RAB22 AND RAB163 MOUSE BRCA2 - PROTEINS THAT SPECIFICALLY INTERACT WITH THE RAD51 PROTEIN/

The human RAD51 protein is a homologue of the bacteria RecA and yeast RAD51 proteins that are involved in homologous recombination and DNA r epair, RAD51 interacts with proteins involved in recombination and als o with tumor suppressor proteins p53 and breast cancer susceptibility gene 1 (BRCA1), We have used the yeast two-hybrid system to clone muri ne cDNA sequences that encode two RAD51-associated molecules, RAB22 an d RAB163. RAB163 encodes the C-terminal portion of mouse BRCA2, the ho mologue of the second breast cancer susceptibility gene protein in hum ans, demonstrating an in vitro association between RAD51 and BRCA2, RA B22 is a novel gene product that also interacts with RAD51 bl vitro, T o detect RAD51 interactions in vivo, we developed a transient nuclear focus assay that was used to demonstrate a complete colocalization of RAB22 with RAD51 in large nuclear foci.