α-Catenin cytomechanics - role in cadherin-dependent adhesion and mechanotransduction

The findings presented here demonstrate the role of alpha-catenin in cadherin-based adhesion and mechanotransduction in different mechanical contexts. Bead-twisting measurements in conjunction with imaging, and the use of different cell lines and alpha-catenin mutants reveal that the acute local mechanical manipulation of cadherin bonds triggers vinculin and actin recruitment to cadherin adhesions in an actin-and alpha-catenin-dependent manner. The modest effect of alpha-catenin on the two-dimensional binding affinities of cell surface cadherins further suggests that forceactivated adhesion strengthening is due to enhanced cadherincytoskeletal interactions rather than to alpha-catenin-dependent affinity modulation. Complementary investigations of cadherin-based rigidity sensing also suggest that, although alpha-catenin alters traction force generation, it is not the sole regulator of cell contractility on compliant cadherin-coated substrata.