Unraveling the core mechanisms of taste formation: conformational changes and signal transduction of GPCRs and ion channel receptors

Deciphering how molecular events underlying taste perception are central to sensory and flavor modulation. The key lies in elucidating how receptors convert chemical recognition into activation signals through conformational changes. Taste arises from two major receptor families: G protein-coupled receptors (GPCRs) and ion channel receptors, which convert chemical stimuli into neural responses through distinct signaling pathways. GPCRs mediate the discrimination of sweet, umami, and bitter, while ion channels rapidly detect sour and salt, together forming a complementary system. Advances in X-ray crystallography and cryo-electron microscopy (cryo-EM) have revealed structural features, conformational dynamics, and signaling mechanisms of diverse taste receptors, deepening insight into taste formation and supporting modern taste theory. This review provides an overview of research on the mechanism of taste formation, highlights key structural analysis technologies, and discusses remaining challenges and future directions. The findings provide theoretical foundations for flavor regulation and therapeutic approaches to taste disorders, advancing molecular-level research in food sensory science.