scholarly journals Cyclic AMP and its receptor protein negatively regulate the coordinate expression of cholera toxin and toxin-coregulated pilus in Vibrio cholerae

1997 ◽  
Vol 94 (1) ◽  
pp. 265-270 ◽  
Author(s):  
K. Skorupski ◽  
R. K. Taylor
Keyword(s):  
Cyclic Amp ◽  
Cholera Toxin ◽  
Vibrio Cholerae ◽  
Receptor Protein ◽  
Coordinate Expression ◽  
Toxin Coregulated Pilus

scholarly journals Type III Secretion Is Essential for the Rapidly Fatal Diarrheal Disease Caused by Non-O1, Non-O139 Vibrio cholerae

mBio ◽  
2011 ◽  
Vol 2 (3) ◽  
Author(s):  
Ok S. Shin ◽  
Vincent C. Tam ◽  
Masato Suzuki ◽  
Jennifer M. Ritchie ◽  
Roderick T. Bronson ◽  
...  
Keyword(s):  
Cholera Toxin ◽  
Vibrio Cholerae ◽  
Intestinal Epithelium ◽  
Type Iii Secretion ◽  
Diarrheal Disease ◽  
Secretion Systems ◽  
Content Type ◽  
Type Iii ◽  
Severe Diarrhea ◽  
Toxin Coregulated Pilus

ABSTRACTCholera is a severe diarrheal disease typically caused by O1 serogroup strains ofVibrio cholerae. The pathogenicity of all pandemicV. choleraeO1 strains relies on two critical virulence factors: cholera toxin, a potent enterotoxin, and toxin coregulated pilus (TCP), an intestinal colonization factor. However, certain non-O1, non-O139V. choleraestrains, such as AM-19226, do not produce cholera toxin or TCP, yet they still cause severe diarrhea. The molecular basis for the pathogenicity of non-O1, non-O139V. choleraehas not been extensively characterized, but many of these strains encode related type III secretion systems (TTSSs). Here, we used infant rabbits to assess the contribution of the TTSS to non-O1, non-O139V. choleraepathogenicity. We found that all animals infected with wild-type AM-19226 developed severe diarrhea even more rapidly than rabbits infected withV. choleraeO1. UnlikeV. choleraeO1 strains, which do not damage the intestinal epithelium in rabbits or humans, AM-19226 caused marked disruptions of the epithelial surface in the rabbit small intestine. TTSS proved to be essential for AM-19226 virulence in infant rabbits; an AM-19226 derivative deficient for TTSS did not elicit diarrhea, colonize the intestine, or induce pathological changes in the intestine. Deletion of either one of the two previously identified or two newly identified AM-19226 TTSS effectors reduced but did not eliminate AM-19226 pathogenicity, suggesting that at least four effectors contribute to this strain’s virulence. In aggregate, our results suggest that the TTSS-dependent virulence in non-O1, non-O139V. choleraerepresents a new type of diarrheagenic mechanism.IMPORTANCECholera, which is caused byVibrio cholerae, is an important cause of diarrheal disease in many developing countries. The mechanisms of virulence of nonpandemic strains that can cause a diarrheal illness are poorly understood. AM-19226, like several other pathogenic, nonpandemicV. choleraestrains, carries genes that encode a type III secretion system (TTSS), but not cholera toxin (CT) or toxin coregulated pilus (TCP). In this study, we used infant rabbits to study AM-19226 virulence. Infant rabbits orally inoculated with this strain rapidly developed a fatal diarrheal disease, which was accompanied by marked disruptions of the intestinal epithelium. This strain’s TTSS proved essential for its pathogenicity, and there was no diarrhea, intestinal pathology, or colonization in rabbits infected with a TTSS mutant. The effector proteins translocated by the TTSS all appear to contribute to AM-19226 virulence. Thus, our study provides insight intoin vivomechanisms by which a novel TTSS contributes to diarrheal disease caused by nonpandemic strains ofV. cholerae.

scholarly journals Suppression of Virulence of Toxigenic Vibrio cholerae by Anethole through the Cyclic AMP (cAMP)-cAMP Receptor Protein Signaling System

PLoS ONE ◽  
2015 ◽  
Vol 10 (9) ◽  
pp. e0137529 ◽  
Author(s):  
M. Shamim Hasan Zahid ◽  
Sharda Prasad Awasthi ◽  
Masahiro Asakura ◽  
Shruti Chatterjee ◽  
Atsushi Hinenoya ◽  
...  
Keyword(s):  
Cyclic Amp ◽  
Vibrio Cholerae ◽  
Receptor Protein ◽  
Protein Signaling ◽  
Camp Receptor Protein ◽  
Signaling System ◽  
Camp Receptor

scholarly journals Interplay between Cyclic AMP-Cyclic AMP Receptor Protein and Cyclic di-GMP Signaling in Vibrio cholerae Biofilm Formation

2008 ◽  
Vol 190 (20) ◽  
pp. 6646-6659 ◽  
Author(s):  
Jiunn C. N. Fong ◽  
Fitnat H. Yildiz
Keyword(s):  
Cyclic Amp ◽  
Vibrio Cholerae ◽  
Transcriptome Analysis ◽  
Biofilm Formation ◽  
Matrix Proteins ◽  
Receptor Protein ◽  
Camp Receptor Protein ◽  
Genes Encoding ◽  
Camp Receptor ◽  
Biofilm Matrix

ABSTRACT Vibrio cholerae is a facultative human pathogen. The ability of V. cholerae to form biofilms is crucial for its survival in aquatic habitats between epidemics and is advantageous for host-to-host transmission during epidemics. Formation of mature biofilms requires the production of extracellular matrix components, including Vibrio polysaccharide (VPS) and matrix proteins. Biofilm formation is positively controlled by the transcriptional regulators VpsR and VpsT and is negatively regulated by the quorum-sensing transcriptional regulator HapR, as well as the cyclic AMP (cAMP)-cAMP receptor protein (CRP) regulatory complex. Transcriptome analysis of cyaA (encoding adenylate cyclase) and crp (encoding cAMP receptor protein) deletion mutants revealed that cAMP-CRP negatively regulates transcription of both VPS biosynthesis genes and genes encoding biofilm matrix proteins. Further mutational and expression analysis revealed that cAMP-CRP negatively regulates transcription of vps genes indirectly through its action on vpsR transcription. However, negative regulation of the genes encoding biofilm matrix proteins by cAMP-CRP can also occur independent of VpsR. Transcriptome analysis also revealed that cAMP-CRP regulates the expression of a set of genes encoding diguanylate cyclases (DGCs) and phosphodiesterases. Mutational and phenotypic analysis of the differentially regulated DGCs revealed that a DGC, CdgA, is responsible for the increase in biofilm formation in the Δcrp mutant, showing the connection between of cyclic di-GMP and cAMP signaling in V. cholerae.

scholarly journals The Cyclic AMP Receptor Protein Modulates Colonial Morphology in Vibrio cholerae

2007 ◽  
Vol 73 (22) ◽  
pp. 7482-7487 ◽  
Author(s):  
Weili Liang ◽  
Anisia J. Silva ◽  
Jorge A. Benitez
Keyword(s):  
Cyclic Amp ◽  
Vibrio Cholerae ◽  
Ectopic Expression ◽  
Receptor Protein ◽  
Intracellular Camp ◽  
Elevated Expression ◽  
Regulatory Input ◽  
Exopolysaccharide Biosynthesis ◽  
Colonial Morphology ◽  
Camp Receptor

ABSTRACT Inactivation of the quorum-sensing regulator HapR causes Vibrio cholerae El Tor biotype strain C7258 to adopt a rugose colonial morphology that correlates with enhanced biofilm formation. V. cholerae mutants lacking the cyclic AMP (cAMP) receptor protein (CRP) produce very little HapR, which results in elevated expression of Vibrio exopolysaccharide (vps) genes and biofilm compared to the wild type. However, Δcrp mutants still exhibited smooth colonial morphology and expressed reduced levels of vps genes compared to isogenic hapR mutants. In this study we demonstrate that deletion of crp and cya (adenylate cyclase) converts a rugose ΔhapR mutant to a smooth one. The smooth ΔhapR Δcrp and ΔhapR Δcya double mutants could be converted back to rugose by complementation with crp and cya, respectively. CRP was found to enhance the expression of VpsR, a strong activator of vps expression, but to diminish transcription of VpsT. Ectopic expression of VpsR in smooth ΔhapR Δcrp and ΔhapR Δcya double mutants restored rugose colonial morphology. Lowering intracellular cAMP levels in a ΔhapR mutant by the addition of glucose diminished VpsR expression and colonial rugosity. On the basis of our results, we propose a model for the regulatory input of CRP on exopolysaccharide biosynthesis.

scholarly journals Transcriptional Regulation of Vibrio cholerae Hemagglutinin/Protease by the Cyclic AMP Receptor Protein and RpoS

2004 ◽  
Vol 186 (19) ◽  
pp. 6374-6382 ◽  
Author(s):  
Anisia J. Silva ◽  
Jorge A. Benitez
Keyword(s):  
Quorum Sensing ◽  
Cyclic Amp ◽  
Vibrio Cholerae ◽  
Transcriptional Activation ◽  
Response Regulator ◽  
Stringent Response ◽  
Receptor Protein ◽  
Mobility Shift ◽  
Deceleration Phase ◽  
Camp Receptor

ABSTRACT Vibrio cholerae secretes a Zn-dependent metalloprotease, hemagglutinin/protease (HA/protease), which is encoded by hapA and displays a broad range of potentially pathogenic activities. Production of HA/protease requires transcriptional activation by the quorum-sensing regulator HapR. In this study we demonstrate that transcription of hapA is growth phase dependent and specifically activated in the deceleration and stationary growth phases. Addition of glucose in these phases repressed hapA transcription by inducing V. cholerae to resume exponential growth, which in turn diminished the expression of a rpoS-lacZ transcriptional fusion. Contrary to a previous observation, we demonstrate that transcription of hapA requires the rpoS-encoded σs factor. The cyclic AMP (cAMP) receptor protein (CRP) strongly enhanced hapA transcription in the deceleration phase. Analysis of rpoS and hapR mRNA in isogenic CRP+ and CRP− strains suggested that CRP enhances the transcription of rpoS and hapR. Analysis of strains containing hapR-lacZ and hapA-lacZ fusions confirmed that hapA is transcribed in response to concurrent quorum-sensing and nutrient limitation stimuli. Mutations inactivating the stringent response regulator RelA and the HapR-controlled AphA regulator did not affect HA/protease expression. Electrophoretic mobility shift experiments showed that pure cAMP-CRP and HapR alone do not bind the hapA promoter. This result suggests that HapR activation of hapA differs from its interaction with the aphA promoter and could involve additional factors.

scholarly journals The Cyclic Dipeptide Cyclo(Phe-Pro) Inhibits Cholera Toxin and Toxin-Coregulated Pilus Production in O1 El Tor Vibrio cholerae

2010 ◽  
Vol 192 (14) ◽  
pp. 3829-3832 ◽  
Author(s):  
Xiaowen R. Bina ◽  
James E. Bina
Keyword(s):  
Cholera Toxin ◽  
Vibrio Cholerae ◽  
Virulence Factors ◽  
Virulence Gene ◽  
Cyclic Dipeptide ◽  
Present Evidence ◽  
Toxin Coregulated Pilus ◽  
El Tor ◽  
Virulence Regulator

ABSTRACT Cyclo(Phe-Pro) is a cyclic dipeptide produced by multiple Vibrio species. In this work, we present evidence that cyclo(Phe-Pro) inhibits the production of the virulence factors cholera toxin (CT) and toxin-coregulated pilus (TCP) in O1 El Tor Vibrio cholerae strain N16961 during growth under virulence gene-inducing conditions. The cyclo(Phe-Pro) inhibition of CT and TCP production correlated with reduced transcription of the virulence regulator tcpPH and was alleviated by overexpression of tcpPH.

scholarly journals Virulence and the Environment: a Novel Role for Vibrio cholerae Toxin-Coregulated Pili in Biofilm Formation on Chitin

2005 ◽  
Vol 187 (10) ◽  
pp. 3551-3555 ◽  
Author(s):  
Gemma Reguera ◽  
Roberto Kolter
Keyword(s):  
Cholera Toxin ◽  
Vibrio Cholerae ◽  
Biofilm Formation ◽  
Intestinal Colonization ◽  
Host Colonization ◽  
Ecological Fitness ◽  
Bacterial Interactions ◽  
Colonization Factor ◽  
Selection For ◽  
Toxin Coregulated Pilus

ABSTRACT The toxin-coregulated pilus (TCP) of Vibrio cholerae is required for intestinal colonization and cholera toxin acquisition. Here we report that TCP mediates bacterial interactions required for biofilm differentiation on chitinaceous surfaces. We also show that undifferentiated TCP− biofilms have reduced ecological fitness and, thus, that chitin colonization may represent an ecological setting outside the host in which selection for a host colonization factor may take place.

scholarly journals Potentiation by cholera toxin of bradykinin-induced inositol phosphate production in the osteoblast-like cell line MC3T3-E1

1993 ◽  
Vol 292 (2) ◽  
pp. 401-408 ◽  
Author(s):  
Y Banno ◽  
T Sakai ◽  
T Kumada ◽  
Y Nozawa
Keyword(s):  
Cyclic Amp ◽  
Cholera Toxin ◽  
Cell Line ◽  
Inositol Phosphates ◽  
Inositol Phosphate ◽  
Receptor Protein ◽  
Osteoblastic Cell ◽  
Osteoblastic Cell Line ◽  
Inositol Phosphate Production ◽  
Receptor Number

Cells of the osteoblastic cell line MC3T3-E1 were shown to contain at least three phosphatidylinositol-specific phospholipase C (PI-PLC) isoenzymes (PLC-beta, PLC-gamma and PLC-delta) by Western blotting analysis with various anti-PLC antibodies. Stimulation of inositol phosphate production in MC3T3-E1 cells by bradykinin (BK) occurred via a GTP-binding protein. Inositol phosphate formation on stimulation by BK was not affected by pretreatment with pertussis toxin, whereas it was potentiated by cholera toxin pretreatment. Elevation of cellular cyclic AMP levels by brief pretreatment with dibutyryl cyclic AMP or forskolin failed to enhance the BK-mediated generation of inositol phosphates, but long-term preincubation with these agents partially mimicked the action of the cholera toxin. Cholera toxin also caused an increase in BK receptor number. Cycloheximide, a protein biosynthesis inhibitor, prevented the potentiating actions of the cholera toxin and the cyclic AMP-elevating agents on BK-induced inositol phosphate production, and also inhibited the increase in BK receptor number. The specific binding of [3H]BK to the whole MC3T3-E1 cells in the presence or absence of cholera toxin was completely inhibited by the B2 BK receptor antagonist D-Arg[Hyp3,Thi5,8,D-Phe7]BK, but not by the B1 BK receptor agonist des-Arg9-BK. These data suggest that the activation of PI-PLC induced by cholera toxin in BK-stimulated MC3T3-E1 cells was caused by an enhancement of the synthesis of BK receptor protein(s), at least part of which was mediated by a sustained increase in the intracellular level of cyclic AMP.

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