ATP-sensitive potassium channel subunit SUR2 (SUR2)

ATP-sensitive potassium channel subunit SUR2 is a regulatory subunit of KATP channels, part of the ATP-binding cassette (ABC) transporter C family. It exists mainly as two splice variants, SUR2A (predominantly cardiac) and SUR2B (predominantly smooth muscle), and co-assembles with Kir6.x (Kir6.1 or Kir6.2) pore-forming subunits to form functional KATP channels. SUR2 senses intracellular nucleotides (Mg-ADP, Mg-ATP) and pharmacologic ligands, linking cellular metabolic state to membrane excitability. SUR2-based KATP channels play fundamental roles in cardiovascular homeostasis, stress response (e.g., ischemic preconditioning), and muscle function. Targeting SUR2 is therapeutically relevant for cardiovascular disorders, certain metabolic and muscular conditions, and as a secondary target for some antidiabetic drugs.

Other names

Sulfonylurea receptor 2SUR2A (isoform)SUR2B (isoform)ABCC9 (gene symbol)

Channel inhibition: Sulfonylureas bind SUR2 and inhibit KATP channel activity, leading to cell membrane depolarization and downstream effects Channel activation: KATP openers bind SUR2, increasing channel opening, hyperpolarizing membranes, and reducing cellular excitability