PARP-1 enhances the mismatch-dependence of 5'-directed excision in human mismatch repair in vitro.

Journal Article (Journal Article)

End-directed mismatch-provoked excision has been reconstituted in several purified systems. While 3'-directed excision displays a mismatch dependence similar to that observed in nuclear extracts (≈20-fold), the mismatch dependence of 5'-directed excision is only 3-4-fold, significantly less than that in extracts (8-10-fold). Utilizing a fractionation-based approach, we have isolated a single polypeptide that enhances mismatch dependence of reconstituted 5'-directed excision and have shown it to be identical to poly[ADP-ribose] polymerase 1 (PARP-1). Titration of reconstituted excision reactions or PARP-1-depleted HeLa nuclear extract with purified PARP-1 showed that the protein specifically enhances mismatch dependence of 5'-directed excision. Analysis of a set of PARP-1 mutants revealed that the DNA binding domain and BRCT fold contribute to the regulation of excision specificity. Involvement of the catalytic domain is restricted to its ability to poly(ADP-ribosyl)ate PARP-1 in the presence of NAD(+), likely through interference with DNA binding. Analysis of protein-protein interactions demonstrated that PARP-1 interacts with mismatch repair proteins MutSα, exonuclease 1, replication protein A (RPA), and as previously shown by others, replication factor C (RFC) and proliferating cell nuclear antigen (PCNA) as well. The BRCT fold plays an important role in the interaction of PARP-1 with the former three proteins.

Full Text

Duke Authors

Cited Authors

  • Liu, Y; Kadyrov, FA; Modrich, P

Published Date

  • November 10, 2011

Published In

Volume / Issue

  • 10 / 11

Start / End Page

  • 1145 - 1153

PubMed ID

  • 21945626

Pubmed Central ID

  • PMC3222275

Electronic International Standard Serial Number (EISSN)

  • 1568-7856

Digital Object Identifier (DOI)

  • 10.1016/j.dnarep.2011.08.012


  • eng

Conference Location

  • Netherlands