Fibroblast growth factor receptor-1 mediates chemotaxis independently of direct SH2-domain protein binding.
Endothelial cells expressing fibroblast growth factor receptor-1 (FGFR-1) migrate and proliferate in response to treatment with FGF. We analysed ligand-induced migration and proliferation of porcine aortic endothelial cells expressing wild-type FGFR-1, point-mutated Y766F FGFR-1, unable to activate phospholipase C-gamma1 (PLC-gamma1), or carboxyl-terminally truncated FGFR-1, lacking either 48 (from amino acid 774 in the FGFR-1 sequence) or 63 (from amino acid 759) amino acid residues of the C-terminal tail. The truncated CT63 FGFR-1 mutant failed to mediate chemotaxis, but was in response to ligand stimulation capable of mediating proliferation of the cells, stimulation of MAP kinase activity and tyrosine phosphorylation of FRS2, an FGFR-1 specific signaling molecule. The defect in migration-capacity of CT63 was not due to loss of Y766, and thereby PLC-gamma1 activation, since cells expressing the mutant Y766F FGFR-1 migrated as efficiently as the wild-type receptor cells. Induction of phospholipase A2 (PLA2) activity by the activated FGFR-1 was dependent on the presence of Y766, and was therefore also not critical for the chemotactic response. Although the FGFR-1 only very inefficiently mediates activation of phosphatidylinositol 3' kinase (PI 3-kinase), the PI 3-kinase inhibitor wortmannin suppressed wild-type FGFR-1 mediated migration. We conclude that the signal transduction pathway for FGFR-1 mediated migration is independent of phosphotyrosine residues in the receptor and requires activation of a wortmannin-sensitive enzyme.
Department of Medical Biochemistry and Microbiology, Biomedical Center, Uppsala, Sweden.
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Landgren
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Klint
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Yokote
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Claesson-Welsh
D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D000730:Androstadienes / Q000494:pharmacology; D000818:Animals; D001011:Aorta; D000077214:Becaplermin; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism; D002455:Cell Division; D002478:Cells, Cultured; D002633:Chemotaxis / Q000502:physiology*; D004730:Endothelium, Vascular / Q000166:cytology* / Q000502:physiology*; D004789:Enzyme Activation; D004791:Enzyme Inhibitors; D007295:Inositol Phosphates / Q000378:metabolism; D007527:Isoenzymes / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D051966:Phospholipase C gamma; D010741:Phospholipases A / Q000096:biosynthesis; D054467:Phospholipases A2; D010750:Phosphoproteins / Q000378:metabolism; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology; D017354:Point Mutation; D020574:Proto-Oncogene Proteins c-sis; D020794:Receptor Protein-Tyrosine Kinases; D051496:Receptor, Fibroblast Growth Factor, Type 1; D020796:Receptor, Platelet-Derived Growth Factor alpha; D017468:Receptors, Fibroblast Growth Factor / Q000737:chemistry / Q000187:drug effects / Q000502:physiology*; D017479:Receptors, Platelet-Derived Growth Factor / Q000096:biosynthesis / Q000737:chemistry / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000187:drug effects; D015398:Signal Transduction; D013552:Swine; D014162:Transfection; D010738:Type C Phospholipases / Q000378:metabolism; D000077191:Wortmannin
D048868:Adaptor Proteins, Signal Transducing; D000730:Androstadienes; D004791:Enzyme Inhibitors; C106534:FRS2 protein, human; D007295:Inositol Phosphates; D007527:Isoenzymes; D008565:Membrane Proteins; D010750:Phosphoproteins; D010982:Platelet-Derived Growth Factor; D020574:Proto-Oncogene Proteins c-sis; D017468:Receptors, Fibroblast Growth Factor; D011993:Recombinant Fusion Proteins; D000077214:Becaplermin; D020794:Receptor Protein-Tyrosine Kinases; D051496:Receptor, Fibroblast Growth Factor, Type 1; D020796:Receptor, Platelet-Derived Growth Factor alpha; D017479:Receptors, Platelet-Derived Growth Factor; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D010741:Phospholipases A; D054467:Phospholipases A2; D010738:Type C Phospholipases; D051966:Phospholipase C gamma; D000077191:Wortmannin