Integrin alphaVbeta3 is sometimes referred to as the 'vitronectin receptor'. Vitronectin interacts with integrins alphaVbeta1 (Marshall et al. 1995), alphaVbeta3 (Pytela et al. 1985, Boettiger et al. 2001), alphaVbeta5 (Panetti & McKeown-Longo 1993) and alpha2b beta3 (Pytela et al. 1986) through Arg-Gly-Asp (RGD) cell binding sequences.
Endothelial cells lining the microvascular wall form a semi-permeable barrier to the movement of blood components. The attachment of endothelial cells to the extracellular matrix (ECM) is largely mediated by transmembrane integrins which recognize short sequence motifs such as Arg-Gly-Asp (RGD) in many ECM proteins.
Integrin alpha5beta1 and alphaVbeta3 bind to the ECM proteins fibronectin and vitronectin respectively. Both are critical for the establishment and stabilization of endothelial monolayers (Cheng & Kramer 1989). Synthetic peptides that compete with ECM proteins for the integrins or antibodies directed against alpha5beta1 and alphaVbeta3 cause endothelial cell detachment (Hayman et al. 1985, Pierschbacher & Ruoslahti 1987).