The challenges of abundance: epithelial junctions and small GTPase signalling

Curr Opin Cell Biol. 2005 Oct;17(5):466-74. doi: 10.1016/


Small GTPases of the Ras superfamily play critical roles in epithelial biogenesis. Many key morphogenetic functions occur when small GTPases act at epithelial junctions, where they mediate an increasingly complex interplay between cell-cell adhesion molecules and fundamental cellular processes, such as cytoskeletal activity, polarity and trafficking. Important recent advances in this field include the role of additional members of the Ras superfamily in cell-cell contact stability and the capacity for polarity determinants to regulate small GTPase signalling. Interestingly, small GTPases may participate in the cross-talk between different adhesive receptors: in tissues classical cadherins can selectively regulate other junctions through cell signalling rather than through a global influence on cell-cell cohesion.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Cell Adhesion Molecules / metabolism
  • Cell Adhesion Molecules / physiology
  • Cell Polarity / physiology
  • Enzyme Activation
  • Epithelial Cells / metabolism*
  • Epithelial Cells / physiology
  • Intercellular Junctions / metabolism*
  • Intercellular Junctions / physiology
  • Mice
  • Models, Biological
  • Monomeric GTP-Binding Proteins / metabolism*
  • Monomeric GTP-Binding Proteins / physiology
  • Signal Transduction / physiology*


  • Cell Adhesion Molecules
  • Monomeric GTP-Binding Proteins