Defective phospholipase D activation in Ki-ras-transformed NIH3T3 cells: evidence for downstream effector of PLC-gamma 1 in PDGF-mediated signal transduction.
Platelet-derived growth factor (PDGF), a potent mitogen for fibroblasts and many other cell types, was used to examine phosphatidylcholine-specific phospholipase D (PLD), phosphoinositide-specific phospholipase C (PI-PLC) and tyrosine phosphorylation in NIH3T3 fibroblast and its Ki-ras-transformed derivative, DT. When cells prelabeled with [3H] myristic acid were stimulated by 10 and 50 ng/ml of PDGF in presence of 0.3% butanol, formation of phosphatidylbutanol (PtdBut) was increased three to six fold in NIH3T3 fibroblasts whereas it was marginal in DT cells. Myo-[3H]inositol-labeled cells showed higher inositol phosphate production in nontransformed control fibroblasts, indicating higher phospholipase C activity compared to the transformed DT cells. PDGF caused increase in tyrosine phosphorylation of a group of proteins with 110-130 kDa, PLC-gamma 1 and PDGF receptor in NIH3T3 cells. There was no significant increase in tyrosine phosphorylation in both PDGF receptor and PLC-gamma 1 in DT cells. These results suggest that PLD acts as a downstream effector molecule of PLC-gamma 1 in the PDGF-mediated signal transduction pathway.
Alam
M S
MS
Department of Biochemistry, Gifu University School of Medicine, Japan.
Banno
Y
Y
Nakashima
S
S
Nozawa
Y
Y
D020001:1-Butanol; D016475:3T3 Cells; D000818:Animals; D015153:Blotting, Western; D000440:Butanols / Q000378:metabolism; D002461:Cell Line, Transformed; D004789:Enzyme Activation; D004790:Enzyme Induction; D011905:Genes, ras; D020404:Glycerophospholipids; D007295:Inositol Phosphates / Q000378:metabolism*; D007700:Kinetics; D051379:Mice; D019814:Myristic Acid; D009227:Myristic Acids / Q000378:metabolism; D010712:Phosphatidic Acids / Q000032:analysis / Q000378:metabolism; D043265:Phosphatidylinositol Diacylglycerol-Lyase; D054801:Phosphoinositide Phospholipase C; D010739:Phospholipase D / Q000096:biosynthesis / Q000378:metabolism*; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism*; D019000:Phosphotyrosine; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D014443:Tyrosine / Q000031:analogs & derivatives / Q000032:analysis
D000440:Butanols; D020404:Glycerophospholipids; D007295:Inositol Phosphates; D009227:Myristic Acids; D010712:Phosphatidic Acids; D010982:Platelet-Derived Growth Factor; C068564:phosphatidylbutanol; D019814:Myristic Acid; D019000:Phosphotyrosine; D014443:Tyrosine; D020001:1-Butanol; D010727:Phosphoric Diester Hydrolases; D054801:Phosphoinositide Phospholipase C; D010739:Phospholipase D; D043265:Phosphatidylinositol Diacylglycerol-Lyase