Mutations in the BRCA2 gene can inhibit the functioning of a mechanism that regulates the activity of the protein encoded by this gene, according to an article in the 31 March 2005 issue of Nature (Vol. 434, No. 7033, pp 598-604).
Eighty per cent of people that inherit mutations in BRCA2 eventually develop early-onset breast cancer, ovarian cancer, or other cancers. The wild-type version of the protein encoded by this gene has a role in DNA repair through its interactions with RAD51, another protein that works to repair DNA damage. The growth of tumours is attributed to defects in DNA damage repair mechanisms.
Stephen West and colleagues report that the interaction of these two proteins is inhibited by phosphorylation of the carboxy-terminal end of BRCA2. Some cancer-associated mutations in BRCA2 change its phosphorylation state, thereby preventing normal regulation of DNA repair. These results provide new insight into why some inherited mutations in BRCA2 can lead to cancer predisposition.
Stephen West (Cancer Research UK London Research Institute, South Mimms, UK)
(C) Nature press release.
Message posted by: Trevor M. D'Souza