A Conserved Residue Cluster That Governs Kinetics of ATP-dependent Gating of Kir6.2 Potassium Channels.

ABSTRACT: ATP-sensitive potassium (KATP) channels are heteromultimeric complexes of an inwardly rectifying Kir channel (Kir6.x) and sulfonylurea receptors. Their regulation by intracellular ATP and ADP generates electrical signals in response to changes in cellular metabolism. We investigated channel elements that control the kinetics of ATP-dependent regulation of KATP (Kir6.2 + SUR1) channels using rapid concentration jumps. WT Kir6.2 channels re-open after rapid washout of ATP with a time constant of ∼60 ms. Extending similar kinetic measurements to numerous mutants revealed fairly modest effects on gating kinetics despite significant changes in ATP sensitivity and open probability. However, we identified a pair of highly conserved neighboring amino acids (Trp-68 and Lys-170) that control the rat

SUBMITTER: Zhang RS 

PROVIDER: S-EPMC4505460 | biostudies-literature | 2015 Jun

REPOSITORIES: biostudies-literature