ATP-binding cassette sub-family C member 9 (Sulfonylurea receptor 2) (ABCC9)

ATP-binding cassette sub-family C member 9 (ABCC9), also known as Sulfonylurea receptor 2 (SUR2), is a regulatory subunit of the ATP-sensitive potassium (KATP) channel (UniProt P57739). It belongs to the ATP-binding cassette (ABC) transporter superfamily and acts as a metabolic sensor, coupling the cellular energetic state (ATP/ADP ratio) to membrane excitability (NCBI Gene 10060). ABCC9 is primarily expressed in cardiac, skeletal, and smooth muscle tissues, where it plays a vital role in regulating vascular tone and protecting the myocardium during ischemic stress (PubMed 16917470). Mutations in the ABCC9 gene are associated with Cantu syndrome, a rare condition characterized by hypertrichosis, osteochondrodysplasia, and cardiomegaly, as well as various forms of cardiomyopathy and atrial fibrillation (PubMed 22703874). Pharmacologically, ABCC9 is a target for potassium channel openers such as minoxidil and nicorandil, which are used to treat hypertension and angina by inducing vasodilation (PubChem CID 4201). Conversely, it can be inhibited by sulfonylureas, although these drugs typically show higher affinity for the SUR1 isoform found in pancreatic beta cells.

Other names

SUR2Sulfonylurea receptor 2ABC37ATFB12CANTUCMS14HHF5SUR2ASUR2B

Allosteric modulation of ATP-sensitive potassium channels to regulate membrane potential in response to intracellular ATP/ADP ratios.