Electrogenic and phosphatidylinositol-4-monophosphate-stimulated Cl − transport by Cl − pump in the rat brain

Abstract

Rat brain Cl −-ATPase was solubilized and reconstituted in asolectin liposomes. Phosphatidylinositol-4-monophosphate increased Cl −-ATPase and ATP-dependent Cl − uptake activities in proteoliposomes. The ATP-dependent Cl − uptake was inhibited by a Cl −-ATPase inhibitor, ethacrynic acid, and increased at an inside-positive membrane potential or in the presence of a protonophore. These findings suggest that Cl −-ATPase is an electrogenic Cl − transporter, or a primary Cl − pump, probably regulated by phosphoinositide turnover in vivo.