ATP-sensitive potassium channel regulatory subunit SUR2B (SUR2B)

The ATP-sensitive potassium (K_(ATP)) channel regulatory subunit SUR2B is a member of the sulfonylurea receptor (SUR) family, which are large auxiliary subunits that regulate the activity of K_(ATP) channels. These channels are critical sensors of cellular metabolic status, coupling cell metabolism to membrane excitability by responding to intracellular levels of ATP and ADP. SUR2B is primarily expressed in brain, vascular smooth muscle, and nonvascular smooth muscle, where it regulates membrane potential and vascular tone. The functional K_(ATP) channel is an octameric complex composed of four pore-forming Kir6.x subunits (Kir6.1 or Kir6.2) and four regulatory sulfonylurea receptor subunits (SUR1, SUR2A, or SUR2B). Channel activity is modulated by intracellular nucleotides and phosphorylation/dephosphorylation events. Pharmacological regulation includes activation by K(+)-channel openers like diazoxide and inhibition by sulfonylurea drugs such as glibenclamide or tolbutamide.

Activation or inhibition of KATP channel activity; Sulfonylureas bind directly to the SUR2B subunit, inhibiting channel activity; Diazoxide activates the channel.