title: Specific insulin/IGF1 hybrid receptor activation assay reveals IGF1 as a more potent ligand than insulin.
abstract: This novel method enables specific measurement of the activation of hybrid receptors formed between the Insulin Receptor (IR) and the Insulin-like Growth Factor 1 Receptor (IGF1R). These hybrid receptors are present in tissues and cell lines expressing both IR and IGF1R. It is therefore challenging to separate the homodimer and hybrid receptor activation properties. This ELISA method enabled fast and quantitative measurements of activated hybrid receptors. The hybrid receptor specificity is obtained from a combination of two specific antibodies for IGF1R and for an IR tyrosine phosphorylation site. The specificity was shown by immunoprecipitations and Western blot analysis. IR exists as two splice variants; consequently, two splice variants of hybrid receptors can be expressed. It is reported here that both splice variants of insulin/IGF1 receptor hybrids are activated by IGF1 with >20-fold higher potency than insulin.
authors.affiliation: Novo Nordisk, Novo Nordisk Park, DK-2760 Måløv, Denmark.
authors.forename: Rita
authors.initials: R
authors.lastname: Slaaby
mesh_terms: D000818:Animals; D006224:Cricetinae; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D056945:Hep G2 Cells; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000235:genetics / Q000378:metabolism; D017526:Receptor, IGF Type 1; D011972:Receptor, Insulin / Q000235:genetics / Q000378:metabolism; D017451:Receptors, Somatomedin / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: C583557:IGF1 protein, human; C000597236:IGF1R protein, human; D017451:Receptors, Somatomedin; D011993:Recombinant Fusion Proteins; D007334:Insulin-Like Growth Factor I; D017526:Receptor, IGF Type 1; D011972:Receptor, Insulin