Identification of an autoinhibitory domain in the insulin receptor tyrosine kinase

Anna Filipek, Thomas R. Soderling

    Research output: Contribution to journalArticle

    2 Scopus citations

    Abstract

    We have tested the hypothesis that activation of the insulin receptor tyrosine kinase is due to autophosphorylation of tyrosines 1146, 1150 and 1151 within a putative autoinhibitory domain. A synthetic peptide corresponding to residues 1134-1162, with tyrosines substituted by alanine or phenylalanine, of the insulin receptor β subunit was tested for its inhibitory potency and specificity towards the tyrosine kinase activity. This synthetic peptide gave inhibition of the insulin receptor tyrosine kinase autophosphorylation and phosphorylation of the exogenous substrate poly(Glu, Tyr) with an approximate IC50 of 100 μM. Inhibition appeared to be independent of the concentrations of insulin or the substrate poly(Glu, Tyr) but was decreased by increasing concentrations of ATP. This same peptide also inhibited the EGF receptor tyrosine kinase but not a serine/threonine protein kinase. These results are consistent with the hypothesis that this autophosphorylation domain contains an autoinhibitory sequence. (Mol Cell Biochem 120: 103-110, 1993)

    Original languageEnglish (US)
    Pages (from-to)103-110
    Number of pages8
    JournalMolecular and Cellular Biochemistry
    Volume120
    Issue number2
    DOIs
    StatePublished - Mar 1 1993

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    Keywords

    • autoinhibitory domain
    • insulin receptor
    • protein tyrosine kinase

    ASJC Scopus subject areas

    • Molecular Biology
    • Clinical Biochemistry
    • Cell Biology

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