title: Cytolethal distending toxin A, B and C subunit proteins are necessary for the genotoxic effect of Escherichia coli CDT-V.
abstract: Cytolethal distending toxins (CDT) are considered the prototype of inhibitory cyclomodulins, and are produced by a wide range of Gram-negative pathogenic bacteria, including Escherichia coli strains of various sero- and pathotypes. CDT is a heterotripartite toxin consisting of three protein subunits, CdtA, CdtB and CdtC. The active subunit, CdtB has DNase activity and causes DNA damage and cell cycle arrest in the target cell. However, several studies have highlighted different roles for CdtA and CdtC subunits. In order to reveal the necessity of CdtA and CdtC subunit proteins in the CDT-specific phenotype, expression clones containing the cdt-V subunit genes were constructed. Using cell culture assays, we demonstrated that clones expressing only the CdtB subunit or in combination with only CdtA or CdtC were unable to trigger the specific cell cycle arrest and changes in cell morphology in HeLa cells. At the same time, the recombinant clone harbouring the whole cdt-V operon caused all the CDT-associated characteristic phenotypes. All these results verify that all the three CDT subunit proteins are necessary for the genotoxic effect caused by CDT-V.
authors: CHU Purpan USC INRA 1360-CPTP, U1043 INSERM, Pathogénie moléculaire et cellulaire des infections à Escherichia coli Toulouse France.
authors: Frederic
authors: F
authors: Taieb
authors: Hungarian Academy of Sciences Enteric Bacteriology and Foodborne Zoonoses Group, Institute for Veterinary Medical Research, Centre for Agriculture Research Hungária krt. 21 H-1143 Budapest Hungary.
authors: Domonkos
authors: D
authors: Sváb
authors: CHU Purpan USC INRA 1360-CPTP, U1043 INSERM, Pathogénie moléculaire et cellulaire des infections à Escherichia coli Toulouse France.
authors: Claude
authors: C
authors: Watrin
authors: CHU Purpan USC INRA 1360-CPTP, U1043 INSERM, Pathogénie moléculaire et cellulaire des infections à Escherichia coli Toulouse France.
authors: Eric
authors: E
authors: Oswald
authors: Hungarian Academy of Sciences Enteric Bacteriology and Foodborne Zoonoses Group, Institute for Veterinary Medical Research, Centre for Agriculture Research Hungária krt. 21 H-1143 Budapest Hungary.
authors: István
authors: I
authors: Tóth
keywords: CDT-V; Cytolethal distending toxin; E. coli; genotoxic effect