Sulfonylurea receptor 1-containing ATP-sensitive potassium channel (SUR1/Kir6.2 KATP channel)

Sulfonylurea receptor 1 (SUR1) is the regulatory subunit of the ATP-sensitive potassium (KATP) channel, a critical ion channel that couples cell metabolism to membrane excitability. In pancreatic beta cells, the KATP channel is a hetero-octamer composed of four SUR1 (encoded by ABCC8) and four Kir6.2 subunits (encoded by KCNJ11). When intracellular ATP rises, the channel closes, causing depolarization and triggering insulin secretion; sulfonylurea drugs bind to SUR1 and forcibly close the channel, stimulating insulin release. KATP channels with SUR1 are also expressed in neural and cardiovascular tissues, mediating cellular responses to metabolic stress. Mutations in SUR1 or Kir6.2 cause several human diseases, notably forms of diabetes and congenital hyperinsulinism. This channel complex is therapeutically targeted by antidiabetic sulfonylureas and KATP channel modulators, and has roles in the pathophysiology of diabetes, ischemic brain injury, and some cardiovascular conditions.

Other names

KATP channel (beta cell type)ATP-sensitive potassium channel (pancreatic type)Kir6.2/SUR1 channelABCC8/KCNJ11 channelPancreatic type KATP channel

Sulfonylureas bind to SUR1 and inhibit the KATP channel, causing cell membrane depolarization, calcium influx, and insulin release from pancreatic beta cells. KATP channel openers (e.g., diazoxide) bind SUR1, promoting channel opening, hyperpolarizing the membrane, and reducing insulin secretion.