Histone deposition onto DNA assisted by specific chaperones forms the chromatin basic unit and serves to package the genome within the cell nucleus. The resulting chromatin organization, often referred to as the epigenome, contributes to a unique transcriptional program that defines cell identity. Importantly, during cellular life, substantial alterations in chromatin structure may arise due to cell stress, including DNA damage, which not only challenges the integrity of the genome but also threatens the epigenome. Considerable efforts have been made to decipher chromatin dynamics in response to genotoxic stress, and to assess how it affects both genome and epigenome stability. Here, we review recent advances in understanding the mechanisms of DNA damage-induced chromatin plasticity in mammalian cells. We focus specifically on the dynamics of histone H3 variants in response to UV irradiation, and highlight the role of their dedicated chaperones in restoring both chromatin structure and function. Finally, we discuss how, in addition to restoring chromatin integrity, the cellular networks that signal and repair DNA damage may also provide a window of opportunity for modulating the information conveyed by chromatin.
Keywords: CAF-1; DNA damage; DNA repair; H3.1; H3.3; HIRA; UV irradiation; chromatin assembly; histone chaperones; histone variants.
© 2014 FEBS.