ATP-sensitive potassium channel (Sulfonylurea receptor 1-Inwardly rectifying potassium channel 6.2) (KATP channel)

The SUR1-Kir6.2 complex is a hetero-octameric ATP-sensitive potassium (KATP) channel that serves as a critical metabolic sensor in pancreatic beta cells and specific neuronal populations [1, 2, 4]. It is composed of four pore-forming inwardly rectifying potassium channel 6.2 (Kir6.2) subunits and four regulatory sulfonylurea receptor 1 (SUR1) subunits [2, 11, 14]. By sensing the intracellular ATP-to-ADP ratio, the channel couples cellular metabolism to membrane excitability; an increase in ATP leads to channel closure, membrane depolarization, and the subsequent release of insulin [1, 8, 11]. Dysregulation of this complex due to genetic mutations results in severe metabolic disorders, including neonatal diabetes (gain-of-function) and congenital hyperinsulinism (loss-of-function) [1, 4, 6, 11]. This channel is a major therapeutic target, with sulfonylurea drugs acting as blockers to stimulate insulin secretion in type 2 diabetes, while openers like diazoxide are used to suppress insulin overproduction in hypoglycemic conditions [12, 15].

Other names

SUR1-Kir6.2Pancreatic ATP-sensitive potassium channelABCC8-KCNJ11 complexBeta-cell KATP channelSulfonylurea receptor 1-Inwardly rectifying potassium channel 6.2 complex

Sulfonylureas and glinides act as channel blockers by binding to the SUR1 subunit, leading to channel closure, membrane depolarization, and stimulated insulin release [1, 8, 11, 12]. Conversely, potassium channel openers like diazoxide bind to SUR1 to maintain the channel in an open state, causing hyperpolarization and inhibition of insulin secretion [12, 15].