Stimulation of phosphatidylethanolamine synthesis in isolated rat hepatocytes by phorbol 12-myristate 13-acetate.
Incubation of freshly isolated rat hepatocytes in the presence of phorbol 12-myristate 13-acetate stimulates the incorporation of [1,2-14C]ethanolamine into phosphatidylethanolamines. This stimulation is strongly dependent on the ethanolamine concentration in the medium and becomes apparent at ethanolamine concentrations above 25 microM. Treatment of hepatocytes with phorbol 12-myristate 13-acetate results in a decreased labelling of intracellular ethanolamine, ethanolaminephosphate and CDPethanolamine. Exposure of cells to phorbol 12-myristate 13-acetate induces an increase of the activity of the enzymes CTP: ethanolaminephosphate cytidylyltransferase and ethanolaminephosphotransferase. These effects are accompanied by a decrease of the pool size of ethanolaminephosphate and CDPethanolamine and an increase of the level of diacylglycerols after 30 min of incubation in the presence of phorbol 12-myristate 13-acetate. Upon prolonged incubation, the CDPethanolamine and diacylglycerol pools are restored to the level found in untreated cells. These results indicate that stimulation of phosphatidylethanolamine synthesis by phorbol 12-myristate 13-acetate is probably exerted at the level of CTP : ethanolaminephosphate cytidylytransferase, although there may be an additional effect on the subsequent step of phosphatidylethanolamine synthesis, the formation of phosphatidylethanolamines from CDPethanolamine and diacylglycerols.
Tijburg
L B
LB
Laboratory of Veterinary Biochemistry, University of Utrecht, The Netherlands.
Houweling
M
M
Geelen
J H
JH
van Golde
L M
LM
D000818:Animals; D019856:Ethanolamine; D004982:Ethanolaminephosphotransferase / Q000378:metabolism; D004983:Ethanolamines / Q000378:metabolism; D066298:In Vitro Techniques; D007700:Kinetics; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D009713:Nucleotidyltransferases / Q000378:metabolism; D010714:Phosphatidylethanolamines / Q000096:biosynthesis*; D010743:Phospholipids / Q000302:isolation & purification; D010770:Phosphotransferases / Q000378:metabolism; D017853:Phosphotransferases (Alcohol Group Acceptor); D012316:RNA Nucleotidyltransferases; D051381:Rats; D011919:Rats, Inbred Strains; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
D004983:Ethanolamines; D010714:Phosphatidylethanolamines; D010743:Phospholipids; D019856:Ethanolamine; D010770:Phosphotransferases; D017853:Phosphotransferases (Alcohol Group Acceptor); C020125:ethanolamine kinase; D009713:Nucleotidyltransferases; D012316:RNA Nucleotidyltransferases; C020126:Ethanolamine-phosphate cytidylyltransferase; D004982:Ethanolaminephosphotransferase; D013755:Tetradecanoylphorbol Acetate