Characterization of the Sweet Taste Receptor T1R2/T1R3 From Chimpanzee and Comparison With the Human T1R2/T1R3

The perception of sweet taste, which is dominantly mediated by the heterodimeric sweet taste receptor composed of two subunits T1R2 and T1R3 (taste receptor type 1 member 2 and taste receptor type 1 member 3), is crucial for the diet of primates. However, there are only a small number of primate species (primarily non-hominid such as New World monkeys and lemuriforms) whose sweet taste receptors have been functionally identified until now. In this study, we characterized the sweet taste receptor T1R2/T1R3 of a hominid species, chimpanzees, humans' closest living relative, a primate. Although the activities and responses of chimpanzee T1R2/T1R3 are mostly comparable to those of human T1R2/T1R3, an obvious discrepancy in sensitivity is revealed between T1R2s/T1R3s of human and chimpanzee toward a variety of sweeteners, including natural and artificial sweet compounds. Moreover, the difference in sweet taste between humans and chimpanzees could be associated with variation in the sequence and structure of their sweet taste receptors. These results serve as a meaningful basis for further exploring the molecular mechanism of sweet taste as well as its evolution in primates.