Open AccessExogenous sphingosine 1-phosphate and sphingosylphosphorylcholine do not stimulate phospholipase D in C6 glioma cells.
Author(s) -
Anna Dygas,
Monika Sidorko,
Marta Bobeszko,
Jolanta Barańska
Publication year - 1999
Publication title -
acta biochimica polonica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.452
H-Index - 78
eISSN - 1734-154X
pISSN - 0001-527X
DOI - 10.18388/abp.1999_4187
Subject(s) - sphingosine , phosphatidylethanol , protein kinase c , sphingosine kinase , phospholipase d , lipid signaling , sphingosine 1 phosphate , sphingosine kinase 1 , chemistry , biochemistry , phosphatidic acid , activator (genetics) , kinase , phospholipid , signal transduction , enzyme , receptor , membrane
In the present study we investigate the effect of exogenous sphingosine, sphingosine 1-phosphate and sphingosylphosphorylcholine on phospholipase D (PLD) activity in glioma C6 cells. The cells were prelabeled with [1-14C]palmitic acid and PLD-mediated synthesis of [14C]phosphatidylethanol was measured. Sphingosine 1-phosphate and sphingosylphosphorylcholine did not stimulate [14C]phosphatidylethanol formation either at low (0.1-10 microM) or high (25-100 microM) concentrations. On the other hand, sphingosine at concentrations of 100-250 microM strongly stimulated PLD activity as compared to the effect of phorbol ester, 12-O-tetradecanoylphorbol 13-acetate (TPA), known as a PLD activator. The effect of TPA on PLD is linked to the activation of protein kinase C. The present study also shows that sphingosine additively enhances TPA-mediated PLD activity. This is in contrast to the postulated role of sphingosine as a protein kinase C inhibitor. These results demonstrate that in glioma C6 cells sphingosine not only affects PLD independently of its effect on protein kinase C, but also is unable to block TPA-mediated PLD activity.