Vinculin regulates cell-surface E-cadherin expression by binding to beta-catenin

J Cell Sci. 2010 Feb 15;123(Pt 4):567-77. doi: 10.1242/jcs.056432. Epub 2010 Jan 19.

Abstract

Vinculin was identified as a component of adherens junctions 30 years ago, yet its function there remains elusive. Deletion studies are consistent with the idea that vinculin is important for the organization of cell-cell junctions. However, this approach removes vinculin from both cell-matrix and cell-cell adhesions, making it impossible to distinguish its contribution at each site. To define the role of vinculin in cell-cell junctions, we established a powerful short hairpin-RNA-based knockdown/substitution model system that perturbs vinculin preferentially at sites of cell-cell adhesion. When this system was applied to epithelial cells, cell morphology was altered, and cadherin-dependent adhesion was reduced. These defects resulted from impaired E-cadherin cell-surface expression. We have investigated the mechanism for the effects of vinculin and found that the reduced surface E-cadherin expression could be rescued by introduction of vinculin, but not of a vinculin A50I substitution mutant that is defective for beta-catenin binding. These findings suggest that an interaction between beta-catenin and vinculin is crucial for stabilizing E-cadherin at the cell surface. This was confirmed by analyzing a beta-catenin mutant that fails to bind vinculin. Thus, our study identifies vinculin as a novel regulator of E-cadherin function and provides important new insight into the dynamic regulation of adherens junctions.

Publication types

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

MeSH terms

  • Adherens Junctions / metabolism
  • Animals
  • Avian Proteins / genetics
  • Avian Proteins / metabolism
  • Cadherins / metabolism*
  • Cell Adhesion / physiology
  • Cell Line
  • Cell Membrane / physiology
  • Chickens
  • Female
  • Humans
  • Mutagenesis, Site-Directed
  • Protein Binding
  • RNA Interference
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Vinculin / antagonists & inhibitors
  • Vinculin / genetics
  • Vinculin / metabolism*
  • beta Catenin / genetics
  • beta Catenin / metabolism*

Substances

  • Avian Proteins
  • CTNNB1 protein, human
  • Cadherins
  • Recombinant Fusion Proteins
  • VCL protein, Gallus gallus
  • VCL protein, human
  • beta Catenin
  • Vinculin