Putative taste receptor. TAS1R1/TAS1R3 responds to the umami taste stimulus (the taste of monosodium glutamate) and also to most of the 20 standard L-amino acids, but not to their D-enantiomers or other compounds. TAS1R2/TAS1R3 recognizes diverse natural and synthetic sweeteners. TAS1R3 is essential for the recognition and response to the disaccharide trehalose. Sequence differences within and between species can significantly influence the selectivity and specificity of taste responses. Forms homodimers or heterodimers with TAS1R1 and TAS1R2. Expressed in circumvallate, foliate and fungiform taste papillae as well as in taste buds on the palate. Also expressed in testis. Not expressed in brain, heart, kidney, liver or spleen. The topographic distribution in various taste papillae is different from those of other T1R members. The Thr-60 variant is predicted to introduce a novel N-linked glycosylation site at Asn-58. The addition of even a short carbohydrate group at Asn-58 is predicted to disrupt one of the contact surfaces required for stability of a dimer. Therefore a Thr-60 variant N-glycosylated at Asn-58 is predicted to be precluded from forming homodimers or heterodimers. Belongs to the G-protein coupled receptor 3 family. TAS1R subfamily.