RPAP3 interacts with Reptin to regulate UV-induced phosphorylation of H2AX and DNA damage.
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.
Ni
Lin
L
Department of Pharmacology, Graduate School of Dentistry, Osaka University, Suita, Osaka, Japan.
Saeki
Makio
M
Xu
Li
L
Nakahara
Hirokazu
H
Saijo
Masafumi
M
Tanaka
Kiyoji
K
Kamisaki
Yoshinori
Y
D000074183:ATPases Associated with Diverse Cellular Activities; D051017:Apoptosis Regulatory Proteins; D002352:Carrier Proteins / Q000378:metabolism* / Q000502:physiology; D016923:Cell Death / Q000528:radiation effects; D002460:Cell Line; D004249:DNA Damage; D004265:DNA Helicases / Q000378:metabolism* / Q000502:physiology; D006657:Histones / Q000378:metabolism*; D006801:Humans; D010766:Phosphorylation; D014466:Ultraviolet Rays
D051017:Apoptosis Regulatory Proteins; D002352:Carrier Proteins; C468783:H2AX protein, human; D006657:Histones; C472351:RPAP3 protein, human; D000074183:ATPases Associated with Diverse Cellular Activities; D004265:DNA Helicases; C122079:RUVBL2 protein, human