Referenced in: none

Automatically associated channels: BKβ1

Title: The BK channel accessory beta1 subunit determines alcohol-induced cerebrovascular constriction.

Authors: Anna N Bukiya, Jianxi Liu, Alejandro M Dopico

Journal, date & volume: FEBS Lett., 2009 Sep 3 , 583, 2779-84

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/19616547

Abstract
Ethanol-induced inhibition of myocyte large conductance, calcium- and voltage-gated potassium (BK) current causes cerebrovascular constriction, yet the molecular targets mediating EtOH action remain unknown. Using BK channel-forming (cbv1) subunits from cerebral artery myocytes, we demonstrate that EtOH potentiates and inhibits current at Ca(i)(2+) lower and higher than approximately 15 microM, respectively. By increasing cbv1's apparent Ca(i)(2+)-sensitivity, accessory BK beta(1) subunits shift the activation-to-inhibition crossover of EtOH action to <3 microM Ca(i)(2+), with consequent inhibition of current under conditions found during myocyte contraction. Knocking-down KCNMB1 suppresses EtOH-reduction of arterial myocyte BK current and vessel diameter. Therefore, BK beta(1) is the molecular effector of alcohol-induced BK current inhibition and cerebrovascular constriction.