Background
Histones are a family of basic proteins that form the core of the nucleosome – the fundamental structural unit of chromatin. In a single nucleosome, core histone proteins H2A, H2B, H3, and H4 form an octamer around which the DNA is tightly wrapped. Among core histones, the H2A family shows the highest sequence divergence, especially in the C-terminal region, leading to variants including H2A.Z, H2A.X, MacroH2A, H2A.B etc. H2A histone family member X (H2A.X) is a histone H2A variant encoded by the H2AFX gene. H2A.X contributes to nucleosome-formation, chromatin-remodeling and DNA double-strand break repair and is considered as a tumor suppressor. An early cellular response to DNA damage is the rapid phosphorylation of H2A.X at position Ser139.
Cellular location
Nucleus