Recent studies indicate that angiogenesis depends, in part, on ligation of integrin α 5 β 1 by
fibronectin. Evidence is now provided that integrin α 5 β 1 regulates the function of integrin α
v β 3 on endothelial cells during their migration in vitro or angiogenesisin vivo. Secretion of
fibronectin by endothelial cells leads to the ligation of integrin α 5 β 1, which potentiates α v
β 3-mediated migration on vitronectin without influencing α v β 3-mediated cell adhesion.
Endothelial cell attachment to vitronectin suppresses protein kinase A (PKA) activity, while …