ATP-sensitive potassium channel, pancreatic beta cell type (K_ATP channel (beta cell))

The ATP-sensitive potassium channel (K_ATP channel) in pancreatic beta cells regulates insulin secretion in response to blood glucose levels. It is a hetero-octamer comprised of four pore-forming Kir6.2 subunits and four regulatory SUR1 subunits. Sulfonylurea drugs treat type 2 diabetes by binding to SUR1, causing channel closure, cell membrane depolarization, calcium influx, and subsequent insulin secretion. Prolonged or excessive activation can lead to secondary drug failure or resistance, and the principal safety concern is increased risk of hypoglycemia, particularly in patients with fragile glycemic control[2][3][4][6][8]. This target is central to the pharmacological management of diabetes but is not a 'receptor' in the classical sense—instead, it is a drug-regulated ion channel complex.

Other names

ATP-sensitive potassium channelK_ATP channelSulfonylurea receptor channelKir6.2/SUR1 channel

Sulfonylureas bind to the SUR1 subunit, closing the K_ATP channel. - Channel closure depolarizes beta cell membrane. - Depolarization opens voltage-dependent calcium channels, causing Ca²⁺ influx. - Intracellular calcium triggers insulin granule exocytosis[2][3][4][6][8].