Binding partner- and force-promoted changes in ?E-catenin conformation probed by native cysteine labeling.

ABSTRACT: Adherens Junctions (AJs) are cell-cell adhesion complexes that sense and propagate mechanical forces by coupling cadherins to the actin cytoskeleton via ?-catenin and the F-actin binding protein ?E-catenin. When subjected to mechanical force, the cadherin•catenin complex can tightly link to F-actin through ?E-catenin, and also recruits the F-actin-binding protein vinculin. In this study, labeling of native cysteines combined with mass spectrometry revealed conformational changes in ?E-catenin upon binding to the E-cadherin•?-catenin complex, vinculin and F-actin. A method to apply physiologically meaningful forces in solution revealed force-induced conformational changes in ?E-catenin when bound to F-actin. Comparisons of wild-type ?E-catenin and a mutant with enhanced vinculin affinity using cysteine labeling and isothermal titration calorimetry provide evidence for allosteric coupling of the N-terminal ?-catenin-binding and the middle (M) vinculin-binding domain of ?E-catenin. Cysteine labeling also revealed possible crosstalk between the actin-binding domain and the rest of the protein. The data provide insight into how binding partners and mechanical stress can regulate the conformation of full-length ?E-catenin, and identify the M domain as a key transmitter of conformational changes.

SUBMITTER: Terekhova K 

PROVIDER: S-EPMC6814714 | biostudies-literature | 2019 Oct

REPOSITORIES: biostudies-literature