Characterization and differential expression of protein kinase C isoforms in PC12 cells. Differentiation parallels an increase in PKC beta II.

Nerve growth factor (NGF) treatment of PC12 cells induced a 2.8-fold increase in protein kinase C activity concomitant with differentiation and acquisition of neuritis. PKC protein isoforms were separated by sequential chromatography on DEAE-Sephacel/hydroxylapatite. A broad peak of PKC activity eluted which corresponded to the alpha PKC isoform. In control cells, message for all six PKC isoforms was detected and expressed as epsilon greater than zeta = gamma greater than delta greater than beta greater than alpha. Western blot of whole cell lysates revealed a large increase in the beta II, while slight changes were observed for the other five PKC isoforms during treatment (1-14 days) with NGF (50 ng/ml). In parallel, coordinate changes in the expression of the individual transcripts for the six isoforms occurred during NGF treatment. Induction and accumulation of PKC beta II may play a role in maintenance of neuronal morphology.