Activation of a brain-specific protein kinase C subspecies in the presence of phosphatidylethanol

Abstract Protein kinase C (PKC) is normally activated by diacylglycerol in the presence of Ca 2+ and phosphatidylserine. At physiological concentrations of Ca 2+ , however, phosphatidylethanol, a product of the phospholipase D-catalyzed transphosphatidylation reaction between membrane phospholipids and ethanol, can replace phosphatidylserine, and activate PKC. This mode of activation is most effective for the γ-subspecies, which is expressed only in central nervous tissue. Phosphatidylmethanol is also effective to some extent. Consideration of these results suggests the possibility that ethanol may exert some effect on signal transduction in this tissue via changes in protein phosphorylation.