In response to ionizing radiation (IR), cells delay cell cycle progression and activate DNA repair. Both processes are vital for genome integrity, but the mechanisms involved in their coordination are not fully understood. In a mass spectrometry screen, we identified the adenosine triphosphate-dependent chromatin-remodeling protein CHD4 (chromodomain helicase DNA-binding protein 4) as a factor that becomes transiently immobilized on chromatin after IR. Knockdown of CHD4 triggers enhanced Cdc25A degradation and p21(Cip1) accumulation, which lead to more pronounced cyclin-dependent kinase inhibition and extended cell cycle delay. At DNA double-strand breaks, depletion of CHD4 disrupts the chromatin response at the level of the RNF168 ubiquitin ligase, which in turn impairs local ubiquitylation and BRCA1 assembly. These cell cycle and chromatin defects are accompanied by elevated spontaneous and IR-induced DNA breakage, reduced efficiency of DNA repair, and decreased clonogenic survival. Thus, CHD4 emerges as a novel genome caretaker and a factor that facilitates both checkpoint signaling and repair events after DNA damage.

• MeSH
• autoantigeny genetika   metabolismus   MeSH
• buněčný cyklus genetika   MeSH
• CDC geny MeSH
• chromatin * genetika   metabolismus   MeSH
• chromozomy metabolismus   MeSH
• DNA genetika   metabolismus   MeSH
• dvouřetězcové zlomy DNA MeSH
• fosfatasy cdc25 genetika   metabolismus   MeSH
• ionizující záření MeSH
• komplex Mi2-NuRD genetika   metabolismus   MeSH
• lidé MeSH
• malá interferující RNA metabolismus   farmakologie   MeSH
• nádorové buněčné linie MeSH
• oprava DNA * MeSH
• poškození DNA * fyziologie   MeSH
• RNA interference MeSH
• signální transdukce * genetika   MeSH
• ubikvitin genetika   metabolismus   MeSH
• ubikvitinace MeSH
• Check Tag
• lidé MeSH