Signal transduction by VEGF receptor-1 wild type and mutant proteins.
The role of the vascular endothelial growth factor receptor-1 (VEGFR-1) in endothelial cell function is unclear. We have previously identified four tyrosine phosphorylation sites in the C-terminal tail of this receptor. We now show that the wild type VEGFR-1 expressed in porcine aortic endothelial (PAE/VEGFR-1) cells was able to transduce signals for increased DNA synthesis and proliferation. Tyrosine phosphorylation of phospholipase Cgamma (PLCgamma), tyrosine phosphatase SHP-2, Crk, and extracellular regulated kinases 1 and 2 (Erk1/2) was registered in response to VEGF-A treatment of the PAE/VEGFR-1 cells. VEGFR-1 mutated at Y1213, Y1242, and Y1333 were constructed and expressed in PAE cells, to the same level as that of PAE/VEGFR-1 cells. The affinities of the wild type and mutated receptors for VEGF-A(165) binding were similar. The mutated VEGFR-1 Y1213F expressed in PAE cells was kinase inactive. PAE cells expressing the mutated VEGFR-1 Y1242F and Y1333F receptors mediated increased tyrosine phosphorylation of PLCgamma in response to VEGF-A stimulation. However, these two mutant VEGFR-1 failed to mediate increased mitogenesis and were unable to stimulate increased tyrosine phosphorylation of SHP-2, Crk, and Erk1/2, indicating that the mutations lead to a perturbation in VEGF-A-induced signal transduction.
Ito
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Department of Genetics and Pathology, Rudbeck Laboratory, Dag Hammarskjöldsv. 20, S-751 85, Uppsala, Sweden.
Huang
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Claesson-Welsh
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D000818:Animals; D002455:Cell Division; D002478:Cells, Cultured; D004247:DNA / Q000096:biosynthesis; D016228:Endothelial Growth Factors / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009154:Mutation; D010766:Phosphorylation; D019000:Phosphotyrosine / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000235:genetics* / Q000502:physiology*; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics* / Q000502:physiology*; D015398:Signal Transduction; D013552:Swine; D014162:Transfection; D042461:Vascular Endothelial Growth Factor A; D040281:Vascular Endothelial Growth Factor Receptor-1
D016228:Endothelial Growth Factors; D011518:Proto-Oncogene Proteins; D042461:Vascular Endothelial Growth Factor A; D019000:Phosphotyrosine; D004247:DNA; D020794:Receptor Protein-Tyrosine Kinases; D040281:Vascular Endothelial Growth Factor Receptor-1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases