VEGF Receptor 1 Antibody (YA6239),MedChemexpress,HY-P86547

FLT1 is a tyrosine-protein kinase that functions as a cell-surface receptor for VEGFA, VEGFB, and PGF, playing essential roles in embryonic vasculature development, angiogenesis regulation, cell survival, migration, macrophage function, chemotaxis, and cancer cell invasion. It acts as a positive regulator of postnatal retinal hyaloid vessel regression (By similarity) and may serve as a negative regulator of embryonic angiogenesis by inhibiting excessive endothelial cell proliferation. In adulthood, it promotes endothelial cell proliferation, survival, and angiogenesis, though its pro-proliferative effects are cell-type specific—enhancing PGF-mediated endothelial cell proliferation and some cancer cell proliferation but not normal fibroblasts (in vitro). With high affinity for VEGFA but low kinase activity, FLT1 may negatively regulate VEGFA signaling by sequestering free VEGFA and preventing KDR binding. It modulates KDR signaling via heterodimerization. Ligand binding triggers multiple signaling cascades, including PLCG activation to produce diacylglycerol and inositol 1,4,5-trisphosphate, activating protein kinase C, and phosphorylating PIK3R1 to activate the phosphatidylinositol 3-kinase pathway. FLT1 also activates MAPK1/ERK2, MAPK3/ERK1, MAP kinase, and AKT1 pathways, and may phosphorylate SRC, YES1, and CBL. It promotes AKT1 phosphorylation at Ser-473 and PTK2/FAK1 phosphorylation. Its truncated kinase domain enhances SRC phosphorylation at Tyr-418 through an unknown mechanism, promoting tumor cell invasion.

Vascular endothelial growth factor receptor 1; VEGFR-1; Fms-like tyrosine kinase 1; FLT-1; Tyrosine-protein kinase FRT; Tyrosine-protein kinase receptor FLT; FLT; Vascular permeability factor receptor;