BRCA1-associated exclusion of 53BP1 from DNA damage sites underlies temporal control of DNA repair.

ABSTRACT: Following irradiation, numerous DNA-damage-responsive proteins rapidly redistribute into microscopically visible subnuclear aggregates, termed ionising-radiation-induced foci (IRIF). How the enrichment of proteins on damaged chromatin actually relates to DNA repair remains unclear. Here, we use super-resolution microscopy to examine the spatial distribution of BRCA1 and 53BP1 proteins within single IRIF at subdiffraction-limit resolution, yielding an unprecedented increase in detail that was not previously apparent by conventional microscopy. Consistent with a role for 53BP1 in promoting DNA double-strand break repair by non-homologous end joining, 53BP1 enrichment in IRIF is most prominent in the G0/G1 cell cycle phases, where it is enriched in dense globular structures. By contrast, as c

SUBMITTER: Chapman JR 

PROVIDER: S-EPMC3445322 | biostudies-literature | 2012 Aug

REPOSITORIES: biostudies-literature