Biological activity and phosphorylation sites of the bacterially expressed cytosolic domain of the KDR VEGF-receptor.
Vascular endothelial growth factor (VEGF) is a potent angiogenic factor which binds to two structurally similar receptor tyrosine kinases, KDR and FLT1. Towards the goal of clarifying the signal transduction pathways by which VEGF activates endothelial cells, we expressed in bacteria an enzymatically active form of the cytosolic domain of the KDR receptor. The expressed protein undergoes autophosphorylation in both bacterial cells and in its purified form. Using peptide mapping and sequencing of peptides, we identified four tyrosine residues that are phosphorylated corresponding to residues 951, 996, 1054, and 1059 of the KDR protein. The location of the phosphorylated residues in the bacterially expressed protein, and/or the consensus sequences around these sites, suggest they may be identical to the phosphorylated sites of KDR in mammalian cells.
Dougher-Vermazen
M
M
Medical Research Division, Lederle Laboratories, Pearl River, New York 10965.
Hulmes
J D
JD
Böhlen
P
P
Terman
B I
BI
D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D003600:Cytosol / Q000378:metabolism*; D004926:Escherichia coli; D008969:Molecular Sequence Data; D010766:Phosphorylation; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics* / Q000378:metabolism; D017978:Receptors, Growth Factor / Q000235:genetics* / Q000378:metabolism; D040262:Receptors, Vascular Endothelial Growth Factor; D011994:Recombinant Proteins; D015398:Signal Transduction
D017978:Receptors, Growth Factor; D011994:Recombinant Proteins; D020794:Receptor Protein-Tyrosine Kinases; D040262:Receptors, Vascular Endothelial Growth Factor