General
- GNAQ (Guanine nucleotide-binding protein G(q) subunit alpha)
Gene loci
- Chromosome 9q21.
Normal function
- Together with GNA11 (its paralogue), it functions as a Gq alpha subunit.
- Encodes Gαq subunit of heterotrimeric G-protein, couples GPCRs to phospholipase Cβ, activates PKC and MAPK pathways.
- Binds GTP upon receptor activation, hydrolyzes GTP to GDP to terminate signaling.
Mutation effects
- Oncogenic mutations (Q209L/P, R183Q) inhibit GTPase activity, causing constitutive activation, hyperactivation of MAPK/ERK, YAP/TAZ, PKC pathways. → Promotes cell proliferation, survival, transformation.
Clinical association
- Uveal melanoma (UM, 46-50% Q209 mutations, initiating event).pmc.ncbi.nlm.nih+1
- Blue nevus, ocular melanocytosis.pmc.ncbi.nlm.nih
- Sturge–Weber syndrome (R183Q somatic, port-wine stain, glaucoma, seizures)
- Choroidal hemangioma, primary myelofibrosis, hepatocellular carcinoma.
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