Eukaryotic translation elongation factor 1A induces anoikis by triggering cell detachment

J Biol Chem. 2012 May 4;287(19):16037-46. doi: 10.1074/jbc.M111.308122. Epub 2012 Mar 7.

Abstract

Anoikis, apoptosis because of loss of cell anchorage, is crucial for tissue homeostasis. Fibronectin not only provides a scaffold for cell anchorage but also harbors a cryptic antiadhesive site capable of inducing β1-integrin inactivation. In this study, this cryptic antiadhesive site is implicated in spontaneous induction of anoikis. Nontransformed fibroblasts (NIH3T3) adhering to a fibronectin substratum underwent anoikis during serum starvation culture. This anoikis was caused by proteolytic exposure of the cryptic antiadhesive site in fibronectin by matrix metalloproteinase. Eukaryotic elongation factor 1A (eEF1A) was identified as a membrane receptor for the exposed antiadhesive site. Serum starvation raised the membrane residence of eEF1A, and siRNA-based disruption of this increase rendered cells anoikis-resistant. By contrast, cells became more susceptible to anoikis in parallel with increased membrane residence of eEF1A by enforced expression. These results demonstrate that eEF1A acts as a membrane receptor for the cryptic antiadhesive site of fibronectin, which contributes to cell regulation, including anoikis, through negative regulation of cell anchorage.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Anoikis / drug effects
  • Anoikis / physiology*
  • Binding Sites
  • Cell Adhesion / drug effects
  • Cell Adhesion / physiology*
  • Cell Line
  • Cell Line, Tumor
  • Cell Membrane / metabolism
  • Cell Survival / drug effects
  • Cell Survival / physiology
  • Culture Media, Serum-Free / pharmacology
  • Electrophoresis, Polyacrylamide Gel
  • Eukaryotic Initiation Factor-1 / genetics
  • Eukaryotic Initiation Factor-1 / metabolism
  • Eukaryotic Initiation Factor-1 / physiology*
  • Extracellular Matrix / metabolism
  • Extracellular Matrix / physiology
  • Fibronectins / metabolism
  • Fibronectins / physiology*
  • Humans
  • K562 Cells
  • Mice
  • Microscopy, Confocal
  • Molecular Sequence Data
  • NIH 3T3 Cells
  • Peptide Elongation Factor 1 / genetics
  • Peptide Elongation Factor 1 / metabolism
  • Peptide Elongation Factor 1 / physiology*
  • RNA Interference

Substances

  • Culture Media, Serum-Free
  • Eukaryotic Initiation Factor-1
  • Fibronectins
  • Peptide Elongation Factor 1
  • eukaryotic peptide initiation factor-1A