title: Insulin-like growth factor I receptor does not contribute to heat shock-induced Activation of Akt and extracellular signal-regulated kinase (ERK) in mouse embryo fibroblasts.
abstract: We have investigated the role of insulin-like growth factor I receptor (IGF-IR) in heat shock-induced activation of the mitogen-activated protein kinase (MAPK) and phosphatidylinositol-3 ' kinase (PI3-K) pathways. We utilized mouse embryo fibroblasts (MEFs) devoid of endogenous IGF-IR (R-) and MEFs overexpressing human IGF-IR (WT) and examined the activation kinetics of extracellular signal-regulated kinase (ERK) and Akt following heat shock treatment. There were no differences in the kinetics or temperature dependence of activation of either ERK or Akt between the cell lines. As expected, heat shock failed to induce autophosphorylation of IGF-IR overexpressed in WT cells. Surprisingly, the autophosphorylation of endogenous epidermal growth factor receptor (EGFR), which is thought to play an important role in heat shock-induced activation of the MAPK and PI3-K pathways, was not observed in either WT or R-cells. These results suggest that neither IGF-IR nor EGFR contributes to the heat shock -induced activation of ERK and Akt in these cell lines.
authors.affiliation: Molecular Diagnosis and Therapeutics, Graduate School, Tokyo Medical and Dental University, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Kataoka
authors.forename: Masahiko
authors.initials: M
authors.lastname: Miura
mesh_terms: D000818:Animals; D002460:Cell Line; D004789:Enzyme Activation / Q000528:radiation effects; D005347:Fibroblasts / Q000378:metabolism* / Q000528:radiation effects; D018869:Heat-Shock Response / Q000502:physiology*; D006358:Hot Temperature; D051379:Mice; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt; D017526:Receptor, IGF Type 1 / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D013696:Temperature
chemical_list: D011518:Proto-Oncogene Proteins; D011994:Recombinant Proteins; D017526:Receptor, IGF Type 1; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D020928:Mitogen-Activated Protein Kinases