Binding partner- and force-promoted changes in αE-catenin conformation probed by native cysteine labeling

Sci Rep. 2019 Oct 25;9(1):15375. doi: 10.1038/s41598-019-51816-3.

Abstract

Adherens Junctions (AJs) are cell-cell adhesion complexes that sense and propagate mechanical forces by coupling cadherins to the actin cytoskeleton via β-catenin and the F-actin binding protein αE-catenin. When subjected to mechanical force, the cadherin•catenin complex can tightly link to F-actin through αE-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 αE-catenin upon binding to the E-cadherin•β-catenin complex, vinculin and F-actin. A method to apply physiologically meaningful forces in solution revealed force-induced conformational changes in αE-catenin when bound to F-actin. Comparisons of wild-type αE-catenin and a mutant with enhanced vinculin affinity using cysteine labeling and isothermal titration calorimetry provide evidence for allosteric coupling of the N-terminal β-catenin-binding and the middle (M) vinculin-binding domain of αE-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 αE-catenin, and identify the M domain as a key transmitter of conformational changes.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Actins / chemistry
  • Actins / metabolism
  • Allosteric Regulation
  • Animals
  • Biomechanical Phenomena
  • Cysteine / metabolism*
  • Mice
  • Models, Molecular
  • Mutant Proteins / metabolism
  • Protein Binding
  • Protein Conformation
  • Solutions
  • Sulfhydryl Compounds / metabolism
  • Vinculin / metabolism
  • alpha Catenin / chemistry*
  • alpha Catenin / metabolism*
  • beta Catenin / chemistry
  • beta Catenin / metabolism

Substances

  • Actins
  • Mutant Proteins
  • Solutions
  • Sulfhydryl Compounds
  • alpha Catenin
  • beta Catenin
  • Vinculin
  • Cysteine