Functional Analysis of the recombination protein RAD51 and its associated molecules.

1999 Fiscal Year Final Research Report Summary

• Project/Area Number: 10680657
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Molecular biology
• Research Institution: Science University of Tokyo
• Principal Investigator: MIZUTA Ryushin Research Institute for Biological Science, assistant professor, 生命科学研究所, 講師 (50297628)
• Project Period (FY): 1998 – 1999
• Keywords: Recombination / RAD51 / RAB22 / XRCC4

Research Abstract

The human RAD51 protein is a homologue of the bacteria RecA and yeast RAD51 protein, both of them are involved in homologous recombination and DNA repair, and physically interacts with BRCA1 protein. However, it is not clear what kind of functions mammalian RAD51 protein has, where is the functional domain and how many factors are involved in its function. To dissect the functional domain we introduced the GFP tagging method and identified the key amino acids for the polymerization and nuclear localization of the RAD51 protein. Using yeast two hybrid system we have cloned two RAD51 associated molecules, RAB22 and RAB163,. RAB22 was a novel molecule and interacted with RAD51 in vitro and in vivo, and made nuclear foci where RAD51 was colocalized. RAB163 turned out mouse BRCA2 C-terminal clone and interacted in vitro with RAD51. We have generated null mutant mouse of the RAB22 gene to elucidate the function in the process of the homologous recombination. We also cloned the new RAD51 associated molecule, named XB7, which was also interacted with XRCC4, one of the key molecules of the DNA end joining. These data suggest that homologous recombination and non homologous end joining used same molecule like XB7.