Effects of insulin, pertussis toxin and cholera toxin on protein synthesis and diacylglycerol production in 3T3 fibroblasts: Evidence for a G-protein mediated activation of phospholipase C in the insulin signal mechanism

J E HESKETH, Gillian Patricia Campbell

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    The rapid increase in protein synthesis that occurs on addition of insulin (1 mU/ml) to
    stepped-down 3T3 cells was blocked by pre-incubation of the cells with pertussis toxin.
    Cholera toxin on the other hand stimulated protein synthesis and this effect was
    insensitive to actinomycin D and inhibited by pro-treatment of the cells with phorbol
    dibutyrate to deplete cell protein kinase C. Insulin was found to cause a rapid and
    transient increase in diacylglycerol (DAG) synthesis. The insulin-induced increase in
    diacylglycerol was blocked by pertussis toxin. Exogenous DAG (10 #M) stimulated
    protein synthesis within 1 hour. The results suggest that insuIin stimulates ribosomal
    activity through a signal mechanism that involves a G-protein mediated activation of
    phospholipase C to increase DAG levels.
    Original languageEnglish
    Pages (from-to)533-541
    Number of pages9
    JournalBioscience Reports
    Issue number7
    Publication statusPublished - Jul 1987


    • insulin
    • protein synthesis
    • G-protein
    • diacylglycerol
    • phospholipase C
    • signal transduction

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