The protein phosphatase inhibitor, okadaic acid, potentiates the stimulatory effect of phorbol ester on phosphatidylcholine synthesis, but not on phospholipid hydrolysis, in fibroblasts.
The potent protein phosphatase inhibitor, okadaic acid, was used to determine the possible role of protein phosphorylation reaction(s) in phorbol ester-induced synthesis and hydrolysis of phosphatidylcholine (PtdCho) in NIH 3T3 fibroblasts. Okadaic acid (2 microM) was found to enhance the stimulatory effects of lower concentrations (2.5-25 nM) of phorbol 12-myristate 13-acetate (PMA) on PtdCho synthesis, but not on PtdCho hydrolysis, after treatments for 30-60 min. These data support a view that in fibroblasts PMA stimulates only PtdCho synthesis, and not PtdCho hydrolysis, by a protein phosphorylation-dependent mechanism.
Kiss
Z
Z
Hormel Institute, University of Minnesota, Austin 55912.
D016475:3T3 Cells; D000818:Animals; D002794:Choline / Q000378:metabolism; D004357:Drug Synergism; D004988:Ethers, Cyclic / Q000494:pharmacology*; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism*; D006868:Hydrolysis; D051379:Mice; D019319:Okadaic Acid; D010713:Phosphatidylcholines / Q000096:biosynthesis*; D010743:Phospholipids / Q000378:metabolism*; D010749:Phosphoprotein Phosphatases / Q000037:antagonists & inhibitors*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
D004988:Ethers, Cyclic; D010713:Phosphatidylcholines; D010743:Phospholipids; D019319:Okadaic Acid; D010749:Phosphoprotein Phosphatases; D002794:Choline; D013755:Tetradecanoylphorbol Acetate