Bordetella bronchiseptica dermonecrotizing toxin induces reorganization of actin stress fibers through deamidation of Gln-63 of the GTP-binding protein Rho

Proc Natl Acad Sci U S A. 1997 Oct 14;94(21):11623-6. doi: 10.1073/pnas.94.21.11623.


Bordetella dermonecrotizing toxin causes assembly of actin stress fibers and focal adhesions in some cultured cells and induces mobility shifts of the small GTP-binding protein Rho on electrophoresis. We attempted to clarify the molecular basis of the toxin action on Rho. Analysis of the amino acid sequence of toxin-treated RhoA revealed the deamidation of Gln-63 to Glu. The substitution of Glu for Gln-63 of RhoA by site-directed mutagenesis caused a mobility shift on electrophoresis, which was indistinguishable from that of the toxin-treated RhoA. Neither mutant RhoA-bearing Glu-63 nor toxin-treated RhoA significantly differed from untreated wild type RhoA in guanosine 5'-[gamma-thio]triphosphate binding activity but both showed a 10-fold reduction in GTP hydrolysis activity relative to untreated RhoA. C3H10T1/2 cells transfected with cDNA of the mutant RhoA bearing Glu-63 showed extensive formation of actin stress fibers similar to the toxin-treated cells. These results indicate that the toxin catalyzes deamidation of Gln-63 of Rho and renders it constitutively active, leading to formation of actin stress fibers.

MeSH terms

  • Actins / drug effects*
  • Actins / metabolism
  • Actins / ultrastructure
  • Amino Acid Sequence
  • Amino Acid Substitution
  • Animals
  • Bacterial Toxins / toxicity*
  • Bordetella bronchiseptica*
  • Cell Line
  • GTP-Binding Proteins / chemistry*
  • GTP-Binding Proteins / drug effects
  • GTP-Binding Proteins / metabolism*
  • Glutamic Acid
  • Glutamine
  • Guanosine 5'-O-(3-Thiotriphosphate) / metabolism
  • Guanosine Triphosphate / metabolism
  • Kinetics
  • Mice
  • Molecular Sequence Data
  • Mutagenesis, Site-Directed
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / drug effects
  • Recombinant Proteins / metabolism
  • Sequence Alignment
  • Transfection
  • Transglutaminases*
  • Virulence Factors, Bordetella*
  • rhoA GTP-Binding Protein


  • Actins
  • Bacterial Toxins
  • Recombinant Proteins
  • Virulence Factors, Bordetella
  • dermonecrotic toxin, Bordetella
  • Glutamine
  • Guanosine 5'-O-(3-Thiotriphosphate)
  • Glutamic Acid
  • Guanosine Triphosphate
  • Transglutaminases
  • GTP-Binding Proteins
  • rhoA GTP-Binding Protein