Fig. 7. Ser/Thr-mutant ß-catenin enhances cell migration. (A) Stable transfectants of 293 cells expressing HA-tagged wt or Ser/Thr-mutant ß-catenin containing all three mutations, were subjected to wound healing experiments. Wound closure was much enhanced in cells expressing Ser/Thr-mutant ß-catenin suggesting an increased migratory potential of the cells. (B) Cells were treated as described in A, but stained with antibodies for the proliferation marker Ki-6. The morphology of the cells is documented with brightfield-photography. No significant difference in cell proliferation was observed between the two cell types. (C) Stable transfectants of 293 cells expressing HA-tagged wt or Ser/Thr-mutant ß-catenin were stained for HA ß-catenin and -catenin with indirect immunofluorescence. Cells expressing HA wt ß-catenin showed a stronger staining at cell-cell-contact sites compared with cells expressing HA Ser/Thr-mutant ß-catenin. The same is true for the distribution of -catenin in both cell-lines. However, significant amounts of -catenin in mutant cells are still localized at the membrane due to the association with endogenous ß-catenin.