| Post Translational Modifications | Monoubiquitinated at either Lys-116 or Lys-117. May also be polyubiquitinated. Ubiquitination is mediated by the CUL3/SPOP E3 complex and does not promote proteasomal degradation. Instead, it is required for enrichment in inactive X chromosome chromatin. |
| Function | 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, including NF-kappa-B, and interferes with the activity of remodeling SWI/SNF complexes. Inhibits histone acetylation by EP300 and recruits class I HDACs, which induces a hypoacetylated state of chromatin. Isoform 1: Isoform that specifically binds poly-ADP-ribose and O-acetyl-ADP-ribose and plays a key role in NAD(+) metabolism. Able to bind to the ends of poly-ADP-ribose chains created by PARP1 and cap them. This prevents PARP1 from further addition of ADP-ribose and thus limits the consumption of nuclear NAD(+), allowing the cell to maintain proper NAD(+) levels in both the nucleus and the mitochondria to promote proper mitochondrial respiration. Increases the expression of genes involved in redox metabolism, including SOD3. Isoform 2: In contrast to isoform 1, does not bind poly-ADP-ribose. Represses SOD3 gene expression. |
| Protein Name | Core Histone Macro-H2a.1Histone Macroh2a1Mh2a1Histone H2a.yH2a/YMedulloblastoma Antigen Mu-Mb-50.205 |
| Cellular Localisation | NucleusChromosomeEnriched In Inactive X Chromosome Chromatin And In Senescence-Associated HeterochromatinRecruited To Dna Damage Sites In An Aplf-Dependent Manner |
| Alternative Protein Names | Core Histone Macro-H2a.1 proteinHistone Macroh2a1 proteinMh2a1 proteinHistone H2a.y proteinH2a/Y proteinMedulloblastoma Antigen Mu-Mb-50.205 proteinMACROH2A1 proteinH2AFY protein |
Information sourced from Uniprot.org
