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 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 Regulation of ytfK by cAMP-CRP Contributes to SpoT-Dependent Accumulation of (p)ppGpp in Response to Carbon Starvation YtfK Responds to Glucose Exhaustion

2021 ◽  
Vol 12 ◽  
Author(s):  
Laura Meyer ◽  
Elsa Germain ◽  
Etienne Maisonneuve
Keyword(s):  
Escherichia Coli ◽  
Cyclic Amp ◽  
Catabolite Repression ◽  
Stringent Response ◽  
Receptor Protein ◽  
Glucose Starvation ◽  
Camp Receptor Protein ◽  
E Coli ◽  
Camp Receptor ◽  
Glucose Availability

Guanosine penta- or tetraphosphate (known as (p)ppGpp) serves as second messenger to respond to nutrient downshift and other environmental stresses, a phenomenon called stringent response. Accumulation of (p)ppGpp promotes the coordinated inhibition of macromolecule synthesis, as well as the activation of stress response pathways to cope and adapt to harmful conditions. In Escherichia coli, the (p)ppGpp level is tightly regulated by two enzymes, the (p)ppGpp synthetase RelA and the bifunctional synthetase/hydrolase SpoT. We recently identified the small protein YtfK as a key regulator of SpoT-mediated activation of stringent response in E. coli. Here, we further characterized the regulation of ytfK. We observed that ytfK is subjected to catabolite repression and is positively regulated by the cyclic AMP (cAMP)-cAMP receptor protein (CRP) complex. Importantly, YtfK contributes to SpoT-dependent accumulation of (p)ppGpp and cell survival in response to glucose starvation. Therefore, regulation of ytfK by the cAMP-CRP appears important to adjust (p)ppGpp level and coordinate cellular metabolism in response to glucose availability.

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 Catabolite Repression of the Citrate Fermentation Genes in Klebsiella pneumoniae: Evidence for Involvement of the Cyclic AMP Receptor Protein

2001 ◽  
Vol 183 (18) ◽  
pp. 5248-5256 ◽  
Author(s):  
Margareta Meyer ◽  
Peter Dimroth ◽  
Michael Bott
Keyword(s):  
Cyclic Amp ◽  
Klebsiella Pneumoniae ◽  
Catabolite Repression ◽  
Response Regulator ◽  
Carbon Sources ◽  
Receptor Protein ◽  
Citrate Lyase ◽  
Citrate Fermentation ◽  
Camp Receptor ◽  
Transcriptional Start Sites

ABSTRACT Klebsiella pneumoniae is able to grow anaerobically with citrate as a sole carbon and energy source by a fermentative pathway involving the Na+-dependent citrate carrier CitS, citrate lyase, and oxaloacetate decarboxylase. The corresponding genes are organized in the divergent citC and citS operons, whose expression is strictly dependent on the citrate-sensing CitA-CitB two-component system. Evidence is provided here that the citrate fermentation genes are subject to catabolite repression, since anaerobic cultivation with a mixture of citrate and glucose or citrate and gluconate resulted in diauxic growth. Glucose, gluconate, and also glycerol decreased the expression of a chromosomalcitS-lacZ fusion by 60 to 75%, whereas a direct inhibition of the citrate fermentation enzymes was not observed. The purified cyclic AMP (cAMP) receptor protein (CRP) of K. pneumoniae bound to two sites in thecitC-citS intergenic region, which were centered at position −41.5 upstream of the citC andcitS transcriptional start sites. Binding was apparently stimulated by the response regulator CitB. These data indicate that catabolite repression of the citrate fermentation genes is exerted by CRP and that in the absence of repressing carbon sources the cAMP-CRP complex serves to enhance the basal, CitB-dependent transcription level.

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 Catabolic Repression of secB Expression Is Positively Controlled by Cyclic AMP (cAMP) Receptor Protein-cAMP Complexes at the Transcriptional Level

1999 ◽  
Vol 181 (6) ◽  
pp. 1892-1899 ◽  
Author(s):  
Hyuk Kyu Seoh ◽  
Phang C. Tai
Keyword(s):  
Cyclic Amp ◽  
Transcription Initiation ◽  
Mutational Analysis ◽  
Receptor Protein ◽  
Transcriptional Level ◽  
Camp Receptor Protein ◽  
Catabolic Repression ◽  
Mobility Shift ◽  
P2 Promoter ◽  
Camp Receptor

ABSTRACT SecB, a protein export-specific chaperone, enhances the export of a subset of proteins across cytoplasmic membranes of Escherichia coli. Previous studies showed that the synthesis of SecB is repressed by the presence of glucose in the medium. The derepression of SecB requires the products of both the cya andcrp genes, indicating that secB expression is under the control of catabolic repression. In this study, twosecB-specific promoters were identified. In addition, 5′ transcription initiation sites from these two promoters were determined by means of secB-lacZ fusions and primer extension. The distal P1 promoter appeared to be independent of carbon sources, whereas the proximal P2 promoter was shown to be subject to control by the cyclic AMP (cAMP) receptor protein (CRP)-cAMP complexes. Gel-mobility shift studies showed that this regulation results from direct interaction between the secB P2 promoter region and the CRP-cAMP complex. Moreover, the CRP binding site on thesecB gene was determined by DNase I footprinting and further substantiated by mutational analysis. The identifiedsecB CRP binding region is centered at the −61.5 region of the secB gene and differed from the putative binding sites predicted by computer analysis.

scholarly journals The Cyclic AMP (cAMP)-cAMP Receptor Protein Signaling System Mediates Resistance of Vibrio cholerae O1 Strains to Multiple Environmental Bacteriophages

2010 ◽  
Vol 76 (13) ◽  
pp. 4233-4240 ◽  
Author(s):  
M. Shamim Hasan Zahid ◽  
T. M. Zaved Waise ◽  
M. Kamruzzaman ◽  
Amar N. Ghosh ◽  
G. Balakrish Nair ◽  
...  
Keyword(s):  
Cyclic Amp ◽  
Vibrio Cholerae ◽  
Parent Strain ◽  
Diarrheal Disease ◽  
Indicator Strain ◽  
Receptor Protein ◽  
Camp Receptor Protein ◽  
Selective Enrichment ◽  
Camp Receptor ◽  
Bacterial Genes

ABSTRACT Toxigenic Vibrio cholerae, the causative agent of the epidemic diarrheal disease cholera, interacts with diverse environmental bacteriophages. These interactions promote genetic diversity or cause selective enrichment of phage-resistant bacterial clones. To identify bacterial genes involved in mediating the phage-resistant phenotype, we screened a transposon insertion library of V. cholerae O1 El Tor biotype strain C6706 to identify mutants showing altered susceptibility to a panel of phages isolated from surface waters in Bangladesh. Mutants with insertion in cyaA or crp genes encoding adenylate cyclase or cyclic AMP (cAMP) receptor protein (CRP), respectively, were susceptible to a phage designated JSF9 to which the parent strain was completely resistant. Application of the cyaA mutant as an indicator strain in environmental phage monitoring enhanced phage detection, and we identified 3 additional phages to which the parent strain was resistant. Incorporation of the cyaA or crp mutations into other V. cholerae O1 strains caused similar alterations in their phage susceptibility patterns, and the susceptibility correlated with the ability of the bacteria to adsorb these phages. Our results suggest that cAMP-CRP-mediated downregulation of phage adsorption may contribute to a mechanism for the V. cholerae O1 strains to survive predation by multiple environmental phages. Furthermore, the cyaA or crp mutant strains may be used as suitable indicators in monitoring cholera phages in the water.

scholarly journals The Cyclic AMP Receptor Protein Regulates Quorum Sensing and Global Gene Expression in Yersinia pestis during Planktonic Growth and Growth in Biofilms

mBio ◽  
2019 ◽  
Vol 10 (6) ◽  
Author(s):  
Jeremy T. Ritzert ◽  
George Minasov ◽  
Ryan Embry ◽  
Matthew J. Schipma ◽  
Karla J. F. Satchell
Keyword(s):  
Gene Expression ◽  
Quorum Sensing ◽  
Carbon Source ◽  
Cyclic Amp ◽  
Yersinia Pestis ◽  
Carbon Sources ◽  
Transcriptional Regulator ◽  
Receptor Protein ◽  
Content Type ◽  
Bacterial Physiology

ABSTRACT Cyclic AMP (cAMP) receptor protein (Crp) is an important transcriptional regulator of Yersinia pestis. Expression of crp increases during pneumonic plague as the pathogen depletes glucose and forms large biofilms within lungs. To better understand control of Y. pestis Crp, we determined a 1.8-Å crystal structure of the protein-cAMP complex. We found that compared to Escherichia coli Crp, C helix amino acid substitutions in Y. pestis Crp did not impact the cAMP dependency of Crp to bind DNA promoters. To investigate Y. pestis Crp-regulated genes during plague pneumonia, we performed RNA sequencing on both wild-type and Δcrp mutant bacteria growing in planktonic and biofilm states in minimal media with glucose or glycerol. Y. pestis Crp was found to dramatically alter expression of hundreds of genes in a manner dependent upon carbon source and growth state. Gel shift assays confirmed direct regulation of the malT and ptsG promoters, and Crp was then linked to Y. pestis growth on maltose as a sole carbon source. Iron regulation genes ybtA and fyuA were found to be indirectly regulated by Crp. A new connection between carbon source and quorum sensing was revealed as Crp was found to regulate production of acyl-homoserine lactones (AHLs) through direct and indirect regulation of genes for AHL synthetases and receptors. AHLs were subsequently identified in the lungs of Y. pestis-infected mice when crp expression was highest in Y. pestis biofilms. Thus, in addition to the well-studied pla gene, other Crp-regulated genes likely have important functions during plague infection. IMPORTANCE Bacterial pathogens have evolved extensive signaling pathways to translate environmental signals into changes in gene expression. While Crp has long been appreciated for its role in regulating metabolism of carbon sources in many bacterial species, transcriptional profiling has revealed that this protein regulates many other aspects of bacterial physiology. The plague pathogen Y. pestis requires this global regulator to survive in blood, skin, and lungs. During disease progression, this organism adapts to changes within these niches. In addition to regulating genes for metabolism of nonglucose sugars, we found that Crp regulates genes for virulence, metal acquisition, and quorum sensing by direct or indirect mechanisms. Thus, this single transcriptional regulator, which responds to changes in available carbon sources, can regulate multiple critical behaviors for causing disease.

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