TAS2R14 | |||||||||||||||||||||||||||||||||||||||||||||||||||
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Aliases | TAS2R14 , T2R14, TRB1, taste 2 receptor member 14 | ||||||||||||||||||||||||||||||||||||||||||||||||||
External IDs | OMIM: 604790 MGI: 2681298 HomoloGene: 87013 GeneCards: TAS2R14 | ||||||||||||||||||||||||||||||||||||||||||||||||||
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Taste receptor type 2 member 14 is a protein that in humans is encoded by the TAS2R14 gene. [5] [6] [7]
Taste receptors for bitter substances (T2Rs/TAS2Rs) belong to the family of G-protein coupled receptors and are related to class A-like GPCRs. There are 25 known T2Rs in humans responsible for bitter taste perception. [8]
Bitter taste receptor hTAS2R14 is one of the human bitter taste receptors, recognizing an enormous variety of structurally different molecules, including natural and synthetic bitter compounds. [9]
TAS2R14 gene [5] [7] (Taste receptor type 2 member 14) is a Protein Coding gene. This gene maps to the taste receptor gene cluster on chromosome 12p13. [10]
An important paralog of this gene is TAS2R13.
Taste receptors harbor many polymorphisms, and several SNPs have a profound impact on the gene function and expression.
Mutation | dbSNP |
---|---|
I5M | rs79297986 |
F63L | rs142263768 |
C67S | rs140545738 |
T86A | rs16925868 |
N87Y | rs146833217 |
I118V | rs4140968 |
F198L | rs202123922 |
L201F | rs35804287 |
K211R | rs111614880 |
Data obtained from 1000 genomes project.
The following residues have been subjected to site-directed mutagenesis. [11]
Location | BW number [12] | Residue |
TM2 | 2.61 | W66 |
ECL1 | 3.28 | L85 |
ECL1 | 3.29 | T86 |
ECL1 | 3.3 | N87 |
TM3 | 3.32 | W89 |
TM3 | 3.33 | T90 |
TM3 | 3.36 | N93 |
TM3 | 3.37 | H94 |
ECL2 | 5.42 | T182 |
ECL2 | 5.43 | S183 |
TM5 | 5.46 | F186 |
TM5 | 5.47 | I187 |
TM6 | 6.48 | Y240 |
TM6 | 6.49 | A241 |
TM6 | 6.51 | F243 |
TM6 | 6.55 | F247 |
TM7 | 7.36 | I263 |
TM7 | 7.39 | Q266 |
TM7 | 7.42 | G269 |
TAS2Rs activation produces modulation of a broad range of signal transduction pathways. The Gαgusducin (Gαgus), which belongs to the Gαi subfamily, was first identified and cloned in 1992 in taste tissue, and has high similarity to the Gα-transducin (Gαtrans) in the retina. Gα16gus44, a chimeric Gα16 (type of Gαq), harboring 44 gustducin specific sequence at its C terminus, or Gαqi5, a Gαq protein containing the five carboxyl-terminal amino acids from Gαi, are often used in order to couple the taste receptor to Gαq pathway and measure calcium or IP3 release. Specifically, stimulation of a GPCR receptor, coupled to Gαq, results in the activation of phospholipase C β2 (PLC), which then stimulates the second messengers 1,4,5-inositol trisphosphate (IP3) and diacylglycerol (DAG). IP3 causes the release of Ca+2 from intracellular stores. Calcium opens Ca-activated TRP ion channels and leads to depolarization of the cell as well as to release of neurotransmitters. [13]
To date, 151 ligands have been identified for T2R14, [14] [15] in addition to 12 synthetic flufenamic acid derivatives. [16]
In addition to the tongue, TAS2R14 is expressed in many other tissues including the heart, [17] thyroid, [18] stomach, [19] skin, [20] urogenital, [21] [22] [23] [24] immune system, [25] and more.
This gene product belongs to the family of taste receptors that are members of the G-protein-coupled receptor superfamily. These proteins are specifically expressed in the taste receptor cells of the tongue and palate epithelia. They are organized in the genome in clusters and are genetically linked to loci that influence bitter perception in mice and humans. In functional expression studies, TAS2R14 responds to (−)-α-thujone, the primary neurotoxic agent in absinthe, and picrotoxin, a poison found in fishberries. [26] This gene maps to the taste receptor gene cluster on chromosome 12p13. [7]
TAS2R14 is also expressed in the smooth muscle of human airways, along with several other bitter taste receptors. Their activation in these cells causes an increase in intracellular calcium ion, which in turn triggers the opening of potassium channels which hyperpolarize the membrane and cause the smooth muscle to relax. Hence, activation of these receptors leads to bronchodilation. [27]
In the respiratory system, several TAS2R subtypes: TAS2R4, TAS2R16, TAS2R14 and TAS2R38, were found to play important roles in innate immune nitric oxide production (NO). [28]
T2R14 causes inhibition of IgE-dependent mast cells. [29]
Associations between single nucleotide polymorphisms in TAS214 gene and male infertility were observed. [23]
Aftertaste is the taste intensity of a food or beverage that is perceived immediately after that food or beverage is removed from the mouth. The aftertastes of different foods and beverages can vary by intensity and over time, but the unifying feature of aftertaste is that it is perceived after a food or beverage is either swallowed or spat out. The neurobiological mechanisms of taste signal transduction from the taste receptors in the mouth to the brain have not yet been fully understood. However, the primary taste processing area located in the insula has been observed to be involved in aftertaste perception.
TAS2R16 is a bitter taste receptor and one of the 25 TAS2Rs. TAS2Rs are receptors that belong to the G-protein-coupled receptors (GPCRs) family. These receptors detect various bitter substances found in nature as agonists, and get stimulated. TAS2R16 receptor is mainly expressed within taste buds present on the surface of the tongue and palate epithelium. TAS2R16 is activated by bitter β-glucopyranosides
A taste receptor or tastant is a type of cellular receptor which facilitates the sensation of taste. When food or other substances enter the mouth, molecules interact with saliva and are bound to taste receptors in the oral cavity and other locations. Molecules which give a sensation of taste are considered "sapid".
Taste receptor 2 member 38 is a protein that in humans is encoded by the TAS2R38 gene. TAS2R38 is a bitter taste receptor; varying genotypes of TAS2R38 influence the ability to taste both 6-n-propylthiouracil (PROP) and phenylthiocarbamide (PTC). Though it has often been proposed that varying taste receptor genotypes could influence tasting ability, TAS2R38 is one of the few taste receptors shown to have this function.
Taste receptor type 2 member 1 (TAS2R1/T2R1) is a protein that in humans is encoded by the TAS2R1 gene. It belongs to the G protein-coupled receptor (GPCR) family and is related to class A-like GPCRs, they contain 7 transmembrane helix bundles and short N-terminus loop. Furthermore, TAS2R1 is member of the 25 known human bitter taste receptors, which enable the perception of bitter taste in the mouth cavity. Increasing evidence indicates a functional role of TAS2Rs in extra-oral tissues.
Taste receptor type 2 member 4 is a protein that in humans is encoded by the TAS2R4 gene.
Taste receptor type 2 member 9 is a protein that in humans is encoded by the TAS2R9 gene.
Taste receptor type 2 member 10 is a protein that in humans is encoded by the TAS2R10 gene. The protein is responsible for bitter taste recognition in mammals. It serves as a defense mechanism to prevent consumption of toxic substances which often have a characteristic bitter taste.
Taste receptor type 2 member 5 is a protein that in humans is encoded by the TAS2R5 gene.
Taste receptor type 1 member 1 is a protein that in humans is encoded by the TAS1R1 gene.
T1R2 - Taste receptor type 1 member 2 is a protein that in humans is encoded by the TAS1R2 gene.
Taste receptor type 1 member 3 is a protein that in humans is encoded by the TAS1R3 gene. The TAS1R3 gene encodes the human homolog of mouse Sac taste receptor, a major determinant of differences between sweet-sensitive and -insensitive mouse strains in their responsiveness to sucrose, saccharin, and other sweeteners.
Taste receptor type 2 member 41 is a protein that in humans is encoded by the TAS2R41 gene.
Taste receptor type 2 member 43 is a protein that in humans is encoded by the TAS2R43 gene.
Taste receptor, type 2, member 31, also known as TAS2R31, is a protein which in humans is encoded by the TAS2R31 gene. This bitter taste receptor has been shown to respond to saccharin in vitro.
Taste receptors for bitter substances (T2Rs/TAS2Rs) belong to the family of G-protein coupled receptors and are related to class A-like GPCRs. There are 25 known T2Rs in humans responsible for bitter taste perception.
Taste receptor type 2 member 19 is a protein that in humans is encoded by the TAS2R19 gene. It seems to be involved in the perception of salt and bitter tastes.
Taste receptor type 2 member 20 is a protein that in humans is encoded by the TAS2R20 gene.
Taste receptor type 2 member 50 is a protein that in humans is encoded by the TAS2R50 gene.
Taste receptor type 2 member 60 is a protein that in humans is encoded by the TAS2R60 gene.
This article incorporates text from the United States National Library of Medicine, which is in the public domain.