ATP-sensitive potassium channel (pancreatic β-cell type) (KATP channel)

The **ATP-sensitive potassium channel** on the pancreatic β-cell membrane is a hetero-octameric ion channel composed of four inwardly rectifying potassium channel subunits (**Kir6.2**, encoded by *KCNJ11*) and four regulatory **sulfonylurea receptor 1** subunits (**SUR1**, encoded by *ABCC8*). This complex links cellular metabolic state—specifically the ratio of ATP/ADP—to membrane potential and thus controls glucose-stimulated insulin secretion. When intracellular ATP levels rise in response to increased glucose metabolism, these channels close, leading to cell depolarization and subsequent opening of voltage-gated calcium channels; this triggers exocytosis of insulin granules. Conversely, when open (low ATP), they help maintain a hyperpolarized state that suppresses insulin release. Mutations in either component can cause disorders such as congenital hyperinsulinism or various forms of diabetes depending on whether the mutation increases or decreases activity. The primary pharmacological targets are antidiabetic drugs like sulfonylureas that inhibit the KATP channels to stimulate endogenous insulin secretion in patients with type 2 diabetes.[1][2][3]

Other names

ATP-sensitive K+ channelKATP channelKir6.2/SUR1 complexInwardly rectifying potassium channel Kir6.2 with sulfonylurea receptor 1

Channel inhibition by sulfonylureas or meglitinides leads to membrane depolarization, opening voltage-dependent calcium channels, increasing intracellular calcium, and stimulating insulin release from pancreatic β-cells[2].