protein
Dual specificity mitogen-activated protein kinase kinase 1
aka MAP kinase kinase 1, MAPKK 1, MKK1
Gene
MAP2K1
Organism
Homo sapiens(9606)
Length
393 aa
Mass
43,439 Da
MAP2K1 encodes dual specificity mitogen-activated protein kinase kinase 1, a 393-amino acid protein kinase essential to the MAPK/ERK signal transduction cascade (UniProt: Q02750). It phosphorylates both threonine and tyrosine residues on extracellular signal-regulated kinases MAPK3/ERK1 and MAPK1/ERK2, propagating signals initiated by growth factors, cytokines, and hormones. The pathway regulates diverse cellular processes including growth, survival, differentiation, and cytoskeletal rearrangement through effects on transcription, metabolism, and organellar dynamics.
Mutations in MAP2K1 are associated with cardiofaciocutaneous syndrome 3 (CFC3), a multiple congenital anomaly disorder characterized by distinctive facial features, congenital heart defects, and intellectual disability, alongside ectodermal abnormalities (UniProt: Q02750). The gene has also been linked to melorheostosis, a sclerosing bone disorder causing hyperostosis of long bones.
MAP2K1 carries SFARI classification as syndromic (SFARI Cat S), indicating curated evidence for association with autism spectrum disorder in a syndromic context, likely through the intellectual disability and developmental features accompanying cardiofaciocutaneous syndrome.
Generated from the curated entity record below. May contain errors — verify against source links.
Proteomics Evidence · AD
↓ Down in ADP3
not detected
P2
not detected
S2
-1.214
S3
not detected
Mean log₂FC across detected fractions: -1.2142 (1 of 4 fractions detected)
Human post-mortem AD brain vs age-matched controls, TMT-labeled, 4 subcellular fractions (P2, P3, S2, S3), DDA proteomics.
Genetic Evidence · ASD
Source: SFARI Gene database · gene.sfari.org
This protein is implicated in both ASD and Alzheimer's Disease. View all cross-disease proteins →
Related Publications
Browse all →Tau molecular diversity contributes to clinical heterogeneity in Alzheimer's disease.
Dujardin Simon et al.Nature medicine2020PMID 32572268Deep Multilayer Brain Proteomics Identifies Molecular Networks in Alzheimer's Disease Progression.
Bai Bing et al.Neuron2020PMID 31926610A Multi-network Approach Identifies Protein-Specific Co-expression in Asymptomatic and Symptomatic Alzheimer's Disease.
Seyfried Nicholas T et al.Cell systems2017PMID 27989508Large-scale deep multi-layer analysis of Alzheimer's disease brain reveals strong proteomic disease-related changes not observed at the RNA level.
Johnson Erik C B et al.Nature neuroscience2022PMID 35115731Organization and regulation of gene transcription.
Cramer PatrickNature2019PMID 31462772Inherited 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
Dual specificity protein kinase which acts as an essential component of the MAP kinase signal transduction pathway. Binding of extracellular ligands such as growth factors, cytokines and hormones to their cell-surface receptors activates RAS and this initiates RAF1 activation. RAF1 then further activates the dual-specificity protein kinases MAP2K1/MEK1 and MAP2K2/MEK2. Both MAP2K1/MEK1 and MAP2K2/MEK2 function specifically in the MAPK/ERK cascade, and catalyze the concomitant phosphorylation of a threonine and a tyrosine residue in a Thr-Glu-Tyr sequence located in the extracellular signal-regulated kinases MAPK3/ERK1 and MAPK1/ERK2, leading to their activation and further transduction of the signal within the MAPK/ERK cascade. Activates BRAF in a KSR1 or KSR2-dependent manner; by binding to KSR1 or KSR2 releases the inhibitory intramolecular interaction between KSR1 or KSR2 protein kinase and N-terminal domains which promotes KSR1 or KSR2-BRAF dimerization and BRAF activation (PubMed:29433126). Depending on the cellular context, this pathway mediates diverse biological functions such as cell growth, adhesion, survival and differentiation, predominantly through the regulation of transcription, metabolism and cytoskeletal rearrangements. One target of the MAPK/ERK cascade is peroxisome proliferator-activated receptor gamma (PPARG), a nuclear receptor that promotes differentiation and apoptosis. MAP2K1/MEK1 has been shown to export PPARG from the nucleus. The MAPK/ERK cascade is also involved in the regulation of endosomal dynamics, including lysosome processing and endosome cycling through the perinuclear recycling compartment (PNRC), as well as in the fragmentation of the Golgi apparatus during mitosis
Disease associations
Cardiofaciocutaneous syndrome 3CFC3
A form of cardiofaciocutaneous syndrome, a multiple congenital anomaly disorder characterized by a distinctive facial appearance, heart defects and intellectual disability. Heart defects include pulmonic stenosis, atrial septal defects and hypertrophic cardiomyopathy. Some affected individuals present with ectodermal abnormalities such as sparse, friable hair, hyperkeratotic skin lesions and a generalized ichthyosis-like condition. Typical facial features are similar to Noonan syndrome. They include high forehead with bitemporal constriction, hypoplastic supraorbital ridges, downslanting palpebral fissures, a depressed nasal bridge, and posteriorly angulated ears with prominent helices. Distinctive features of CFC3 include macrostomia and horizontal shape of palpebral fissures.
Melorheostosis, isolatedMEL
A sclerosing bone disorder characterized by hyperostosis of the cortex of tubular bones, frequently involving one limb. The lesions may be accompanied by abnormalities of adjacent soft tissue, joint contractures, sclerodermatous skin lesions, muscle atrophy, or hemangioma.
Sources
Last updated 5/8/2026, 1:08:25 AM