Truncation of CD9 EC2 reverses CD9 influence on spatial distribution of FAK as well as reduction of FAK and cytoskeletal F-actin colocalization in FN-adherent CHO cells.

CHO MOCK, A6, and Δ133-192 cells were grown on FN for 3 hours, followed by FAK and cytoskeleton F-actin labeling as described in “Materials and methods.” Images of the basal surface of the adherent cells using laser scanning confocal microscopy revealed that the spatial distribution of FAK (green) in CD9 expressing CHO A6 cells appeared to be altered compared with that of CHO MOCK and CHO Δ133-192 cells, while the spatial distribution of F-actin (red) appeared to be equivalent in each cell type. CHO A6 cells also had less FAK and F-actin colocalization (yellow). The reversal of FAK distribution and F-actin colocalization in CHO Δ133-192 cells indicates that CD9 EC2 influences these phenomena. Original magnification × 40.