title: Nerve growth factor stimulation of p42/p44 mitogen-activated protein kinase in PC12 cells: role of G(i/o), G protein-coupled receptor kinase 2, beta-arrestin I, and endocytic processing.
abstract: In this study, we have shown that nerve growth factor (NGF)-dependent activation of the p42/p44 mitogen-activated protein kinase (p42/p44 MAPK) pathway in PC12 cells can be partially blocked by pertussis toxin (which inactivates the G proteins G(i/o)). This suggests that the Trk A receptor may use a G protein-coupled receptor pathway to signal to p42/p44 MAPK. This was supported by data showing that the NGF-dependent activation of p42/p44 MAPK is potentiated in cells transfected with G protein-coupled receptor kinase 2 (GRK2) or beta-arrestin I. Moreover, GRK2 is constitutively bound with the Trk A receptor, whereas NGF stimulates the pertussis toxin-sensitive binding of beta-arrestin I to the TrkA receptor-GRK2 complex. Both GRK2 and beta-arrestin I are involved in clathrin-mediated endocytic signaling to p42/p44 MAPK. Indeed, inhibitors of clathrin-mediated endocytosis (e.g., monodansylcadaverine, concanavalin A, and hyperosmolar sucrose) reduced the NGF-dependent activation of p42/p44 MAPK. Finally, we have found that the G protein-coupled receptor-dependent component regulating p42/p44 MAPK is required for NGF-induced differentiation of PC12 cells. Thus, NGF-dependent inhibition of DNA synthesis was partially blocked by PD098059 (inhibitor of MAPK kinase-1 activation) and pertussis toxin. Our findings are the first to show that the Trk A receptor uses a classic G protein-coupled receptor-signaling pathway to promote differentiation of PC12 cells.
authors.affiliation: Department of Physiology and Pharmacology, Strathclyde Institute for Biomedical Sciences, University of Strathclyde, Glasgow, Scotland, United Kingdom.
authors.forename: S
authors.initials: S
authors.lastname: Rakhit
authors.forename: S
authors.initials: S
authors.lastname: Pyne
authors.forename: N J
authors.initials: NJ
authors.lastname: Pyne
mesh_terms: D000818:Animals; D019390:Arrestins / Q000502:physiology*; D002454:Cell Differentiation / Q000502:physiology; D002966:Clathrin / Q000037:antagonists & inhibitors / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D004247:DNA / Q000096:biosynthesis / Q000187:drug effects; D004705:Endocytosis / Q000187:drug effects / Q000502:physiology; D004789:Enzyme Activation; D054769:G-Protein-Coupled Receptor Kinase 2; D019206:GTP-Binding Protein alpha Subunits, Gi-Go / Q000502:physiology; D020962:Heterotrimeric GTP-Binding Proteins / Q000502:physiology; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D020932:Nerve Growth Factor / Q000378:metabolism*; D016716:PC12 Cells; D019869:Phosphatidylinositol 3-Kinases / Q000502:physiology; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000502:physiology*; D051381:Rats; D020917:Receptor, trkA / Q000378:metabolism; D014443:Tyrosine / Q000378:metabolism; D051552:beta-Adrenergic Receptor Kinases; D000071557:beta-Arrestins
chemical_list: D019390:Arrestins; D002966:Clathrin; D017868:Cyclic AMP-Dependent Protein Kinases; D004247:DNA; D054769:G-Protein-Coupled Receptor Kinase 2; D019206:GTP-Binding Protein alpha Subunits, Gi-Go; D020962:Heterotrimeric GTP-Binding Proteins; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D020932:Nerve Growth Factor; D019869:Phosphatidylinositol 3-Kinases; D017346:Protein Serine-Threonine Kinases; D020917:Receptor, trkA; D014443:Tyrosine; D051552:beta-Adrenergic Receptor Kinases; D000071557:beta-Arrestins; C496569:Grk2 protein, rat