Fig. 2. Segregation of Vβ3- and 5β1-integrins in focal adhesions. The segregation of Vβ3- and 5β1-integrins in focal adhesions (depicted schematically in Fig. 1D) is shown here by antibody staining (Felsenfeld et al., 1999). (A) Src-deficient cells that expressing a truncated form of Src tagged with GFP (Src-251GFP) were fixed and stained with antibodies recognizing β1 integrins, Vβ3 integrins and vinculin. (B) In higher-magnification views, the Vβ3 subunit can be seen to colocalize at the periphery of focal adhesions, with vinculin and Src-251GFP. Vinculin staining was co-distributed with that of Src-251GFP in all cases. (C). By contrast, β1 integrins distributed in longer peripheral stripes (consistent with the distribution of stress fibers) that did not overlap with the distribution of Vβ3–Src-251GFP. Arrowhead indicates the boundary of staining. (D) Overlap of GFP and vinculin staining without β1 integrins is indicated by yellow pixels. Scale bars: 10 µm (A) and 5 µm (D). Images reproduced with permission (Felsenfeld et al., 1999).