FIGURE 4.
The formation of podosome rosettes triggered by expression of Hckca in fibroblasts requires FLNa. MEF-3T3 fibroblasts and MEF-3T3 fibroblasts expressing human p59Hckca/p61Hckca were stained for mFLNa and F-actin and observed by confocal microscopy. A, control cells did not form podosome rosettes, whereas the cells expressing p59 Hckca/p61Hckca showed FLNa accumulation at podosome rosettes (arrowheads). B, MEF-3T3 fibroblasts expressing p59Hckca/p61Hckca-GFP and stained for FLNa and F-actin showed accumulation of Hck and FLNa and F-actin at podosome rosettes (arrowheads). Fluorescence intensity profiles along the white dashed line are shown. C, expression of p59Hckca/p61Hckca-GFP in NIH3T3 stably expressing shRNA against luciferase (control) or against mFLNa were stained for F-actin (scale bar, 10 μm). D, quantification of p59Hckca/p61Hckca-GFP expressing cells forming podosome rosettes (mean ± S.D. of three independent experiments).