and S. L. Forsburg Schizosaccharomyces pombe Rdh54 (TID1) Acts with Rhp54 (RAD54) to Repair Meiotic Double-Strand Breaks Mol. Biol. Cell, November 1, 2003; 14(11): 4707 - 4720. [Abstract] [Full Text] [PDF]

				P. Meister, M. Poidevin, S. Francesconi, I. Tratner, P. Zarzov, and G. Baldacci Nuclear factories for signalling and repairing DNA double strand breaks in living fission yeast Nucleic Acids Res., September 1, 2003; 31(17): 5064 - 5073. [Abstract] [Full Text] [PDF]

				L. S. Symington Role of RAD52 Epistasis Group Genes in Homologous Recombination and Double-Strand Break Repair Microbiol. Mol. Biol. Rev., December 1, 2002; 66(4): 630 - 670. [Abstract] [Full Text] [PDF]

				W. J. Kim, E. J. Park, H. Lee, R. H. Seong, and S. D. Park Physical Interaction between Recombinational Proteins Rhp51 and Rad22 in Schizosaccharomyces pombe J. Biol. Chem., August 9, 2002; 277(33): 30264 - 30270. [Abstract] [Full Text] [PDF]