Phosphorylation of histone H2A.X as a DNA‑associated biomarker (Review)
Matthias B. Stope
Abstract
The complex genomic structure of eukaryotic cells is primarily achieved by the binding of DNA to histones. Different members of the histone families form a complex with genomic DNA and, as a nucleosome, constitute the functional unit of chromatin. In addition to their structural functionality, histones are also involved in other molecular mechanisms, such as DNA damage recognition and repair. A very important factor of DNA damage management is the histone H2A.X. The phosphorylation of H2A.X initiates various processes of the DNA repair systems and plays significant roles in cellular regulation. The H2A.X phosphorylation status represents a central sum parameter for genome integrity and allows conclusions to be drawn about DNA‑associated processes in cells and tissues. As a biomarker for DNA damage and genotoxicity, as well as a clinical marker for radiotherapy outcome, drug efficacy and tissue regeneration, the H2A.X phosphorylation status represents an effective biomarker for current and future biomedical applications. The present brief review article provides an overview of the various molecular functions and cellular events in which the phosphorylation of histone H2A.X can occur.