scholarly journals cAMP Receptor Protein Positively Regulates the Expression of Genes Involved in the Biosynthesis of Klebsiella oxytoca Tilivalline Cytotoxin

2021 ◽  
Vol 12 ◽  
Author(s):  
Diana Rodríguez-Valverde ◽  
Nancy León-Montes ◽  
Jorge Soria-Bustos ◽  
Jessica Martínez-Cruz ◽  
Ricardo González-Ugalde ◽  
...  
Keyword(s):  
Gene Expression ◽  
Metabolic Regulation ◽  
Divalent Cations ◽  
Klebsiella Oxytoca ◽  
Carbon Sources ◽  
Enteric Bacteria ◽  
Receptor Protein ◽  
Camp Receptor Protein ◽  
Environmental Signals ◽  
Camp Receptor

Klebsiella oxytoca is a resident of the human gut. However, certain K. oxytoca toxigenic strains exist that secrete the nonribosomal peptide tilivalline (TV) cytotoxin. TV is a pyrrolobenzodiazepine that causes antibiotic-associated hemorrhagic colitis (AAHC). The biosynthesis of TV is driven by enzymes encoded by the aroX and NRPS operons. In this study, we determined the effect of environmental signals such as carbon sources, osmolarity, and divalent cations on the transcription of both TV biosynthetic operons. Gene expression was enhanced when bacteria were cultivated in tryptone lactose broth. Glucose, high osmolarity, and depletion of calcium and magnesium diminished gene expression, whereas glycerol increased transcription of both TV biosynthetic operons. The cAMP receptor protein (CRP) is a major transcriptional regulator in bacteria that plays a key role in metabolic regulation. To investigate the role of CRP on the cytotoxicity of K. oxytoca, we compared levels of expression of TV biosynthetic operons and synthesis of TV in wild-type strain MIT 09-7231 and a Δcrp isogenic mutant. In summary, we found that CRP directly activates the transcription of the aroX and NRPS operons and that the absence of CRP reduced cytotoxicity of K. oxytoca on HeLa cells, due to a significant reduction in TV production. This study highlights the importance of the CRP protein in the regulation of virulence genes in enteric bacteria and broadens our knowledge on the regulatory mechanisms of the TV cytotoxin.

scholarly journals The Yersinia enterocoliticaPhospholipase Gene yplA Is Part of the Flagellar Regulon

2000 ◽  
Vol 182 (8) ◽  
pp. 2314-2320 ◽  
Author(s):  
Deborah H. Schmiel ◽  
Glenn M. Young ◽  
Virginia L. Miller
Keyword(s):  
Virulence Genes ◽  
Receptor Protein ◽  
Camp Receptor Protein ◽  
Transcriptional Fusion ◽  
Logarithmic Growth Phase ◽  
Environmental Signals ◽  
Flagellar Regulon ◽  
Camp Receptor ◽  
Logarithmic Growth ◽  
Regulatory Sites

ABSTRACT Yersinia enterocolitica yplA encodes a phospholipase required for virulence. Virulence genes are often regulated in response to environmental signals; therefore, yplA expression was examined using a yplA::lacZYtranscriptional fusion. Maximal yplA expression occurred between pH 6.5 and pH 7.5 and was induced in the mid-logarithmic growth phase. Potential Fnr, cyclic AMP (cAMP)-cAMP receptor protein (Crp), and ςF regulatory sites were identified in the nucleotide sequence. Reduction of yplA expression by aeration, addition of glucose and sucrose, and application of high temperature and salt is consistent with Fnr-, cAMP-Crp-, and ςF-mediated regulation, respectively. Expression ofyplA was reduced in flhDC and fliAnull strains, indicating that yplA is part of the flagellar regulon.

A multitude of CRP/FNR-like transcription proteins in Bradyrhizobium japonicum

2006 ◽  
Vol 34 (1) ◽  
pp. 156-159 ◽  
Author(s):  
S. Mesa ◽  
H. Hennecke ◽  
H.-M. Fischer
Keyword(s):  
Gene Expression ◽  
Bradyrhizobium Japonicum ◽  
Sequence Similarity ◽  
Regulatory Protein ◽  
Regulatory System ◽  
Receptor Protein ◽  
Camp Receptor Protein ◽  
Low Oxygen ◽  
Denitrification Gene ◽  
Camp Receptor

In Bradyrhizobium japonicum, the nitrogen-fixing soya bean endosymbiont and facultative denitrifier, three CRP (cAMP receptor protein)/FNR (fumarate and nitrate reductase regulatory protein)-type transcription factors [FixK1, FixK2 and NnrR (nitrite and nitric oxide reductase regulator)] have been studied previously in the context of the regulation of nitrogen fixation and denitrification. The gene expression of both fixK1 and nnrR depends on FixK2, which acts as a key distributor of the ‘low-oxygen’ signal perceived by the two-component regulatory system FixLJ. While the targets for FixK1 are not known, NnrR transduces the nitrogen oxide signal to the level of denitrification gene expression. Besides these three regulators, the complete genome sequence of this organism has revealed the existence of 13 additional CRP/FNR-type proteins whose functions have not yet been studied. Based on sequence similarity and phylogenetic analysis, we discuss in this paper the peculiarities of these additional factors.

scholarly journals AnCrpA, a cAMP receptor protein, regulatesnif-related gene expression in the cyanobacteriumAnabaenasp. strain PCC 7120 grown with nitrate

FEBS Letters ◽  
2006 ◽  
Vol 581 (1) ◽  
pp. 21-28 ◽  
Author(s):  
Takayuki Suzuki ◽  
Hidehisa Yoshimura ◽  
Shigeki Ehira ◽  
Masahiko Ikeuchi ◽  
Masayuki Ohmori
Keyword(s):  
Gene Expression ◽  
Receptor Protein ◽  
Related Gene ◽  
Camp Receptor Protein ◽  
Camp Receptor ◽  
Pcc 7120

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 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.

Transcriptional regulation of sdiA by cAMP-receptor protein, LeuO, and environmental signals in Salmonella enterica serovar Typhimurium

2012 ◽  
Vol 58 (1) ◽  
pp. 10-22 ◽  
Author(s):  
Amy L. Turnbull ◽  
Wook Kim ◽  
Michael G. Surette
Keyword(s):  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Receptor Protein ◽  
Camp Receptor Protein ◽  
Late Stationary Phase ◽  
Environmental Signals ◽  
Serovar Typhimurium ◽  
Elevated Expression ◽  
Transcriptional Changes ◽  
Camp Receptor

The sdiA gene encodes for a LuxR-type transcription factor, which is active when bound to N-acyl homoserine lactones (AHLs). Because Salmonella enterica serovar Typhimurium does not produce AHLs, SdiA senses signals produced by other organisms. SdiA is not expressed constitutively, and response is limited to conditions in which elevated expression occurs, but little is known about the regulation of sdiA expression. Here we map the sdiA promoter and define several regulators that directly or indirectly act on the promoter. The major activator of sdiA expression is cAMP-receptor protein (CRP), and we define the CRP operator in the sdiA promoter using promoter and crp mutants. LeuO activates sdiA expression to a lesser extent than does CRP. We demonstrate that LeuO directly binds the sdiA promoter and the Rcs phosphorelay represses sdiA expression. In this study, NhaR, IlvY, and Fur affected sdiA expression indirectly and weakly. Expression in late-stationary phase depended on RpoS. AHL-dependent expression of the SdiA-regulated gene rck correlated to the observed sdiA transcriptional changes in regulator mutants. The data demonstrate that regulation of sdiA involves integration of multiple environmental and metabolic signals.

scholarly journals Novel Roles of cAMP Receptor Protein (CRP) in Regulation of Transport and Metabolism of Carbon Sources

PLoS ONE ◽  
2011 ◽  
Vol 6 (6) ◽  
pp. e20081 ◽  
Author(s):  
Tomohiro Shimada ◽  
Nobuyuki Fujita ◽  
Kaneyoshi Yamamoto ◽  
Akira Ishihama
Keyword(s):  
Carbon Sources ◽  
Receptor Protein ◽  
Camp Receptor Protein ◽  
Regulation Of Transport ◽  
Camp Receptor

scholarly journals The yiaKLX1X2PQRS and ulaABCDEFG Gene Systems Are Required for the Aerobic Utilization of l-Ascorbate in Klebsiella pneumoniae Strain 13882 with l-Ascorbate-6-Phosphate as the Inducer

2008 ◽  
Vol 190 (20) ◽  
pp. 6615-6624 ◽  
Author(s):  
Evangelina Campos ◽  
Lucia de la Riva ◽  
Fernando Garces ◽  
Rosa Giménez ◽  
Juan Aguilar ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Genetic System ◽  
Enteric Bacteria ◽  
Metabolic Process ◽  
Receptor Protein ◽  
Camp Receptor Protein ◽  
Phosphotransferase System ◽  
Present Evidence ◽  
Aerobic Conditions ◽  
Camp Receptor

ABSTRACT The capacity to both ferment and oxidize l-ascorbate has been widely documented for a number of enteric bacteria. Here we present evidence that all the strains of Klebsiella pneumoniae tested in this study ferment l-ascorbate using the ula regulon-encoded proteins. Under aerobic conditions, several phenotypes were observed for the strains. Our results showed that the yiaK-S system is required for this aerobic metabolic process. Gel shift experiments performed with UlaR and YiaJ and probes corresponding to the specific promoters indicated that l-ascorbate-6-phosphate is the effector molecule recognized by both regulators, since binding of the repressors to their recognition sites was impaired by the presence of this compound. We demonstrated that in K. pneumoniae cells l-ascorbate-6-phosphate is formed only by the action of the UlaABC phosphotransferase system. This finding explains why strains that lack the ula genetic system and therefore are unable to form the inducer intracellularly cannot efficiently use this vitamin as a carbon source under either anaerobic or aerobic conditions. Thus, efficient aerobic metabolism of l-ascorbate in K. pneumoniae is dependent on the presence of both the yiaK-S and ula systems. The expression of the yiaK-S operon, but not the expression of the ula regulon, is controlled by oxygen availability. Both systems are regulated by the cyclic AMP (cAMP)-cAMP receptor protein (CRP) complex and by IHF.

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