Referenced in: none

Automatically associated channels: Kir2.1 , Slo1

Title: Receptor stimulation causes slow inhibition of IRK1 inwardly rectifying K+ channels by direct protein kinase A-mediated phosphorylation.

Authors: E Wischmeyer, A Karschin

Journal, date & volume: Proc. Natl. Acad. Sci. U.S.A., 1996 Jun 11 , 93, 5819-23

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/8650176

Abstract
Strongly rectifying IRK-type inwardly rectifying K+ channels are involved in the control of neuronal excitability in the mammalian brain. Whole-cell patch-clamp experiments show that cloned rat IRK1 (Kir 2.1) channels, when heterologously expressed in mammalian COS-7 cells, are inhibited following the activation of coexpressed serotonin (5-hydroxytryptamine) type 1A receptors by receptor agonists. Inhibition is mimicked by internal perfusion with GTP[gamma-S] and elevation of internal cAMP concentrations. Addition of the catalytic subunits of protein kinase A (PKA) to the internal recording solution causes complete inhibition of wild-type IRK1 channels, but not of mutant IRK1(S425N) channels in which a C-terminal PKA phosphorylation site has been removed. Our data suggest that in the nervous system serotonin may negatively control IRK1 channel activity by direct PKA-mediated phosphorylation.