histone H2A type 1-B/E; histone-H2A.5; H2A/m; H2A.2; H2A/a (HIST1H2AB, H2AFM, HIST1H2AE, H2AFA, H2A.5)

^[1]^[2]

Function

core component of nucleosome
chromatin-associated form is phosphorylated on Thr-121 during mitosis (probable)
deiminated on Arg-4 in granulocytes upon Ca+2 entry
monoubiquitination of Lys-120 by RING1 & RNF2/RING2 complex gives a specific tag for epigenetic transcriptional repression & participates in X chromosome inactivation in females
role in initiation of both imprinted & random X inactivation
ubiquitinated H2A is enriched in inactive X chromosome chromatin
ubiquitination of H2A functions downstream of methylation of Lys-27 of histone H3
monoubiquitination of Lys-120 by RNF2/RING2 can also be induced by ultraviolet & may be involved in DNA repair
following DNA double-strand breaks, ubiquitinated through Lys-63 linkage of ubiquitin moieties by the E2 ligase UBE2N & the E3 ligases RNF8 & RNF168, leading to the recruitment of DNA repair proteins to sites of DNA damage
monoubiquitination & ionizing radiation-induced Lys-63 linked ubiquitination are distinct events
phosphorylation on Ser-2 is enhanced during mitosis
phosphorylation on Ser-2 by RPS6KA5/MSK1 directly represses transcription
acetylation of H3 inhibits Ser-2 phosphorylation by RPS6KA5/MSK1
symmetric dimethylation on Arg-4 by the PRDM1/PRMT5 complex may play a role in the germ-cell lineage (putative)

belongs to the histone H2A family

↑ UniProt http://www.uniprot.org/uniprot/P04908.html
↑ Boyne MT et al Precise characterization of human histones in the H2A gene family by top down mass spectrometry. J Proteome Res. 2006 Feb;5(2):248-53. PMID: https://www.ncbi.nlm.nih.gov/pubmed/16457589