Phospho-VEGF Receptor 2 (Tyr951) Recombinant Rabbit mAb (S-4034)

Phospho-VEGF Receptor 2 (Tyr951) refers to the activated form of vascular endothelial growth factor receptor 2 (VEGFR2, also known as KDR/Flk-1) following autophosphorylation at tyrosine residue 951 within its kinase insert domain, representing one of the key autophosphorylation sites of VEGFR2. Upon VEGF-A binding and subsequent VEGFR2 dimerization, the intracellular kinase domain is activated, leading to autophosphorylation at Tyr951, which creates a docking site for the SH2 domain of the T-cell-specific adaptor protein (TSAd), thereby recruiting TSAd and further activating c-Src kinase. This signaling axis primarily regulates actin stress fiber formation, endothelial cell migration, and angiogenic sprouting, while having a relatively minor impact on mitosis. In developing vasculature, Tyr951 phosphorylation is observed only in a subset of blood vessels, whereas it is particularly prominent in tumor vasculature; TSAd deficiency significantly reduces tumor vascularization and tumor growth. Additionally, Tyr951 phosphorylation participates in VEGF-induced vascular permeability by influencing VE-cadherin rearrangement at endothelial cell junctions through the TSAd-c-Src pathway. Therefore, Phospho-VEGFR2 (Tyr951) is commonly used as an important marker for assessing the activation status of the VEGFR2 migration/angiogenesis signaling branch, holding significant implications in tumor angiogenesis and anti-angiogenic therapy research.