Truncation of CD9 EC2 reverses CD9-induced reduction of integrin α5β1 and cytoskeletal F-actin colocalization in fibronectin-adherent CHO cells.
CHO MOCK, A6, and Δ133-192 cells were grown on FN for 3 hours, followed by integrin α5β1 and cytoskeleton F-actin labeling as described in “Materials and methods.” Images of the basal surface of the cells by laser scanning confocal microscopy revealed that PB1-labeled α5β1 (green) and phalloidin-TRITC–labeled F-actin (red) were found in each cell type. Colocalization of α5β1 and F-actin (yellow) was reduced in CHO A6 cells compared to CHO MOCK and CHO Δ133-192 cells, suggesting that CD9 EC2 influences α5β1–F-actin colocalization. As described earlier,23 it is evident that CD9 CHO and CHO Δ133-192 cells have a polygonal spread morphology, whereas mock or naive CHO cells exhibit a bipolar fibroblast morphology. Original magnification × 60.
