Taste Receptor Genes

Bachmanov, Alexander A.; Beauchamp, Gary K.

doi:10.1146/annurev.nutr.26.061505.111329

Cited by 390 publications

(405 citation statements)

References 177 publications

(254 reference statements)

Supporting

Mentioning

394

Contrasting

Unclassified

Order By: Relevance

“…93 The concept of umami, which perhaps translates best into English as “savory” or “meaty,” was suggested by Japanese investigators as a unique quality exemplified by monosodium glutamate (MSG). Umami also has a synergistic property: When MSG is combined with ribonucleotides such as inosine monophosphate (compounds often found in meat), the perceived intensity of the mixture is higher than the intensity of either compound alone.…”

Section: Umami: Savory or Meatymentioning

confidence: 99%

Genetics of Taste and Smell

Reed

Knaapila

2010

Progress in Molecular Biology and Translational Science

218

118

View full text Add to dashboard Cite

Eating is dangerous. While food contains nutrients and calories that animals need to produce heat and energy, it may also contain harmful parasites, bacteria, or chemicals. To guide food selection, the senses of taste and smell have evolved to alert us to the bitter taste of poisons and the sour taste and off-putting smell of spoiled foods. These sensory systems help people and animals to eat defensively, and they provide the brake that helps them avoid ingesting foods that are harmful. But choices about which foods to eat are motivated by more than avoiding the bad; they are also motivated by seeking the good, such as fat and sugar. However, just as not everyone is equally capable of sensing toxins in food, not everyone is equally enthusiastic about consuming high-fat, high-sugar foods. Genetic studies in humans and experimental animals strongly suggest that the liking of sugar and fat is influenced by genotype; likewise, the abilities to detect bitterness and the malodors of rotting food are highly variable among individuals. Understanding the exact genes and genetic differences that affect food intake may provide important clues in obesity treatment by allowing caregivers to tailor dietary recommendations to the chemosensory landscape of each person.

show abstract

Section: Umami: Savory or Meatymentioning

confidence: 99%

Genetics of Taste and Smell

Reed

Knaapila

2010

Progress in Molecular Biology and Translational Science

218

118

View full text Add to dashboard Cite

show abstract

“…The receptors for sweet, umami and bitter tastes are G protein-coupled receptors (GPCRs) (1). Sweet taste is mediated largely by a heteromer of two closely related Tas1r (type 1 taste receptor) family GPCRs: Tas1r2 and Tas1r3 (2)(3)(4)(5).…”

mentioning

confidence: 99%

“…JN130349-JN130360 (sea lion, fur seal, Pacific Harbor seal, Asian small-clawed otter, spotted hyena, fossa, banded linsang, aardwolf, Canadian otter, spectacled bear, raccoon, and red wolf Tas1r2 sequences, respectively); JN413105 (sea lion Tas1r1); JN413106 (sea lion Tas1r3); JN622015 (dolphin Tas1r1); JN622016 (dolphin Tas1r2); JN622017 (dolphin Tas1r3); and JN622018-JN622027 (dolphin Tas2rs)]. 1 To whom correspondence may be addressed. E-mail: pjiang@monell.org or beauchamp@ monell.org.…”

mentioning

confidence: 99%

Major taste loss in carnivorous mammals

Jiang

Josue

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

251

201

View full text Add to dashboard Cite

Mammalian sweet taste is primarily mediated by the type 1 taste receptor Tas1r2/Tas1r3, whereas Tas1r1/Tas1r3 act as the principal umami taste receptor. Bitter taste is mediated by a different group of G protein-coupled receptors, the Tas2rs, numbering 3 to ∼66, depending on the species. We showed previously that the behavioral indifference of cats toward sweet-tasting compounds can be explained by the pseudogenization of the Tas1r2 gene, which encodes the Tas1r2 receptor. To examine the generality of this finding, we sequenced the entire coding region of Tas1r2 from 12 species in the order Carnivora. Seven of these nonfeline species, all of which are exclusive meat eaters, also have independently pseudogenized Tas1r2 caused by ORF-disrupting mutations. Fittingly, the purifying selection pressure is markedly relaxed in these species with a pseudogenized Tas1r2. In behavioral tests, the Asian otter (defective Tas1r2) showed no preference for sweet compounds, but the spectacled bear (intact Tas1r2) did. In addition to the inactivation of Tas1r2, we found that sea lion Tas1r1 and Tas1r3 are also pseudogenized, consistent with their unique feeding behavior, which entails swallowing food whole without chewing. The extensive loss of Tas1r receptor function is not restricted to the sea lion: the bottlenose dolphin, which evolved independently from the sea lion but displays similar feeding behavior, also has all three Tas1rs inactivated, and may also lack functional bitter receptors. These data provide strong support for the view that loss of taste receptor function in mammals is widespread and directly related to feeding specializations.diet | sweetener I t is widely believed that most mammals perceive five basic taste qualities: sweet, umami, bitter, salty, and sour. The receptors for sweet, umami and bitter tastes are G protein-coupled receptors (GPCRs) (1). Sweet taste is mediated largely by a heteromer of two closely related Tas1r (type 1 taste receptor) family GPCRs: Tas1r2 and Tas1r3 (2-5). Tas1r1, another member of the Tas1r family, in combination with Tas1r3, forms an umami taste receptor (6). Tas1r receptors are class C GPCRs. Unlike sweet and umami tastes, bitter taste is mediated by Tas2r family GPCRs, which belong to class A GPCRs and are structurally unrelated to Tas1r family receptors (7,8). The genes encoding Tas2r receptors, the Tas2r genes, differ substantially in gene number and primary sequences among species, most likely reflecting the likelihood that these genes are required for detecting toxic or harmful substances in a species' ecological niche (9-11).Direct evidence for a close correlation between taste function and feeding ecology comes from work on domestic and wild Felidae. Cats, obligate carnivores, are behaviorally insensitive to sweet-tasting compounds (12, 13). We proposed that this behavioral insensitivity was a consequence of the pseudogenization of Tas1r2 (14). Tas1r2 also is known to be pseudogenized in chicken, tongueless Western clawed frogs, and vampire bats (11,15). The loss of th...

show abstract

“…1). The Tas1r3 gene encoding T1r3 is allelic to Sac (2-7), the major genetic determinant of saccharin and sugar preference in inbred mice (8)(9)(10).…”

mentioning

confidence: 99%

Glucose transporters and ATP-gated K ⁺ (K _ATP ) metabolic sensors are present in type 1 taste receptor 3 (T1r3)-expressing taste cells

Yee

Sukumaran

Kotha

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

192

178

View full text Add to dashboard Cite

Although the heteromeric combination of type 1 taste receptors 2 and 3 (T1r2 + T1r3) is well established as the major receptor for sugars and noncaloric sweeteners, there is also evidence of T1r-independent sweet taste in mice, particularly so for sugars. Before the molecular cloning of the T1rs, it had been proposed that sweet taste detection depended on ( a ) activation of sugar-gated cation channels and/or ( b ) sugar binding to G protein-coupled receptors to initiate second-messenger cascades. By either mechanism, sugars would elicit depolarization of sweet-responsive taste cells, which would transmit their signal to gustatory afferents. We examined the nature of T1r-independent sweet taste; our starting point was to determine if taste cells express glucose transporters (GLUTs) and metabolic sensors that serve as sugar sensors in other tissues. Using RT-PCR, quantitative PCR, in situ hybridization, and immunohistochemistry, we determined that several GLUTs (GLUT2, GLUT4, GLUT8, and GLUT9), a sodium–glucose cotransporter (SGLT1), and two components of the ATP-gated K + (K ATP ) metabolic sensor [sulfonylurea receptor (SUR) 1 and potassium inwardly rectifying channel (Kir) 6.1] were expressed selectively in taste cells. Consistent with a role in sweet taste, GLUT4, SGLT1, and SUR1 were expressed preferentially in T1r3-positive taste cells. Electrophysiological recording determined that nearly 20% of the total outward current of mouse fungiform taste cells was composed of K ATP channels. Because the overwhelming majority of T1r3-expressing taste cells also express SUR1, and vice versa, it is likely that K ATP channels constitute a major portion of K + channels in the T1r3 subset of taste cells. Taste cell-expressed glucose sensors and K ATP may serve as mediators of the T1r-independent sweet taste of sugars.

show abstract

Taste Receptor Genes

Cited by 390 publications

References 177 publications

Genetics of Taste and Smell

Genetics of Taste and Smell

Major taste loss in carnivorous mammals

Glucose transporters and ATP-gated K ⁺ (K _ATP ) metabolic sensors are present in type 1 taste receptor 3 (T1r3)-expressing taste cells

Contact Info

Product

Resources

About

Taste Receptor Genes

Cited by 390 publications

References 177 publications

Genetics of Taste and Smell

Genetics of Taste and Smell

Major taste loss in carnivorous mammals

Glucose transporters and ATP-gated K + (K ATP ) metabolic sensors are present in type 1 taste receptor 3 (T1r3)-expressing taste cells

Contact Info

Product

Resources

About

Glucose transporters and ATP-gated K ⁺ (K _ATP ) metabolic sensors are present in type 1 taste receptor 3 (T1r3)-expressing taste cells