ATP-sensitive inward rectifier potassium channel subunits Kir6.1 and Kir6.2 (Kir6.1/Kir6.2)

Kir6.1 and Kir6.2 are the pore-forming subunits of ATP-sensitive potassium (KATP) channels, which serve as critical metabolic sensors by coupling intracellular ATP/ADP ratios to membrane excitability [3, 12]. These subunits form hetero-octameric complexes with regulatory sulfonylurea receptor (SUR) subunits, with Kir6.2 typically pairing with SUR1 in pancreatic beta cells and SUR2A in the heart, while Kir6.1 pairs with SUR2B in vascular smooth muscle [1, 10]. In the pancreas, Kir6.2-containing channels regulate insulin secretion; their closure in response to high ATP levels triggers membrane depolarization and calcium influx [5, 13]. In the vasculature, Kir6.1-containing channels maintain resting membrane potential and regulate vascular tone, playing a key role in blood pressure control and the response to vasodilators [2, 11]. Dysfunction of these subunits due to genetic mutations leads to several clinical disorders, such as neonatal diabetes and congenital hyperinsulinism (Kir6.2) or Cantu syndrome and cardiovascular instabilities (Kir6.1) [4, 9, 16]. Pharmacologically, these channels are major targets for sulfonylurea drugs, which inhibit the channel to treat type 2 diabetes, and potassium channel openers like diazoxide and minoxidil, used for hyperinsulinism and hypertension [8, 10, 17].

Other names

KCNJ8KCNJ11Kir6.1Kir6.2BIRHHF2PHHIIKATPTNDM3PNDM2MODY13Potassium inwardly rectifying channel subfamily J member 8Potassium inwardly rectifying channel subfamily J member 11

Drugs targeting these subunits act as either channel blockers (e.g., sulfonylureas) that inhibit potassium efflux to stimulate insulin secretion or channel openers (e.g., diazoxide, minoxidil) that increase potassium efflux to induce hyperpolarization and vasodilation.