Identification of a novel intermediate filament-linked N-cadherin/gamma-catenin complex involved in the establishment of the cytoarchitecture of differentiated lens fiber cells

Dev Biol. 2008 Jul 15;319(2):298-308. doi: 10.1016/j.ydbio.2008.04.036. Epub 2008 May 8.


Tissue morphogenesis and maintenance of complex tissue architecture requires a variety of cell-cell junctions. Typically, cells adhere to one another through cadherin junctions, both adherens and desmosomal junctions, strengthened by association with cytoskeletal networks during development. Both beta- and gamma-catenins are reported to link classical cadherins to the actin cytoskeleton, but only gamma-catenin binds to the desmosomal cadherins, which links them to intermediate filaments through its association with desmoplakin. Here we provide the first biochemical evidence that, in vivo, gamma-catenin also mediates interactions between classical cadherins and the intermediate filament cytoskeleton, linked through desmoplakin. In the developing lens, which has no desmosomes, we discovered that vimentin became linked to N-cadherin complexes in a differentiation-state specific manner. This newly identified junctional complex was tissue specific but not unique to the lens. To determine whether in this junction N-cadherin was linked to vimentin through gamma-catenin or beta-catenin we developed an innovative "double" immunoprecipitation technique. This approach made possible, for the first time, the separation of N-cadherin/gamma-catenin from N-cadherin/beta-catenin complexes and the identification of multiple members of each of these isolated protein complexes. The study revealed that vimentin was associated exclusively with N-cadherin/gamma-catenin junctions. Assembly of this novel class of cadherin junctions was coincident with establishment of the unique cytoarchitecture of lens fiber cells. In addition, gamma-catenin had a distinctive localization to the vertices of these hexagonally shaped differentiating lens fiber cells, a region devoid of actin; while beta-catenin co-localized with actin at lateral cell interfaces. We believe this novel vimentin-linked N-cadherin/gamma-catenin junction provides the tensile strength necessary to establish and maintain structural integrity in tissues that lack desmosomes.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Actins / analysis
  • Actins / physiology
  • Animals
  • Cadherins / physiology*
  • Cell Differentiation / physiology
  • Chick Embryo
  • Epithelial Cells / cytology
  • Fluorescent Antibody Technique
  • Intermediate Filament Proteins / physiology*
  • Lens, Crystalline / cytology*
  • Lens, Crystalline / embryology*
  • Vimentin / physiology
  • gamma Catenin / physiology*


  • Actins
  • Cadherins
  • Intermediate Filament Proteins
  • Vimentin
  • gamma Catenin