H2AC25 Gene: Histone H2A Variant | Function, Location, and Disease Links

H2AC25 (H2A clustered histone 25) is a replication-dependent histone H2A variant encoded by a gene located in the histone cluster 1 on chromosome 6p22.1. Histones are basic nuclear proteins responsible for nucleosome structure, wrapping DNA into chromatin. H2AC25 is synthesized during S-phase and incorporated into nucleosomes, playing a critical role in DNA packaging, transcription regulation, DNA repair, and chromosome stability. The protein contains a conserved histone fold domain and a C-terminal tail subject to post-translational modifications, including acetylation, methylation, and phosphorylation, which influence chromatin dynamics. H2AC25 is part of the H2A family, which includes multiple variants with distinct functions. Mutations and altered expression of H2AC25 have been implicated in various cancers and developmental disorders, though its specific roles are still under investigation.

Tissue Expression

Cell Line Expression

Hotspot Mutations

Mutation functional classification

• Packaging of Telomere Ends

• Chromatin organization

• Formation of the beta-catenin:TCF transactivating complex

• RNA Polymerase I Promoter Opening

• Nucleosome assembly

H2AC25 encodes histone H2A type 1-J, a core histone protein that forms the nucleosome by dimerizing with H2B, H3, and H4. The protein is 129 amino acids long with a molecular weight of approximately 14 kDa. It contains a conserved histone fold domain (residues 17-100) and a flexible C-terminal tail (residues 101-129) that protrudes from the nucleosome and is subject to various post-translational modifications. H2AC25 is synthesized during S-phase and incorporated into newly replicated chromatin. It plays a role in DNA packaging, gene regulation, and DNA repair. The protein is highly similar to other H2A variants, with slight differences in the C-terminal tail that may confer specific functions. H2AC25 is expressed in proliferating cells and tissues, with highest levels in testis and bone marrow. Mutations in H2AC25 are rare and not well-studied; its role in disease is not clearly established.