Spatial control of EGF receptor activation by reversible dimerization on living cells

Nature. 2010 Apr 1;464(7289):783-7. doi: 10.1038/nature08827. Epub 2010 Mar 7.


Epidermal growth factor receptor (EGFR) is a type I receptor tyrosine kinase, the deregulation of which has been implicated in a variety of human carcinomas. EGFR signalling is preceded by receptor dimerization, typically thought to result from a ligand-induced conformational change in the ectodomain that exposes a loop (dimerization arm) required for receptor association. Ligand binding may also trigger allosteric changes in the cytoplasmic domain of the receptor that is crucial for signalling. Despite these insights, ensemble-averaging approaches have not determined the precise mechanism of receptor activation in situ. Using quantum-dot-based optical tracking of single molecules combined with a novel time-dependent diffusivity analysis, here we present the dimerization dynamics of individual EGFRs on living cells. Before ligand addition, EGFRs spontaneously formed finite-lifetime dimers kinetically stabilized by their dimerization arms. The dimers were primed both for ligand binding and for signalling, such that after EGF addition they rapidly showed a very slow diffusivity state that correlated with activation. Although the kinetic stability of unliganded dimers was in principle sufficient for EGF-independent activation, ligand binding was still required for signalling. Interestingly, dimers were enriched in the cell periphery in an actin- and receptor-expression-dependent fashion, resulting in a peripheral enhancement of EGF-induced signalling that may enable polarized responses to growth factors.

Publication types

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

MeSH terms

  • Actins / metabolism
  • Animals
  • CHO Cells
  • Cell Line, Tumor
  • Cell Polarity*
  • Cell Survival
  • Cricetinae
  • Cricetulus
  • Diffusion
  • Enzyme Activation / drug effects
  • Enzyme Stability / drug effects
  • Epidermal Growth Factor / metabolism
  • Epidermal Growth Factor / pharmacology
  • ErbB Receptors / agonists
  • ErbB Receptors / chemistry*
  • ErbB Receptors / genetics
  • ErbB Receptors / metabolism*
  • GRB2 Adaptor Protein / genetics
  • GRB2 Adaptor Protein / metabolism
  • Gene Expression Regulation
  • Humans
  • Kinetics
  • Ligands
  • Protein Multimerization* / drug effects
  • Protein Transport
  • Signal Transduction
  • Thermodynamics


  • Actins
  • GRB2 Adaptor Protein
  • GRB2 protein, human
  • Ligands
  • Epidermal Growth Factor
  • ErbB Receptors