Abstract
Hepatocyte growth factor/scatter factor (HGF/SF) is a multifunctional cytokine that induces mitogenesis, motility, invasion, and morphogenesis of several epithelial and endothelial cell lines in culture. The receptor for HGF/SF has been identified as the Met tyrosine kinase. To investigate the signaling pathways that are involved in these events, we have generated chimeric receptors containing the extracellular domain of the colony-stimulating factor-1 (CSF-1) receptor fused to the transmembrane and intracellular domains of the Met receptor (MET). Madin-Darby canine kidney (MDCK) epithelial cells expressing the CSF-MET chimera dissociate and scatter in response to CSF-1. However, cells expressing a mutant CSF-MET receptor containing a phenylalanine substitution for tyrosine 1356 were unable to scatter or form branching tubules following stimulation with CSF-1. Tyrosine 1356 is essential for the recruitment of multiple substrates including the p85 subunit of PI3-kinase, phospholipase C gamma, and Grb2. In this study, we have investigated the role of PI3-kinase and a downstream target of PI3-kinase, pp70S6K, in the induction of MDCK cell scatter in response to HGF/SF. Our results demonstrate that following stimulation with HGF/SF, activation of PI3-kinase but not pp70S6K is essential for MDCK cell scatter.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Amino Acid Sequence
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Androstadienes / pharmacology
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Animals
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Blotting, Western
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Cadherins / analysis
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Cadherins / metabolism
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Cell Adhesion Molecules / analysis
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Cell Adhesion Molecules / metabolism
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Cell Line
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Cell Movement / drug effects
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Cell Movement / physiology*
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Cytoskeletal Proteins / analysis
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Cytoskeletal Proteins / metabolism
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Desmoplakins
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Dogs
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Enzyme Activation
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Enzyme Inhibitors / pharmacology
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Hepatocyte Growth Factor / pharmacology*
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Kidney
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Macrophage Colony-Stimulating Factor / pharmacology
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Molecular Sequence Data
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Peptide Fragments / chemistry
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Phosphatidylinositol 3-Kinases
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Phosphotransferases (Alcohol Group Acceptor) / metabolism*
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Protein Serine-Threonine Kinases / isolation & purification
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Protein Serine-Threonine Kinases / metabolism
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Proto-Oncogene Proteins c-met
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Receptor Protein-Tyrosine Kinases / biosynthesis
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Receptor Protein-Tyrosine Kinases / physiology*
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Receptor, Macrophage Colony-Stimulating Factor / biosynthesis
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Receptor, Macrophage Colony-Stimulating Factor / metabolism
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Recombinant Fusion Proteins / biosynthesis
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Recombinant Fusion Proteins / metabolism
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Ribosomal Protein S6 Kinases
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Signal Transduction
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Substrate Specificity
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Wortmannin
Substances
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Androstadienes
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Cadherins
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Cell Adhesion Molecules
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Cytoskeletal Proteins
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Desmoplakins
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Enzyme Inhibitors
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Peptide Fragments
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Recombinant Fusion Proteins
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Hepatocyte Growth Factor
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Macrophage Colony-Stimulating Factor
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Phosphotransferases (Alcohol Group Acceptor)
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Proto-Oncogene Proteins c-met
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Receptor Protein-Tyrosine Kinases
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Receptor, Macrophage Colony-Stimulating Factor
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Protein Serine-Threonine Kinases
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Ribosomal Protein S6 Kinases
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Wortmannin