Fig. 4. Maximal cortactin-enhanced migration requires N-WASP. (A) Western blot showing expression of the HA-FL, HA-Ct and HA-CtW525L cortactin (upper blot) or endogenous cortactin (lower blot) in NW^–/– or rescued MEFs. Arrowheads indicate HA-FL cortactin. Expression of all HA-tagged constructs was equivalent to or less than endogenous cortactin levels. UI, uninfected cells. (B) HA-tagged, or in some assays GFP-tagged, cortactin-expressing cells were assayed for wound closure at 0, 2, 4 and 6 hours after wounding. Data are the average of four to five experiments at the 6-hour time point±s.e.m. Asterisks indicate statistically significant differences from wound closure results in control cells (P<0.05). (C) Representative results from wounding assay experiments are shown with images taken at 0 and 6 hours after wounding. The fold change in wound area is indicated underneath each figure.