Overlapping roles for PARP1 and PARP2 in the recruitment of endogenous XRCC1 and PNKP into oxidized chromatin

Hanzlikova, Hana, Gittens, William, Krejcikova, Katerina, Zeng, Zhihong and Caldecott, Keith W (2017) Overlapping roles for PARP1 and PARP2 in the recruitment of endogenous XRCC1 and PNKP into oxidized chromatin. Nucleic Acids Research, 45 (5). pp. 2546-2557. ISSN 1362-4962

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A critical step of DNA single-strand break repair is the rapid recruitment of the scaffold protein XRCC1 that interacts with, stabilizes and stimulates multiple enzymatic components of the repair process. XRCC1 recruitment is promoted by PARP1, an enzyme that is activated following DNA damage and synthesizes ADP-ribose polymers that XRCC1 binds directly. However, cells possess two other DNA strand breakinduced PARP enzymes, PARP2 and PARP3, for which the roles are unclear. To address their involvement in the recruitment of endogenous XRCC1 into oxidized chromatin we have established ‘isogenic’ human diploid cells in which PARP1 and/or PARP2, or PARP3 are deleted. Surprisingly, we show that either PARP1 or PARP2 are sufficient for near-normal XRCC1 recruitment at oxidative single-strand breaks (SSBs) as indicated by the requirement for loss of both proteins to greatly reduce or ablate XRCC1 chromatin binding following H2O2 treatment. Similar results were observed for PNKP; an XRCC1 protein partner important for repair of oxidative SSBs. Notably,concentrations of PARP inhibitor >1000-fold higher than the IC50 were required to ablate both ADP-ribosylation and XRCC1 chromatin binding following H2O2 treatment. These results demonstrate that very low levels of ADP-ribosylation, synthesized by either PARP1 or PARP2, are sufficient for XRCC1 recruitment following oxidative stress.

Item Type: Article
Schools and Departments: School of Life Sciences > Sussex Centre for Genome Damage and Stability
Research Centres and Groups: Genome Damage and Stability Centre
Subjects: Q Science > Q Science (General)
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Depositing User: Sarah Frances
Date Deposited: 30 Aug 2017 10:38
Last Modified: 11 Mar 2022 13:31
URI: http://sro.sussex.ac.uk/id/eprint/69936

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Project NameSussex Project NumberFunderFunder Ref
Chromosomal Single-strand break Repair: Mechanisms & Degenerative DiseaseG0830MRC-MEDICAL RESEARCH COUNCILMR/J006750/1
Cellular and Pathological Responses to Chromosome DNA Single-Strand BreaksG2053MRC-MEDICAL RESEARCH COUNCILMR/P010121/1