Ena/VASP proteins can regulate distinct modes of actin organization at cadherin-adhesive contacts

Mol Biol Cell. 2006 Mar;17(3):1085-95. doi: 10.1091/mbc.e05-07-0644. Epub 2005 Dec 21.

Abstract

Functional interactions between classical cadherins and the actin cytoskeleton involve diverse actin activities, including filament nucleation, cross-linking, and bundling. In this report, we explored the capacity of Ena/VASP proteins to regulate the actin cytoskeleton at cadherin-adhesive contacts. We extended the observation that Ena/vasodilator-stimulated phosphoprotein (VASP) proteins localize at cell-cell contacts to demonstrate that E-cadherin homophilic ligation is sufficient to recruit Mena to adhesion sites. Ena/VASP activity was necessary both for F-actin accumulation and assembly at cell-cell contacts. Moreover, we identified two distinct pools of Mena within individual homophilic adhesions that cells made when they adhered to cadherin-coated substrata. These Mena pools localized with Arp2/3-driven cellular protrusions as well as at the tips of cadherin-based actin bundles. Importantly, Ena/VASP activity was necessary for both modes of actin activity to be expressed. Moreover, selective depletion of Ena/VASP proteins from the tips of cadherin-based bundles perturbed the bundles without affecting the protrusive F-actin pool. We propose that Ena/VASP proteins may serve as higher order regulators of the cytoskeleton at cadherin contacts through their ability to modulate distinct modes of actin organization at those contacts.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actin Cytoskeleton / metabolism
  • Actin-Related Protein 2-3 Complex / metabolism
  • Actins / metabolism*
  • Animals
  • CHO Cells
  • Cadherins / metabolism*
  • Cell Adhesion / drug effects
  • Cell Communication / physiology
  • Cell Surface Extensions / metabolism
  • Cells, Cultured
  • Cricetinae
  • Cricetulus
  • Cytochalasin D / pharmacology
  • Cytoskeleton / metabolism
  • DNA-Binding Proteins / metabolism*
  • Epithelial Cells / cytology
  • Epithelial Cells / metabolism
  • Humans
  • Intracellular Signaling Peptides and Proteins
  • Protein Serine-Threonine Kinases / metabolism
  • Protein Transport
  • Signal Transduction
  • rho-Associated Kinases

Substances

  • Actin-Related Protein 2-3 Complex
  • Actins
  • Cadherins
  • DNA-Binding Proteins
  • ENA-VASP proteins
  • Intracellular Signaling Peptides and Proteins
  • Cytochalasin D
  • Protein Serine-Threonine Kinases
  • rho-Associated Kinases