Angiopoietin

Angiopoietins are growth factors that control the sprouting of blood vessels in tissue angiogenesis. So far, four forms have been identified: Ang1, Ang2, and ANG3 Ang4.

In addition, there are proteins that are in close relationship to the Angiopoetinen: ANGPTL2, ANGPTL3, ANGPTL4. Ang1 and Ang2 are the formation of mature blood vessels necessary, this has been shown in studies with knock-out mice. Angiopoietin 1 is released from the myocardium in early development, and later by perivascular cells in adult tissue.

Angiopoietin receptors

Angiopoietin acts by binding of endothelial cells to the tyrosine kinase receptor Tie2. Tie receptors are endothelium-specific receptor tyrosine kinases.

  • Tie 1 in endothelial cell lines and leukemia cells
  • Tie 2 ( tek ) in cardiac tissue

The ligand to the receptor is angiopoietin, the receptor then triggers the phosphorylation of. Once bound, it regulates the maturation of blood vessels during angiogenesis and controls the stability of the built vessels.

Overall, can produce all kinds of Angiopoetins ( Ang1, Ang2, ANG3, Ang4 ) bind to the Tie2 receptor, but only Ang1 phosphorylation triggers. For Ang1 must be present as a tetramer. Ang2 can inhibit the phosphorylation induced by Ang1.

Further reading

  • Barton WA, Tzvetkova D, Nikolov DB: Structure of the angiopoietin- 2 Receptor Binding Domain and Identification of Surfaces Involved in Tie2 recognition. In: Structure. 13 May 2005, pp. 825-832. doi: 10.1016/j.str.2005.03.009. PMID 15,893,672th
  • Felcht M, Luck R, Schering A, Seidel P, Srivastava K, Hu J, Bartol A, Kienast Y, Vettel C, Loos EK, Kutschera S, Bartels S, S Appak, Besemfelder E, Terhardt D, Chavakis E, Wieland T, Small C, Thomas M, Uemura A, Goerdt S, Augustin HG: Angiopoietin -2 differentially Regulates angiogenesis and integrin signaling through the TIE2. In: The Journal of clinical investigation. June 2012, p 122 (6). doi: 10.1172/JCI58832. PMID 22,585,576th
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