KCNJ11: Genetic Polymorphisms and Risk of Diabetes Mellitus

Figure 2

Mechanism of insulin secretion by the KATP channel in pancreatic beta cells. The Kir6.2 and SUR1 proteins in the KATP channel mediate insulin secretion. An increase in glucose levels stimulates the KATP channel to allow the entry of potassium ions. An increase in intracellular potassium ions depolarizes the cell membrane and induces calcium channels to increase intracellular free Ca²⁺ levels. The calcium ions trigger other components of the insulin secretion pathway to release granules at or near the plasma membrane. KATP: ATP-sensitive potassium channel; Kir6.2: inward-rectifier potassium ion channel; SUR1: sulfonylurea receptor 1; ATP: adenosine triphosphate; K⁺: potassium ion; Ca²⁺: calcium ion. The calcium channel is composed of , , , , and subunits.