Potassium channel ATP-sensitive subunit Kir6.2 (Kir6.2)

The ATP-sensitive potassium channel is an **octameric complex** comprising four **Kir6.2 subunits** and four regulatory **sulfonylurea receptor subunits (SUR1)**. Kir6.2 forms the channel pore and is the site for direct ATP-mediated inhibition. The channel is a central metabolic sensor: high intracellular ATP (energy-rich state) closes the channel by binding to Kir6.2, while low ATP (energy-depleted state) allows it to open, permitting **K\(_\{\}\)\(^{+}\) efflux** and regulating membrane potential. In pancreatic beta cells, this mechanism controls insulin secretion by coupling glucose metabolism to electrical activity. The channel is clinically significant as the target of antidiabetic sulfonylureas and other drugs, and is implicated in multiple metabolic and neurological diseases due to genetic variation or abnormal regulation.

Other names

Inward rectifier potassium channel Kir6.2KCNJ11K\(_\{\text{ATP}\}\) channel subunit Kir6.2ATP-sensitive potassium channel pore subunit Kir6.2

Sulfonylureas and meglitinides bind to the regulatory SUR1 subunit, leading to closure of the Kir6.2 pore and stimulation of insulin secretion ATP binds directly to Kir6.2, causing channel closure and reducing K\(_\{\}\)\(^{+}\) efflux, which depolarizes the cell membrane and promotes insulin release ADP and Mg-nucleotides can modulate channel activity via SUR1 Channel openers like diazoxide stabilize the open state