The sweet taste receptor, glucose transporters, and the ATP-sensitive K⁺ (K_ATP) channel: sugar sensing for the regulation of energy homeostasis

Sugar detection in the oral cavity does not solely depend on the TAS1R2 + TAS1R3 sweet receptor. Similar to gut, pancreas, and hypothalamic neurons, in the tongue glucose transporters and ATP-sensitive K⁺ (K_ATP) channels are also involved in sugar detection. Among them, the K_ATP channel is the target for the antiobesity hormone leptin, which inhibits sugar-sensitive cells such as sweet taste cells, pancreatic β-cells, and hypothalamic orexigenic neurons. Sugar signals from the taste organ elicit cephalic-phase insulin release, and those from the gut contribute to sweet preference for caloric sugars. All of these systems are indispensable for maintaining energy homeostasis. Thus, an exquisite system for sugar detection/signaling to regulate energy homeostasis exists in our body.