title: Involvement of a pertussis-toxin sensitive G protein in the induction of gene expression by insulin.
abstract: Binding of insulin to its receptor triggers multiple cellular responses, including changes in metabolism and in gene expression, resulting from the activation of multiple signalling pathways. Pertussis toxin has been shown to block an insulin-stimulated phospholipase C, resulting in an inhibition of the synthesis of phospholipid second messengers by insulin. In the present study, we investigated the significance of this pathway for the induction of growth-related genes by insulin treatment of H35 hepatoma cells. We found that pertussis toxin dramatically inhibits the induction of c-fos mRNA by insulin. Although c-jun and ornithine decarboxylase induction were also inhibited by pertussis toxin, they were much less sensitive than c-fos. These results indicate an important for lipid second messengers in mitogenic signalling by insulin and further demonstrate distinct roles for this pathway in the induction of c-fos and c-jun.
authors.affiliation: University of Texas M. D. Anderson Cancer Center Science Park-Research Division, Smithville, USA.
authors.forename: A P
authors.initials: AP
authors.lastname: Butler
authors.forename: L A
authors.initials: LA
authors.lastname: Martinez
authors.forename: R L
authors.initials: RL
authors.lastname: Montgomery
mesh_terms: D000818:Animals; D004305:Dose-Response Relationship, Drug; D019204:GTP-Binding Proteins / Q000378:metabolism*; D005786:Gene Expression Regulation; D007328:Insulin / Q000502:physiology*; D007700:Kinetics; D037342:Pertussis Toxin; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics* / Q000378:metabolism; D016755:Proto-Oncogene Proteins c-jun / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D015398:Signal Transduction; D014407:Tumor Cells, Cultured; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
chemical_list: D007328:Insulin; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D012333:RNA, Messenger; D010566:Virulence Factors, Bordetella; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins