H2AFX

H2A histone family, member X
PDB rendering based on 1aoi.
Available structures PDB Ortholog search: PDBe, RCSB List of PDB id codes 1YDP, 2AZM, 2D31, 2DYP, 3SHV, 3SQD, 3SZM, 3U3Z
Identifiers
Symbols	H2AFX ; H2A.X; H2A/X; H2AX
External IDs	OMIM: 601772 MGI: 102688 HomoloGene: 134201 GeneCards: H2AFX Gene
Gene ontology Molecular function • DNA binding • damaged DNA binding • protein binding • enzyme binding • histone binding • protein heterodimerization activity Cellular component • chromosome, telomeric region • nucleosome • nuclear chromatin • condensed nuclear chromosome • male germ cell nucleus • XY body • nucleus • nucleoplasm • replication fork • site of double-strand break Biological process • DNA damage checkpoint • double-strand break repair via homologous recombination • DNA repair • double-strand break repair • nucleosome assembly • cellular response to DNA damage stimulus • meiotic nuclear division • spermatogenesis • response to ionizing radiation • positive regulation of DNA repair Sources: Amigo / QuickGO
RNA expression pattern
More reference expression data
Orthologs
Species	Human	Mouse
Entrez	3014	15270
Ensembl	ENSG00000188486	ENSMUSG00000049932
UniProt	P16104	P27661
RefSeq (mRNA)	NM_002105	NM_010436
RefSeq (protein)	NP_002096	NP_034566
Location (UCSC)	Chr 11: 118.96 – 118.97 Mb	Chr 9: 44.33 – 44.34 Mb
PubMed search

H2AFX (H2A histone family, member X) is one of several genes coding for histone H2A. In humans and other eukaryotes, the DNA is wrapped around histone-groups, consisting of core histones H2A, H2B, H3 and H4. Thus, the H2AX contributes to the nucleosome-formation and therefore the structure of DNA.

H2AX becomes phosphorylated on serine 139, then called gamma-H2AX, as a reaction on DNA Double-strand breaks (DSB). The kinases of the PI3-family (Ataxia telangiectasia mutated, ATR and DNA-PKcs) are responsible for this phosphorylation, especially ATM. The modification can happen accidentally during replication fork collapse or in the response to ionizing radiation but also during controlled physiological processes such as V(D)J recombination. Gamma-H2AX is a sensitive target for looking at DSBs in cells. The role of the phosphorylated form of the histone in DNA repair is under discussion but it is known that because of the modification the DNA becomes less condensed, potentially allowing space for the recruitment of proteins necessary during repair of DSBs. Mutagenesis experiments have shown that the modification is necessary for the proper formation of ionizing radiation induced foci in response to double strand breaks, but is not required for the recruitment of proteins to the site of DSBs.

Interactions

H2AX has been shown to interact with MDC1,^[1][2] Nibrin,^[3] TP53BP1,^[4][5][6] Bloom syndrome protein,^[4] BRCA1^[7][8][9] and BARD1.^[7][9]

References

• ncbi

Further reading

PDB gallery 1aoi: COMPLEX BETWEEN NUCLEOSOME CORE PARTICLE (H3,H4,H2A,H2B) AND 146 BP LONG DNA FRAGMENT  1eqz: X-RAY STRUCTURE OF THE NUCLEOSOME CORE PARTICLE AT 2.5 A RESOLUTION  1hq3: CRYSTAL STRUCTURE OF THE HISTONE-CORE-OCTAMER IN KCL/PHOSPHATE  1kx3: X-Ray Structure of the Nucleosome Core Particle, NCP146, at 2.0 A Resolution  1kx4: X-Ray Structure of the Nucleosome Core Particle, NCP146b, at 2.6 A Resolution  1kx5: X-Ray Structure of the Nucleosome Core Particle, NCP147, at 1.9 A Resolution  1s32: Molecular Recognition of the Nucleosomal 'Supergroove'  1tzy: Crystal Structure of the Core-Histone Octamer to 1.90 Angstrom Resolution  2aro: Crystal Structure Of The Native Histone Octamer To 2.1 Angstrom Resolution, Crystalised In The Presence Of S-Nitrosoglutathione  2cv5: Crystal structure of human nucleosome core particle  2f8n: 2.9 Angstrom X-ray structure of hybrid macroH2A nucleosomes  2hio: HISTONE OCTAMER (CHICKEN), CHROMOSOMAL PROTEIN  2nzd: Nucleosome core particle containing 145 bp of DNA