MAPK1

Chr 22AD

mitogen-activated protein kinase 1

Also known as: ERK, ERK-2, ERK2, ERT1, MAPK2, NS13, P42MAPK, PRKM1

The MAPK1 protein is a serine/threonine kinase that serves as an essential component of the MAP kinase/ERK signaling pathway, regulating cellular processes including proliferation, differentiation, transcription, and development through phosphorylation of diverse nuclear and cytoplasmic substrates. Mutations cause autosomal dominant Noonan syndrome 13, a developmental disorder affecting multiple organ systems. This gene is highly constrained against loss-of-function variants (pLI 0.997, LOEUF 0.175), indicating that complete loss of protein function is likely incompatible with normal development.

OMIMResearchSummary from RefSeq, OMIM, UniProt
GOFmechanismADLOEUF 0.171 OMIM phenotype
Clinical SummaryMAPK1
Population Constraint (gnomAD)
Highly constrained gene — heterozygous loss-of-function variants are very rare in the population (pLI 1.00). One damaged copy is likely sufficient to cause disease.
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Clinical Trials
2 active or recruiting trials — potential therapeutic options may be available

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Dual constrained — LoF & missense intolerant
LoF Constraint
0.17LOEUF
pLI 0.997
Z-score 3.83
OE 0.00 (0.000.17)
Highly constrained

Highly LoF-intolerant (top ~10% of genes)

Missense Constraint
3.61Z-score
OE missense 0.26 (0.200.33)
48 obs / 186.9 exp
Constrained

Highly missense-constrained (top ~0.1%)

Observed / Expected Ratios
LoF OE0.00 (0.000.17)
00.351.4
Missense OE0.26 (0.200.33)
00.61.4
Synonymous OE1.08
01.21.6
LoF obs/exp: 0 / 17.1Missense obs/exp: 48 / 186.9Syn Z: -0.49
Curated Mechanism (G2P)Gene2Phenotype (DDG2P) ↗
moderateMAPK1-related Noonan syndromeGOFAD
DN
0.4289th %ile
GOF
0.5071th %ile
LOF
0.72top 10%

The highest-scoring mechanism for this gene is loss-of-function (haploinsufficiency).

LOFprediction above median · 1 literature citation · LOEUF 0.17

Note: In-silico variant effect predictors (SIFT, PolyPhen, REVEL, CADD) may underestimate pathogenicity of missense variants in genes with GOF or DN mechanisms. Consider functional evidence and clinical context.

Literature Evidence

LOFWe demonstrate haplo-insufficient ERK2 expression in patients with a novel ?1 Mb micro-deletion in distal 22q11.2, a region that includes ERK2. These patients exhibit conotruncal and craniofacial anomalies that arise from perturbation of neural crest development and exhibit defects comparable to thePMID:18952847

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312. Mechanism ranking also informed by gnomAD constraint, ClinVar, and ClinGen data.

ClinVar Variant Classifications

0 submitted variants in ClinVar

Protein Context — Lollipop Plot

MAPK1 · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

3D Protein StructureAlphaFold
Clinical Literature
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