RAS is required for epidermal growth factor-stimulated arachidonic acid release in rat-1 fibroblasts.
Previous studies have provided suggestive evidence for an interaction between ras activation and signalling pathways involved in agonist-stimulated arachidonic acid release in a variety of cell systems. In order to clarify this interaction, we have measured epidermal growth factor (EGF)-stimulated arachidonic acid release in rat-1 fibroblasts transfected with the N-17 dominant negative mutation of ras. Cells transfected with the N-17 ras mutant, display a markedly attenuated arachidonic acid-release response to EGF, compared to sham-transfected and non-transfected cells. In contrast, the response to phorbol myristate acetate (PMA) was not attenuated in the N-17-mutant expressing cells. No differences were detected between sham-transfected and N-17 mutant expressing cells in levels of immunodetectable EGF receptor, cytosolic phospholipase A2 or mitogen-activated protein (MAP) kinase. Attenuation of EGF-stimulated arachidonic acid release in the N-17 mutant expressing cells, was accompanied by a marked diminution in EGF-stimulated tyrosine phosphorylation of MAP kinase. We conclude that the signalling pathway involved in epidermal growth factor-stimulated arachidonic acid release is similar to the signalling pathway for mitogenic responses to epidermal growth factor and requires ras activation, likely followed by a downstream cascade of kinases eventuating in MAP kinase activation.
Warner
L C
LC
Department of Medicine, University of Toronto, Canada.
Hack
N
N
Egan
S E
SE
Goldberg
H J
HJ
Weinberg
R A
RA
Skorecki
K L
KL
D000818:Animals; D001095:Arachidonic Acids / Q000378:metabolism*; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000032:analysis / Q000378:metabolism / Q000502:physiology; D002460:Cell Line; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D066246:ErbB Receptors / Q000032:analysis; D005347:Fibroblasts / Q000737:chemistry / Q000166:cytology* / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000235:genetics; D011905:Genes, ras / Q000235:genetics / Q000502:physiology*; D009154:Mutation / Q000235:genetics; D010741:Phospholipases A / Q000032:analysis; D054467:Phospholipases A2; D010766:Phosphorylation; D011233:Precipitin Tests; D051381:Rats; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014162:Transfection; D014316:Tritium; D014443:Tyrosine / Q000378:metabolism
D001095:Arachidonic Acids; D014316:Tritium; D014443:Tyrosine; D004815:Epidermal Growth Factor; D066246:ErbB Receptors; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D010741:Phospholipases A; D054467:Phospholipases A2; D013755:Tetradecanoylphorbol Acetate