ATP-sensitive potassium channel (KATP channel; composed of sulfonylurea receptor 1 (SUR1) and inward rectifier potassium channel subunit Kir6.2) (KATP channel (SUR1/Kir6.2 complex))

The ATP-sensitive potassium channel (KATP channel) is an octameric transmembrane protein complex composed of four inwardly rectifying potassium channel (Kir6.2) subunits and four sulfonylurea receptor 1 (SUR1) subunits. SUR1, encoded by the ABCC8 gene, belongs to the ATP-binding cassette (ABC) transporter family and serves as the regulatory subunit, while Kir6.2 (KCNJ11) forms the potassium-conducting pore. Together, these proteins couple the metabolic state of the cell (sensing ATP/ADP ratios) to membrane excitability, most prominently in pancreatic beta cells to control insulin secretion, but also in cardiac and some neuronal tissues. Sulfonylureas (e.g., glibenclamide, tolbutamide) target SUR1 to close the channel, triggering beta-cell membrane depolarization and insulin release, making this channel a major target for type 2 diabetes therapy. Mutations in either ABCC8 or KCNJ11 lead to significant metabolic disorders, including congenital hyperinsulinism and neonatal diabetes. The channel's tissue-specific roles extend to cardioprotection and neuroprotection during metabolic stress and ischemic injury.

Other names

KATP channelATP-sensitive potassium channelSulfonylurea receptor 1Kir6.2KIR6.x/SUR complex

Sulfonylureas block SUR1, closing the KATP channel, leading to membrane depolarization and secretion of insulin; KATP channel openers (e.g., diazoxide) activate the channel, leading to hyperpolarization and reduced insulin secretion or modulation of vascular/cardiac tone; Physiological ligands (ATP inhibits the channel, ADP activates via binding regulatory subunits)