Guanine nucleotide-binding protein G(q) subunit alpha

UniProt P50148 Organism Homo sapiens Gene GAQ, GNAQ EC 3.6.5.-

Also known as: GAQ, GNAQ

Function

Guanine nucleotide-binding proteins (G proteins) function as transducers downstream of G protein-coupled receptors (GPCRs) in numerous signaling cascades. The alpha chain contains the guanine nucleotide binding site and alternates between an active, GTP-bound state and an inactive, GDP-bound state. Signaling by an activated GPCR promotes GDP release and GTP binding. The alpha subunit has a low GTPase activity that converts bound GTP to GDP, thereby terminating the signal. Both GDP release and GTP hydrolysis are modulated by numerous regulatory proteins. 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). 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). Together with GNA11, required for heart development (By similarity).

Classification

Family (Pfam): PF00503 G-alpha
InterPro: Gprotein_alpha_Q, Gprotein_alpha_su, GproteinA_insert, P-loop_NTPase
Functional cluster: Small GTPases (Ras/Rab) & related

Experimental structures · PDB · 36

6VU5 EM 3.50A
7DFL EM 3.30A
7EZM EM 2.90A
7F6G EM 2.90A
7F6H EM 2.90A
7F6I EM 2.80A
7F8W EM 3.10A
7W3Z EM 3.00A
7W40 EM 3.00A
7XOW EM 3.10A
8G59 EM 2.64A
8IA7 EM 3.10A
… and 24 more

A predicted model is available from AlphaFold.

Gene Ontology · 40

Disease associations

familial multiple nevi flammei MONDO:0008094
Sturge-Weber syndrome MONDO:0008501

Neighborhood · nearest proteins

Nearest neighbours of Guanine nucleotide-binding protein G(q) subunit alpha: 3 by sequence/function similarity (left); 3 co-cited in the literature (right).

Related proteins · sequence + function similarity

Co-cited proteins · studied together in the literature

Gastrin/cholecystokinin type B receptor 2 shared papers
Guanine nucleotide-binding protein G(q) subunit alpha 1 shared papers
Substance-K receptor 1 shared papers
Guanine nucleotide-binding protein subunit alpha-11 3 shared papers
Guanine nucleotide-binding protein subunit alpha-11 1 shared papers
Guanine nucleotide-binding protein G(q) subunit alpha 1 shared papers
B2 bradykinin receptor 1 shared papers
Chaperone Ric-8A 1 shared papers
1-phosphatidylinositol 4,5-bisphosphate phosphodiesterase beta-3 1 shared papers
Platelet endothelial cell adhesion molecule 1 shared papers
Na(+)/H(+) exchange regulatory cofactor NHE-RF1 1 shared papers
Guanine nucleotide-binding protein G(i) subunit alpha-1 3 shared papers

Literature · 27 cited papers

The mechanism of Galphaq regulation of PLCbeta3-catalyzed PIP2 hydrolysis. Proc. Natl. Acad. Sci. U.S.A. · 2023
Structural insights into human brain-gut peptide cholecystokinin receptors. Cell Discov. · 2022
Structures of the human cholecystokinin receptors bound to agonists and antagonists. Nat. Chem. Biol. · 2021
Structures of Galpha proteins in complex with their chaperone reveal quality control mechanisms. Cell Rep. · 2020
Targeted Elimination of G Proteins and Arrestins Defines Their Specific Contributions to Both Intensity and Duration of G Protein-coupled Receptor Signaling. J. Biol. Chem. · 2016
N-terminome analysis of the human mitochondrial proteome. Proteomics · 2015
An enzyme assisted RP-RPLC approach for in-depth analysis of human liver phosphoproteome. J. Proteomics · 2014
A bacterial toxin catalyzing tyrosine glycosylation of Rho and deamidation of Gq and Gi proteins. Nat. Struct. Mol. Biol. · 2013
A novel Galphas-binding protein, Gas-2 like 2, facilitates the signaling of the A2A adenosine receptor. Biochim. Biophys. Acta · 2013
Sturge-Weber syndrome and port-wine stains caused by somatic mutation in GNAQ. N. Engl. J. Med. · 2013
GNAQ and GNA11 mutations in melanocytomas of the central nervous system. Acta Neuropathol. · 2012
Expression of G protein alphaq subunit is decreased in lymphocytes from rheumatoid arthritis patients and is correlated with disease activity. Scand. J. Immunol. · 2012
… and 15 more in the literature graph

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