Figure 2.

Surface expression of α_v, β₃ and β₅ integrins in GD25 and GD25-β1 cells. Integrin heterodimers were immunoprecipitated from surface biotinylated untransfected (−/−) or β₁A- and β₁B-transfected GD25 cells with polyclonal antibodies specific for α_v (A), β₃ (B), and β₅ (C) integrin subunits, respectively. After separation by nonreducing SDS-PAGE and Western blot, the immunoprecipitated proteins were detected with the use of peroxidase-conjugated streptavidin and ECL as described in MATERIALS AND METHODS. Notice that, although the expression of either integrin β₁ A or B isoforms does not alter significantly the expression level of the α_V integrin subunit, it induces a net change of the α_Vβ₃/α_Vβ₅ ratio.