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The angiopoietins are protein growth factors that promote angiogenesis, the formation of blood vessels. There are now four identified angiopoietins: Ang1, Ang2, Ang3, Ang4. Ang1 and Ang2 are required for the formation of mature blood vessels, as demonstrated by mouse knock out studies [1].
[edit] Angiopoietin Receptors
The Tie receptors are tyrosine kinases, so named because they mediate cell signals by inducing the phosphorylation of key tyrosines, thus initiating the binding and activation of downstream, intracellular enzymes; this process is called cell signalling, and it is the method by which cells are induced to activate or inhibit key regulatory functions. It is somewhat controversial which of the Tie receptors mediate functional signals downstream of Ang stimulation - but it is clear that at least Tie-2 is capable of physiologic activation as a result of binding the angiopoietins
[edit] Clinical Relevance
Angiopoietin 2 is elevated in patients with angiosarcoma (PMID 15149523)
[edit] References
- ^ Thurston G. Role of Angiopoietins and Tie receptor tyrosine kinases in angiogenesis and lymphangiogenesis. Cell Tissue Res. 2003 Oct;314(1):61-8. Epub 2003 Aug 12.
[edit] External links
