THE BRCA2 IS A HISTONE ACETYLTRANSFERASE

Patients carrying mutations in BRCA1 or BRCA2 tumor suppressor genes h ave shown to have high risk in developing breast and ovarian cancers. Two potential functions of BRCA2 were proposed which includes role in the regulation of transcription and also in DNA repair. Forty-five-ami no acid region encoded by exon 3 of BRCA2 was shown to have transcript ional activation function. Recent studies of the several enzymes invol ved in acetylation and deacetylation of histone residues have revealed a possible relationship between gene transcriptional activation and h istone acetylation, Since BRCA2 appear to function as a transcriptiona l factor, we have tested for Histone acetyl transferase (HAT) activity of BRCA2, Here, we present evidence that BRCA2 has intrinsic HAT acti vity, which maps to the aminoterminal region of BRCA2, Our results dem onstrate that BRCA2 proteins acetylate primarily H3 and H4 of free his tones. These observations suggest that HAT activity of BRCA2 may play an important role in the regulation of transcription and tumor suppres sor function.