Mislocalization of BRCA1-complex due to ABRAXAS Arg361Gln mutation

It interacts with BRCA1 via its C-terminal phospho-peptide binding motif while the N-terminal associates with RAP80, and thereby recruits the BRCA1-complex at the site of DNA damage. Nonetheless, how ABRAXAS helps in the structural integrity of BRCA1-complex, and its DNA repair mechanism remains elusive.

To elucidate the role of ABRAXAS in the DNA repair process, we characterized the ABRAXAS wild type and Arg361Gln mutant using in silico and in vitro approach. It has been observed that ABRAXAS Arg361Gln mutant is responsible for defective nuclear localization of BRCA1-complex, and hence important for DNA repair function. We found conformational changes in ABRAXAS mutant, which impaired binding to RAP80 and further disturb BRCA1-complex localization.