Activation of the K(ATP) channel by Mg-nucleotide interaction with SUR1.

ABSTRACT: The mechanism of adenosine triphosphate (ATP)-sensitive potassium (K(ATP)) channel activation by Mg-nucleotides was studied using a mutation (G334D) in the Kir6.2 subunit of the channel that renders K(ATP) channels insensitive to nucleotide inhibition and has no apparent effect on their gating. K(ATP) channels carrying this mutation (Kir6.2-G334D/SUR1 channels) were activated by MgATP and MgADP with an EC(50) of 112 and 8 µM, respectively. This activation was largely suppressed by mutation of the Walker A lysines in the nucleotide-binding domains of SUR1: the remaining small (∼10%), slowly developing component of MgATP activation was fully inhibited by the lipid kinase inhibitor LY294002. The EC(50) for activation of Kir6.2-G334D/SUR1 currents by MgADP was lower than that for MgATP, and th

SUBMITTER: Proks P 

PROVIDER: S-EPMC2947056 | biostudies-literature | 2010 Oct

REPOSITORIES: biostudies-literature