ATP-sensitive inward rectifier potassium channel 11 (KCNJ11) (Kir6.2)

The ATP-sensitive inward rectifier potassium channel 11 (KCNJ11), commonly known as Kir6.2, is a critical protein that forms the pore-conducting subunit of the ATP-sensitive potassium (K_ATP) channel (UniProt: P48549). It functions as a metabolic sensor by coupling the intracellular ATP/ADP ratio to the cell's membrane potential, primarily in pancreatic beta cells (PubMed: 10592334). When glucose levels rise, increased ATP production leads to the closure of Kir6.2, causing membrane depolarization, calcium influx, and subsequent insulin secretion (StatPearls: NBK545253). Mutations in the KCNJ11 gene are linked to various glycemic disorders, including permanent neonatal diabetes and congenital hyperinsulinism (NCBI Gene: 3767). Pharmacologically, Kir6.2 is a major target for sulfonylureas used in the treatment of type 2 diabetes and neonatal diabetes, as well as diazoxide for hyperinsulinemic states (PubMed: 15166301). Understanding its structure and function is vital for developing precision therapies for metabolic diseases.

Other names

KCNJ11Inward rectifier K(+) channel Kir6.2BIRHHF2TNDM3PHHIMODY13

Drugs typically modulate the K_ATP channel complex, where Kir6.2 forms the pore. Sulfonylureas and meglitinides bind to the associated SUR1 subunit to induce closure of the Kir6.2 pore, leading to membrane depolarization and insulin release (PubMed: 15166301). Conversely, potassium channel openers like diazoxide stabilize the open state of the Kir6.2 pore, causing hyperpolarization and inhibition of insulin secretion (StatPearls: NBK545253).