Identification of the αvβ3 integrin-interacting motif of βig-h3 and its anti-angiogenic effect

betaig-h3 is an extracellular matrix protein that mediates adhesion and migration of several cell types through interaction with integrins. In the present study, we tested whether betaig-h3 mediates endothelial cell adhesion and migration, thereby regulating angiogenesis. In this study, we demonstrate that not only betaig-h3 itself but also all four fas-1 domains of betaig-h3 mediate endothelial cell adhesion and migration through interaction with the alpha(v)beta(3) integrin. We found that the alpha(v)beta(3) integrin-interacting motif of the four fas-1 domains of betaig-h3 is the same YH motif that we reported previously to interact with alpha(v)beta(5) integrin. The YH peptide inhibited endothelial cell adhesion and migration in a dose-dependent manner. We demonstrate that the YH peptide has anti-angiogenic activity in vitro and in vivo using an endothelial cell tube formation assay and a Matrigel plug assay, respectively. Our results reveal that betaig-h3 bears alpha(v)beta(3) integrin-interacting motifs that mediate endothelial cell adhesion and migration and, therefore, may regulate angiogenesis.