Background
Histones are subjected to a variety of enzyme catalyzed modifications, including acetylation, methylation, ubiquitylation and newly discovered succinylation, crotonylation and 2-hydroxyisobutyrylation, etc. These modifications have a direct effect on the accessibility of chromatin to transcription factors and, therefore, on gene expression. Histone H2A.x is a ubiquitously expressed variant of histone H2A and phosphorylation of histone H2A.x at Ser139 (termed γ-H2AX) is located in a unique C-terminal region and regulated by various kinases, including the ataxia telangiectasia-mutated (ATM) protein, the AT and Rad3-related protein, and DNA-dependent protein kinase, all of which were reported to be involved in the responses of mammalian cells to DNA double-strand breaks.
Cellular location
Nucleus
