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 Cyclic AMP (cAMP) Receptor Protein-cAMP Complex Regulates Heparosan Production in Escherichia coli Strain Nissle 1917

2015 ◽  
Vol 81 (22) ◽  
pp. 7687-7696 ◽  
Author(s):  
Huihui Yan ◽  
Feifei Bao ◽  
Liping Zhao ◽  
Yanying Yu ◽  
Jiaqin Tang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Cyclic Amp ◽  
Carbon Sources ◽  
Coli Strain ◽  
Site Directed Mutagenesis ◽  
Receptor Protein ◽  
Upstream Region ◽  
Camp Receptor Protein ◽  
Content Type ◽  
Camp Receptor

ABSTRACTHeparosan serves as the starting carbon backbone for the chemoenzymatic synthesis of heparin, a widely used clinical anticoagulant drug. The availability of heparosan is a significant concern for the cost-effective synthesis of bioengineered heparin. The carbon source is known as the pivotal factor affecting heparosan production. However, the mechanism by which carbon sources control the biosynthesis of heparosan is unclear. In this study, we found that the biosynthesis of heparosan was influenced by different carbon sources. Glucose inhibits the biosynthesis of heparosan, while the addition of either fructose or mannose increases the yield of heparosan. Further study demonstrated that the cyclic AMP (cAMP)-cAMP receptor protein (CRP) complex binds to the upstream region of the region 3 promoter and stimulates the transcription of the gene cluster for heparosan biosynthesis. Site-directed mutagenesis of the CRP binding site abolished its capability of binding CRP and eliminated the stimulative effect on transcription.1H nuclear magnetic resonance (NMR) analysis was further performed to determine theEscherichia colistrain Nissle 1917 (EcN) heparosan structure and quantify extracellular heparosan production. Our results add to the understanding of the regulation of heparosan biosynthesis and may contribute to the study of other exopolysaccharide-producing strains.

Determination of the rates of synthesis and degradation of adenosine 3′,5′-cyclic monophosphate in Escherichia coli CRP− and CRP+ strains

1978 ◽  
Vol 56 (9) ◽  
pp. 849-852 ◽  
Author(s):  
Ann D. E. Fraser ◽  
Hiroshi Yamazaki
Keyword(s):  
Escherichia Coli ◽  
Receptor Protein ◽  
Camp Receptor Protein ◽  
Balanced Growth ◽  
E Coli ◽  
Cyclic Monophosphate ◽  
Camp Receptor ◽  
Extracellular Camp ◽  
Synthesis And Degradation

We have developed a method for estimating the rates of synthesis and degradation of adenosine 3′,5′-cyclic monophosphate (cAMP) in Escherichia coli during balanced growth. Applying this method, we have found that an E. coli CRP− mutant 5333 (deficient for cAMP receptor protein) synthesizes cAMP about 25 times faster than does its CRP+ parent 1100. This accounts for the abnormally high intracellular and extracellular cAMP accumulation in 5333.

scholarly journals Cyclic AMP (cAMP) and cAMP Receptor Protein Influence both Synthesis and Uptake of Extracellular Autoinducer 2 in Escherichia coli

2005 ◽  
Vol 187 (6) ◽  
pp. 2066-2076 ◽  
Author(s):  
Liang Wang ◽  
Yoshifumi Hashimoto ◽  
Chen-Yu Tsao ◽  
James J. Valdes ◽  
William E. Bentley
Keyword(s):  
Escherichia Coli ◽  
Cyclic Amp ◽  
Carbon Sources ◽  
Cell Communication ◽  
Receptor Protein ◽  
Upstream Region ◽  
E Coli ◽  
Autoinducer 2 ◽  
Serovar Typhimurium ◽  
Camp Receptor

ABSTRACT Bacterial autoinducer 2 (AI-2) is proposed to be an interspecies mediator of cell-cell communication that enables cells to operate at the multicellular level. Many environmental stimuli have been shown to affect the extracellular AI-2 levels, carbon sources being among the most important. In this report, we show that both AI-2 synthesis and uptake in Escherichia coli are subject to catabolite repression through the cyclic AMP (cAMP)-CRP complex, which directly stimulates transcription of the lsr (for “luxS regulated”) operon and indirectly represses luxS expression. Specifically, cAMP-CRP is shown to bind to a CRP binding site located in the upstream region of the lsr promoter and works with the LsrR repressor to regulate AI-2 uptake. The functions of the lsr operon and its regulators, LsrR and LsrK, previously reported in Salmonella enterica serovar Typhimurium, are confirmed here for E. coli. The elucidation of cAMP-CRP involvement in E. coli autoinduction impacts many areas, including the growth of E. coli in fermentation processes.

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 Studies of the distribution of Escherichia coli cAMP-receptor protein and RNA polymerase along the E. coli chromosome

2005 ◽  
Vol 102 (49) ◽  
pp. 17693-17698 ◽  
Author(s):  
D. C. Grainger ◽  
D. Hurd ◽  
M. Harrison ◽  
J. Holdstock ◽  
S. J. W. Busby
Keyword(s):  
Escherichia Coli ◽  
Rna Polymerase ◽  
Receptor Protein ◽  
Camp Receptor Protein ◽  
E Coli ◽  
Camp Receptor

Regulatory role of cAMP receptor protein over Escherichia coli fumarase genes

2012 ◽  
Vol 50 (3) ◽  
pp. 426-433 ◽  
Author(s):  
Yu-Pei Chen ◽  
Hsiao-Hsien Lin ◽  
Chi-Dung Yang ◽  
Shin-Hong Huang ◽  
Ching-Ping Tseng
Keyword(s):  
Escherichia Coli ◽  
Regulatory Role ◽  
Receptor Protein ◽  
Camp Receptor Protein ◽  
Camp Receptor

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.

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