Okadaic acid stimulates the activity of the nerve growth factor-sensitive S6 kinase of PC12 cells.
PC12 pheochromocytoma cells contain at least two different and separable kinases that phosphorylate the S6 protein of the ribosomes. The activity of one of these S6 kinases is increased by treatment of the cells with nerve growth factor and of the other by treatment with epidermal growth factor. Okadaic acid increases the activity of the nerve growth factor-sensitive S6 kinase. The data suggest that the nerve growth factor-sensitive S6 kinase is activated by phosphorylation on serine or threonine residues and is inactivated by either phosphatase 1 or phosphatase 2A, probably the latter.
Mogi
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Section on Growth Factors National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892.
Guroff
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D000818:Animals; D004305:Dose-Response Relationship, Drug; D004533:Egtazic Acid / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D004988:Ethers, Cyclic / Q000008:administration & dosage / Q000494:pharmacology*; D005994:Glycerophosphates / Q000494:pharmacology; D009414:Nerve Growth Factors / Q000494:pharmacology*; D019319:Okadaic Acid; D010749:Phosphoprotein Phosphatases / Q000494:pharmacology; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*; D054645:Protein Phosphatase 1; D054648:Protein Phosphatase 2; D038601:Ribosomal Protein S6; D012269:Ribosomal Proteins / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D004988:Ethers, Cyclic; D005994:Glycerophosphates; D009414:Nerve Growth Factors; D038601:Ribosomal Protein S6; D012269:Ribosomal Proteins; D019319:Okadaic Acid; D004533:Egtazic Acid; D011494:Protein Kinases; D010749:Phosphoprotein Phosphatases; D054645:Protein Phosphatase 1; D054648:Protein Phosphatase 2; C031463:beta-glycerophosphoric acid