GNAQ
Function
Guanine nucleotide-binding proteins (G proteins) function as transducers downstream of G protein-coupled receptors (GPCRs) in numerous signaling cascades (PubMed:37991948). The alpha chain contains the guanine nucleotide binding site and alternates between an active, GTP-bound state and an inactive, GDP-bound state (PubMed:37991948). Signaling by an activated GPCR promotes GDP release and GTP binding (PubMed:37991948). The alpha subunit has a low GTPase activity that converts bound GTP to GDP, thereby terminating the signal (PubMed:37991948). Both GDP release and GTP hydrolysis are modulated by numerous regulatory proteins (PubMed:37991948). Signaling is mediated via phospholipase C-beta-dependent inositol lipid hydrolysis for signal propagation: activates phospholipase C-beta: following GPCR activation, GNAQ activates PLC-beta (PLCB1, PLCB2, PLCB3 or PLCB4), leading to production of diacylglycerol (DAG) and inositol 1,4,5-trisphosphate (IP3) (PubMed:37991948). Required for platelet activation (By similarity). Regulates B-cell selection and survival and is required to prevent B-cell-dependent autoimmunity (By similarity). Regulates chemotaxis of BM-derived neutrophils and dendritic cells (in vitro) (By similarity). Transduces FFAR4 signaling in response to long-chain fatty acids (LCFAs) (PubMed:27852822). Together with GNA11, required for heart development (By similarity).
Involvement in disease
Capillary malformations, congenital
CMC
A form of vascular malformations that are present from birth, tend to grow with the individual, do not regress spontaneously, and show normal rates of endothelial cell turnover. Capillary malformations are distinct from capillary hemangiomas, which are highly proliferative lesions that appear shortly after birth and show rapid growth, slow involution, and endothelial hypercellularity.
None
The disease is caused by variants affecting the gene represented in this entry.
Sturge-Weber syndrome
SWS
A syndrome characterized by an intracranial vascular anomaly, leptomeningeal angiomatosis, most often involving the occipital and posterior parietal lobes. The most common features are facial cutaneous vascular malformations (port-wine stains), seizures, and glaucoma. Stasis results in ischemia underlying the leptomeningeal angiomatosis, leading to calcification and laminar cortical necrosis. The clinical course is highly variable and some children experience intractable seizures, intellectual disability, and recurrent stroke-like episodes.
None
The disease is caused by variants affecting the gene represented in this entry.
Post-translational modifications
Palmitoylated by ZDHHC3 and ZDHHC7 (PubMed:19001095). Palmitoylation occurs in the Golgi and participates in the localization of GNAQ to the plasma membrane (PubMed:19001095).
(Microbial infection) Deamidated at Gln-209 by Photorhabdus asymbiotica toxin PAU_02230, blocking GTP hydrolysis of heterotrimeric GNAQ or GNA11 and G-alphai (GNAI1, GNAI2 or GNAI3) proteins, thereby activating RhoA.
Histaminylated at Gln-209 residues by TGM2.
Sequence Similarities
Belongs to the G-alpha family. G(q) subfamily.
Tissue Specificity
Predominantly expressed in ovary, prostate, testis and colon. Down-regulated in the peripheral blood lymphocytes (PBLs) of rheumatoid arthritis patients (at protein level).
Cellular localization
- Cell membrane
- Lipid-anchor
- Golgi apparatus
- Nucleus
- Nucleus membrane
- Colocalizes with the adrenergic receptors, ADREN1A and ADREN1B, at the nuclear membrane of cardiac myocytes.
Alternative names
GAQ, GNAQ, Guanine nucleotide-binding protein G(q) subunit alpha, Guanine nucleotide-binding protein alpha-q