Tie2 Signaling

The Tie2/Tek receptor tyrosine kinase plays a pivotal role in vascular and hematopoietic development and is expressed exclusively on endothelial lineage. Tie2 interacts with a group of ligands belonging to angiopoietin family and undergoes activation.<br>These ligands show opposing actions, angiopoietin 1 and angiopoietin 4 stimulate the Tie2 phosphorylation and angiopoietin 2 inhibits it. Upon tyrosine phosphorylation Tie2 acts as a scaffold for various signaling proteins involved in different signal transduction cascades that can effect survival of endothelium and angiogenic sprout formation.

Tie2/Tek受体酪氨酸激酶在血管和造血发育中扮演着至关重要的角色，且仅表达于内皮谱系。Tie2与属于血管生成素家族的一组配体相互作用并发生激活。这些配体表现出相反的作用，血管生成素1和血管生成素4刺激Tie2磷酸化，而血管生成素2则抑制其磷酸化。在酪氨酸磷酸化后，Tie2作为各种信号蛋白的支架，参与不同的信号转导级联反应，这些反应可影响内皮细胞的存活和血管生成芽的形成。