ENHANCEMENT OF CDP-DG-INOSITOL TRANSFERASE-ACTIVITY IN SRC-TRANSFORMED AND ERBB2-TRANSFORMED CELLS

Phosphatidylinositol (PI) synthesis was activated in Rous sarcoma viru s-infected NIH3T3 or activated erbB2-transformed NIH3T3 cells. The in vitro activity of CDP-DG:inositol transferase prepared from these cell s was also higher than that from normal parent NIH3T3 cells, although phospholipase C and PI kinase activities were not significantly differ ent among these cells. A tyrosine kinase inhibitor, erbstatin, inhibit ed the PI synthesis in cultured cells, suggesting that Src and ErbBa-a ssociated tyrosine kinases are involved in activation of CDP-DG:inosit ol transferase in these cell lines. (C) 1994 Academic Press, Inc.