Rapamycin-induced inhibition of the 70-kilodalton S6 protein kinase.
The immunosuppressant rapamycin inhibited proliferation of the H4IIEC hepatoma cell line. Rapamycin, but not its structural analog FK506, also inhibited the basal and insulin-stimulated activity of the p70 ribosomal protein S6 kinase. By contrast, insulin stimulation of the p85 Rsk S6 kinase and mitogen-activated protein (MAP) kinase activity were unaffected by drug. Rapamycin treatment of COS cells transfected with recombinant p70 S6 kinase completely inhibited the appearance of the hyperphosphorylated form of p70 S6 kinase concomitant with the inhibition of enzyme activity toward 40S subunits. Thus, rapamycin inhibits a signal transduction element that is necessary for the activation of p70 S6 kinase and mitogenesis but unnecessary for activation of p85 Rsk S6 kinase or MAP kinase.
Price
D J
DJ
Diabetes Unit, Massachusetts General Hospital, Boston.
Grove
J R
JR
Calvo
V
V
Avruch
J
J
Bierer
B E
BE
D000818:Animals; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D002460:Cell Line; D002852:Chromatography, Ion Exchange; D016572:Cyclosporine / Q000494:pharmacology; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D007328:Insulin / Q000494:pharmacology; D007700:Kinetics; D008114:Liver Neoplasms, Experimental; D011090:Polyenes / Q000494:pharmacology*; D047428:Protein Kinase Inhibitors; D011494:Protein Kinases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors / Q000302:isolation & purification; D019893:Ribosomal Protein S6 Kinases; D012270:Ribosomes / Q000201:enzymology; D020123:Sirolimus; D016559:Tacrolimus / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014162:Transfection
D007166:Immunosuppressive Agents; D007328:Insulin; D011090:Polyenes; D047428:Protein Kinase Inhibitors; D011994:Recombinant Proteins; D016572:Cyclosporine; D011494:Protein Kinases; D019893:Ribosomal Protein S6 Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D013755:Tetradecanoylphorbol Acetate; D020123:Sirolimus; D016559:Tacrolimus