CERAMIDE-INDUCED TRANSLOCATION OF PROTEIN-KINASE-C-ZETA IN PRIMARY CULTURES OF ASTROCYTES

The present research was undertaken to study the possible involvement of the atypical protein kinase C (PKC) zeta in ceramide signal transdu ction in primary cultures of rat astrocytes. As shown by Western blot analysis, translocation of immunoreactive PKC zeta to the particulate fraction occurred upon exposure of astrocytes to cell-permeable cerami de analogs or to exogenous sphingomyelinase. The particulate fraction may correspond to a perinuclear area, as indicated by immunocytochemic al techniques. Furthermore, treatment of cells with N-octanoylsphingos ine led to an increased phosphorylation of PKC zeta. Results thus show that stimulation of PKC zeta may be one of the intracellular events t riggered by activation of the sphingomyelin pathway. (C) 1997 Federati on of European Biochemical Societies.