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. Involved in stable X chromosome inactivation. Inhibits the binding of transcription factors and interferes with the activity of remodeling SWI/SNF complexes. Inhibits histone acetylation by EP300 and recruits class I HDACs, which induces an hypoacetylated state of chromatin. In addition, isoform 1, but not isoform 2, binds ADP-ribose and O-acetyl-ADP- ribose, and may be involved in ADP-ribose-mediated chromatin modulation. 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. Interacts with SPOP. Part of a complex consisting of H2AFY, CUL3 and SPOP. Interacts with HDAC1 and HDAC2. Ubiquitous. 3 isoforms of the human protein are produced by alternative splicing. Note: This description may include information from UniProtKB.
Molecular Function: chromatin DNA binding; double-stranded methylated DNA binding; enzyme binding; nucleosomal DNA binding; protein binding; protein kinase binding; protein serine/threonine kinase inhibitor activity; rDNA binding
Biological Process: chromatin silencing; dosage compensation; negative regulation of gene expression, epigenetic; negative regulation of histone H3-K4 methylation; negative regulation of histone phosphorylation; negative regulation of transcription from RNA polymerase II promoter; positive regulation of gene expression, epigenetic; positive regulation of keratinocyte differentiation; positive regulation of maintenance of mitotic sister chromatid cohesion; regulation of cell growth; regulation of gene expression, epigenetic; regulation of lipid metabolic process