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 K
ir6.x and four SUR subunits form
an ion conducting channel commonly referred to as the
K
ATP channel.The primary function of the sulfonylurea receptor is to sense
intracellular levels of the nucleotides ATP and ADP and in
response facilitate the open or closing its associated Kir
6.x
potassium channel. Hence the K
ATP
channel monitors the
energy balance within the cell (2).