Tyrosine-protein kinase that acts as a cell-surface receptor for VEGFA, VEGFC and/or VEGFD and plays an essential role in the regulation of angiogenesis and vascular development. Promotes proliferation, survival, migration and differentiation of endothelial cells. Promotes reorganization of the actin cytoskeleton. Binding of vascular growth factors leads to the activation of several signaling cascades. Activation of PLCG1 leads to the production of the cellular signaling molecules diacylglycerol and inositol 1,4,5-trisphosphate and the activation of protein kinase C. Mediates activation of MAPK1/ERK2, MAPK3/ERK1 and the MAP kinase signaling pathway, as well as of the AKT1 signaling pathway. Mediates phosphorylation of PIK3R1, the regulatory subunit of phosphatidylinositol 3-kinase, reorganization of the actin cytoskeleton and activation of PTK2/FAK1. Required for VEGFA-mediated induction of NOS2 and NOS3, leading to the production of the signaling molecule nitric oxide (NO) by endothelial cells (By similarity). ATP + L-tyrosyl-[protein] = ADP + H(+) + O-phospho-L-tyrosyl-[protein] Present in an inactive conformation in the absence of bound ligand. Binding of VEGFA, VEGFC or VEGFD leads to dimerization and activation by autophosphorylation on tyrosine residues (By similarity). Detected on caveolae-enriched lipid rafts at the cell surface. Is recycled from the plasma membrane to endosomes and back again. Phosphorylation triggered by VEGFA binding promotes internalization and subsequent degradation. Localized with RAP1A at cell-cell junctions (By similarity). In all endothelial tissues during onset of vascularization. In later development, present in lung, heart, intestine and skin. Expressed in whole mesoderm at onset of gastrulation. From day 2, confined to endothelial tissues and expression continues to be widespread throughout vascularization until E9 where it becomes restricted to specific regions such as the spinal cord and heart valves. In vitro, it is induced by basic fibroblast growth factor (bFGF), uniquely in the first 24 hours of cell culture. The second and third Ig-like C2-type (immunoglobulin-like) domains are sufficient for VEGF binding. Autophosphorylated on tyrosine residues upon ligand binding. Autophosphorylation occurs in trans, i.e. one subunit of the dimeric receptor phosphorylates tyrosine residues on the other subunit (By similarity). Belongs to the protein kinase superfamily. Tyr protein kinase family. CSF-1/PDGF receptor subfamily.