title: Phosphorylation of tyrosines 1158, 1162 and 1163 on a synthetic dodecapeptide by the insulin receptor protein-tyrosine kinase.
abstract: To investigate the mechanism of tyrosine phosphorylation by the insulin receptor protein-tyrosine kinase, we utilized a synthetic dodecapeptide substrate (RRDIYETDYYRK; amino acids 1155-1165) containing the three major insulin receptor autophosphorylation sites. (1) We show that all three tyrosines on this peptide are rapidly phosphorylated and that phosphorylation is probably initiated at tyrosine 9. This peptide thus serves as a useful tool to study the mechanism of transphosphorylation by the insulin receptor. (2) A proteolytic activity was detected in purified receptor preparations that removed basic residues from the peptide and prevented it binding to phosphocellulose paper. Such activity could pose a serious problem when using peptide substrates to assay for protein kinases in other acellular systems.
authors.affiliation: Department of Biochemistry, School of Medical Sciences, University of Bristol, UK.
authors.forename: M
authors.initials: M
authors.lastname: Dickens
authors.forename: J M
authors.initials: JM
authors.lastname: Tavaré
authors.forename: B
authors.initials: B
authors.lastname: Clack
authors.forename: L
authors.initials: L
authors.lastname: Ellis
authors.forename: R M
authors.initials: RM
authors.lastname: Denton
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000138:chemical synthesis / Q000378:metabolism*; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000302:isolation & purification / Q000378:metabolism*; D011972:Receptor, Insulin / Q000235:genetics / Q000378:metabolism; D014162:Transfection; D014443:Tyrosine
chemical_list: D009842:Oligopeptides; D014443:Tyrosine; D011505:Protein-Tyrosine Kinases; D011972:Receptor, Insulin