Fig. 6.
β-catenin is basally relocalized in Src-transformed cells that are surrounded by normal cells. (A) Immunofluorescence of XZ sections of β-catenin and F-actin. ts-Src MDCK cells were stained with CMFDA (green) and cultured with ts-Src MDCK cells (left panels) or with normal MDCK cells (middle and right panels) in the absence or presence of Blebbistatin. Cells were stained with anti-β-catenin antibody (red) and phalloidin (blue). Scale bar: 10 μm. Arrowheads indicate the lateral membrane domain where immunofluorescence of β-catenin is absent but that of F-actin is present. (B) Quantification of the length of lateral membrane domains with β-catenin—F-actin fluorescence. The length of basolateral domains stained with β-catenin or F-actin was measured, and the ratio of the length (β-catenin—F-actin) was calculated. MM, between normal MDCK cells; MS, between normal and ts-Src MDCK cells; SS, between ts-Src MDCK cells. Data are mean ± s.d. *P<4×10−11, **P<4×10−27, ***P<9×10−29, ****P<8×10−8; n=101, 87, 27, 81, 20 and 64 cell-cell contact sites from three independent experiments. (C) Quantification of the length of cell-cell contact area. The length of cell-cell contact area stained with F-actin was measured. Data are mean ± s.d. *P<2×10−28, **P<2×10−17, ***P<7×10−6; n=84, 78, 19, 80 and 21 cell-cell contact sites from three independent experiments. Values are expressed as a ratio relative to cell-cell contact sites between ts-Src MDCK cells where ts-Src MDCK cells alone are cultured.