BRCA1-BRCT mutations alter the subcellular localization of BRCA1 in vitro

Abstract

Background/Aim: Numerous missense mutations have been determined in the BRCT domain of the BRCA1 gene, affecting localization and interaction of BRCA1 with other proteins. Materials and Methods: We examined whether the M1775K and V1809F mutations in the BRCT domain affect BRCA1 cellular localization. Cells were transfected with pEGFP-C3-BRCA1 and detected by fluorescence microscopy. Results: Following induction of DNA damage, cytoplasmic mislocalization was observed for both M1775K and V1809F mutants compared to EGFP-BRCA1wt and the less common variant M1652I. These results indicate that M1775K and V1809F mutations may change the function of the protein by affecting BRCA1 localization. Conclusion: There is a correlation between subcellular localization of BRCA1 and diminished DNA repair observed in breast cancer cells, which may be explained by structural variations and altered binding properties of phosphopeptides.