Insulin activates nuclear factor kappa B in mammalian cells through a Raf-1-mediated pathway.
We examined the effect of insulin on nuclear factor kappa B (NF-kappa B) activity in Chinese ovary (CHO) cells overexpressing wild-type (CHO-R cells) or -defective insulin receptors mutated at Tyr1162 and Tyr1163 autophosphorylation sites (CHO-Y2 cells). In CHO-R cells, insulin caused a specific, time-, and concentration-dependent activation of NF-kappa B. The insulin-induced DNA-binding complex was identified as the p50/p65 heterodimer. Insulin activation of NF-kappa B: 1) was related to insulin receptor number and tyrosine kinase activity since it was markedly reduced in parental CHO cells which proved to respond to insulin growth factor-1 and phorbol 12-myristate 13-acetate (PMA) activation, and was dramatically decreased in CHO-Y2 cells; 2) persisted in the presence of cycloheximide and was blocked by pyrrolidine dithiocarbamate, aspirin and sodium salicylate, three compounds interfering with I kappa B degradation and/or NF-kappa B.I kappa B complex dissociation; 3) was independent of both PMA-sensitive and atypical (zeta) protein kinases C; and 4) was dependent on Raf-1 kinase activity since insulin-stimulated NF-kappa B DNA binding activity was inhibited by 8-bromo-cAMP, a Raf-1 kinase inhibitor. Moreover, insulin activation of NF-kappa B-driven luciferase reporter gene expression was blocked in CHO-R cells expressing a Raf-1 dominant negative mutant. This is the first evidence that insulin activates NF-kappa B in mammalian cells through a post-translational mechanism requiring both insulin receptor tyrosine kinase and Raf-1 kinase activities.
Bertrand
F
F
INSERM U.402, Laboratoire de Biologie Cellulaire, Faculté de Médecine Saint-Antoine, Paris, France.
Philippe
C
C
Antoine
P J
PJ
Baud
L
L
Groyer
A
A
Capeau
J
J
Cherqui
G
G
D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D001241:Aspirin / Q000494:pharmacology; D001483:Base Sequence; D001665:Binding Sites; D016466:CHO Cells; D006224:Cricetinae; D003513:Cycloheximide / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D007328:Insulin / Q000494:pharmacology*; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology; D007700:Kinetics; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D016328:NF-kappa B / Q000302:isolation & purification / Q000378:metabolism*; D015345:Oligonucleotide Probes; D010766:Phosphorylation; D017354:Point Mutation; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism*; D019908:Proto-Oncogene Proteins c-raf; D011759:Pyrrolidines / Q000494:pharmacology; D011972:Receptor, Insulin / Q000096:biosynthesis / Q000502:physiology*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D012980:Sodium Salicylate / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013859:Thiocarbamates / Q000494:pharmacology; D051841:Transcription Factor RelB; D014157:Transcription Factors; D014162:Transfection; D014443:Tyrosine
D000975:Antioxidants; D004791:Enzyme Inhibitors; D007328:Insulin; D016328:NF-kappa B; D015345:Oligonucleotide Probes; D011518:Proto-Oncogene Proteins; D011759:Pyrrolidines; C497593:RELB protein, human; D011994:Recombinant Proteins; D013859:Thiocarbamates; D014157:Transcription Factors; D051841:Transcription Factor RelB; D015124:8-Bromo Cyclic Adenosine Monophosphate; C020972:pyrrolidine dithiocarbamic acid; D014443:Tyrosine; D007334:Insulin-Like Growth Factor I; D003513:Cycloheximide; D011972:Receptor, Insulin; D017346:Protein Serine-Threonine Kinases; D019908:Proto-Oncogene Proteins c-raf; D013755:Tetradecanoylphorbol Acetate; D001241:Aspirin; D012980:Sodium Salicylate