Truncation of CD9 EC2 reverses CD9 influence on level of α-actinin expression and cytoskeletal F-actin colocalization in FN-adherent CHO cells.

CHO MOCK, A6, and Δ133-228 cells were grown on FN for 3 hours, followed by α-actinin 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 less labeled α-actinin (green) in CHO A6 cells than in MOCK or Δ133-192 cells. However, the level of labeled F-actin (red) was equivalent among the cell types. The amount of α-actinin colocalized with F-actin was reduced in CD9 expressing CHO A6 cells compared with CHO MOCK cells. CHO Δ133-192 cells had equivalent α-actinin staining and colocalization with F-actin as seen in CHO MOCK cells. Original magnification × 40.