CAMP-dependent regulation of I_Ks single-channel kinetics.

ABSTRACT: The delayed potassium rectifier current, I_Ks , is composed of KCNQ1 and KCNE1 subunits and plays an important role in cardiac action potential repolarization. During β-adrenergic stimulation, 3'-5'-cyclic adenosine monophosphate (cAMP)-dependent protein kinase A (PKA) phosphorylates KCNQ1, producing an increase in I_Ks current and a shortening of the action potential. Here, using cell-attached macropatches and single-channel recordings, we investigate the microscopic mechanisms underlying the cAMP-dependent increase in I_Ks current. A membrane-permeable cAMP analog, 8-(4-chlorophenylthio)-cAMP (8-CPT-cAMP), causes a marked leftward shift of the conductance-voltage relation in macropatches, with or without an increase in current size. Sing

SUBMITTER: Thompson E 

PROVIDER: S-EPMC5560775 | biostudies-literature | 2017 Aug

REPOSITORIES: biostudies-literature