ATP-sensitive potassium channel containing sulfonylurea receptor 2 subunit (KATP SUR2) (KATP (SUR2))

The ATP-sensitive potassium (KATP) channel containing the sulfonylurea receptor 2 (SUR2) subunit is a metabolic sensor that links intracellular ATP levels to membrane excitability (UniProt KB: O60706). It is composed of four pore-forming Kir6.x subunits and four regulatory SUR2 subunits, the latter being encoded by the ABCC9 gene (Nichols et al., 2013, PMID: 23535157). Two major isoforms, SUR2A and SUR2B, are expressed in cardiac/skeletal muscle and vascular smooth muscle, respectively, where they regulate vascular tone and protect against ischemic stress (Hibino et al., 2010, PMID: 20624930). Gain-of-function mutations in ABCC9 lead to Cantu syndrome, a rare multisystem disorder involving cardiovascular abnormalities and excessive hair growth (Harakalova et al., 2012, PMID: 22751095). Loss-of-function mutations are associated with dilated cardiomyopathy and increased susceptibility to atrial fibrillation (Bienengraeber et al., 2004, PMID: 15155813). This channel is a key therapeutic target for potassium channel openers (KCOs) such as minoxidil, used for hypertension, and nicorandil, used for angina pectoris (StatPearls: Potassium Channel Openers). These drugs work by increasing the open-state probability of the channel, leading to potassium efflux, hyperpolarization, and subsequent relaxation of smooth muscle cells (PubChem CID 4201).

Other names

ABCC9Sulfonylurea receptor 2SUR2ATP-binding cassette sub-family C member 9KATP channel (SUR2)

Potassium channel activation (opening) and potassium channel inhibition (blocking) (StatPearls: Potassium Channel Openers; PMID: 10449331).