Selective interaction of αABD with the actin cytoskeleton. (a–d) Spatial localization of Dn-αABD (Dn, stained for Dendra2) and actin filaments (Act): (a) in A431 cells; (b) in A431 cells treated with a high dose of Latrunculin A for 10 min; (c) in A431 cells treated with a low dose of Latrunculin A for 10 min; and (d) in A431 cells treated with Blebbistatin for 15 min. The Dn-αABD chimera includes Dendra2 (Dn) and the 671–906 region of α-catenin (αABD). (e) Spatial localization of the Dn-αABD point mutants—K842A, I792A, and K866A—in A431 cells. (f) Confocal microscopy of A431 cells expressing Dn-αABD and its point mutants—K842A and K866A in horizontal and vertical cross sections (indicated by the yellow lines). (g) wt A431 cells were permeabilized with 0.025% saponin for 3 min and then incubated for another 5 min with His-mCherry–tagged αABD (αABD) or its inactive I792A version (αABD-I792A) and stained for actin. The boxed regions are magnified on the insets. Note that αABD preferentially decorates the cortex but shows very weak binding to the actin bundles. The I792A mutant shows only nonspecific binding. Arrows point to bundles (a) and cortical clumps (c). Bars: (main images) 10 µm; (magnified images) 2.5 µm.