A TIE receptor tyrosine kinase that is found almost exclusively on ENDOTHELIAL CELLS. It is required for both normal embryonic vascular development (NEOVASCULARIZATION, PHYSIOLOGIC) and tumor angiogenesis (NEOVASCULARIZATION, PATHOLOGIC).

The first to be discovered member of the angiopoietin family. It may play a role in increasing the sprouting and branching of BLOOD VESSELS. Angiopoietin-1 specifically binds to and stimulates the TIE-2 RECEPTOR. Several isoforms of angiopoietin-1 occur due to ALTERNATIVE SPLICING of its mRNA.

A TIE receptor found predominantly on ENDOTHELIAL CELLS. It is considered essential for vascular development and can form a heterodimer with the TIE-2 RECEPTOR. The TIE-1 receptor may play a role in regulating BLOOD VESSEL stability and maturation.

An angiopoietin that is closely related to ANGIOPOIETIN-1. It binds to the TIE-2 RECEPTOR without receptor stimulation and antagonizes the effect of ANGIOPOIETIN-1. However its antagonistic effect may be limited to cell receptors that occur within the vasculature. Angiopoietin-2 may therefore play a role in down-regulation of BLOOD VESSEL branching and sprouting.

A family of structurally-related angiogenic proteins of approximately 70 kDa in size. They have high specificity for members of the TIE RECEPTOR FAMILY.

A family of structurally-related tyrosine kinase receptors that are expressed predominantly in ENDOTHELIAL CELLS and are essential for development of BLOOD VESSELS (NEOVASCULARIZATION, PHYSIOLOGIC). The name derives from the fact that they are tyrosine kinases that contain Ig and EGF domains.

A class of cellular receptors that have an intrinsic PROTEIN-TYROSINE KINASE activity.