A pathogenic bacterium triggers epithelial signals to form a functional bacterial receptor that mediates actin pseudopod formation

EMBO J. 1996 Jun 3;15(11):2613-24.


Enteropathogenic E. coli (EPEC) belongs to a group of bacterial pathogens that induce actin accumulation beneath adherent bacteria. We found that EPEC adherence to epithelial cells mediates the formation of fingerlike pseudopods (up to 10 microm) beneath bacteria. These actin-rich structures also contain tyrosine phosphorylated host proteins concentrated at the pseudopod tip beneath adherent EPEC. Intimate bacterial adherence (and pseudopod formation) occurred only after prior bacterial induction of tyrosine phosphorylation of an epithelial membrane protein, Hp90, which then associates directly with an EPEC adhesin, intimin. These interactions lead to cytoskeletal nucleation and pseudopod formation. This is the first example of a bacterial pathogen that triggers signals in epithelial cells which activates receptor binding activity to a specific bacterial ligand and subsequent cytoskeletal rearrangement.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / physiology*
  • Adhesins, Bacterial*
  • Bacterial Adhesion*
  • Bacterial Outer Membrane Proteins / metabolism*
  • Carrier Proteins*
  • Cell Size
  • Epithelium / metabolism
  • Epithelium / microbiology
  • Escherichia coli / pathogenicity*
  • Escherichia coli Proteins*
  • HeLa Cells
  • Humans
  • Membrane Proteins / metabolism*
  • Microscopy, Electron, Scanning
  • Molecular Weight
  • Phosphoproteins / metabolism*
  • Phosphotyrosine / metabolism
  • Signal Transduction


  • Actins
  • Adhesins, Bacterial
  • Bacterial Outer Membrane Proteins
  • Carrier Proteins
  • Escherichia coli Proteins
  • Membrane Proteins
  • Phosphoproteins
  • eaeA protein, E coli
  • Phosphotyrosine