Abstract
The phosphorylation of the histone variant H2AX to form γH2AX is an early and critical histone modification during the DNA damage response. This phosphorylation has proven to be a highly specific molecular marker for tracking the initiation and resolution of DNA damage. In this study, we investigate the roles of three phosphatases in removing the 'γ' phospho-epitope from H2AX in Drosophila Kc167 cells. We found that the bulk of the X-ray-induced γH2AX signal is erased by the PP2A-type phosphatase MTS (microtubule star).