RPAP3 interacts with Reptin to regulate UV-induced phosphorylation of H2AX and DNA damage

J Cell Biochem. 2009 Apr 1;106(5):920-8. doi: 10.1002/jcb.22073.


We have previously reported that Monad, a novel WD40 repeat protein, potentiates apoptosis induced by tumor necrosis factor-alpha and cycloheximide. By affinity purification and mass spectrometry, RNA polymerase II-associated protein 3 (RPAP3) was identified as a Monad binding protein and may function with Monad as a novel modulator of apoptosis pathways. Here we report that Reptin, a highly conserved AAA + ATPase that is part of various chromatin-remodeling complexes, is also involved in the association of RPAP3 by immunoprecipitation and confocal microscopic analysis. Overexpression of RPAP3 induced HEK293 cells to death after UV-irradiation. Loss of RPAP3 by RNAi improved HeLa cell survival after UV-induced DNA damage and attenuated the phosphorylation of H2AX. Depletion of Reptin reduced cell survival and facilitated the phosphorylation on H2AX. These results suggest that RPAP3 modulates UV-induced DNA damage by regulating H2AX phosphorylation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ATPases Associated with Diverse Cellular Activities
  • Carrier Proteins / metabolism*
  • Carrier Proteins / physiology
  • Cell Death / radiation effects
  • Cell Line
  • DNA Damage*
  • DNA Helicases / metabolism*
  • DNA Helicases / physiology
  • Histones / metabolism*
  • Humans
  • Phosphorylation
  • Ultraviolet Rays*


  • Carrier Proteins
  • H2AX protein, human
  • Histones
  • RPAP3 protein, human
  • ATPases Associated with Diverse Cellular Activities
  • DNA Helicases
  • RUVBL2 protein, human