Tetradecanoyl-phorbol acetate stimulates phosphatidylcholine biosynthesis in HeLa cells by an increase in the rate of the reaction catalyzed by CTP:phosphocholine cytidylyltransferase.

Studies have been performed on the mechanism by which 12-O-tetradecanoyl-phorbol-13-acetate (TPA) stimulates phosphatidylcholine biosynthesis in HeLa cells. The phorbol acetate did not alter the transport of choline into the cells, nor did it stimulate choline phosphorylation. When [methyl-3H]choline was added to HeLa cells for a 1 h pulse, virtually all of the radioactivity in the aqueous phase of the cell extracts became associated with phosphocholine. The addition of the phorbol ester caused an accelerated disappearance of radioactivity from phosphocholine and a concomitant increase in the incorporation into phosphatidylcholine. The radioactivity associated with CDPcholine remained low and constant throughout the experiment. These results provide strong evidence that TPA accelerates phosphatidylcholine biosynthesis in HeLa cells by stimulation of the reaction catalyzed by CTP:phosphocholine cytidylyltransferase.