Referenced in: none

Automatically associated channels: Cav1.2 , Slo1

Title: Assembly of a Ca2+-dependent BK channel signaling complex by binding to beta2 adrenergic receptor.

Authors: Guoxia Liu, Jingyi Shi, Lin Yang, Luxiang Cao, Soo Mi Park, Jianmin Cui, Steven O Marx

Journal, date & volume: EMBO J., 2004 Jun 2 , 23, 2196-205

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/15141163

Abstract
Large-conductance voltage and Ca2+-activated potassium channels (BKCa) play a critical role in modulating contractile tone of smooth muscle, and neuronal processes. In most mammalian tissues, activation of beta-adrenergic receptors and protein kinase A (PKAc) increases BKCa channel activity, contributing to sympathetic nervous system/hormonal regulation of membrane excitability. Here we report the requirement of an association of the beta2-adrenergic receptor (beta2AR) with the pore forming alpha subunit of BKCa and an A-kinase-anchoring protein (AKAP79/150) for beta2 agonist regulation. beta2AR can simultaneously interact with both BKCa and L-type Ca2+ channels (Cav1.2) in vivo, which enables the assembly of a unique, highly localized signal transduction complex to mediate Ca2+- and phosphorylation-dependent modulation of BKCa current. Our findings reveal a novel function for G protein-coupled receptors as a scaffold to couple two families of ion channels into a physical and functional signaling complex to modulate beta-adrenergic regulation of membrane excitability.