PARP-mediated repair, homologous recombination, and back-up non-homologous end joining-like repair of single-strand nicks.

ABSTRACT: Double-strand breaks (DSBs) in chromosomal DNA can induce both homologous recombination (HR) and non-homologous end-joining (NHEJ). Recently we showed that single-strand nicks induce HR with a significant reduction in toxicity and mutagenic effects associated with NHEJ. To further investigate the differences and similarities of DSB- and nick-induced repair, we used an integrated reporter system in human cells to measure HR and NHEJ produced by the homing endonuclease I-AniI and a designed 'nickase' variant that nicks the same target site, focusing on the PARP and HR repair pathways. PARP inhibitors, which block single-strand break repair, increased the rate of nick-induced HR up to 1.7-fold but did not affect DSB-induced HR or mutNHEJ. Additionally, expression of the PALB2 WD40 domain in t

SUBMITTER: Metzger MJ 

PROVIDER: S-EPMC3683368 | biostudies-literature | 2013 Jul

REPOSITORIES: biostudies-literature