title: The role of ras proteins in insulin signal transduction.
abstract: Ras-proteins are guanine nucleotide binding proteins, which, in the GTP bound state emit a strong mitogenic signal. In the GDP bound state, the protein appears inactive. We have found that stimulation by insulin of cells expressing elevated levels of insulin receptors results in a rapid conversion of Ras-GDP into Ras-GTP. This process is part of the signalling pathway leading to immediate-early gene expression and a mitogenic response. There seems to be no involvement of Ras-GTP formation in the process of insulin stimulated glucose transport. Though the precise mechanism by which Ras is converted to the GTP bound state remains to be established, a tight correlation exists between receptor autophosphorylation and Ras-GTP formation.
authors.affiliation: Department of Medical Biochemistry, Sylvius Laboratory, Leiden, The Netherlands.
authors.forename: J A
authors.initials: JA
authors.lastname: Maassen
authors.forename: B M
authors.initials: BM
authors.lastname: Burgering
authors.forename: R H
authors.initials: RH
authors.lastname: Medema
authors.forename: A P
authors.initials: AP
authors.lastname: Osterop
authors.forename: G C
authors.initials: GC
authors.lastname: van der Zon
authors.forename: W
authors.initials: W
authors.lastname: Möller
authors.forename: J L
authors.initials: JL
authors.lastname: Bos
mesh_terms: D000818:Animals; D011905:Genes, ras / Q000502:physiology*; D006801:Humans; D007328:Insulin / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology*
chemical_list: D007328:Insulin