Insulin-like growth factor I and insulin rapidly increase casein kinase II activity in BALB/c 3T3 fibroblasts.
We have tested whether growth factors added to serum-deprived BALB/c 3T3 fibroblasts alter the casein kinase II activity measured in cell extracts. A rapid phosphocellulose chromatography method was developed that provides a 40-fold partial purification of casein kinase II activity assayed with the specific substrate peptide Arg-Arg-Glu-Glu-Glu-Thr-Glu-Glu-Glu. Using this technique, kinase activity is stimulated 1.6-2.5-fold when isolated from fibroblasts treated with insulin or insulin-like growth factor I (IGF-I). The activated kinase activity exhibits the specific properties of casein kinase II such as the ability to utilize [gamma-32P]GTP as phosphate donor and marked inhibition by low concentrations of heparin. Activation of casein kinase II appears specific for these hormones because epidermal growth factor and platelet-derived growth factor have no effect on the kinase activity when added to fibroblasts under conditions where they markedly stimulate [3H]thymidine incorporation into DNA. Increases of casein kinase II activity by insulin and IGF-I were detected within 1 min of their addition to cell cultures. IGF-I is more potent in stimulating casein kinase II than insulin in mouse fibroblasts. These results demonstrate that casein kinase II is a selective target for insulin and IGF-I action in BALB/c fibroblasts, consistent with the hypothesis that this kinase plays a role in cellular signaling by these hormones.
D000818:Animals; D047388:Casein Kinases; D002478:Cells, Cultured; D004815:Epidermal Growth Factor / Q000494:pharmacology; D005347:Fibroblasts / Q000201:enzymology; D006160:Guanosine Triphosphate / Q000378:metabolism; D006493:Heparin / Q000494:pharmacology; D007328:Insulin / Q000494:pharmacology*; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D007700:Kinetics; D051379:Mice; D008807:Mice, Inbred BALB C; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology; D011494:Protein Kinases / Q000378:metabolism*; D013002:Somatomedins / Q000494:pharmacology*; D013936:Thymidine / Q000378:metabolism
D007328:Insulin; D010982:Platelet-Derived Growth Factor; D013002:Somatomedins; D004815:Epidermal Growth Factor; D007334:Insulin-Like Growth Factor I; D006160:Guanosine Triphosphate; D006493:Heparin; D011494:Protein Kinases; D047388:Casein Kinases; D013936:Thymidine