Variant histone H2A which replaces conventional H2A in a subset of nucleosomes where it represses transcription. Nucleosomes wrap and compact DNA into chromatin, limiting DNA accessibility to the cellular machineries which require DNA as a template. Histones thereby play a central role in transcription regulation, DNA repair, DNA replication and chromosomal stability. DNA accessibility is regulated via a complex set of post-translational modifications of histones, also called histone code, and nucleosome remodeling. May be involved in stable X chromosome inactivation. The nucleosome is a histone octamer containing two molecules each of H2A, H2B, H3 and H4 assembled in one H3-H4 heterotetramer and two H2A-H2B heterodimers. Enriched in inactive X chromosome chromatin and in senescence-associated heterochromatin. Present in liver, kidney and adrenal gland (at protein level). In the liver, present in cells of the bile ducts and parenchymal cells, but not in hepatocytes. In the kidney, present in proximal and distal convoluted tubules and in glomeruli. Present at highest levels in the parietal layer of Bowman capsule. In the adrenal gland, present in the outer cells of the capsule.