TIE-2 Protein, Human (Active, Y897S, sf9, His-Strep)

TIE-2, a tyrosine-protein kinase, acts as a cell-surface receptor for ANGPT1, ANGPT2, and ANGPT4, exerting comprehensive control over angiogenesis, endothelial cell behavior, and vascular stability. It regulates diverse processes, including endothelial cell survival, proliferation, migration, adhesion, and actin cytoskeleton reorganization, while also playing a crucial role in maintaining vascular quiescence and preventing the leakage of pro-inflammatory plasma proteins and leukocytes from blood vessels, resulting in anti-inflammatory effects. Essential for normal angiogenesis during embryonic development and post-natal hematopoiesis, TIE-2 exhibits context-dependent angiogenic activation or inhibition after birth. In quiescent vessels, ANGPT1, oligomerizing, recruits TIE-2 to cell-cell contacts, activating phosphatidylinositol 3-kinase and AKT1 signaling cascades, promoting vascular stability. Conversely, in migrating endothelial cells lacking cell-cell adhesions, ANGPT1 recruits TIE-2 to extracellular matrix contacts, stimulating sprouting angiogenesis through focal adhesion complex formation and activation of downstream kinases. ANGPT1 signaling induces receptor dimerization and autophosphorylation, providing binding sites for scaffold proteins and effectors. Modulation by ANGPT2, TIE1 heterodimer formation, and proteolytic processing into a soluble extracellular domain contribute to the intricate regulation of TIE-2 signaling, with the soluble domain acting as a decoy receptor for angiopoietins. TIE-2 phosphorylates DOK2, GRB7, GRB14, PIK3R1, SHC1, and TIE1.