Identification and characterization of the rlp1 super(+), the novel Rad51 paralog in the fission yeast Schizosaccharomyces pombe

• Published in: DNA repair 2004-10, Vol.3 (10), p.1363-1374
• Main Authors: Khasanov, F K, Salakhova, A F, Chepurnaja, O V, Korolev, V G, Bashkirov, VI
• Format: Article
• Language: English
• Subjects: Schizosaccharomyces pombe; Yeasts
• ISSN: 1568-7864
• DOI: 10.1016/j.dnarep.2004.05.010

A new DNA repair gene from fission yeast Schizosaccharomyces pombe rlp1 super(+) (RecA-like protein) has been identified. Rlp1 shows homology to RecA-like proteins, and is the third S. pombe Rad51 paralog besides Rhp55 and Rhp57. The new gene encodes a 363 aa protein with predicted Mr of 41,700 and has NTP-binding motif. The rlp1 Delta mutant is sensitive to methyl methanesulfonate (MMS), ionizing radiation (IR), and camptothecin (CPT), although to a lesser extent than the deletion mutants of rhp55 super(+) and rhp51 super(+) genes. In contrast to other recombinational repair mutants, the rlp1 Delta mutant does not exhibit sensitivity to UV light and mitomycin C (MMC). Mitotic recombination is moderately reduced in rlp1 mutant. Epistatic analysis of MMS and IR-sensitivity of rlp1 Delta mutant indicates that rlp1 super(+) acts in the recombinational pathway of double-strand break (DSB) repair together with rhp51 super(+), rhp55 super(+), and rad22 super(+) genes. Yeast two-hybrid analysis suggests that Rlp1 may interact with Rhp57 protein. We propose that Rlp1 have an accessory role in repair of a subset of DNA damage induced by MMS and IR, and is required for the full extent of DNA recombination and cell survival under condition of a replication fork collapse.