Enhancement of CDP-DG:inositol transferase activity in src- and erbB2-transformed cells.

Phosphatidylinositol (PI) synthesis was activated in Rous sarcoma virus-infected NIH3T3 or activated erbB2-transformed NIH3T3 cells. The in vitro activity of CDP-DG:inositol transferase prepared from these cells was also higher than that from normal parent NIH3T3 cells, although phospholipase C and PI kinase activities were not significantly different among these cells. A tyrosine kinase inhibitor, erbstatin, inhibited the PI synthesis in cultured cells, suggesting that Src and ErbB2-associated tyrosine kinases are involved in activation of CDP-DG:inositol transferase in these cell lines.