The structure and function of the ATP-sensitive K+ channel in insulin-secreting pancreatic beta-cells

ATP-sensitive K+ channels (K-ATP channels) play important Poles in many cel lular functions by coupling cell metabolism to electrical activity. The K-A TP channels in pancreatic beta-cells are thought to be critical in the regu lation of glucose-induced and sulfonylurea-induced insulin secretion. Until recently, however, the molecular structure of the K-ATP channel nas not kn own. Cloning members of the novel inwardly rectifying K+ channel subfamily Kir6.0 (Kir6.1 and Kir6.2) and the sulfonylurea receptors (SUR1 and SUR2) h as clarified the molecular structure of K-ATP channels. The pancreatic beta -cell K-ATP channel comprises two subunits: a Kir6.2 subunit and an SUR1 su bunit. Molecular biological and molecular genetic studies have provided ins ights into the physiological and pathophysiological roles of the pancreatic beta-cell K-ATP channel in insulin secretion.