Inward Rectifier Potassium Channel Blockers

The inward-rectifier potassium channel family (also known as 2-TM channels) include the strong inward-rectifier channels (K_ir2.x), the G-protein-activated inward-rectifier channels (K_ir3.x) and the ATP-sensitive channels (K_ir6.x), which combine with sulphonylurea receptors (SUR).

Structurally, the pore-forming subunit of K_ir channels is the α-subunit. It contains a single pore domain between two membrane spanning regions. Four α-subunits combine to form a tetramer, with the pore domain of each subunit contributing to the structure of the central pore. Heteromeric channels can also be formed within subfamilies, e.g. K_ir3.2 with K_ir3.3.