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Details on Person UniProt:P16104 H2AX

Class:IdReferenceGeneProduct:56152
_chainChangeLoginitiator methionine:1 added on Fri February 6 2015;chain:2-143 added on Fri February 6 2015;initiator methionine:1 for 56152 removed on Fri Nov 03 2023;initiator methionine: for 56152 added on Fri Nov 03 2023;initiator methionine: for 56152 removed on Fri Aug 15 2025;initiator methionine:1 for 56152 added on Fri Aug 15 2025
_displayNameUniProt:P16104 H2AX
_timestamp2025-08-15 22:16:02
chaininitiator methionine:1
chain:2-143
checksumD4683775C2E6C3A9
commentFUNCTION Variant histone H2A which replaces conventional H2A in a subset of nucleosomes. 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. Required for checkpoint-mediated arrest of cell cycle progression in response to low doses of ionizing radiation and for efficient repair of DNA double strand breaks (DSBs) specifically when modified by C-terminal phosphorylation.SUBUNIT 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. The octamer wraps approximately 147 bp of DNA (Probable). Interacts with numerous proteins required for DNA damage signaling and repair when phosphorylated on Ser-140 (PubMed:12419185, PubMed:12607005, PubMed:15201865). These include MDC1, TP53BP1, BRCA1 and the MRN complex, composed of MRE11, RAD50, and NBN (PubMed:12419185, PubMed:12607005, PubMed:15201865). Interaction with the MRN complex is mediated at least in part by NBN (PubMed:12419185). Also interacts with DHX9/NDHII when phosphorylated on Ser-140 and MCPH1 when phosphorylated at Ser-140 or Tyr-143 (PubMed:15613478). Interacts with ARRB2; the interaction is detected in the nucleus upon OR1D2 stimulation (PubMed:16820410). Interacts with WRAP53/TCAB1 (PubMed:26734725, PubMed:27715493). Interacts with HDGFL2 (PubMed:26721387). Interacts with DNA damage up-regulated protein DDUP (PubMed:35849344). Forms a complex with DDUP and RAD18 following DDUP phosphorylation (PubMed:35849344).SUBUNIT (Microbial infection) Interacts with Epstein-Barr virus protein EBNA6.INTERACTION Synthesized in G1 as well as in S-phase.DOMAIN The [ST]-Q motif constitutes a recognition sequence for kinases from the PI3/PI4-kinase family.PTM Phosphorylated by VRK1 (PubMed:31527692). Phosphorylated on Ser-140 (to form gamma-H2AX or H2AX139ph) in response to DNA double strand breaks (DSBs) generated by exogenous genotoxic agents and by stalled replication forks, and may also occur during meiotic recombination events and immunoglobulin class switching in lymphocytes. Phosphorylation can extend up to several thousand nucleosomes from the actual site of the DSB and may mark the surrounding chromatin for recruitment of proteins required for DNA damage signaling and repair. Widespread phosphorylation may also serve to amplify the damage signal or aid repair of persistent lesions. Phosphorylation of Ser-140 (H2AX139ph) in response to ionizing radiation is mediated by both ATM and PRKDC while defects in DNA replication induce Ser-140 phosphorylation (H2AX139ph) subsequent to activation of ATR and PRKDC. Dephosphorylation of Ser-140 by PP2A is required for DNA DSB repair. In meiosis, Ser-140 phosphorylation (H2AX139ph) may occur at synaptonemal complexes during leptotene as an ATM-dependent response to the formation of programmed DSBs by SPO11. Ser-140 phosphorylation (H2AX139ph) may subsequently occurs at unsynapsed regions of both autosomes and the XY bivalent during zygotene, downstream of ATR and BRCA1 activation. Ser-140 phosphorylation (H2AX139ph) may also be required for transcriptional repression of unsynapsed chromatin and meiotic sex chromosome inactivation (MSCI), whereby the X and Y chromosomes condense in pachytene to form the heterochromatic XY-body. During immunoglobulin class switch recombination in lymphocytes, Ser-140 phosphorylation (H2AX139ph) may occur at sites of DNA-recombination subsequent to activation of the activation-induced cytidine deaminase AICDA. Phosphorylation at Tyr-143 (H2AXY142ph) by BAZ1B/WSTF determines the relative recruitment of either DNA repair or pro-apoptotic factors. Phosphorylation at Tyr-143 (H2AXY142ph) favors the recruitment of APBB1/FE65 and pro-apoptosis factors such as MAPK8/JNK1, triggering apoptosis. In contrast, dephosphorylation of Tyr-143 by EYA proteins (EYA1, EYA2, EYA3 or EYA4) favors the recruitment of MDC1-containing DNA repair complexes to the tail of phosphorylated Ser-140 (H2AX139ph).PTM Monoubiquitination of Lys-120 (H2AXK119ub) by RING1 and RNF2/RING2 complex gives a specific tag for epigenetic transcriptional repression (By similarity). Following DNA double-strand breaks (DSBs), it is ubiquitinated through 'Lys-63' linkage of ubiquitin moieties by the E2 ligase UBE2N and the E3 ligases RNF8 and RNF168, leading to the recruitment of repair proteins to sites of DNA damage. Ubiquitination at Lys-14 and Lys-16 (H2AK13Ub and H2AK15Ub, respectively) in response to DNA damage is initiated by RNF168 that mediates monoubiquitination at these 2 sites, and 'Lys-63'-linked ubiquitin are then conjugated to monoubiquitin; RNF8 is able to extend 'Lys-63'-linked ubiquitin chains in vitro. H2AK119Ub and ionizing radiation-induced 'Lys-63'-linked ubiquitination (H2AK13Ub and H2AK15Ub) are distinct events.PTM Acetylation at Lys-6 (H2AXK5ac) by KAT5 component of the NuA4 histone acetyltransferase complex promotes NBN/NBS1 assembly at the sites of DNA damage (PubMed:17709392, PubMed:26438602). Acetylation at Lys-37 increases in S and G2 phases. This modification has been proposed to play a role in DNA double-strand break repair (By similarity).SIMILARITY Belongs to the histone H2A family.
descriptionrecommendedName: Histone H2AX shortName: H2a/x alternativeName: Histone H2A.X
geneNameH2AX
H2AFX
identifierP16104
isSequenceChangedFALSE
keyword3D-structure
Acetylation
Cell cycle
Chromosome
DNA damage
DNA recombination
DNA repair
DNA-binding
Host-virus interaction
Isopeptide bond
Meiosis
Nucleosome core
Nucleus
Phosphoprotein
Proteomics identification
Reference proteome
Ubl conjugation
modified[InstanceEdit:9836292] Weiser, Joel, 2023-05-25
[InstanceEdit:9852000] Weiser, Joel, 2023-11-03
[InstanceEdit:9862192] Weiser, Joel, 2024-02-26
[InstanceEdit:9917590] Weiser, Joel, 2024-08-09
[InstanceEdit:9926675] Weiser, Joel, 2024-11-03
[InstanceEdit:9963647] Weiser, Joel, 2025-08-15
nameH2AX
referenceDatabase[ReferenceDatabase:2] UniProt
referenceGene[ReferenceDNASequence:8957749] ENSEMBL:ENSG00000188486 H2AX [Homo sapiens]
secondaryIdentifierH2AX_HUMAN
Q4ZGJ7
Q6IAS5
sequenceLength143
species[Species:48887] Homo sapiens
(referenceEntity)[EntityWithAccessionedSequence:56151] H2AFX [nucleoplasm] [Homo sapiens]
[EntityWithAccessionedSequence:75170] p-S140-H2AFX [nucleoplasm] [Homo sapiens]
[EntityWithAccessionedSequence:977583] H2AFX [extracellular region] [Homo sapiens]
[EntityWithAccessionedSequence:5218317] Me2sR4-H2AFX [nucleoplasm] [Homo sapiens]
[EntityWithAccessionedSequence:5682847] K63PolyUb-K14,K16,p-S140-H2AFX [nucleoplasm] [Homo sapiens]
[EntityWithAccessionedSequence:5683942] p-Y143-H2AFX [nucleoplasm] [Homo sapiens]
[EntityWithAccessionedSequence:5683953] p-S140,Y143-H2AFX [nucleoplasm] [Homo sapiens]
[EntityWithAccessionedSequence:9943854] acK H2AFX [nucleoplasm] [Homo sapiens]
(referenceSequence)[ModifiedResidue:75169] O-phospho-L-serine at 140
[ModifiedResidue:5218323] symmetric dimethyl-L-arginine at 4
[GroupModifiedResidue:5682850] ubiquitinylated lysine (K63polyUb [nucleoplasm]) at 14
[GroupModifiedResidue:5682853] ubiquitinylated lysine (K63polyUb [nucleoplasm]) at 16
[ModifiedResidue:5683944] O4'-phospho-L-tyrosine at 143
[ModifiedResidue:9943855] N6-acetyl-L-lysine at unknown position
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No pathways have been reviewed or authored by UniProt:P16104 H2AX (56152)