title: Differential regulations of phosphatidylcholine biosynthesis in U937 cells by inhibitors of protein and tyrosine kinases.
abstract: 1. The differential effects of inhibitors of protein kinase (PK) or tyrosine kinase (TK) on phosphatidylcholine (PC) biosynthesis in monocyte-like U937 cells were compared in pulse-chase-studies in which the cells prelabelled with [3H]choline for 30 min were chased in the absence or presence of kinase inhibitors. 2. PKA inhibitor (H-89) decreased the label incorporation into PC, while PKA activator (8-BrcAMP) had no effect. 3. PKC inhibitors (chelerythrine and hypericin) inhibited PC biosynthesis; on the other hand, PKC activator (SC-10) was stimulatory. 4. The inhibition of PC biosynthesis by H-89 and chelerythrine was accompanied by the inactivation of CTP: cholinephosphate cytidylyltransferase (CT). 5. In contrast, TK inhibitor (genistein) markedly stimulated CT and PC biosynthesis, while erbstatin and tyrphostin No. 25 showed no effect.
authors.affiliation: Miami Heart Research Institute, FL 33140-2999.
authors.forename: A J
authors.initials: AJ
authors.lastname: Chu
mesh_terms: D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D002396:Catechols / Q000494:pharmacology; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors; D019833:Genistein; D006801:Humans; D006873:Hydroquinones / Q000494:pharmacology; D007529:Isoflavones / Q000494:pharmacology; D007546:Isoquinolines / Q000494:pharmacology; D009000:Monocytes / Q000187:drug effects* / Q000378:metabolism; D009570:Nitriles / Q000494:pharmacology; D010713:Phosphatidylcholines / Q000096:biosynthesis*; D047428:Protein Kinase Inhibitors; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors*; D013449:Sulfonamides; D014407:Tumor Cells, Cultured; D020032:Tyrphostins
chemical_list: D002396:Catechols; D006873:Hydroquinones; D007529:Isoflavones; D007546:Isoquinolines; D009570:Nitriles; D010713:Phosphatidylcholines; D047428:Protein Kinase Inhibitors; D013449:Sulfonamides; D020032:Tyrphostins; C060152:tyrphostin 47; D015124:8-Bromo Cyclic Adenosine Monophosphate; D019833:Genistein; D011505:Protein-Tyrosine Kinases; D017868:Cyclic AMP-Dependent Protein Kinases; C063509:N-(2-(4-bromocinnamylamino)ethyl)-5-isoquinolinesulfonamide; C048212:erbstatin