A Cytolethal Distending Toxin Variant from Aggregatibacter actinomycetemcomitans with an Aberrant CdtB That Lacks the Conserved Catalytic Histidine 160

A Cytolethal Distending Toxin Variant from Aggregatibacter actinomycetemcomitans with an Aberrant CdtB That Lacks the Conserved Catalytic Histidine 160

The periodontopathogen Aggregatibacter actinomycetemcomitans synthesizes several virulence factors, including cytolethal distending toxin (CDT). The active CDT holoenzyme is an AB-type tripartite genotoxin that affects eukaryotic cells. Subunits CdtA and CdtC (B-components) allow binding and intracellular translocation of the active CdtB (A-component), which elicits nuclear DNA damage. Differen...

Apoptosis in Nonproliferating Macrophages Cytolethal Distending Toxin Induces Aggregatibacter actinomycetemcomitans

Distending Toxin Cytolethal A. actinomycetemcomitans

Aggregatibacter actinomycetemcomitans cytolethal distending toxin induces apoptosis in nonproliferating macrophages by a phosphatase-independent mechanism.

Aggregatibacter actinomycetemcomitans strains that express cytolethal distending toxin (Cdt) are associated with localized aggressive periodontitis. However, the in vivo targets of Cdt in the human oral cavity have not been firmly established. Here, we demonstrate that A. actinomycetemcomitans Cdt kills proliferating and nonproliferating U937 monocytic cells at a comparable specific activity, a...

The Aggregatibacter actinomycetemcomitans Cytolethal Distending Toxin Active Subunit CdtB Contains a Cholesterol Recognition Sequence Required for Toxin Binding and Subunit Internalization.

Induction of cell cycle arrest in lymphocytes following exposure to the Aggregatibacter actinomycetemcomitans cytolethal distending toxin (Cdt) is dependent upon the integrity of lipid membrane microdomains. Moreover, we have previously demonstrated that the association of Cdt with target cells involves the CdtC subunit which binds to cholesterol via a cholesterol recognition amino acid consens...