EGF receptor exposed to oxidative stress acquires abnormal phosphorylation and aberrant activated conformation that impairs canonical dimerization

PLoS One. 2011;6(8):e23240. doi: 10.1371/journal.pone.0023240. Epub 2011 Aug 10.


Crystallographic studies have offered understanding of how receptor tyrosine kinases from the ErbB family are regulated by their growth factor ligands. A conformational change of the EGFR (ErbB1) was shown to occur upon ligand binding, where a solely ligand-mediated mode of dimerization/activation was documented. However, this dogma of dimerization/activation was revolutionized by the discovery of constitutively active ligand-independent EGFR mutants. In addition, other ligand-independent activation mechanisms may occur. We have shown that oxidative stress (ox-stress), induced by hydrogen peroxide or cigarette smoke, activates EGFR differently than its ligand, EGF, thereby inducing aberrant phosphorylation and impaired trafficking and degradation of EGFR. Here we demonstrate that ox-stress activation of EGFR is ligand-independent, does not induce "classical" receptor dimerization and is not inhibited by the tyrosine kinase inhibitor AG1478. Thus, an unprecedented, apparently activated, state is found for EGFR under ox-stress. Furthermore, this activation mechanism is temperature-dependent, suggesting the simultaneous involvement of membrane structure. We propose that ceramide increase under ox-stress disrupts cholesterol-enriched rafts leading to EGFR re-localization into the rigid, ceramide-enriched rafts. This increase in ceramide also supports EGFR aberrant trafficking to a peri-nuclear region. Therefore, the EGFR unprecedented and activated conformation could be sustained by simultaneous alterations in membrane structure under ox-stress.

Publication types

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

MeSH terms

  • Animals
  • Cell Membrane / drug effects
  • Cell Membrane / metabolism
  • Ceramides / metabolism
  • Cholesterol / metabolism
  • Enzyme Activation / drug effects
  • ErbB Receptors / chemistry*
  • ErbB Receptors / metabolism*
  • Humans
  • Hydrogen Peroxide / pharmacology
  • Ligands
  • Mice
  • Models, Biological
  • NIH 3T3 Cells
  • Oxidative Stress* / drug effects
  • Phosphorylation / drug effects
  • Protein Binding / drug effects
  • Protein Multimerization / drug effects*
  • Protein Structure, Tertiary
  • Protein Transport / drug effects
  • Pyrazoles / pharmacology
  • Pyrimidines / pharmacology
  • Quinazolines
  • Temperature
  • Tyrphostins / pharmacology
  • src-Family Kinases / metabolism


  • 4-amino-5-(4-methylphenyl)-7-(tert-butyl)pyrazolo(3,4-d)pyrimidine
  • Ceramides
  • Ligands
  • Pyrazoles
  • Pyrimidines
  • Quinazolines
  • Tyrphostins
  • RTKI cpd
  • Cholesterol
  • Hydrogen Peroxide
  • ErbB Receptors
  • src-Family Kinases