Src mediates stimulation by vascular endothelial growth factor of the phosphorylation of focal adhesion kinase at tyrosine 861, and migration and anti-apoptosis in endothelial cells

Biochem J. 2001 Nov 15;360(Pt 1):255-64. doi: 10.1042/0264-6021:3600255.


Vascular endothelial growth factor (VEGF) stimulates the tyrosine phosphorylation of focal adhesion kinase (FAK), increases focal adhesion formation and is chemotactic for human umbilical-vein endothelial cells (HUVECs). In the present study we identified the major sites of VEGF-induced FAK tyrosine phosphorylation and investigated the mechanism mediating this pathway in the action of VEGF. VEGF increased the focal adhesion localization of FAK phosphorylated at Tyr-397 (Y397) and Y861 but stimulated a marked increase in phosphorylation at Y861 without significantly affecting the total level of phospho-Y397 FAK. Inhibition of Src with the specific inhibitor 4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine (PP2) completely blocked VEGF-induced Y861 phosphorylation without decreasing the level of phospho-Y397 FAK. We also examined the role of Src in mediating endothelial functions of VEGF in which FAK has been implicated as having a role. PP2 markedly inhibited VEGF-induced chemotaxis and wound-healing cell migration. The Src inhibitor also decreased the anti-apoptotic effect of VEGF determined by surface staining of annexin V but did not increase FAK proteolysis or prevent the VEGF-dependent inhibition of FAK proteolysis. In contrast, the specific PtdIns 3-kinase inhibitor LY294002 induced apoptosis and markedly decreased p125(FAK) expression and increased FAK proteolysis but had little effect on Y861 phosphorylation. These findings identify Src-dependent FAK phosphorylation at Y861 as a novel VEGF-induced signalling pathway in endothelial cells and suggest that this pathway might be involved in the mechanisms mediating VEGF-induced endothelial cell migration and anti-apoptosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis
  • Blotting, Western
  • Cell Adhesion
  • Cell Division
  • Cell Movement
  • Cell Survival
  • Cells, Cultured
  • Chemotaxis
  • Chromones / pharmacology
  • Endothelial Growth Factors / metabolism*
  • Endothelium, Vascular / cytology
  • Endothelium, Vascular / metabolism
  • Enzyme Inhibitors / pharmacology
  • Focal Adhesion Kinase 1
  • Focal Adhesion Protein-Tyrosine Kinases
  • Humans
  • Immunoblotting
  • Lymphokines / metabolism*
  • Microscopy, Fluorescence
  • Morpholines / pharmacology
  • Phosphorylation
  • Protein Structure, Tertiary
  • Protein-Tyrosine Kinases / metabolism*
  • Signal Transduction
  • Time Factors
  • Tyrosine / metabolism*
  • Umbilical Veins / cytology
  • Vascular Endothelial Growth Factor A
  • Vascular Endothelial Growth Factors
  • Wound Healing
  • src-Family Kinases / metabolism*


  • Chromones
  • Endothelial Growth Factors
  • Enzyme Inhibitors
  • Lymphokines
  • Morpholines
  • Vascular Endothelial Growth Factor A
  • Vascular Endothelial Growth Factors
  • 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one
  • Tyrosine
  • Protein-Tyrosine Kinases
  • Focal Adhesion Kinase 1
  • Focal Adhesion Protein-Tyrosine Kinases
  • PTK2 protein, human
  • src-Family Kinases