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

✍ Scribed by Lin Ni; Makio Saeki; Li Xu; Hirokazu Nakahara; Masafumi Saijo; Kiyoji Tanaka; Yoshinori Kamisaki

• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 266 KB
• Volume: 106
• Category: Article
• ISSN: 0730-2312
• DOI: 10.1002/jcb.22073

✦ Synopsis

Abstract

We have previously reported that Monad, a novel WD40 repeat protein, potentiates apoptosis induced by tumor necrosis factor‐α 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. J. Cell. Biochem. 106: 920–928, 2009. © 2009 Wiley‐Liss, Inc.