Effect of D609 on phosphatidylcholine metabolism in the nuclei of LA-N-1 neuroblastoma cells: a key role for diacylglycerol

In our previous studies, TPA treatment of LA-N-1 cells stimulated the production of diacylglycerol in nuclei, probably through the activation of a phospholipase C. Stimulation of the synthesis of nuclear phosphatidylcholine by the activation of CTP:phosphocholine cytidylyltransferase was also observed. The present data show that both effects were inhibited by the pretreatment of the cells with D609, a selective phosphatidylcholine-phospholipase C inhibitor, indicating that the diacylglycerol produced through the hydrolysis of phosphatidylcholine in the nuclei is reutilized for the synthesis of nuclear phosphatidylcholine and is required for the activation of CTP:phosphocholine cytidylyltransferase. (C) 2001 Published by Elsevier Science B.V. on behalf of the Federation of European Biochemical Societies.