ATP-sensitive potassium channel subunit sulfonylurea receptor 2A (SUR2A)

The ATP-sensitive potassium channel subunit sulfonylurea receptor 2A (SUR2A) is a regulatory protein encoded by the ABCC9 gene that forms the metabolic-sensing component of KATP channels in cardiac and skeletal muscle (UniProt: O60706). As a member of the ATP-binding cassette (ABC) transporter superfamily, SUR2A couples the intracellular ATP/ADP ratio to membrane excitability, allowing the cell to respond to energetic stress (PubMed: 9154454). In the heart, SUR2A-containing channels provide a critical cardioprotective mechanism during ischemia by shortening the action potential and reducing calcium influx (PubMed: 22403174). Mutations in the ABCC9 gene are linked to several clinical conditions, most notably Cantú syndrome, which presents with hypertrichosis and cardiovascular abnormalities, as well as forms of dilated cardiomyopathy (PubMed: 25135138). Pharmacologically, SUR2A is the primary target for potassium channel openers like nicorandil, used in the management of angina, and minoxidil, used for hypertension (PubChem: CID 4474). While sulfonylureas also interact with SUR2A, they typically exhibit higher selectivity for the SUR1 isoform in pancreatic tissues, making SUR2A a specific focus for cardiovascular therapeutic development.

Other names

ABCC9Sulfonylurea receptor 2ATP-binding cassette sub-family C member 9SUR2KATP channel regulatory subunit SUR2A

Drugs targeting SUR2A primarily function as potassium channel openers (KCOs), which bind to the regulatory subunit to increase the open-state probability of the KATP channel, leading to hyperpolarization and muscle relaxation (PubMed: 10449331). Alternatively, sulfonylureas can bind to SUR2A to inhibit channel activity, though they are generally less potent on this isoform compared to SUR1 (PubMed: 9154454).