Disease relevance of rhp51

• Rhp51 K155A, which has a single substitution in this motif, failed to rescue hypersensitivity of a rhp51 mutant to methyl methanesulfonate (MMS) and UV, whereas it binds normally to Rhp51 and Rad22, a Rad52 homolog [1].

High impact information on rhp51

• Rhp55 was required for interchromosomal gene conversion; however, an alternative DSB repair mechanism was used in an rhp55Delta background involving ku70(+) and rhp51(+) [2].
• Furthermore, the lethality of a rad60-1 rqh1Delta double mutant was suppressed by the deletion of rhp51 or rhp57 [3].
• The deletion of rhp51 suppressed the aberrant mitosis of rad60-1 cells and caused mitotic arrest [3].
• The gene that complements the MMS sensitivity of this mutant was cloned and designated rad60. rad60 encodes a protein with 406 amino acids which has the conserved ubiquitin-2 motif found in ubiquitin family proteins. rad60-1 is hypersensitive to UV and gamma rays, epistatic to rhp51, and defective in the repair of DSBs caused by gamma-irradiation [4].
• The MMS sensitivity was more severe at lower temperature and was suppressed by the presence of a multicopy plasmid bearing the rhp51 gene [5].

Biological context of rhp51

• Moreover, pku80 rhp51 double mutants showed a significantly reduced telomere hybridization signal [6].
• Mutations in genes involved in nucleotide excision repair (rad13) and recombinational repair (rhp51) are much more alkylation sensitive than mag1 mutants [7].
• On the other hand, overexpression of Rhp51 K155A led to a delay in G(2) with decondensed nuclei, which resembled the phenotype of rhp51 [1].
• Regulation of DNA damage inducible rhp51+ gene, a rec A homolog from Schizosaccharomyces pombe [8].

References