Analysis of Biological Effects and Signaling Properties of Flt-1 (VEGFR-1) and KDR (VEGFR-2)

• Published in: The Journal of biological chemistry Vol. 276; no. 5; pp. 3222 - 3230
• Main Authors: Gille, Hendrik, Kowalski, Joe, Li, Bing, LeCouter, Jennifer, Moffat, Barbara, Zioncheck, Thomas F., Pelletier, Nicolas, Ferrara, Napoleone
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 02.02.2001; American Society for Biochemistry and Molecular Biology
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M002016200

Endothelial cells express two related vascular endothelial growth factor (VEGF) receptor tyrosine kinases, KDR (kinase-insert domain containing receptor, or VEGFR-2) and Flt-1 (fms-like tyrosine kinase, or VEGFR-1). Although considerable experimental evidence links KDR activation to endothelial cell mitogenesis, there is still significant uncertainty concerning the role of individual VEGF receptors for other biological effects such as vascular permeability. VEGF mutants that bind to either KDR or Flt-1 with high selectivity were used to determine which of the two receptors serves to mediate different VEGF functions. In addition to mediating mitogenic signaling, selective KDR activation was sufficient for the activation of intracellular signaling pathways implicated in cell migration. KDR stimulation caused tyrosine phosphorylation of both phosphatidylinositol 3-kinase and phospholipase Cγ in primary endothelial cells and stimulated cell migration. KDR-selective VEGF was also able to induce angiogenesis in the rat cornea to an extent indistinguishable from wild type VEGF. We also demonstrate that KDR, but not Flt-1, stimulation is responsible for the induction of vascular permeability by VEGF.