Rabbit anti-Human VEGFR2/Flk-1 mAb(DET) (RMK0020)

VEGF R2 [also known as KDR (kinase insert domain receptor) in humans or Flk-1(fetal liverkinase-1) in mice], is a member of the class III subfamily of receptor tyrosine kinases (RTKs) that also includes VEGF R1 (Flt-1) and VEGF R3 (Flt-4). All three receptors contain seven Ig-like repeats within their extracellular domains and kinase insert domains in their intracellularregions. The expression patterns of VEGF R1, VEGF R2, and VEGF R3 are almost exclusivelyrestricted to endothelial cells.These receptors play essential roles in angiogenesis. VEGF R2binds VEGF-A (VEGF121, VEGF165, VEGF189 and VEGF206 splice variants), VEGF-C and VEGF-D.The full-length cDNA for VEGF R2 encodes a 1356 amino acid (aa) precursor protein with a19 aa signal peptide. The mature protein is composed of a 745 aa extracellular domain, a25 aa transmembrane domain and a 567 aa cytoplasmic domain. The gene for VEGF R2 maps to human chromosome 4q31.2—q32, a locus distinct from locations for other type III growth factor RTKs .VEGF R1, VEGF R2, and VEGF R3 are preferentially expressed in the proliferating endothelium of vessels lining and/or penetrating solid tumors. VEGF R2, however, is more widely distributed and expressed in all vessel-derived endothelial cells in comparison to VEGF R1. VEGF R2 is also localized in endothelial cells and perivascular cells of capillaries within the lamina propria of seminiferous tubules, Leydig cells and Sertoli cells.In contrast to VEGF R1, which binds both PlGF and VEGF with high affinity, VEGF R2 binds VEGF but not PlGF with high affinity. In vitro studies further demonstrate that PlGF/VEGFheterodimers can bind with high affinity to soluble VEGF R2, but PlGF homodimers fail to bind this receptor . Soluble forms of VEGF R1 and VEGF R2 also differ significantly from oneanother in terms of their abilities to block VEGF-induced cell proliferation and migration.