Target cell polarity and membrane phosphorylation in relation to the mechanism of action of antidiuretic hormone

Abstract

The plasma mebrane of the bovine renal collecting duct epithelial cell resolved into its apical (luminal) and basal lateral (contraluminal) components by free flow electrophoresis. The contraluminal, but not the luminal, membrane was found to contain antidiuretic hormone sensitive adenylate cyclase. The luminal membrane was found to contain a cyclic 3':5' adenosine monophosphate sensitive self phosphorylating system consisting of a membrane bound protein kinase and its membrane bound substrates; this intrinsic protein kinase was not present in the contraluminal membrane. These findings provide direct evidence that the initiating steps in the action of antidiuretic hormone on the kidney take place at the contraluminal pole of the hormone sensitive target cell and that the late or terminal steps occur at the luminal pole, where they involve an alteration in the level of membrane phosphorylation.