Poly(ADP-ribose) polymerase 1 accelerates single-strand break repair in concert with poly(ADP-ribose) glycohydrolase

Mol Cell Biol. 2007 Aug;27(15):5597-605. doi: 10.1128/MCB.02248-06. Epub 2007 Jun 4.

Abstract

Single-strand breaks are the commonest lesions arising in cells, and defects in their repair are implicated in neurodegenerative disease. One of the earliest events during single-strand break repair (SSBR) is the rapid synthesis of poly(ADP-ribose) (PAR) by poly(ADP-ribose) polymerase (PARP), followed by its rapid degradation by poly(ADP-ribose) glycohydrolase (PARG). While the synthesis of poly(ADP-ribose) is important for rapid rates of chromosomal SSBR, the relative importance of poly(ADP-ribose) polymerase 1 (PARP-1) and PARP-2 and of the subsequent degradation of PAR by PARG is unclear. Here we have quantified SSBR rates in human A549 cells depleted of PARP-1, PARP-2, and PARG, both separately and in combination. We report that whereas PARP-1 is critical for rapid global rates of SSBR in human A549 cells, depletion of PARP-2 has only a minor impact, even in the presence of depleted levels of PARP-1. Moreover, we identify PARG as a novel and critical component of SSBR that accelerates this process in concert with PARP-1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line, Tumor
  • Chickens
  • DNA Breaks, Single-Stranded*
  • DNA Repair* / drug effects
  • DNA-Binding Proteins / metabolism
  • Glycoside Hydrolases / deficiency
  • Glycoside Hydrolases / metabolism*
  • HeLa Cells
  • Histones / metabolism
  • Humans
  • Hydrogen Peroxide / pharmacology
  • Oxidative Stress / drug effects
  • Poly(ADP-ribose) Polymerases / metabolism*
  • X-ray Repair Cross Complementing Protein 1

Substances

  • DNA-Binding Proteins
  • H2AX protein, human
  • Histones
  • X-ray Repair Cross Complementing Protein 1
  • Hydrogen Peroxide
  • Poly(ADP-ribose) Polymerases
  • Glycoside Hydrolases
  • poly ADP-ribose glycohydrolase