protein
Histone-lysine N-methyltransferase 2A
aka Lysine N-methyltransferase 2A
Gene
KMT2A
Organism
Homo sapiens(9606)
Length
3969 aa
Mass
431,764 Da
KMT2A (Histone-lysine N-methyltransferase 2A) is a chromatin-modifying enzyme that catalyzes methylation of lysine-4 on histone H3 (H3K4me) as the catalytic subunit of the MLL1/MLL complex (UniProt: Q03164). The protein also facilitates histone H4 acetylation and works with other complex components to establish active chromatin states. KMT2A requires cofactors for full methyltransferase activity and binds unmethylated CpG elements to maintain their nonmethylated state.
KMT2A plays essential roles in early development, hematopoiesis, and circadian gene regulation by establishing permissive chromatin for transcription activation, particularly of genes like HOXA9. Mutations in KMT2A cause Wiedemann-Steiner syndrome (WDSTS), characterized by intellectual disability, distinctive facial features including long eyelashes and thick eyebrows, hypertrichosis cubiti, and short stature (UniProt: Q03164).
KMT2A is classified as a syndromic autism-risk gene in SFARI (SFARI Cat S), indicating association with autism in the context of broader developmental syndromes. This reflects the protein's critical role in neurodevelopmental processes through epigenetic regulation of transcription during early brain development.
Generated from the curated entity record below. May contain errors — verify against source links.
Genetic Evidence · ASD
Source: SFARI Gene database · gene.sfari.org
Related Publications
Browse all →Inherited and De Novo Genetic Risk for Autism Impacts Shared Networks.
Ruzzo Elizabeth K et al.Cell2019PMID 31398340Inherited and multiple de novo mutations in autism/developmental delay risk genes suggest a multifactorial model.
Guo Hui et al.Molecular autism2018PMID 30564305Whole genome sequencing resource identifies 18 new candidate genes for autism spectrum disorder.
C Yuen Ryan K et al.Nature neuroscience2017PMID 28263302Identification of common genetic risk variants for autism spectrum disorder.
Grove Jakob et al.Nature genetics2019PMID 30804558Synaptic, transcriptional and chromatin genes disrupted in autism.
De Rubeis Silvia et al.Nature2014PMID 25363760
Function
Histone methyltransferase that plays an essential role in early development and hematopoiesis (PubMed:12453419, PubMed:15960975, PubMed:19187761, PubMed:19556245, PubMed:20677832, PubMed:21220120, PubMed:26886794). Catalytic subunit of the MLL1/MLL complex, a multiprotein complex that mediates both methylation of 'Lys-4' of histone H3 (H3K4me) complex and acetylation of 'Lys-16' of histone H4 (H4K16ac) (PubMed:12453419, PubMed:15960975, PubMed:19187761, PubMed:19556245, PubMed:20677832, PubMed:21220120, PubMed:24235145, PubMed:26886794). Catalyzes methyl group transfer from S-adenosyl-L-methionine to the epsilon-amino group of 'Lys-4' of histone H3 (H3K4) via a non-processive mechanism. Part of chromatin remodeling machinery predominantly forms H3K4me1 and H3K4me2 methylation marks at active chromatin sites where transcription and DNA repair take place (PubMed:12453419, PubMed:15960975, PubMed:19187761, PubMed:19556245, PubMed:20677832, PubMed:21220120, PubMed:25561738, PubMed:26886794). Has weak methyltransferase activity by itself, and requires other component of the MLL1/MLL complex to obtain full methyltransferase activity (PubMed:19187761, PubMed:26886794). Has no activity toward histone H3 phosphorylated on 'Thr-3', less activity toward H3 dimethylated on 'Arg-8' or 'Lys-9', while it has higher activity toward H3 acetylated on 'Lys-9' (PubMed:19187761). Binds to unmethylated CpG elements in the promoter of target genes and helps maintain them in the nonmethylated state (PubMed:20010842). Required for transcriptional activation of HOXA9 (PubMed:12453419, PubMed:20010842, PubMed:20677832). Promotes PPP1R15A-induced apoptosis (PubMed:10490642). Plays a critical role in the control of circadian gene expression and is essential for the transcriptional activation mediated by the CLOCK-BMAL1 heterodimer (By similarity). Establishes a permissive chromatin state for circadian transcription by mediating a rhythmic methylation of 'Lys-4' of histone H3 (H3K4me) and this histone modification directs the circadian acetylation at H3K9 and H3K14 allowing the recruitment of CLOCK-BMAL1 to chromatin (By similarity). Also has auto-methylation activity on Cys-3882 in absence of histone H3 substrate (PubMed:24235145)
Disease associations
Wiedemann-Steiner syndromeWDSTS
A syndrome characterized by hairy elbows (hypertrichosis cubiti), intellectual disability, a distinctive facial appearance, and short stature. Facial characteristics include long eyelashes, thick or arched eyebrows with a lateral flare, and downslanting and vertically narrow palpebral fissures.
Sources
Last updated 5/6/2026, 5:24:31 AM