Effects of a tumor promoter on phospholipid metabolism in HeLa cells.
The tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) caused a marked stimulation of inorganic [32P]orthophosphate incorporation into HeLa-cell phosphatidylcholine (PC), phosphatidylethanolamine (PE), and lysophosphatidylethanolamine. The increased incorporation of inorganic [32P]orthophosphate into PE and lysophosphatidylethanolamine in the presence of TPA was not associated with an increase in PE synthesis as detected by the incorporation of [3H]serine or [3H]ethanolamine. The PC-specific exchange protein from beef liver was used to insert PC labeled with [3H]choline, inorganic [32P]orthophosphate, or [14C]arachidonic acid plus [3H]palmitic acid into the outer monolayer of intact HeLa cell membranes. Radioactivity from the latter two compounds was rapidly incorporated into PE and lysophosphatidylethanolamine; the incorporation was stimulated by TPA. It was concluded that TPA stimulated the formation of PE by base exchange between ethanolamine and PC.
D006367:HeLa Cells / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D010704:Phorbols / Q000494:pharmacology*; D010710:Phosphates / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism*; D010761:Phosphorus Radioisotopes; D013329:Structure-Activity Relationship; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
D010704:Phorbols; D010710:Phosphates; D010743:Phospholipids; D010761:Phosphorus Radioisotopes; D013755:Tetradecanoylphorbol Acetate