Angiopoietin-1 (human, recombinant)

Angiopoietin-1 (ANG-1) is a member of the angiopoietin family of growth factors. It is composed of a superclustering domain, which mediates oligomerization, a coiled-coil domain, and a fibrinogen-like domain, which facilitates receptor binding. ANG-1 is ubiquitously expressed and forms homomultimers, which are required for activation of its receptors, tunica interna endothelial cell kinase 2 (Tie2) and Tie1. It plays a role in angiogenesis, vascular remodeling and permeability, inflammation, hematopoiesis, and inhibition of apoptosis in endothelial cells. Mutations in ANGPT1, the gene encoding ANG-1, are associated with hereditary angioedema. Increased protein levels of ANG-1 correlate with increased levels of Tie2 in patients with colorectal cancer. Cayman's Angiopoietin-1 (human, recombinant) protein is a disulfide-linked homodimer. The reduced monomer, composed of ANG-1 (amino acids 16-261 and 277-498) fused to human IgG1 Fc at its C-terminus, consists of 721 amino acids, has a calculated molecular weight of 82 kDa, and a predicted N-terminus of His16 after signal peptide cleavage.. Protein function: Binds and activates TEK/TIE2 receptor by inducing its dimerization and tyrosine phosphorylation. Plays an important role in the regulation of angiogenesis, endothelial cell survival, proliferation, migration, adhesion and cell spreading, reorganization of the actin cytoskeleton, but also maintenance of vascular quiescence. Required for normal angiogenesis and heart development during embryogenesis. After birth, activates or inhibits angiogenesis, depending on the context. Inhibits angiogenesis and promotes vascular stability in quiescent vessels, where endothelial cells have tight contacts. In quiescent vessels, ANGPT1 oligomers recruit TEK to cell- cell contacts, forming complexes with TEK molecules from adjoining cells, and this leads to preferential activation of phosphatidylinositol 3-kinase and the AKT1 signaling cascades. In migrating endothelial cells that lack cell-cell adhesions, ANGT1 recruits TEK to contacts with the extracellular matrix, leading to the formation of focal adhesion complexes, activation of PTK2/FAK and of the downstream kinases MAPK1/ERK2 and MAPK3/ERK1, and ultimately to the stimulation of sprouting angiogenesis. Mediates blood vessel maturation/stability. Implicated in endothelial developmental processes later and distinct from that of VEGF. Appears to play a crucial role in mediating reciprocal interactions between the endothelium and surrounding matrix and mesenchyme. [The UniProt Consortium]