Physical Interaction between Recombinational Proteins Rhp51 and Rad22 in Schizosaccharomyces pombe

• Published in: The Journal of biological chemistry Vol. 277; no. 33; pp. 30264 - 30270
• Main Authors: Kim, Woo Jae, Park, Eon Joo, Lee, Hyojin, Seong, Rho Hyun, Park, Sang Dai
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 16-08-2002; American Society for Biochemistry and Molecular Biology
• Subjects: Amino Acid Sequence; DNA Repair; DNA-Binding Proteins; Fungal Proteins - chemistry; Fungal Proteins - genetics; Fungal Proteins - metabolism; Molecular Sequence Data; Mutation; Protein Binding; Rad51 Recombinase; Recombination, Genetic; Schizosaccharomyces - metabolism; Schizosaccharomyces pombe Proteins; Sequence Homology, Amino Acid; Two-Hybrid System Techniques
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M202517200

In eukaryotes, Rad51 and Rad52 are two key components of homologous recombination and recombinational repair. These two proteins interact with each other. Here we investigated the role of interaction between Rhp51 and Rad22, the fission yeast homologs of Rad51 and Rad52, respectively, on the function of each protein. We identified a direct association between the two proteins and their self-interactions both in vivo and in vitro. We also determined the binding domains of each protein that mediate these interactions. To characterize the role of Rhp51-Rad22 interaction, we used random mutagenesis to identify the mutants Rhp51 and Rad22, which cannot interact each other. Interestingly, we found that mutant Rhp51 protein, which cannot interact with either Rad22 or Rti1 (G282D), lost its DNA repair ability. In contrast, mutant Rad22 proteins, which cannot specifically bind to Rhp51 (S379L and P381L), maintained their DNA repair ability. These results suggest that the interaction between Rhp51 and Rad22 is crucial for the recombinational repair function of Rhp51. However, the significance of this interaction on the function of Rad22 remains to be characterized further.