CHARACTERIZATION OF BRCA2 - TEMPERATURE SENSITIVITY OF DETECTION AND CELL-CYCLE-REGULATED EXPRESSION

People carrying a mutant BRCA2 gene are susceptible to breast, ovarian , pancreatic and other tumors. Many facets of BRCA2 have been studied, including its mutation in human cancers, its role in mouse embryogene sis and its RNA expression in different tissues and different mouse em bryogenesis stages. However, there has been very little characterizati on of BRCA2 protein. We investigated the biochemical and biological pr operties of BRCA2 by using a monoclonal antibody we generated against the N-terminal portion of BRCA2, We discovered that the detection of B RCA2 by immunoblot analysis was sensitive to the temperature used to d enature the samples before gel electrophoresis. BRCA2 was easily detec table when samples were denatured at low temperature instead of boilin g. Although the precise mechanism underlying this observation is not c lear yet, this finding mill significantly improve our ability to study BRCA2, We examined the expression of BRCA2 using an immunoblot analys is protocol modified according to this observation. We showed that BRC A2 was presented in every human cell lines examined, including Capan-1 , which expressed a truncated BRCA2 due to a BRCA2 frameshift mutation . We also showed that the expression of BRCA2 was cell-cycle regulated . Our results suggest that BRCA2 has an important role in cell growth regulation.