A bacterial toxin that controls cell cycle progression as a deoxyribonuclease I-like protein

Science. 2000 Oct 13;290(5490):354-7. doi: 10.1126/science.290.5490.354.


Many bacterial pathogens encode a multisubunit toxin, termed cytolethal distending toxin (CDT), that induces cell cycle arrest, cytoplasm distention, and, eventually, chromatin fragmentation and cell death. In one such pathogen, Campylobacter jejuni, one of the subunits of this toxin, CdtB, was shown to exhibit features of type I deoxyribonucleases. Transient expression of this subunit in cultured cells caused marked chromatin disruption. Microinjection of low amounts of CdtB induced cytoplasmic distention and cell cycle arrest. CdtB mutants with substitutions in residues equivalent to those required for catalysis or magnesium binding in type I deoxyribonucleases did not cause chromatin disruption. CDT holotoxin containing these mutant forms of CdtB did not induce morphological changes or cell cycle arrest.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Bacterial Toxins / chemistry
  • Bacterial Toxins / genetics
  • Bacterial Toxins / metabolism*
  • Bacterial Toxins / toxicity*
  • COS Cells
  • Campylobacter jejuni* / genetics
  • Campylobacter jejuni* / pathogenicity
  • Cell Death
  • Cell Line
  • Cell Nucleus / metabolism
  • Chromatin / ultrastructure
  • DNA / metabolism*
  • DNA Damage*
  • Deoxyribonuclease I / chemistry
  • Deoxyribonuclease I / metabolism*
  • G2 Phase*
  • Microinjections
  • Molecular Sequence Data
  • Mutation
  • Transfection


  • Bacterial Toxins
  • Chromatin
  • cytolethal distending toxin
  • DNA
  • Deoxyribonuclease I