scholarly journals The global regulatory system Csr senses glucose through the phosphoenolpyruvate: carbohydrate phosphotransferase system

2015 ◽  
Vol 99 (4) ◽  
pp. 623-626 ◽  
Author(s):  
Deyanira Pérez-Morales ◽  
Víctor H. Bustamante
Keyword(s):  
Regulatory System ◽  
Phosphotransferase System ◽  
Global Regulatory System

scholarly journals A Global Regulatory Role of Gluconeogenic Genes in Escherichia coli Revealed by Transcriptome Network Analysis

2005 ◽  
Vol 280 (43) ◽  
pp. 36079-36087 ◽  
Author(s):  
Katy C. Kao ◽  
Linh M. Tran ◽  
James C. Liao
Keyword(s):  
Escherichia Coli ◽  
Dynamic Environment ◽  
Regulatory System ◽  
Underlying Mechanism ◽  
Receptor Protein ◽  
Phosphotransferase System ◽  
Global Regulators ◽  
Transcription Regulators ◽  
Camp Receptor ◽  
Global Regulatory System

In bacterial adaptation to the dynamic environment, metabolic genes are typically thought to be the executors, whereas global transcription regulators are regarded as the decision makers. Although the feedback from metabolic consequence is believed to be important, much less is understood. This work demonstrates that the gluconeogenic genes in Escherichia coli, ppsA, sfcA, and maeB, provide a feedback loop to the global regulator, cAMP receptor protein (CRP), in carbon source transition. Disruption of one of the gluconeogenic pathways has no phenotype in balanced growth, but causes a significant delay in the diauxic transition from glucose to acetate. To investigate the underlying mechanism, we measured the transcriptome profiles during the transition using DNA microarray, and network component analysis was employed to obtain the transcription factor activities. Results showed that one of the global regulators, CRP, was insufficiently activated during the transition in the ppsA deletion mutant. Indeed, addition of cAMP partially rescued the delay in transition. These results suggest that the gluconeogenic flux to phosphoenolpyruvate is important for full activation of adenylate cyclase through the phosphorylated enzyme IIAglu of the phosphotransferase system. Reduction of this flux causes insufficient activation of CRP and a global metabolic deficiency, which exemplifies a significant feedback interaction from metabolism to the a global regulatory system.

scholarly journals The Two-Component Regulatory System TCS08 Is Involved in Cellobiose Metabolism of Streptococcus pneumoniae R6

2006 ◽  
Vol 189 (4) ◽  
pp. 1342-1350 ◽  
Author(s):  
Stuart J. McKessar ◽  
Regine Hakenbeck
Keyword(s):  
Streptococcus Pneumoniae ◽  
Response Regulator ◽  
Regulatory System ◽  
Phosphotransferase System ◽  
Two Component System ◽  
Transcription Profiles ◽  
Regulatory Systems ◽  
Two Component ◽  
Cognate Response Regulator ◽  
Gram Positive Cocci

ABSTRACT The two-component system TCS08 is one of the regulatory systems that is important for virulence of Streptococcus pneumoniae. In order to investigate the TCS08 regulon, we have analyzed transcription profiles of mutants derived from S. pneumoniae R6 by microarray analysis. Since deletion mutants are often without a significant phenotype, we constructed a mutation in the histidine kinase HK08, T133P, in analogy to the phosphatase mutation T230P in the H box of the S. pneumoniae CiaH kinase described recently (D. Zähner, K. Kaminski, M. van der Linden, T. Mascher, M. Merai, and R. Hakenbeck, J. Mol. Microbiol. Biotechnol. 4:211-216, 2002). In addition, a deletion mutation was constructed in rr08, encoding the cognate response regulator. The most heavily suppressed genes in the hk08 mutant were spr0276 to spr0282, encoding a putative cellobiose phosphoenolpyruvate sugar phosphotransferase system (PTS). Whereas the R6 Smr parent strain and the Δrr08 mutant readily grew on cellobiose, the hk08 mutant and selected mutants with deletions in the PTS cluster did not, strongly suggesting that TCS08 is involved in the catabolism of cellobiose. Homologues of the TCS08 system were found in closely related streptococci and other gram-positive cocci. However, the genes spr0276 to spr0282, encoding the putative cellobiose PTS, represent a genomic island in S. pneumoniae and homologues were found in Streptococcus gordonii only, suggesting that this system might contribute to the pathogenicity potential of the pneumococcus.

scholarly journals Variable Expressions of Staphylococcus aureus Bicomponent Leucotoxins Semiquantified by Competitive Reverse Transcription-PCR

2000 ◽  
Vol 66 (9) ◽  
pp. 3931-3938 ◽  
Author(s):  
St�phane Bronner ◽  
Patricia Stoessel ◽  
Alain Gravet ◽  
Henri Monteil ◽  
Gilles Pr�vost
Keyword(s):  
Staphylococcus Aureus ◽  
Reverse Transcription ◽  
Regulatory System ◽  
Optimization Procedure ◽  
Reverse Transcription Pcr ◽  
Expression Of Genes ◽  
Genes Encoding ◽  
Specific Mrnas ◽  
Casamino Acids ◽  
Global Regulatory System

ABSTRACT A competitive reverse transcription-PCR method was developed for the semiquantitation of the expression of genes encoding bicomponent leucotoxins of Staphylococcus aureus, e.g., Panton-Valentine leucocidin (lukPV), gamma-hemolysin (hlgA and hlgCB), and LukE-LukD (lukED). The optimization procedure included RNA preparation; reverse transcription; the use of various amounts of enzymes, antisense primer, and RNA; and the final amplification chain reaction. Reproducible results were obtained, with sensitivity for detection of cDNA within the range of 1 mRNA/104 CFU to 102 mRNA/CFU, depending on the gene. Both specific mRNAs were more significantly expressed at the late-exponential phase of growth. Expression was about 100-fold higher in yeast extract-Casamino Acids-pyruvate medium than in heart infusion medium. Expression of the widely distributed gamma-hemolysin locus in the NTCC 8178 strain was around 10-fold diminished compared with that in the ATCC 49775 strain. Because of the lower level of hlgA expression, the corresponding protein, which is generally not abundant in culture supernatant, should be investigated for its contribution to the leucotoxin-associated virulence. The agr, sar, and agr sar mutant strains revealed a great dependence with regard to leucotoxin expression on the global regulatory system inS. aureus, except that expression of hlgA was not affected in the agr mutant.

scholarly journals A global regulatory system links virulence and antibiotic resistance to envelope homeostasis in Acinetobacter baumannii

2018 ◽  
Vol 14 (5) ◽  
pp. e1007030 ◽  
Author(s):  
Edward Geisinger ◽  
Nadav J. Mortman ◽  
Germán Vargas-Cuebas ◽  
Albert K. Tai ◽  
Ralph R. Isberg
Keyword(s):  
Antibiotic Resistance ◽  
Acinetobacter Baumannii ◽  
Regulatory System ◽  
Global Regulatory System

scholarly journals Identification of Quorum-Sensing-Regulated Genes of Burkholderia cepacia

2003 ◽  
Vol 185 (21) ◽  
pp. 6456-6462 ◽  
Author(s):  
Claudio Aguilar ◽  
Arianna Friscina ◽  
Giulia Devescovi ◽  
Milan Kojic ◽  
Vittorio Venturi
Keyword(s):  
Quorum Sensing ◽  
Burkholderia Cepacia ◽  
Regulatory System ◽  
Extracellular Proteins ◽  
Gram Negative Bacteria ◽  
Gene Promoters ◽  
Regulation Of Expression ◽  
Putative Gene ◽  
Homoserine Lactones ◽  
Global Regulatory System

ABSTRACT Quorum sensing is a regulatory mechanism (operating in response to cell density) which in gram-negative bacteria usually involves the production of N-acyl homoserine lactones (HSL). Quorum sensing in Burkholderia cepacia has been associated with the regulation of expression of extracellular proteins and siderophores and also with the regulation of swarming and biofilm formation. In the present study, several quorum-sensing-controlled gene promoters of B. cepacia ATCC 25416 were identified and characterized. A total of 28 putative gene promoters show CepR-C8-HSL-dependent expression, suggesting that quorum sensing in B. cepacia is a global regulatory system.

scholarly journals A Response Regulator That Represses Transcription of Several Virulence Operons in the Group A Streptococcus

1999 ◽  
Vol 181 (12) ◽  
pp. 3649-3657 ◽  
Author(s):  
Michael J. Federle ◽  
Kevin S. McIver ◽  
June R. Scott
Keyword(s):  
Group A Streptococcus ◽  
Response Regulator ◽  
Regulatory System ◽  
Insertion Mutant ◽  
Multiple Gene ◽  
Streptolysin S ◽  
Streptolysin O ◽  
Group A ◽  
Complement C5a ◽  
Global Regulatory System

ABSTRACT A search for homologs of the Bacillus subtilis PhoP response regulator in the group A streptococcus (GAS) genome revealed three good candidates. Inactivation of one of these, recently identified as csrR (J. C. Levin and M. R. Wessels, Mol. Microbiol. 30:209–219, 1998), caused the strain to produce mucoid colonies and to increase transcription ofhasA, the first gene in the operon for capsule synthesis. We report here that a nonpolar insertion in this gene also increased transcription of ska (encoding streptokinase),sagA (streptolysin S), and speMF (mitogenic factor) but did not affect transcription of slo(streptolysin O), mga (multiple gene regulator of GAS),emm (M protein), scpA (complement C5a peptidase), or speB or speC (pyrogenic exotoxins B and C). The amounts of streptokinase, streptolysin S, and capsule paralleled the levels of transcription of their genes in all cases. Because CsrR represses genes unrelated to those for capsule synthesis, and because CsrA-CsrB is a global regulatory system inEscherichia coli whose mechanism is unrelated to that of these genes in GAS, the locus has been renamed covR, for “control of virulence genes” in GAS. Transcription of thecovR operon was also increased in the nonpolar insertion mutant, indicating that CovR represses its own synthesis as well. All phenotypes of the covR nonpolar insertion mutant were complemented by the covR gene on a plasmid. CovR acts on operons expressed both in exponential and in stationary phase, demonstrating that the CovR-CovS pathway is separate from growth phase-dependent regulation in GAS. Therefore, CovR is the first multiple-gene repressor of virulence factors described for this important human pathogen.

scholarly journals A dual sRNA inStaphylococcus aureusinduces a metabolic switch responding to glucose consumption

2018 ◽  
Author(s):  
D. Bronesky ◽  
E. Desgranges ◽  
A. Corvaglia ◽  
P. François ◽  
C.J. Caballero ◽  
...  
Keyword(s):  
High Glucose ◽  
Pathogenic Bacteria ◽  
Protein A ◽  
Regulatory System ◽  
Glucose Consumption ◽  
Carbon Utilization ◽  
Metabolic Switch ◽  
Environmental Signals ◽  
Non Coding Rna ◽  
Global Regulatory System

ABSTRACTPathogenic bacteria must rapidly adapt to ever-changing environmental signals or nutrient availability resulting in metabolism remodeling. The carbon catabolite repression represents a global regulatory system, allowing the bacteria to express genes involved in carbon utilization and metabolization of the preferred carbon source. InStaphylococcus aureus, regulation of catabolite repressing genes is mediated by the carbon catabolite protein A (CcpA). Here, we have identified a CcpA-dependent small non-coding RNA, RsaI that is inhibited by high glucose concentrations. RsaI represses the translation of mRNAs encoding a major permease of glucose uptake, the FN3K enzyme that protects proteins against damages caused by high glucose concentrations, and IcaR, the transcriptional repressor of exopolysaccharide production. Besides, RsaI regulates the activities of other sRNAs responding to the uptake of glucose-6 phosphate or NO. Finally, RsaI inhibits the expression of several enzymes involved in carbon catabolism pathway, and activates genes involved in energy production, fermentation and NO detoxification when the glucose concentration decreases. This multifunctional RNA provides a signature for a metabolic switch when glucose is scarce and growth is arrested.

The impact of artificial intelligence and machine learning on the global economy and its implication for the hospitality sector in India

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sudhanshu Bhushan
Keyword(s):  
Artificial Intelligence ◽  
Machine Learning ◽  
Global Economy ◽  
Regulatory System ◽  
Content Type ◽  
Original Contribution ◽  
Hospitality Sector ◽  
Global Regulatory System ◽  
The Impact ◽  
Practical Implications

Purpose The purpose of this paper is to explore and evaluate the existing and future impact of artificial intelligence (AI) and machine learning on the global economy. It includes viewing the inclusion of AI in different sectors, its impact on industries, the trends of the forerunning companies that are capitalizing on AI and the idea of crystalizing exponential growth while maintaining a balance between the understanding of humans and the subsequent possibilities of AI. Design/methodology/approach This paper is based on secondary research, reviewing literature based on different industries and perspectives. Findings The global potential of AI is exponential; the development of AI should be effective. Globally, we see contrasting views, defining the consequences of AI. Hence, the balance between humans and AI, protocols and a global regulatory system needs to be established to prevent catastrophic results soon. Practical implications The benefits of AI are enormous. The rising incorporation of AI must take into consideration the basic safety fundamentals for a better future. Social implications This paper will enable readers to understand the importance of AI in the global economy, its current involvement in major industries and the subsequent need for balance in technology. Originality/value This conceptual review is by its nature and original contribution and, specifically, an interpretation for India.

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