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

ATP-sensitive inward rectifier potassium channel 11, commonly known as Kir6.2, is a critical pore-forming subunit of the ATP-sensitive potassium (KATP) channel complex. Primarily expressed in pancreatic beta cells, cardiomyocytes, and neurons, Kir6.2 functions as a metabolic sensor that links the energy status of the cell (ATP/ADP ratio) to its electrical activity [UniProt: Q14654]. In the pancreas, an increase in ATP causes the channel to close, triggering membrane depolarization and insulin secretion, a process essential for maintaining glucose homeostasis [NCBI Gene: 3767]. Mutations in the KCNJ11 gene encoding Kir6.2 are associated with various glucose metabolism disorders, including permanent neonatal diabetes mellitus and congenital hyperinsulinism [PubMed: 15115830]. Kir6.2 is a major pharmacological target; sulfonylureas and meglitinides inhibit the channel to treat type 2 diabetes, while diazoxide activates it to treat hyperinsulinemia [StatPearls: NBK507774]. Beyond the pancreas, Kir6.2 plays roles in the cardiovascular system's response to stress and protection against cardiac ischemia [PubMed: 11884744].

Other names

KCNJ11Potassium channel, inwardly rectifying subfamily J member 11BIRHHF2TNDM3PHHIIKATP

Kir6.2 forms the pore-forming subunit of the ATP-sensitive potassium (KATP) channel complex, which is typically coupled with the Sulfonylurea Receptor (SUR). Sulfonylureas and meglitinides act as inhibitors (blockers) that bind to the regulatory SUR subunit to close the Kir6.2 pore, leading to cell depolarization and subsequent insulin release. Conversely, potassium channel openers like Diazoxide act as agonists that keep the channel in an open state, hyperpolarizing the cell and inhibiting insulin secretion.