Phospholipid-sensitive, Ca2+-dependent protein kinase activity in rat embryo fibroblasts transformed by herpes...

Increased cytosolic phospholipid-sensitive, Ca2+-dependent protein kinase C (PK-C) activity is correlated with the highly tumorigenic potential of rat embryo fibroblasts transformed by herpes simplex virus type 2 (HSV-2). Treatment of the cells with 12-O-tetradecanoylphorbol-13-acetate (TPA) caused a decrease in the cytosolic PK-C with a concomitant increase in PK-C recovered in the membrane fraction. Translocation of the PK-C was dependent upon length of exposure to the phorbol diester. PK-C activity in the cytosolic fraction could be stimulated by TPA without the addition of phosphatidylserine and diacylglycerol. It is tempting to speculate that HSV-2 induction of cellular PK-C activity may be important in phosphorylation of proteins needed for promotion of HSV-2-induced carcinogenesis.