Involvement of the nectin-afadin complex in PDGF-induced cell survival

J Cell Sci. 2008 Jun 15;121(Pt 12):2008-17. doi: 10.1242/jcs.024620. Epub 2008 May 27.

Abstract

The nectin-afadin complex is involved in the formation of cell-cell junctions, such as adherens junctions (AJs) and tight junctions (TJs). Nectins are Ca(2+)-independent immunoglobulin-like cell-cell adhesion molecules, whereas afadin is an intracellular nectin-binding protein that connects nectins to the cadherin-catenin system at AJs and to the claudin-zona-occludens (ZO) protein system at TJs. Afadin(-/-) mice show embryonic lethality, resulting from impaired migration and improper differentiation of cells due to disorganization of cell-cell junctions during gastrulation. However, it remains to be elucidated whether disruption of afadin affects apoptosis. In the present study, we first found that embryoid bodies derived from afadin-knockout embryonic stem (ES) cells contained many more apoptotic cells than those derived from wild-type ES cells. We also revealed that apoptosis induced by serum starvation or Fas-ligand stimulation was increased in cultured NIH3T3 cells when afadin or nectin-3 was knocked down. The nectin-afadin complex was involved in the platelet-derived growth factor (PDGF)-induced activation of phosphatidylinositol 3-kinase (PI3K)-Akt signaling for cell survival. This complex was associated with PDGF receptor on the plasma membrane at cell-cell adhesion sites. Thus, the nectin-afadin complex is involved in PDGF-induced cell survival, at least through the PI3K-Akt signaling pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Apoptosis / genetics
  • Cell Adhesion Molecules / antagonists & inhibitors
  • Cell Adhesion Molecules / genetics
  • Cell Adhesion Molecules / metabolism*
  • Cell Survival / drug effects
  • Cell Survival / physiology*
  • Embryonic Stem Cells / cytology
  • Embryonic Stem Cells / metabolism
  • Enzyme Activation
  • Fas Ligand Protein / pharmacology
  • Humans
  • Intercellular Junctions / metabolism
  • Intercellular Junctions / ultrastructure
  • Mice
  • Mice, Knockout
  • Microfilament Proteins / genetics
  • Microfilament Proteins / metabolism*
  • NIH 3T3 Cells
  • Nectins
  • Phosphatidylinositol 3-Kinases / metabolism*
  • Platelet-Derived Growth Factor / metabolism*
  • RNA, Small Interfering
  • Signal Transduction
  • Up-Regulation

Substances

  • Cell Adhesion Molecules
  • Fas Ligand Protein
  • Microfilament Proteins
  • NECTIN3 protein, human
  • Nectin3 protein, mouse
  • Nectins
  • Platelet-Derived Growth Factor
  • RNA, Small Interfering
  • afadin
  • Phosphatidylinositol 3-Kinases