title: RPAP3 interacts with Reptin to regulate UV-induced phosphorylation of H2AX and DNA damage.
abstract: 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.
authors.affiliation: Department of Pharmacology, Graduate School of Dentistry, Osaka University, Suita, Osaka, Japan.
authors.forename: Lin
authors.initials: L
authors.lastname: Ni
authors.forename: Makio
authors.initials: M
authors.lastname: Saeki
authors.forename: Li
authors.initials: L
authors.lastname: Xu
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Nakahara
authors.forename: Masafumi
authors.initials: M
authors.lastname: Saijo
authors.forename: Kiyoji
authors.initials: K
authors.lastname: Tanaka
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Kamisaki
mesh_terms: 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
chemical_list: 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