The Bordetella type III secretion system effector BteA contains a conserved N-terminal motif that guides bacterial virulence factors to lipid rafts

Cell Microbiol. 2009 Dec;11(12):1735-49. doi: 10.1111/j.1462-5822.2009.01361.x. Epub 2009 Jul 24.


The Bordetella type III secretion system (T3SS) effector protein BteA is necessary and sufficient for rapid cytotoxicity in a wide range of mammalian cells. We show that BteA is highly conserved and functionally interchangeable between Bordetella bronchiseptica, Bordetella pertussis and Bordetella parapertussis. The identification of BteA sequences required for cytotoxicity allowed the construction of non-cytotoxic mutants for localization studies. BteA derivatives were targeted to lipid rafts and showed clear colocalization with cortical actin, ezrin and the lipid raft marker GM1. We hypothesized that BteA associates with the cytoplasmic face of lipid rafts to locally modulate host cell responses to Bordetella attachment. B. bronchiseptica adhered to host cells almost exclusively to GM1-enriched lipid raft microdomains and BteA colocalized to these same sites following T3SS-mediated translocation. Disruption of lipid rafts with methyl-beta-cyclodextrin protected cells from T3SS-induced cytotoxicity. Localization to lipid rafts was mediated by a 130-amino-acid lipid raft targeting domain at the N-terminus of BteA, and homologous domains were identified in virulence factors from other bacterial species. Lipid raft targeting sequences from a T3SS effector (Plu4750) and an RTX-type toxin (Plu3217) from Photorhabdus luminescens directed fusion proteins to lipid rafts in a manner identical to the N-terminus of BteA.

Publication types

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

MeSH terms

  • Amino Acid Motifs*
  • Amino Acid Sequence
  • Animals
  • Bacterial Adhesion / drug effects
  • Bacterial Proteins / chemistry*
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Bordetella / drug effects
  • Bordetella / genetics
  • Bordetella / metabolism*
  • Bordetella Infections / metabolism*
  • Bordetella Infections / microbiology
  • Cell Line
  • Cytoskeletal Proteins / metabolism
  • Host-Pathogen Interactions
  • Humans
  • Membrane Microdomains / drug effects
  • Membrane Microdomains / metabolism*
  • Mice
  • Molecular Sequence Data
  • Rats
  • Secretory Pathway*
  • Virulence Factors, Bordetella / metabolism*
  • beta-Cyclodextrins / pharmacology


  • Bacterial Proteins
  • Cytoskeletal Proteins
  • Virulence Factors, Bordetella
  • beta-Cyclodextrins
  • ezrin
  • methyl-beta-cyclodextrin