Poly(ADP) ribose polymerase promotes DNA polymerase theta-mediated end joining by activation of end resection
Abstract
The DNA polymerase theta (Polθ)-mediated end joining (TMEJ) pathway for repair of chromosomal double strand breaks (DSBs) is essential in cells deficient in other DSB repair pathways, including hereditary breast cancers defective in homologous recombination. Strand-break activated poly(ADP) ribose polymerase 1 (PARP1) has been implicated in TMEJ, but the modest specificity of existing TMEJ assays means the extent of effect and the mechanism behind it remain unclear. We describe here a series of TMEJ assays with improved specificity and show ablation of PARP activity reduces TMEJ activity 2-4-fold. The reduction in TMEJ is attributable to a reduction in the 5’ to 3’ resection of DSB ends that is essential for engagement of this pathway and is compensated by increased repair by the nonhomologous-end joining pathway. This limited role for PARP activity in TMEJ helps better rationalize the combined employment of inhibitors of PARP and Polθ in cancer therapy.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Aug 04, 2022
- Source ID
- 10.1038/s41467-022-32166-7
Entities
People
- Adam J. Luthman
- Dale A Ramsden
- Gaorav P Gupta
- Megan E Luedeman
- Susanna Stroik
- Wanjuan Feng
Organizations
- National Cancer Institute
- National Institute of General Medical Sciences
- United States Department of Defense
- United States Department of Health and Human Services