Phosphorylation of focal adhesion kinase (FAK) on Ser732 is induced by rho-dependent kinase and is essential for proline-rich tyrosine kinase-2-mediated phosphorylation of FAK on Tyr407 in response to vascular endothelial growth factor.
Focal adhesion kinase (FAK) is phosphorylated on tyrosine and serine residues after cell activation. In the present work, we investigated the relationship between tyrosine and serine phosphorylation of FAK in promoting endothelial cell migration in response to vascular endothelial growth factor (VEGF). We found that VEGF induces the activation of the Rho-dependent kinase (ROCK) downstream from vascular endothelial growth factor receptor (VEGFR) 2. In turn, activated ROCK directly phosphorylates FAK on Ser732. Proline-rich tyrosine kinase-2 (Pyk2) is also activated in response to VEGF. Its activation requires the clustering of integrin alphavbeta3 and triggers directly the phosphorylation of Tyr407 within FAK, an event necessary for cell migration. Interestingly, ROCK-mediated phosphorylation of Ser732 is essential for Pyk2-dependent phosphorylation of Tyr407, because the latter is abrogated in cells expressing a FAK mutant that is nonphosphorylatable on Ser732. We suggest that VEGF elicits the activation of the VEGFR2-ROCK pathway, leading to phosphorylation of Ser732 within FAK. In turn, phosphorylation of Ser732 would change the conformation of FAK, making it accessible to Pyk2 activated in response to its association with integrin beta3. Then, activated Pyk2 triggers the phosphorylation of FAK on Tyr407, promoting cell migration.
Le Boeuf
Fabrice
F
Le Centre de Recherche en Cancérologie de l'Université Laval, Québec, Québec G1R-2J6, Canada.
Houle
François
F
Sussman
Mark
M
Huot
Jacques
J
D000818:Animals; D016227:Benzoquinones / Q000494:pharmacology; D002417:Cattle; D002465:Cell Movement / Q000187:drug effects; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects; D051418:Focal Adhesion Kinase 2 / Q000378:metabolism*; D051416:Focal Adhesion Protein-Tyrosine Kinases / Q000737:chemistry / Q000378:metabolism*; D022001:Focal Adhesions / Q000187:drug effects; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D047029:Lactams, Macrocyclic / Q000494:pharmacology; D051379:Mice; D009154:Mutation / Q000235:genetics; D010766:Phosphorylation / Q000187:drug effects; D010768:Phosphoserine / Q000378:metabolism*; D019000:Phosphotyrosine / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D021381:Protein Transport / Q000187:drug effects; D013552:Swine; D042461:Vascular Endothelial Growth Factor A / Q000494:pharmacology*; D016596:Vinculin / Q000378:metabolism; D054460:rho-Associated Kinases
D016227:Benzoquinones; D018841:HSP90 Heat-Shock Proteins; D047908:Intracellular Signaling Peptides and Proteins; D047029:Lactams, Macrocyclic; D042461:Vascular Endothelial Growth Factor A; D016596:Vinculin; D010768:Phosphoserine; D019000:Phosphotyrosine; D051418:Focal Adhesion Kinase 2; D051416:Focal Adhesion Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; D054460:rho-Associated Kinases; C001277:geldanamycin