Molecular mechanism for orienting membrane and actin dynamics to nascent cell-cell contacts in epithelial cells

J Biol Chem. 2002 Nov 22;277(47):45371-6. doi: 10.1074/jbc.M207747200. Epub 2002 Sep 18.

Abstract

The small GTPase Rac1 has been implicated in regulation of cell migration and cell-cell adhesion in epithelial cells. Little is known, however, about the spatial and temporal coordination of Rac1 activity required to balance these competing processes. We fractionated endogenous Rac1-containing protein complexes from membranes of Madin-Darby canine kidney cells and identified three major complexes comprising a Rac1.PAK (p21-activated kinase) complex, and 11 S and 16 S Rac1 complexes. Significantly, Rac1 shifts from the 11 S to a 16 S particle during initiation of cell-cell adhesion. This shift may reflect a diffusion trapping mechanism by which these Rac1 complexes are localized to cadherin-mediated cell-cell contacts through an interaction with annexin II.

Publication types

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

MeSH terms

  • Actins / metabolism*
  • Animals
  • Annexin A1 / metabolism
  • Annexin A2 / metabolism
  • Cadherins / metabolism
  • Cell Adhesion / physiology
  • Cell Fractionation
  • Cell Line
  • Cell Membrane / metabolism*
  • Chromones / metabolism
  • Dogs
  • Enzyme Inhibitors / metabolism
  • Epithelial Cells / metabolism*
  • Intercellular Junctions / metabolism*
  • Macromolecular Substances
  • Morpholines / metabolism
  • Phosphatidylinositol 3-Kinases / metabolism
  • Phosphoinositide-3 Kinase Inhibitors
  • rac1 GTP-Binding Protein / genetics
  • rac1 GTP-Binding Protein / metabolism*

Substances

  • Actins
  • Annexin A1
  • Annexin A2
  • Cadherins
  • Chromones
  • Enzyme Inhibitors
  • Macromolecular Substances
  • Morpholines
  • Phosphoinositide-3 Kinase Inhibitors
  • 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one
  • rac1 GTP-Binding Protein