Role of Phosphoinositide 3-Kinase and Endocytosis in Nerve Growth Factor-Induced Extracellular Signal-Regulated Kinase Activation via Ras and Rap1
| Autor: | Philip J.S. Stork, Randall D. York, Edwin W. McCleskey, Savraj S. Grewal, Paula E. Stenberg, Derek C. Molliver |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
MAPK/ERK pathway
Time Factors Mitogen-activated protein kinase kinase PC12 Cells Chromatography Affinity Phosphatidylinositol 3-Kinases 1-Methyl-3-isobutylxanthine Ganglia Spinal Nerve Growth Factor Enzyme Inhibitors Luciferases Internalization Cell Growth and Development Cells Cultured media_common biology rap1 GTP-Binding Proteins Cell Differentiation Immunohistochemistry Endocytosis Cell biology Proto-Oncogene Proteins c-raf Mitogen-Activated Protein Kinases Signal transduction Signal Transduction Neurotrophin Cell Survival Morpholines media_common.quotation_subject Blotting Western Transfection Models Biological Animals Receptor trkA Molecular Biology Flavonoids Dose-Response Relationship Drug MAP kinase kinase kinase Colforsin Cell Biology Rats Enzyme Activation Microscopy Electron Nerve growth factor Microscopy Fluorescence nervous system Chromones ras Proteins biology.protein |
| Zdroj: | Molecular and Cellular Biology. 20:8069-8083 |
| ISSN: | 1098-5549 |
| Popis: | Neurotrophins promote multiple actions on neuronal cells including cell survival and differentiation. The best-studied neurotrophin, nerve growth factor (NGF), is a major survival factor in sympathetic and sensory neurons and promotes differentiation in a well-studied model system, PC12 cells. To mediate these actions, NGF binds to the TrkA receptor to trigger intracellular signaling cascades. Two kinases whose activities mediate these processes include the mitogen-activated protein (MAP) kinase (or extracellular signal-regulated kinase [ERK]) and phosphoinositide 3-kinase (PI3-K). To examine potential interactions between the ERK and PI3-K pathways, we studied the requirement of PI3-K for NGF activation of the ERK signaling cascade in dorsal root ganglion cells and PC12 cells. We show that PI3-K is required for TrkA internalization and participates in NGF signaling to ERKs via distinct actions on the small G proteins Ras and Rap1. In PC12 cells, NGF activates Ras and Rap1 to elicit the rapid and sustained activation of ERKs respectively. We show here that Rap1 activation requires both TrkA internalization and PI3-K, whereas Ras activation requires neither TrkA internalization nor PI3-K. Both inhibitors of PI3-K and inhibitors of endocytosis prevent GTP loading of Rap1 and block sustained ERK activation by NGF. PI3-K and endocytosis may also regulate ERK signaling at a second site downstream of Ras, since both rapid ERK activation and the Ras-dependent activation of the MAP kinase kinase kinase B-Raf are blocked by inhibition of either PI3-K or endocytosis. The results of this study suggest that PI3-K may be required for the signals initiated by TrkA internalization and demonstrate that specific endocytic events may distinguish ERK signaling via Rap1 and Ras. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|