GNAQ Gene: Structure, Function, and Clinical Significance
A comprehensive overview of the GNAQ gene, its protein product, associated diseases, expression patterns, and mutations.
Gene Information Card
| Symbol | GNAQ |
|---|---|
| Full Name | G protein subunit alpha q |
| Gene Type | protein coding |
| Chromosomal Location | 9q21.2 |
| NCBI Gene ID | 2776 ncbi.nlm.nih.gov/gene/2776 |
| Ensembl ID | ENSG00000156052 |
| UniProt ID | P50148 |
| OMIM ID | 600998 |
| HGNC ID | 4390 |
| Aliases | G-ALPHA-q, CMC1, GNAQ, SWS, GPHAQ |
Description
The GNAQ gene encodes the alpha subunit of the heterotrimeric G protein Gq. This protein is a critical component of G protein-coupled receptor (GPCR) signaling pathways, mediating intracellular responses to various extracellular stimuli. GNAQ is involved in cell growth, differentiation, and apoptosis. Mutations in GNAQ are associated with several diseases, including uveal melanoma, Sturge-Weber syndrome, and capillary malformations. The protein functions as a signal transducer, activating downstream effectors such as phospholipase C beta (PLCβ), leading to the production of inositol trisphosphate (IP3) and diacylglycerol (DAG), which modulate calcium release and protein kinase C activity.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Uveal Melanoma | Activating mutations (e.g., Q209P/L) lead to constitutive activation of the MAPK and PI3K/AKT pathways, promoting tumorigenesis. | COSMIC, ClinVar, multiple studies |
| Sturge-Weber Syndrome | Somatic mosaic mutations (e.g., R183Q) cause aberrant Gq signaling, leading to vascular malformations and neurological symptoms. | OMIM, ClinVar, literature |
| Capillary Malformations | Somatic mutations (e.g., R183Q) are found in affected skin and brain tissues, contributing to abnormal vascular development. | OMIM, ClinVar |
| Leptomeningeal Melanocytosis | Activating mutations (e.g., Q209P) are implicated in the pathogenesis of this rare melanocytic proliferation. | COSMIC, case reports |
| Melanocytic Nevi | Activating mutations (e.g., Q209L) are found in a subset of benign nevi, suggesting a role in melanocyte proliferation. | COSMIC, literature |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 12.4 | Medium |
| Heart | 8.2 | Low |
| Liver | 6.1 | Low |
| Kidney | 7.5 | Low |
| Lung | 9.3 | Low |
| Skin | 10.5 | Medium |
| Testis | 15.2 | Medium |
| Ovary | 11.8 | Medium |
| Colon | 8.9 | Low |
| Spleen | 7.0 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HeLa | 12.5 | Cervical adenocarcinoma; moderate expression |
| A549 | 9.8 | Lung carcinoma; low expression |
| MCF7 | 11.2 | Breast adenocarcinoma; moderate expression |
| HepG2 | 8.5 | Hepatocellular carcinoma; low expression |
| K562 | 7.9 | Chronic myelogenous leukemia; low expression |
| SH-SY5Y | 14.3 | Neuroblastoma; high expression |
| U87MG | 13.1 | Glioblastoma; moderate expression |
| HUVEC | 10.0 | Endothelial cells; moderate expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| Q209P | Missense | ~50% in uveal melanoma | Constitutive activation of Gq, leading to oncogenic signaling |
| Q209L | Missense | ~20% in uveal melanoma | Constitutive activation, similar to Q209P |
| R183Q | Missense | Somatic mosaic in Sturge-Weber syndrome | Impaired GTPase activity, leading to prolonged activation |
| R183C | Missense | Rare in capillary malformations | Similar to R183Q, reduced GTP hydrolysis |
| G48V | Missense | Rare in other cancers | Altered GTP binding, potential gain-of-function |
Mutation functional classification
Loss of Function (LOF)
Loss-of-function mutations in GNAQ are rare and not well characterized. They may lead to reduced Gq signaling, potentially affecting GPCR-mediated responses, but no specific disease association has been established.
Gain of Function (GOF)
Gain-of-function mutations, particularly at Q209 and R183, are common in uveal melanoma and Sturge-Weber syndrome. These mutations impair GTPase activity, leading to constitutive activation of downstream pathways such as MAPK and PI3K/AKT, driving cell proliferation and survival.
Dominant Negative (DN)
No dominant-negative mutations have been reported for GNAQ. The known pathogenic mutations are predominantly gain-of-function.
View complete mutation data：
Gene Ontology (GO)
| • G protein-coupled receptor signaling pathway | • GTPase activity |
| • Signal transduction | • Phospholipase C activation |
| • Calcium ion homeostasis | • Cell proliferation |
| • Apoptotic process | • Regulation of MAPK cascade |
| • Heterotrimeric G-protein complex | • Plasma membrane |
Pathways
• GPCR downstream signaling
• MAPK signaling pathway
• PI3K-Akt signaling pathway
• Phospholipase C-mediated signaling
• Calcium signaling pathway
• VEGF signaling pathway
• Melanogenesis
• Wnt signaling pathway (crosstalk)
Protein Summary
The GNAQ protein (UniProt P50148) is a 359-amino acid alpha subunit of the heterotrimeric G protein Gq. It is composed of a GTPase domain and a helical domain. The protein is anchored to the plasma membrane via lipid modifications (myristoylation and palmitoylation). Upon GPCR activation, GNAQ exchanges GDP for GTP, leading to dissociation from beta/gamma subunits and activation of effector proteins such as phospholipase C beta. This results in the production of IP3 and DAG, which increase intracellular calcium and activate protein kinase C. GNAQ is widely expressed, with highest levels in brain and testis. Pathogenic mutations at Q209 and R183 lead to constitutive activation, contributing to oncogenesis and vascular malformations.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| GNAQ Knockout HEK293 Cell Line | EDJ-KQ202 | Human | 2776 | Details Get a Quote |
| GNAQ Knockout HCT 116 Cell Line | EDJ-KQ19369 | Human | 2776 | Details Get a Quote |
| GNAQ Knockout A-549 Cell Line | EDJ-KQ20716 | Human | 2776 | Details Get a Quote |
| GNAQ Knockout HeLa Cell Line | EDJ-KQ20717 | Human | 2776 | Details Get a Quote |
| GNAQ (p.Q209P) Point Mutation in HAP1 Cell Line | EDC03637 | Human | 2776 | Details Get a Quote |
| GNAQ (p.Q209R) Point Mutation in HAP1 Cell Line | EDC03638 | Human | 2776 | Details Get a Quote |
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