α-Catenin affects force transmission and adhesion maturation. (A) Displacement as a function of time of 2-µm-diameter FN-coated pillars by MEFs spreading on top of them (see example in inset image). The graphs shown are mean ± SEM (in lighter hues). n > 30 pillars in each case. (B) Micrographs of a WT MEFs, α-catenin KD MEFs, and α-catenin KD MEFs expressing WT GFP-α-catenin/GFP-α-catenin L344P/GFP-α-catenin L344A/GFP-α-catenin V796A, all immunostained for vinculin after 6 h of spreading on FN-coated coverslips (GFP channel not depicted). (C–E) Quantifications of the number of mature adhesions per square micrometer, cell areas, and cell heights of the six cell types 6 h after plating on FN-coated coverslips (n > 20 cells in all cases). (F) Velocities and accumulated distances measured from MEF single-cell motility videos (n > 17 cells in all cases). (G and H) Quantifications of the number of mature adhesions per square micrometer and areas of vinculin^−/− MEFs expressing WT mCherry-vinculin or mCherry-vinculin A50I, alone or together with WT GFP-α-catenin or GFP-α-catenin L344P (n > 15 cells in all cases). Statistical analysis of the adhesions, cell areas, cell heights, and cell motility (C–H) were tested by ANOVA followed by Tukey’s post hoc test (*, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001).