The replication protein A (RPA) is involved in most, if not all, nuclear metabolism involving single-stranded DNA. Here, we show that RPA is involved in genome maintenance at stalled replication forks by the homologous recombination repair system in humans. Depletion of the RPA protein inhibited the formation of RAD51 nuclear foci after hydroxyurea-induced replication stalling leading to persistent unrepaired DNA double-strand breaks (DSBs). We demonstrate a direct role of RPA in homology directed recombination repair. We find that RPA is dispensable for checkpoint kinase 1 (Chk1) activation and that RPA directly binds RAD52 upon replication stress, suggesting a direct role in recombination repair. In addition we show that inhibition of Chk1 with UCN-01 decreases dissociation of RPA from the chromatin and inhibits association of RAD51 and RAD52 with DNA. Altogether, our data suggest a direct role of RPA in homologous recombination in assembly of the RAD51 and RAD52 proteins. Furthermore, our data suggest that replacement of RPA with the RAD51 and RAD52 proteins is affected by checkpoint signalling.

• MeSH
• aktivace enzymů MeSH
• CDC geny MeSH
• DNA opravný a rekombinační protein Rad52 genetika   metabolismus   MeSH
• hydroxymočovina metabolismus   MeSH
• inhibitory syntézy nukleových kyselin metabolismus   MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• oprava DNA * MeSH
• poškození DNA MeSH
• proteinkinasy genetika   metabolismus   MeSH
• rekombinasa Rad51 metabolismus   MeSH
• replikace DNA * MeSH
• replikační protein A genetika   metabolismus   MeSH
• signální transdukce * fyziologie   MeSH
• Check Tag
• lidé MeSH