Calmodulin inhibits entry of Bordetella pertussis adenylate cyclase into animal cells

Shattuck, R L; Storm, Daniel R.

doi:10.1021/bi00344a001

Cited by 39 publications

(27 citation statements)

References 27 publications

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“…These findings rule out a role for the Fc receptor and for antibody-mediated cross-linking of toxin molecules as explanations for the enhanced hemolytic activity of AC toxin in the presence of MAb 3D1. Exposure of AC toxin to calmodulin prior to incubation with sheep erythrocytes has also been observed to inhibit intoxication and augment AC toxin-induced hemolysis (11,14,28,32). Furthermore, in a recent report by Osickova et al, substitution of lysines for glutamates 509 and 516 in the hydrophobic domain of AC toxin was shown to ablate the capacity of the mutant toxin to intoxicate target cells, as well as to significantly enhance hemolytic activity (25).…”

Section: Resultsmentioning

confidence: 99%

Translocation-Specific Conformation of Adenylate Cyclase Toxin from Bordetella pertussis Inhibits Toxin-Mediated Hemolysis

Gray¹,

Lee²,

Gray³

et al. 2001

J Bacteriol

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Bordetella pertussis adenylate cyclase (AC) toxin belongs to the RTX family of toxins but is the only member with a known catalytic domain. The principal pathophysiologic function of AC toxin appears to be rapid production of intracellular cyclic AMP (cAMP) by insertion of its catalytic domain into target cells (referred to as intoxication). Relative to other RTX toxins, AC toxin is weakly hemolytic via a process thought to involve oligomerization of toxin molecules. Monoclonal antibody (MAb) 3D1, which binds to an epitope (amino acids 373 to 399) at the distal end of the catalytic domain of AC toxin, does not affect the enzymatic activity of the toxin (conversion of ATP into cAMP in a cell-free system) but does prevent delivery of the catalytic domain to the cytosol of target erythrocytes. Under these conditions, however, the ability of AC toxin to cause hemolysis is increased three-to fourfold. To determine the mechanism by which the hemolytic potency of AC toxin is altered, we used a series of deletion mutants. A mutant toxin, ⌬AC, missing amino acids 1 to 373 of the catalytic domain, has hemolytic activity comparable to that of wild-type toxin. However, binding of MAb 3D1 to ⌬AC enhances its hemolytic activity three-to fourfold similar to the enhancement of hemolysis observed with 3D1 addition to wild-type toxin. Two additional mutants, ⌬N489 (missing amino acids 6 to 489) and ⌬N518 (missing amino acids 6 to 518), exhibit more rapid hemolysis with quicker onset than wild-type toxin does, while ⌬N549 (missing amino acids 6 to 549) has reduced hemolytic activity compared to wild-type AC toxin. These data suggest that prevention of delivery of the catalytic domain or deletion of the catalytic domain, along with additional amino acids distal to it, elicits a conformation of the toxin molecule that is more favorable for hemolysis.

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Section: Resultsmentioning

confidence: 99%

Translocation-Specific Conformation of Adenylate Cyclase Toxin from Bordetella pertussis Inhibits Toxin-Mediated Hemolysis

Gray¹,

Lee²,

Gray³

et al. 2001

J Bacteriol

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“…Inhibition of intoxication by exogenous calmodulin is a peculiar phenomenon because it is target cell-specific (44,45,48). In several cell types, addition of calmodulin to AC toxin prior to addition to cells has little or no effect on intoxication, whereas in others an inhibitory effect is striking.…”

Section: Discussionmentioning

confidence: 99%

Distinct Mechanisms for K+ Efflux, Intoxication, and Hemolysis by Bordetella pertussis AC Toxin

Gray

Szabó

Otero

et al. 1998

Journal of Biological Chemistry

118

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Adenylate cyclase (AC) toxin from Bordetella pertussis delivers its catalytic domain to the interior of target cells where it converts host ATP to cAMP in a process referred to as intoxication. This toxin also hemolyzes sheep erythrocytes by a mechanism presumed to include pore formation and osmotic lysis. Intoxication and hemolysis appear at strikingly different toxin concentrations and evolve over different time scales, suggesting that different molecular processes may be involved. The present study was designed to test the hypothesis that intoxication and hemolysis occur by distinct mechanisms.Although the hemolytic activity of AC toxin has a lag of >1 h, intoxication starts immediately. Because of this difference, we sought a surrogate or precursor lesion that leads to hemolysis, and potassium efflux has been observed from erythrocytes treated with other poreforming toxins. AC toxin elicits an increase in K ؉ efflux from sheep erythrocytes and Jurkat cells, a human Tcell leukemia line, that begins within minutes of toxin addition. The toxin concentration dependence along with the analysis of the time course suggest that toxin monomers are sufficient to elicit release of K ؉ and to deliver the catalytic domain to the cell interior. Hemolysis, on the other hand, is a highly cooperative event that likely requires a subsequent oligomerization of these individual units. Although induction of K ؉ efflux shares some structural and environmental requirements with both intoxication and hemolysis, it can occur under conditions in which intoxication is reduced or prevented. The data presented here suggest that the transmembrane pathway by which K ؉ is released is separate and distinct from the structure required for intoxication but may be related to, or a precursor of, that which is ultimately responsible for hemolysis.

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“…Whether purified soluble AC has toxic effects on human immunologic cells has not been reported (79,83,100,(141)(142)(143).…”

Section: Acmentioning

confidence: 99%

Pertussis: the disease and new diagnostic methods

Friedman

1988

Clin Microbiol Rev

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Bordetella pertussis, the causative agent of whooping cough, produces an acute and chronic respiratory infection in infants and young children. B. pertussis is still a major health problem of young children throughout the world even though effective immunization against whooping cough is available. While predominantly a childhood disease, it has been reported also to be a cause of persistent cough in adults. This review discusses the numerous bacterial virulence factors that may play roles in the pathogenesis of pertussis and in immunity to infection. The present problems with pertussis diagnosis, recent advances, and future prospects for new and improved rapid diagnostics tests also are explored.

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Calmodulin inhibits entry of Bordetella pertussis adenylate cyclase into animal cells

Cited by 39 publications

References 27 publications

Translocation-Specific Conformation of Adenylate Cyclase Toxin from Bordetella pertussis Inhibits Toxin-Mediated Hemolysis

Translocation-Specific Conformation of Adenylate Cyclase Toxin from Bordetella pertussis Inhibits Toxin-Mediated Hemolysis

Distinct Mechanisms for K+ Efflux, Intoxication, and Hemolysis by Bordetella pertussis AC Toxin

Pertussis: the disease and new diagnostic methods

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