BRCA1 foci in normal S-phase nuclei are linked to interphase centromeres and replication of pericentric heterochromatin.

ABSTRACT: Breast cancer-associated protein 1 (BRCA1) forms foci at sites of induced DNA damage, but any significance of these normal S-phase foci is unknown. BRCA1 distribution does not simply mirror or overlap that of replicating DNA; however, BRCA1 foci frequently abut sites of BrdU incorporation, mostly at mid-to-late S phase. Although BRCA1 does not overlap XIST RNA across the inactive X chromosome, BRCA1 foci position overwhelmingly in heterochromatic regions, particularly the nucleolar periphery where many centromeres reside. In humans and mice, including early embryonic cells, BRCA1 commonly associates with interphase centromere-kinetochore complexes, including pericentric heterochromatin. Proliferating cell nuclear antigen or BrdU labeling demonstrates that BRCA1 localizes adjacent to, or "p

SUBMITTER: Pageau GJ 

PROVIDER: S-EPMC2064668 | biostudies-literature | 2006 Dec

REPOSITORIES: biostudies-literature