title: Down-regulation of epidermal growth factor receptors by nerve growth factor in PC12 cells is p140(trk)-, Ras-, and Src-dependent.
abstract: Nerve growth factor (NGF) treatment causes a profound down-regulation of epidermal growth factor receptors during the differentiation of PC12 cells. This process is characterized by a progressive decrease in epidermal growth factor (EGF) receptor level measured by 125I-EGF binding, tyrosine phosphorylation, and Western blotting. Treatment of the cells with NGF for 5 days produces a 95% reduction in the amount of [35S]methionine-labeled EGF receptors. This down-regulation does not occur in PC12nnr5 cells, which lack the p140(trk) NGF receptor. However, in PC12nnr5 cells stably transfected with p140(trk), the NGF-induced heterologous down-regulation of EGF receptors is reconstituted in part. NGF-induced heterologous down-regulation, but not EGF-induced homologous down-regulation of EGF receptors, is blocked in Ras- and Src-dominant-negative PC12 cells. Treatment with either pituitary adenylate cyclase-activating peptide (PACAP) or staurosporine stimulates neurite outgrowth in PC12 cell variants, but neither induces down-regulation of EGF receptors. NGF treatment of PC12 cells in suspension induces down-regulation of EGF receptors in the absence of neurite outgrowth. These results strongly suggest a p140(trk)-, Ras- and Src-dependent mechanism of NGF-induced down-regulation of EGF receptors and separate this process from NGF-induced neurite outgrowth in PC12 cells.
authors.affiliation: Section on Growth Factors, NICHD, National Institutes of Health, Bethesda, Maryland 20892, USA.
authors.forename: P
authors.initials: P
authors.lastname: Lazarovici
authors.forename: M
authors.initials: M
authors.lastname: Oshima
authors.forename: D
authors.initials: D
authors.lastname: Shavit
authors.forename: M
authors.initials: M
authors.lastname: Shibutani
authors.forename: H
authors.initials: H
authors.lastname: Jiang
authors.forename: M
authors.initials: M
authors.lastname: Monshipouri
authors.forename: D
authors.initials: D
authors.lastname: Fink
authors.forename: V
authors.initials: V
authors.lastname: Movsesyan
authors.forename: G
authors.initials: G
authors.lastname: Guroff
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D015536:Down-Regulation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D066246:ErbB Receptors / Q000096:biosynthesis*; D009414:Nerve Growth Factors / Q000494:pharmacology*; D016501:Neurites / Q000187:drug effects; D009479:Neuropeptides / Q000494:pharmacology; D016716:PC12 Cells; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051381:Rats; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism; D020917:Receptor, trkA; D017475:Receptors, Nerve Growth Factor / Q000378:metabolism; D015398:Signal Transduction; D019311:Staurosporine / Q000494:pharmacology; D018631:ras Proteins / Q000378:metabolism; D019061:src-Family Kinases / Q000378:metabolism
chemical_list: C495403:Adcyap1 protein, rat; D004791:Enzyme Inhibitors; D009414:Nerve Growth Factors; D009479:Neuropeptides; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D011518:Proto-Oncogene Proteins; D017475:Receptors, Nerve Growth Factor; D066246:ErbB Receptors; D020794:Receptor Protein-Tyrosine Kinases; D020917:Receptor, trkA; D019061:src-Family Kinases; D018631:ras Proteins; D019311:Staurosporine