Abstract
Ionizing irradiation induces lethal genome damages like DNA double strand breaks (DSBs) in human cells. Reorganization of damaged chromatin, such as posttranslational modification and/or exchange of histones, has been shown to play a role in the regulation of DNA damage response. Histone variant H2AZ in yeast is deposited close to the DSBs early but transiently and directs DNA resection, single DSBs-induced checkpoint activation, and DSBs anchoring. However, the role of H2AZ in the reorganization of damaged chromatin in human cells is still unclear. To investigate the role of H2AZ in DNA damage response, we analyzed the dynamics of H2AZ upon DNA damage induced by a UVA-laser microirradiation. Living cell imaging techniques revealed that H2AZ is released from damaged chromatin from just after induction of DSBs by UVA-laser microirradiation. This suggests that human H2AZ is involved in the regulation of DNA damage response at the very early stage via reorganization of damaged chromatin.
