scholarly journals Repression of VvpM Protease Expression by Quorum Sensing and the cAMP-cAMP Receptor Protein Complex inVibrio vulnificus

2018 ◽  
Vol 200 (7) ◽  
Author(s):  
Jeong-A Kim ◽  
Mi-Ae Lee ◽  
You-Chul Jung ◽  
Bo-Ram Jang ◽  
Kyu-Ho Lee
Keyword(s):  
Transcription Factors ◽  
Stationary Phase ◽  
Cell Density ◽  
Transcription Initiation ◽  
Vibrio Vulnificus ◽  
The Other ◽  
Receptor Protein ◽  
Camp Receptor Protein ◽  
Content Type ◽  
Camp Receptor

ABSTRACTSepticemia-causingVibrio vulnificusproduces at least three exoproteases, VvpE, VvpS, and VvpM, all of which participate in interactions with human cells. Expression of VvpE and VvpS is induced in the stationary phase by multiple transcription factors, including sigma factor S, SmcR, and the cAMP-cAMP receptor protein (cAMP-CRP) complex. Distinct roles of VvpM, such as induction of apoptosis, lead us to hypothesize VvpM expression is different from that of the other exoproteases. Its transcription, which was found to be independent of sigma S, is induced at the early exponential phase and then becomes negligible upon entry into the stationary phase. SmcR and CRP were studied regarding the control ofvvpMexpression. Transcription ofvvpMwas repressed by SmcR and cAMP-CRP complex individually, which specifically bound to the regions −2 to +20 and +6 to +27, respectively, relative to thevvpMtranscription initiation site. Derepression ofvvpMgene expression was 10- to 40-fold greater in ansmcR crpdouble mutant than in single-gene mutants. Therefore, these results show that the expression ofV. vulnificusexoproteases is differentially regulated, and in this way, distinct proteases can engage in specific interactions with a host.IMPORTANCEAn opportunistic human pathogen,Vibrio vulnificusproduces multiple extracellular proteases that are involved in diverse interactions with a host. The total exoproteolytic activity is detected mainly in the supernatants of the high-cell-density cultures. However, some proteolytic activity derived from a metalloprotease, VvpM, was present in the supernatants of the low-cell-density cultures sampled at the early growth period. In this study, we present the regulatory mechanism for VvpM expression via repression by at least two transcription factors. This type of transcriptional regulation is the exact opposite of those for expression of the otherV. vulnificusexoproteases. Differential regulation of each exoprotease's production then facilitates the pathogen's participation in the distinct interactions with a host.

scholarly journals cAMP Receptor Protein ControlsVibrio choleraeGene Expression in Response to Host Colonization

mBio ◽  
2018 ◽  
Vol 9 (4) ◽  
Author(s):  
Jainaba Manneh-Roussel ◽  
James R. J. Haycocks ◽  
Andrés Magán ◽  
Nicolas Perez-Soto ◽  
Kerstin Voelz ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factors ◽  
Vibrio Cholerae ◽  
Expression Patterns ◽  
Lifestyle Changes ◽  
Receptor Protein ◽  
Camp Receptor Protein ◽  
Host Colonization ◽  
Content Type ◽  
Camp Receptor

ABSTRACTThe bacteriumVibrio choleraeis native to aquatic environments and can switch lifestyles to cause disease in humans. Lifestyle switching requires modulation of genetic systems for quorum sensing, intestinal colonization, and toxin production. Much of this regulation occurs at the level of gene expression and is controlled by transcription factors. In this work, we have mapped the binding of cAMP receptor protein (CRP) and RNA polymerase across theV. choleraegenome. We show that CRP is an integral component of the regulatory network that controls lifestyle switching. Focusing on a locus necessary for toxin transport, we demonstrate CRP-dependent regulation of gene expression in response to host colonization. Examination of further CRP-targeted genes reveals that this behavior is commonplace. Hence, CRP is a key regulator of manyV. choleraegenes in response to lifestyle changes.IMPORTANCECholera is an infectious disease that is caused by the bacteriumVibrio cholerae. Best known for causing disease in humans, the bacterium is most commonly found in aquatic ecosystems. Hence, humans acquire cholera following ingestion of food or water contaminated withV. cholerae. Transition between an aquatic environment and a human host triggers a lifestyle switch that involves reprogramming ofV. choleraegene expression patterns. This process is controlled by a network of transcription factors. In this paper, we show that the cAMP receptor protein (CRP) is a key regulator ofV. choleraegene expression in response to lifestyle changes.

scholarly journals Interactions between the Escherichia coli cAMP receptor protein and the C-terminal domain of the α subunit of RNA polymerase at Class I promoters

1999 ◽  
Vol 337 (3) ◽  
pp. 415-423 ◽  
Author(s):  
Emma C. LAW ◽  
Nigel J. SAVERY ◽  
Stephen J. W. BUSBY
Keyword(s):  
Escherichia Coli ◽  
Rna Polymerase ◽  
Transcription Initiation ◽  
Class I ◽  
Receptor Protein ◽  
Camp Receptor Protein ◽  
Α Subunit ◽  
Terminal Domain ◽  
Up Elements ◽  
Camp Receptor

The Escherichia coli cAMP receptor protein (CRP) is a factor that activates transcription at over 100 target promoters. At Class I CRP-dependent promoters, CRP binds immediately upstream of RNA polymerase and activates transcription by making direct contacts with the C-terminal domain of the RNA polymerase α subunit (αCTD). Since αCTD is also known to interact with DNA sequence elements (known as UP elements), we have constructed a series of semi-synthetic Class I CRP-dependent promoters, carrying both a consensus DNA-binding site for CRP and a UP element at different positions. We previously showed that, at these promoters, the CRP–αCTD interaction and the CRP–UP element interaction contribute independently and additively to transcription initiation. In this study, we show that the two halves of the UP element can function independently, and that, in the presence of the UP element, the best location for the DNA site for CRP is position -69.5. This suggests that, at Class I CRP-dependent promoters where the DNA site for CRP is located at position -61.5, the two αCTDs of RNA polymerase are not optimally positioned. Two experiments to test this hypothesis are presented.

scholarly journals Sycrp2 Is Essential for Twitching Motility in the CyanobacteriumSynechocystissp. Strain PCC 6803

2018 ◽  
Vol 200 (21) ◽  
Author(s):  
Wei-Yu Song ◽  
Sha-Sha Zang ◽  
Zheng-Ke Li ◽  
Guo-Zheng Dai ◽  
Ke Liu ◽  
...  
Keyword(s):  
Cell Motility ◽  
Receptor Protein ◽  
Upstream Region ◽  
Twitching Motility ◽  
Camp Receptor Protein ◽  
Mobility Shift ◽  
Content Type ◽  
Receptor Proteins ◽  
Camp Receptor ◽  
Pcc 6803

ABSTRACTTwo cAMP receptor proteins (CRPs), Sycrp1 (encoded bysll1371) and Sycrp2 (encoded bysll1924), exist in the cyanobacteriumSynechocystissp. strain PCC 6803. Previous studies have demonstrated that Sycrp1 has binding affinity for cAMP and is involved in motility by regulating the formation of pili. However, the function of Sycrp2 remains unknown. Here, we report thatsycrp2disruption results in the loss of motility ofSynechocystissp. PCC 6803, and that the phenotype can be recovered by reintroducing thesycrp2gene into the genome ofsycrp2-disrupted mutants. Electron microscopy showed that thesycrp2-disrupted mutant lost the pilus apparatus on the cell surface, resulting in a lack of cell motility. Furthermore, the transcript level of thepilA9-pilA11operon (essential for cell motility and regulated by the cAMP receptor protein Sycrp1) was markedly decreased insycrp2-disrupted mutants compared with the wild-type strain. Moreover, yeast two-hybrid analysis and a pulldown assay demonstrated that Sycrp2 interacted with Sycrp1 to form a heterodimer and that Sycrp1 and Sycrp2 interacted with themselves to form homodimers. Gel mobility shift assays revealed that Sycrp1 specifically binds to the upstream region ofpilA9. Together, these findings indicate that inSynechocystissp. PCC 6803, Sycrp2 regulates the formation of pili and cell motility by interacting with Sycrp1.IMPORTANCEcAMP receptor proteins (CRPs) are widely distributed in cyanobacteria and play important roles in regulating gene expression. Although many cyanobacterial species have two cAMP receptor-like proteins, the functional links between them are unknown. Here, we found that Sycrp2 in the cyanobacteriumSynechocystissp. strain PCC 6803 is essential for twitching motility and that it interacts with Sycrp1, a known cAMP receptor protein involved with twitching motility. Our findings indicate that the two cAMP receptor-like proteins in cyanobacteria do not have functional redundancy but rather work together.

N-oxide sensing and denitrification: the DNR transcription factors

2006 ◽  
Vol 34 (1) ◽  
pp. 185-187 ◽  
Author(s):  
S. Rinaldo ◽  
G. Giardina ◽  
M. Brunori ◽  
F. Cutruzzolà
Keyword(s):  
Nitric Oxide ◽  
Transcription Factors ◽  
Steady State ◽  
Nitrate Reductase ◽  
Gene Clusters ◽  
Transcriptional Regulators ◽  
Receptor Protein ◽  
Camp Receptor Protein ◽  
Denitrification Gene ◽  
Camp Receptor

All denitrifiers can keep the steady-state concentrations of nitrite and nitric oxide (NO) below cytotoxic levels by controlling the expression of denitrification gene clusters by redox signalling through transcriptional regulators belonging to the CRP (cAMP receptor protein)/FNR (fumarate and nitrate reductase regulator) superfamily.

scholarly journals Spacing requirements for interactions between the C-terminal domain of the α subunit of Escherichia coli RNA polymerase and the cAMP receptor protein

1998 ◽  
Vol 330 (1) ◽  
pp. 413-420 ◽  
Author(s):  
S. Georgina LLOYD ◽  
J. W. Stephen BUSBY ◽  
J. Nigel SAVERY
Keyword(s):  
Escherichia Coli ◽  
Rna Polymerase ◽  
Binding Site ◽  
Transcription Initiation ◽  
Receptor Protein ◽  
Camp Receptor Protein ◽  
Α Subunit ◽  
Synthetic Promoters ◽  
Terminal Domain ◽  
Camp Receptor

During transcription initiation at bacterial promoters, the C-terminal domain of the RNA polymerase α subunit (αCTD) can interact with DNA-sequence elements (known as UP elements) and with activator proteins. We have constructed a series of semi-synthetic promoters carrying both an UP element and a consensus DNA-binding site for the Escherichia coli cAMP receptor protein (CRP; a factor that activates transcription by making direct contacts with αCTD). At these promoters, the UP element was located at a variety of distances upstream of the CRP-binding site, which was fixed at position -41.5 bp upstream of the transcript start. At some positions, the UP element caused enhanced promoter activity whereas, at other positions, it had very little effect. In no case was the CRP-dependence of the promoter relieved. DNase I and hydroxyl-radical footprinting were used to study ternary RNA polymerase-CRP-promoter complexes formed at two of the most active of these promoters, and co-operativity between the binding of CRP and purified α subunits was studied. The footprints show that αCTD binds to the UP element as it is displaced upstream but that this displacement does not prevent αCTD from being contacted by CRP. Models to account for this are discussed.

scholarly journals Positive Effect of Carbon Sources on Natural Transformation in Escherichia coli: Role of Low-Level Cyclic AMP (cAMP)-cAMP Receptor Protein in the Derepression ofrpoS

2015 ◽  
Vol 197 (20) ◽  
pp. 3317-3328 ◽  
Author(s):  
Mengyue Guo ◽  
Huanyu Wang ◽  
Nengbin Xie ◽  
Zhixiong Xie
Keyword(s):  
Escherichia Coli ◽  
Natural Transformation ◽  
Carbon Sources ◽  
Transformation Frequency ◽  
Receptor Protein ◽  
Camp Receptor Protein ◽  
Content Type ◽  
E Coli ◽  
Camp Receptor

ABSTRACTNatural plasmid transformation ofEscherichia coliis a complex process that occurs strictly on agar plates and requires the global stress response factor σS. Here, we showed that additional carbon sources could significantly enhance the transformability ofE. coli. Inactivation of phosphotransferase system genes (ptsH,ptsG, andcrr) caused an increase in the transformation frequency, and the addition of cyclic AMP (cAMP) neutralized the promotional effect of carbon sources. This implies a negative role of cAMP in natural transformation. Further study showed thatcrpandcyaAmutations conferred a higher transformation frequency, suggesting that the cAMP-cAMP receptor protein (CRP) complex has an inhibitory effect on transformation. Moreover, we observed thatrpoSis negatively regulated by cAMP-CRP in early log phase and that bothcrpandcyaAmutants show no transformation superiority whenrpoSis knocked out. Therefore, it can be concluded that both thecrpandcyaAmutations derepressrpoSexpression in early log phase, whereby they aid in the promotion of natural transformation ability. We also showed that the accumulation of RpoS during early log phase can account for the enhanced transformation aroused by additional carbon sources. Our results thus demonstrated that the presence of additional carbon sources promotes competence development and natural transformation by reducing cAMP-CRP and, thus, derepressingrpoSexpression during log phase. This finding could contribute to a better understanding of the relationship between nutrition state and competence, as well as the mechanism of natural plasmid transformation inE. coli.IMPORTANCEEscherichia coli, which is not usually considered to be naturally transformable, was found to spontaneously take up plasmid DNA on agar plates. Researching the mechanism of natural transformation is important for understanding the role of transformation in evolution, as well as in the transfer of pathogenicity and antibiotic resistance genes. In this work, we found that carbon sources significantly improve transformation by decreasing cAMP. Then, the low level of cAMP-CRP derepresses the general stress response regulator RpoS via a biphasic regulatory pattern, thereby contributing to transformation. Thus, we demonstrate the mechanism by which carbon sources affect natural transformation, which is important for revealing information about the interplay between nutrition state and competence development inE. coli.

scholarly journals N-Acetyl-d-Glucosamine Induces the Expression of Multidrug Exporter Genes, mdtEF, via Catabolite Activation in Escherichia coli

2006 ◽  
Vol 188 (16) ◽  
pp. 5851-5858 ◽  
Author(s):  
Hidetada Hirakawa ◽  
Yoshihiko Inazumi ◽  
Yasuko Senda ◽  
Asuka Kobayashi ◽  
Takahiro Hirata ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Signaling Pathways ◽  
Protein Gene ◽  
The Other ◽  
Receptor Protein ◽  
Camp Receptor Protein ◽  
Gene Encoding ◽  
E Coli ◽  
Camp Receptor ◽  
Multiple Signaling

ABSTRACT The expression of MdtEF, a multidrug exporter in Escherichia coli, is positively controlled through multiple signaling pathways, but little is known about signals that induce MdtEF expression. In this study, we investigated compounds that induce the expression of the mdtEF genes and found that out of 20 drug exporter genes in E. coli, the expression of mdtEF is greatly induced by N-acetyl-d-glucosamine (GlcNAc). The induction of mdtEF by GlcNAc is not mediated by the evgSA, ydeO, gadX, and rpoS signaling pathways that have been known to regulate mdtEF expression. On the other hand, deletion of the nagE gene, encoding the phosphotransferase (PTS) system for GlcNAc, prevented induction by GlcNAc. The induction of mdtEF by GlcNAc was also greatly inhibited by the addition of cyclic AMP (cAMP) and completely abolished upon deletion of the cAMP receptor protein gene (crp). Other PTS sugars, glucose and d-glucosamine, also induced mdtEF gene expression. These results suggest that mdtEF expression is stimulated through catabolite control.

scholarly journals Mutations That StimulateflhDCExpression in Escherichia coli K-12

2015 ◽  
Vol 197 (19) ◽  
pp. 3087-3096 ◽  
Author(s):  
Karen A. Fahrner ◽  
Howard C. Berg
Keyword(s):  
Escherichia Coli ◽  
Transcription Factors ◽  
Insertion Sequence ◽  
Receptor Protein ◽  
Upstream Region ◽  
Single Nucleotide ◽  
Content Type ◽  
Sequence Elements ◽  
Camp Receptor ◽  
K 12

ABSTRACTMotility is a beneficial attribute that enables cells to access and explore new environments and to escape detrimental ones. The organelle of motility inEscherichia coliis the flagellum, and its production is initiated by the activating transcription factors FlhD and FlhC. The expression of these factors by theflhDCoperon is highly regulated and influenced by environmental conditions. TheflhDCpromoter is recognized by σ70and is dependent on the transcriptional activator cyclic AMP (cAMP)-cAMP receptor protein complex (cAMP-CRP). A number of K-12 strains exhibit limited motility due to low expression levels offlhDC. We report here a large number of mutations that stimulateflhDCexpression in such strains. They include single nucleotide changes in the −10 element of the promoter, in the promoter spacer, and in the cAMP-CRP binding region. In addition, we show that insertion sequence (IS) elements or a kanamycin gene located hundreds of base pairs upstream of the promoter can effectively enhance transcription, suggesting that the topology of a large upstream region plays a significant role in the regulation offlhDCexpression. None of the mutations eliminated the requirement for cAMP-CRP for activation. However, several mutations allowed expression in the absence of the nucleoid organizing protein, H-NS, which is normally required forflhDCexpression.IMPORTANCETheflhDCoperon ofEscherichia coliencodes transcription factors that initiate flagellar synthesis, an energetically costly process that is highly regulated. Few deregulating mutations have been reported thus far. This paper describes new single nucleotide mutations that stimulateflhDCexpression, including a number that map to the promoter spacer region. In addition, this work shows that insertion sequence elements or a kanamycin gene located far upstream from the promoter or repressor binding sites also stimulate transcription, indicating a role of regional topology in the regulation offlhDCexpression.

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