ATP-sensitive potassium channels: Structures, functions, and pathophysiology

Abstract

ATP-sensitive potassium channels (K(ATP) channels) play important roles in various tissues by coupling cell metabolic status to electrical activity. Recently, molecular biological and electrophysiological techniques have revealed the molecular basis of the K(ATP) channels to be a complex of the Kir6.0 subunit, a member of the inwardly rectifying K+ channel subfamily Kir6.0, and the sulfonylurea receptor (SUR) subunit, a member of ATP-binding cassette (ABC) super family; the functional diversity of the various K(ATP) channels is being determined by a combination of the Kir6.0 subunit (Kir6.1 or Kir6.2) and the SUR subunit (SUR1 or SUR2) comprising it. Recent studies of the K(ATP) channels have suggested mechanisms of K(ATP) channel regulation and pathophysiology and also a new model in which ABC proteins regulate the functional expression of ion channels.