In molecular biology, the sulfonylurea receptors (SUR) are membrane proteins which are the molecular targets of the sulfonylurea class of antidiabetic drugs whose mechanism of action is to promote insulin release from pancreatic beta cells. More specifically, SUR proteins are subunits of the inward-rectifier potassium ion channels Kir6.x (6.1 and 6.2).[1] The association of four Kir6.x and four SUR subunits form an ion conducting channel commonly referred to as the KATP channel.[2]
Three forms of the sulfonylurea receptor are known, SUR1 encoded by the ABCC8 gene, and SUR2A and SUR2B, which are splice variants arising from a single ABCC9 gene.[3]