Entrez ID	Official symbol	Synonyms	Description	Location	Type of protein	External annotation
346562	GNAT3	GDCA	G protein subunit alpha transducin 3	7q21.11	protein-coding	Genecard

uniprot_summary

refseq_summary

Guanine nucleotide-binding protein (G protein) alpha subunit playing a prominent role in bitter and sweet taste transduction as well as in umami (monosodium glutamate, monopotassium glutamate, and inosine monophosphate) taste transduction. Transduction by this alpha subunit involves coupling of specific cell-surface receptors with a cGMP-phosphodiesterase; Activation of phosphodiesterase lowers intracellular levels of cAMP and cGMP which may open a cyclic nucleotide-suppressible cation channel leading to influx of calcium, ultimately leading to release of neurotransmitter. Indeed, denatonium and strychnine induce transient reduction in cAMP and cGMP in taste tissue, whereas this decrease is inhibited by GNAT3 antibody. Gustducin heterotrimer transduces response to bitter and sweet compounds via regulation of phosphodiesterase for alpha subunit, as well as via activation of phospholipase C for beta and gamma subunits, with ultimate increase inositol trisphosphate and increase of intracellular Calcium. GNAT3 can functionally couple to taste receptors to transmit intracellular signal: receptor heterodimer TAS1R2/TAS1R3 senses sweetness and TAS1R1/TAS1R3 transduces umami taste, whereas the T2R family GPCRs act as bitter sensors. Functions also as lumenal sugar sensors in the gut to control the expression of the Na+-glucose transporter SGLT1 in response to dietaty sugar, as well as the secretion of Glucagon-like peptide-1, GLP-1 and glucose-dependent insulinotropic polypeptide, GIP. Thus, may modulate the gut capacity to absorb sugars, with implications in malabsorption syndromes and diet-related disorders including diabetes and obesity.

Sweet, bitter, and umami tastes are transmitted from taste receptors by a specific guanine nucleotide binding protein. The protein encoded by this gene is the alpha subunit of this heterotrimeric G protein, which is found not only in the oral epithelium but also in gut tissues. Variations in this gene have been linked to metabolic syndrome.

Flase

Caregory	Description	Value	Value range ( Low - High )	Comment
PLI	The probability of being loss-of-function (LoF) intolerant	-	[0, ..., 1]	Genes with high pLI scores (pLI ≥ 0.9) are extremely LoF intolerant, whereby genes with low pLI scores (pLI ≤ 0.1) are LoF tolerant. The score is calculated based on high-quality exome sequence data (ExAC) for 60,706 individuals of diverse ethnicities.
Haploinsufficiency (HI) score rank	Predicted probability of exhibiting haploinsufficiency		[100, ..., 1]	High ranks (e.g. 0-10%) indicate a gene is more likely to exhibit haploinsufficiency, low ranks (e.g. 90-100%) indicate a gene is more likely to NOT exhibit haploinsufficiency (DECIPHER, PMID: 20976243). haploinsufficiency means a single functional copy of a gene is insufficient to maintain its normal function and is extremely intolerant of LoF variation.
Gene brain expressed	Queried gene is expressed in brain tissues	Flase	[False, True]	The gene expression data are extracted from GTEx v7 and BrainSpan. A gene with the expression value of (log 2 based (TPM+1)) at least 1 TPM/RPKM/FPKM in one or more tissues related to the brain is considered brain-expressed.
Protein brain expressed	Queried protein is expressed in brain tissues	[False, True]	The protein expression data are extracted from ProteomicsDB (v2018.09). A protein with the expression value of (log based 10 (iBAQ intensity)) at least 0.5 in one or more tissues related to the brain is considered brain-expressed protein.
Carrying LoF DNMs	Number of loss-of-function DNMs hit the queried gene	0 (Case)	[0, ..., 67] with average of 0.160	Loss of function (LoF) mutations include frameshift indels, nonsense (stop-gained) and splice-site mutations, which can result in the gene product having less or no function and can have deleterious consequences.
		0 (Control)	[0, ..., 6] with average of 0.044
Carrying missense DNMs	Number of missense DNMs hit the queried gene	1 (Case)	[0, ..., 55] with average of 0.846	Missense mutations can result in changes in protein sequences, but are commonly considered to have less deleterious impacts than LoF mutations.
		0 (Control)	[0, ..., 21] with average of 0.300
FMRP binding targets	FMRP inteacting parters	False	[False, True]	FMRP loss of function causes Fragile X syndrome (FXS). The binding targets identified crosslinking immunoprecipitation (HITS-CLIP) in mouse brains (PMID:21784246). Many FMRP targets are among genes implicated in different neuropsychiatric diseases, such as autism, schizophrenia.
Postsynaptic density (PSD)	Protein associates with postsynaptic membranes of excitatory synapses	False	[False, True]	Abnormalities with PSD proteins are linked to various neuropsychiatric diseases including neurodevelopmental disorders.
Human essential genes	-	False	[False, True]	Genes are thought to be critical for human survival.