FIGURE 3.

TGase is localized to the leading edges of actively migrating cells. Duplicate sets of scratch assays were performed on cultures of HeLa cells treated without (Untreated) or with EGF. A, one set of cultures was fixed 3 h after scratching the wound. Immunofluorescence was performed on these samples using a TGase antibody, rhodamine-conjugated phalloidin (Actin), and DAPI. The resulting fluorescence images shown are of cells along one edge of the wound. The location of the scratched wound is indicated (scratch) and membrane-localized TGase is denoted with arrows. B, a second set of cell cultures was either fixed immediately after scratching the wound (Untreated-0 h) or 15 h after scratching the wound (Untreated-15 h and EGF-15 h) and then visualized by light microscopy. Each panel represents a single image that shows both edges of a wound that was scratched in a monolayer of cells exposed to the indicated culturing conditions. The extent of wound closure for each condition is shown. The dashed lines represent the widths of the wounds at the start of the assay.