Identification of a novel member of the T1R family of putative taste receptors

In the gustatory system, the recognition of sugars, amino acids and bitter- tasting compounds is the function of specialized G rotein-coupled receptors . Recently, two members of novel subfamily of G protein-coupled receptors w ere proposed to function as taste receptors based on their specific express ion in taste receptor cells. Here, we report the identification of a third member, T1R3, of this family of receptors. T1R3 maps near the telomere of m ouse chromosome 4 rendering it a candidate for the Sac locus, a primary det erminant of sweet preference in mice. Consistent with its candidacy for the Sac locus, T1R3 displays taste receptor cell-specific expression. In addit ion, taster and non-taster strains of mouse harbor different alleles of T1R 3.