H2AX
H2AX is a variant of histone H2A, a core component of nucleosomes that package DNA in eukaryotic chromatin. It is encoded by the H2AFX gene in humans and is expressed broadly in most cell types as part of the histone H2A family.
In response to DNA double-strand breaks, the PI3K-related kinases ATM, ATR, and DNA-PKcs phosphorylate serine 139
Functionally, gamma-H2AX signaling helps stabilize broken DNA ends, facilitates the accumulation of repair factors, and influences
Loss or deficiency of H2AX impairs DNA damage signaling and increases cellular sensitivity to ionizing radiation