Vascular Endothelial Growth Factor Receptor-1 (VEGFR-1), also known as Flt-1, is a receptor tyrosine kinase that plays a crucial role in the regulation of angiogenesis and vasculogenesis. It is one of the key receptors for vascular endothelial growth factors (VEGFs), which are essential for the development and maintenance of blood and lymphatic vessels .
VEGFR-1 is composed of several domains, including seven immunoglobulin-like domains (D1-D7) in its extracellular region, a single transmembrane domain, and an intracellular tyrosine kinase domain . The D1-D7 domains are critical for ligand binding and receptor activation. The recombinant form of VEGFR-1 D1-7 (Mouse) is a truncated version that includes only the extracellular ligand-binding domains, making it useful for studying ligand-receptor interactions and signaling pathways .
VEGFR-1 binds to multiple ligands, including VEGF-A, VEGF-B, and Placenta Growth Factor (PlGF). Among these, VEGF-A and PlGF are particularly important for angiogenesis. VEGF-A binds to both VEGFR-1 and VEGFR-2, while VEGF-B and PlGF bind exclusively to VEGFR-1 . The binding of these ligands to VEGFR-1 triggers a cascade of downstream signaling events that promote endothelial cell proliferation, migration, and survival .
VEGFR-1 has distinct biological functions compared to other VEGF receptors. While VEGFR-2 is primarily responsible for mediating angiogenic signals, VEGFR-1 acts as a decoy receptor that modulates the availability of VEGF ligands for VEGFR-2. This regulatory mechanism ensures a balanced angiogenic response . Additionally, VEGFR-1 is involved in the recruitment of monocytes and macrophages to sites of inflammation and tissue repair .
The recombinant form of VEGFR-1 D1-7 (Mouse) has significant therapeutic potential. It can be used to develop VEGFR-1 inhibitors that block ligand binding and receptor activation, thereby inhibiting pathological angiogenesis in diseases such as cancer and age-related macular degeneration . Furthermore, understanding the structural and functional aspects of VEGFR-1 can aid in the design of targeted therapies for various vascular disorders .