K_ir6.2 is a member of the inward rectifier K⁺ channels (K_ir channels), a large family of voltage-independent K⁺ channels largely involved in stabilization of the membrane resting potential and in K⁺ transport across membranes. K_ir channels can be modulated by a variety of intracellular agents such as protons, GTP-binding proteins and adenine nucleotides.  

The ATP-sensitive channel (K_ATP) is especially important since it couples cellular metabolism (intracellular ATP levels) with cell excitability. K_ATP channels have been described in pancreatic b-cells, neurons, heart, skeletal and smooth muscle.  

The K_ATP channel is composed of a K_ir6.2 or K_ir6.1 subunit and a sulphonylurea receptor (SUR) subunit.  

The pancreatic K_ATP channel for example, is composed of a complex of K_ir6.2 and   SUR1 subunits, while the cardiac K_ATP channel is composed of K_ir6.2 and SUR2A complexes. 

Impaired b-cell K_ATP channel function due to mutations in either K_ir6.2 or SUR1 subunits has been linked to the recessive autosomal disorder called persistent hyperinsulinemic hypoglycemia of infancy (PHHI). In addition, a K_ir6.2 variant has recently been linked to an increased risk of developing type-2 diabetes.