关键词: G蛋白偶联受体, 嗅、味觉受体, 配体（基）, G蛋白级联放大, 生物传感器

Abstract:

The mammalian gustatory system is classified into five primary tastes: umami, sweet, salty, sour and bitter,
which enable us to evaluate food constituents. The tastes have been identified as the major members of the G protein-coupled
receptor (GPCR) family, the largest family of receptor proteins in mammals (referred to as taste receptor type 1 (T1R) and
type 2 (T2R)). Another taste quality related to lipid sensing is mediated by free fatty acid (FFA) GPCR family. An increasing
number of reports on the expression of odorant and taste receptors in tissues beyond the nose and mouth started to appear in the
literature. But most literatures have been relied on reverse transcription PCR (RT-PCR) and microarray data without demonstrating
either protein expression or function. Recently, some publications are appearing on the function of odorant and taste receptors in
the gastrointestinal tract. These studies reinforce the broader potential and even more important roles beyond the odorant and taste
receptors. In this review, the prevailing evidence for the expression of odorant and taste GPCRs in cells and tissues beyond the
nose and mouth is summarized, and then the putative function for these receptors in diverse physiological functions, ranging from
nutrient sensing, regulation of nutrient uptake, metabolic balance, energy control and metabolic disorder is highlighted. Finally,
the future trends and potential applications of detection technologies for these GPCRs are expected for the evaluation of functional
ingredients such as resveratrol, polyphenols, flavonoids and other phytochemicals.

Key words: G protein-coupled receptors, odorant/taste GPCRs, ligand, G protein cascade, biosensor