ATP-sensitive potassium channel subunit Kir6.2–sulfonylurea receptor 1 complex (Kir6.2–SUR1 channel (also known as the KATP channel))

The ATP-sensitive potassium (KATP) channel formed by the pore-forming Kir6.2 subunit and the regulatory sulfonylurea receptor 1 (SUR1) subunit is a critical metabolic sensor chiefly found in pancreatic β-cells but also in cardiac and neuronal tissues[1][2][3][4][5]. This hetero-octameric complex couples the metabolic state (intracellular ATP/ADP levels) to cellular membrane excitability by controlling the flow of K+ ions[1][2][3][4]. When ATP binds the Kir6.2–SUR1 channel, it closes, leading to cellular depolarization and triggering insulin secretion; when open (e.g., at low ATP), K+ efflux hyperpolarizes the cell, decreasing insulin release[1][2][4][5]. SUR1 (an ABC transporter family member) is essential for channel gating but does not act as a transporter—rather, it modulates Kir6.2’s sensitivity to nucleotides and pharmacological agents[2][3][4][6]. Drugs targeting this channel are central to the treatment of type 2 diabetes (sulfonylureas, which close the channel to promote insulin release), and rare channelopathies (e.g., diazoxide for hyperinsulinism, which opens the channel)[2][4][5]. Mutations in Kir6.2 (gene KCNJ11) or SUR1 (gene ABCC8) underlie several monogenic disorders including neonatal diabetes and congenital hyperinsulinism[2][4]. The channel's tissue-specific expression and crucial role in insulin secretion, cardiac protection, and neuronal function make it a major therapeutic target[1][2][4][5].

Other names

Sulfonylurea receptor 1/Kir6.2 channelKATP channelATP-sensitive potassium channel SUR1/Kir6.2SUR1/Kir6.2 complexKir6.2–SUR1

Drugs act as either inhibitors, closing the channel (e.g., sulfonylureas bind SUR1 to stimulate insulin secretion), or as channel openers/activators, keeping the channel open (e.g., diazoxide binds SUR1 to inhibit insulin secretion).