Interaction of the enteropathogenic Escherichia coli protein, translocated intimin receptor (Tir), with focal adhesion proteins

Cell Motil Cytoskeleton. 2000 Dec;47(4):307-18. doi: 10.1002/1097-0169(200012)47:4<307::AID-CM5>3.0.CO;2-Q.


When enteropathogenic Escherichia coli (EPEC) attach and infect host cells, they induce a cytoskeletal rearrangement and the formation of cytoplasmic columns of actin filaments called pedestals. The attached EPEC and pedestals move over the surface of the host cell in an actin-dependent reaction [Sanger et al., 1996: Cell Motil Cytoskeleton 34:279-287]. The discovery that EPEC inserts the protein, translocated intimin receptor (Tir), into the membrane of host cells, where it binds the EPEC outer membrane protein, intimin [Kenny et al., 1997: Cell 91:511-520], suggests Tir serves two functions: tethering the bacteria to the host cell and providing a direct connection to the host's cytoskeleton. The sequence of Tir predicts a protein of 56.8 kD with three domains separated by two predicted trans-membrane spanning regions. A GST-fusion protein of the N-terminal 233 amino acids of Tir (Tir1) binds to alpha-actinin, talin, and vinculin from cell extracts. GST-Tir1 also coprecipitates purified forms of alpha-actinin, talin, and vinculin while GST alone does not bind these three focal adhesion proteins. Biotinylated probes of these three proteins also bound Tir1 cleaved from GST. Similar associations of alpha-actinin, talin, and vinculin were also detected with the C-terminus of Tir, i.e., Tir3, the last 217 amino acids. Antibody staining of EPEC-infected cultured cells reveals the presence of focal adhesion proteins beneath the attached bacteria. Our experiments support a model in which the cytoplasmic domains of Tir recruit a number of focal adhesion proteins that can bind actin filaments to form pedestals. Since pedestals also contain villin, tropomyosin and myosin II [Sanger et al., 1996: Cell Motil. Cytoskeleton 34:279-287], the pedestals appear to be a novel structure sharing properties of both focal adhesions and microvilli.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actinin / metabolism
  • Amino Acid Sequence
  • Biotinylation
  • Cytoplasm / metabolism
  • Escherichia coli / metabolism*
  • Escherichia coli Proteins*
  • Focal Adhesions / metabolism*
  • Glutathione Transferase / metabolism
  • Microscopy, Confocal
  • Microscopy, Fluorescence
  • Models, Biological
  • Molecular Sequence Data
  • Precipitin Tests
  • Protein Binding
  • Protein Structure, Tertiary
  • Receptors, Cell Surface / chemistry*
  • Receptors, Cell Surface / metabolism*
  • Recombinant Fusion Proteins / metabolism
  • Sequence Homology, Amino Acid
  • Talin / metabolism
  • Vinculin / metabolism


  • Escherichia coli Proteins
  • Receptors, Cell Surface
  • Recombinant Fusion Proteins
  • Talin
  • Tir protein, E coli
  • Actinin
  • Vinculin
  • Glutathione Transferase