Choline derived from the phosphatidylcholine specific phospholipase D is not directly available for the CDP choline pathway in phorbol ester-treated C3H10T1/2 Cl 8 fibroblasts.
We have shown that 12-O-tetradecanoylphorbol 13-acetate (TPA) increases protein kinase C (PKC)-mediated choline transport, incorporation of choline into phosphatidylcholine (PtdCho) and PtdCho degradation by phospholipase D (PLD) in C3H10T1/2 Cl 8 cells. Dual prelabeling experiment using [3H]/[14C]choline indicated that intracellular choline generated from the PLD reaction was not directly recycled to PtdCho synthesis within the cell, and that a large fraction of the choline was transported out of the TPA-treated cells. In contrast, medium derived choline was preferably channeled to PtdCho synthesis. These results indicate that in TPA-treated cells, the choline derived from the PKC-mediated increased PLD activity and the choline newly taken up by the cell behave as two distinctly different metabolic pools.
Thorsen
V A
VA
Department of Biochemistry and Molecular Biology, University of Bergen, Norway.
Bruland
O
O
Lillehaug
J R
JR
Holmsen
H
H
D000818:Animals; D002460:Cell Line; D002794:Choline / Q000378:metabolism*; D003566:Cytidine Diphosphate Choline / Q000378:metabolism*; D005347:Fibroblasts; D007211:Indoles / Q000494:pharmacology; D008301:Maleimides / Q000494:pharmacology; D051379:Mice; D008809:Mice, Inbred C3H; D010713:Phosphatidylcholines / Q000378:metabolism; D010739:Phospholipase D / Q000378:metabolism*; D010767:Phosphorylcholine / Q000378:metabolism; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
D007211:Indoles; D008301:Maleimides; D010713:Phosphatidylcholines; D010767:Phosphorylcholine; D003566:Cytidine Diphosphate Choline; D011493:Protein Kinase C; D010739:Phospholipase D; C088060:bisindolylmaleimide; D002794:Choline; D013755:Tetradecanoylphorbol Acetate