Molecular mechanisms of signal transduction by bitter taste receptors

GPCRs(G蛋白偶联受体)是膜蛋白中最大、种类最多的一类。人类能够分辨出五种味道，即甜、鲜味、苦、酸和盐。甜味、鲜味和苦味的信号转导是通过GPCRs进行的，而酸味和盐味的信号转导是通过离子通道进行的。感受苦味的分子事件始于特定的水溶性分子(味精)与苦味受体的跨膜区结合，启动细胞内的信号级联反应。然而，这些苦味受体的分子作用机制却知之甚少。了解苦味受体如何与它们的味觉者相互作用，将有助于设计出增强食物风味的人工味觉。本研究计划结合细胞、生物化学和生物物理的方法来阐明苦味受体信号转导的分子机制，将加深我们对苦味感受的理解。

GPCRs (G-protein coupled receptors) constitute the largest and the most diverse group of membrane proteins. Humans are capable of detecting five tastes which are, sweet, umami, bitter, sour and salt. While the signal transduction for sweet, umami and bitter tastes are through GPCRs, the sour and salt tastes are sensed by ion channels. The molecular events in the perception of bitter taste start with the binding of specific water-soluble molecules (tastants) to the transmembrane domains of bitter receptors initiating an intracellular signaling cascade. However, the molecular mechanisms of action of these bitter receptors are poorly understood. Knowledge about how bitter receptors interact with their tastants will enable design of artificial tastants that enhance food flavor. This research program focuses on elucidating the molecular mechanisms of signal transduction by bitter receptors using a combination of cellular, biochemical and biophysical approaches, and will enhance our understanding of bitter taste perception.