An insulin receptor peptide (1135-1156) stimulates guanosine 5'-[gamma-thio]triphosphate binding to the 67 kDa G-protein associated with the insulin receptor.

Academic Article

Abstract

  • Peptides representing two putative G-protein-binding motifs (GPBP1 and GPBP2) derived from insulin-receptor sequences were tested for their ability to stimulate guanosine 5'-[gamma-thio]-triphosphate (GTP[S]; 'GTP gamma S') binding to a preparation containing the 41 and 67 kDa G-proteins that are associated with the insulin receptor [Jo, Cha, Davis and McDonald (1992) Endocrinology (Baltimore) 131, 2855-2861]. GPBP2 (residues 1135-1156) specifically stimulated GTP[S] binding, whereas GPBP1 (1319-1333) did not. Substitution of Arg-1152 with Gln in GPBP2 corresponding to a mutation site in insulin-resistant patients [Cocozza, Porcellini, Riccardi, Monticelli, Condorelli, Ferrera, Pianese, Miele, Capaldo, Beguinot and Varrone (1992) Diabetes 41, 521-526] attenuated the stimulatory potency of GPBP2. Size-exclusion chromatography and studies with purified 67 kDa G-protein revealed that GPBP2 stimulated GTP[S] binding only to the 67 kDa G-protein. These studies provide evidence for a potential regulatory site for G-protein interaction with the insulin receptor in the tyrosine kinase domain.
  • Published In

    Keywords

  • Amino Acid Sequence, Binding Sites, GTP-Binding Proteins, Guanosine 5'-O-(3-Thiotriphosphate), Humans, Molecular Sequence Data, Peptide Fragments, Receptor, Insulin
  • Author List

  • Jo H; Radding W; Anantharamaiah GM; McDonald JM
  • Start Page

  • 19
  • End Page

  • 24
  • Volume

  • 294 ( Pt 1)