Figure 7.

Expression of actopaxin phosphorylation mutants interferes with wound closure. Scrape wound assays were performed using U2OS parental and actopaxin WT, Quint, and S4/8D cells. Cells were plated in complete media at a confluent density and scored with a micropipette tip. (A) Hoffman images were taken at 0, 6, and 12 h after wounding, and average wound closure rates are shown. Quint cells have reduced closure rates compared with parental and WT cells, whereas S4/8D cells demonstrated an enhanced closure rate. Average rates of closure were calculated from three separate experiments. (B) Analysis of cell morphology at the wound edge. Parental, WT, Quint, and S4/8D cells were plated on coverslips and wounded as above. Slips were processed for indirect immunofluorescence at 1 and 4 h after wounding. Cells were stained with rhodamine phalloidin to visualize actin stress fibers. Quint cells at the wound edge lacked significant lamellipodia (e and f) as compared with parental and WT cells (a–d). S4/8D cells demonstrated enhanced lamellipodia formation (g and h). Bar, 5 μm.