DNA repair by a Rad22-Mus81-dependent pathway that is independent of Rhp51.

Journal article

In budding yeast most Rad51-dependent and -independent recombination depends on Rad52. In contrast, its homologue in fission yeast, Rad22, was assumed to play a less critical role possibly due to functional redundancy with another Rad52-like protein Rti1. We show here that this is not the case. Rad22 like Rad52 plays a central role in recombination being required for both Rhp51-dependent and -independent events. Having established this we proceed to investigate the involvement of the Mus81-Eme1 endonuclease in these pathways. Mus81 plays a relatively minor role in the Rhp51-dependent repair of DNA damage induced by ultraviolet light. In contrast Mus81 has a key role in the Rad22-dependent (Rhp51-independent) repair of damage induced by camptothecin, hydroxyurea and methyl-methanesulfonate. Furthermore, spontaneous intrachromosomal recombination that gives rise to deletion recombinants is impaired in a mus81 mutant. From these data we propose that a Rad22-Mus81-dependent (Rhp51-independent) pathway is an important mechanism for the repair of DNA damage in fission yeast. Consistent with this we show that in vitro Rad22 can promote strand invasion to form a D-loop that can be cleaved by Mus81.

Authors: Doe, C; Osman, F; Dixon, J; Whitby, M

• Publication status: Published
• Journal: Nucleic acids research
• Volume: 32
• Issue: 18
• Pages: 5570-5581
• Publication date: 2004-01-01
• DOI: 10.1093/nar/gkh853
• EISSN: 1362-4962
• ISSN: 0305-1048
• Language: English
• Keywords: Endonucleases; Models, Genetic; DNA, Fungal; Saccharomyces cerevisiae Proteins; DNA-Binding Proteins; Rad51 Recombinase; Repetitive Sequences, Nucleic Acid; Recombination, Genetic; Schizosaccharomyces; Schizosaccharomyces pombe Proteins; Mutation; Nucleic Acid Conformation; DNA Repair