scholarly journals HypVW is an HOCl-Sensing Two Component System in Escherichia coli

2021 ◽  
Author(s):  
Sara El Hajj ◽  
Camille Henry ◽  
Alexandra Vergnes ◽  
Laurent Loiseau ◽  
Brasseur Gael ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Hypochlorous Acid ◽  
Methionine Sulfoxide ◽  
Methionine Sulfoxide Reductase ◽  
Bacterial Cells ◽  
E Coli ◽  
Two Component ◽  
Redox Switch ◽  
Two Component Systems ◽  
Methionine Residues

Two component systems (TCS) are signalling pathways that allow bacterial cells to sense, respond and adapt to fluctuating environments. Among the classical TCS of Escherichia coli, YedVW has been recently showed to be involved in the regulation of msrPQ, encoding for the periplasmic methionine sulfoxide reductase system. In this study, we demonstrate that hypochlorous acid (HOCl) induces the expression of msrPQ in a YedVW dependant manner, whereas H2O2, NO and paraquat (a superoxide generator) do not. Therefore, YedV appears to be an HOCl-sensing histidine kinase. Based on this finding, we proposed to rename this system HypVW.  Moreover, using a directed mutagenesis approach, we show that Met residues located in the periplasmic loop of HypV (formerly YedV) are important for its activity. Given that HOCl oxidizes preferentially Met residues, we bring evidences that HypV could be activated via the reversible oxidation of its methionine residues, thus conferring to MsrPQ a role in switching HypVW off. Based on these results, we propose that the activation of HypV by HOCl could occur through a Met redox switch. HypVW appears to be the first characterized TCS able to detect HOCl in E. coli. This study represents an important step in understanding the mechanisms of reactive chlorine species resistance in prokaryotes.

HprSR is a Reactive Chlorine Species-Sensing, Two-Component System in Escherichia coli

2021 ◽  
Author(s):  
Sara El Hajj ◽  
Camille Henry ◽  
Camille Andrieu ◽  
Alexandra Vergnes ◽  
Laurent Loiseau ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Hypochlorous Acid ◽  
Methionine Sulfoxide ◽  
Methionine Sulfoxide Reductase ◽  
Repair System ◽  
Bacterial Cells ◽  
Two Component System ◽  
Component System ◽  
Two Component ◽  
Redox Switch

Two-component systems (TCS) are signalling pathways that allow bacterial cells to sense, respond and adapt to fluctuating environments. Among the classical TCS of Escherichia coli , HprSR has recently been shown to be involved in the regulation of msrPQ , which encodes the periplasmic methionine sulfoxide reductase system. In this study, we demonstrate that hypochlorous acid (HOCl) induces the expression of msrPQ in an HprSR-dependant manner, whereas H 2 O 2 , NO and paraquat (a superoxide generator) do not. Therefore, HprS appears to be an HOCl-sensing histidine kinase. Using a directed mutagenesis approach, we show that Met residues located in the periplasmic loop of HprS are important for its activity: as HOCl preferentially oxidizes Met residues, we provide evidence that HprS could be activated via the reversible oxidation of its methionine residues, meaning that MsrPQ plays a role in switching HprSR off. We propose that the activation of HprS by HOCl could occur through a Met redox switch. HprSR appears to be the first characterized TCS able to detect reactive chlorine species (RCS) in E. coli . This study represents an important step towards understanding the mechanisms of RCS resistance in prokaryotes. IMPORTANCE Understanding how bacteria respond to oxidative stress at the molecular level is crucial in the fight against pathogens. HOCl is one of the most potent industrial and physiological microbiocidal oxidants. Therefore bacteria have developed counterstrategies to survive HOCl-induced stress. Over the last decade, important insights into these bacterial protection factors have been obtained. Our work establishes HprSR as a reactive chlorine species-sensing, two-component system in Escherichia coli MG1655, which regulates the expression of MsrPQ, a repair system for HOCl-oxidized proteins. Moreover we provide evidence suggesting that HOCl could activate HprS through a methionine redox switch.

scholarly journals Elucidation of Regulatory Modes for Five Two-Component Systems in Escherichia coli Reveals Novel Relationships

mSystems ◽  
2020 ◽  
Vol 5 (6) ◽  
Author(s):  
Kumari Sonal Choudhary ◽  
Julia A. Kleinmanns ◽  
Katherine Decker ◽  
Anand V. Sastry ◽  
Ye Gao ◽  
...  
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Target Gene ◽  
Target Genes ◽  
Rna Seq ◽  
Content Type ◽  
E Coli ◽  
Component Systems ◽  
Two Component ◽  
Two Component Systems

ABSTRACT Escherichia coli uses two-component systems (TCSs) to respond to environmental signals. TCSs affect gene expression and are parts of E. coli’s global transcriptional regulatory network (TRN). Here, we identified the regulons of five TCSs in E. coli MG1655: BaeSR and CpxAR, which were stimulated by ethanol stress; KdpDE and PhoRB, induced by limiting potassium and phosphate, respectively; and ZraSR, stimulated by zinc. We analyzed RNA-seq data using independent component analysis (ICA). ChIP-exo data were used to validate condition-specific target gene binding sites. Based on these data, we do the following: (i) identify the target genes for each TCS; (ii) show how the target genes are transcribed in response to stimulus; and (iii) reveal novel relationships between TCSs, which indicate noncognate inducers for various response regulators, such as BaeR to iron starvation, CpxR to phosphate limitation, and PhoB and ZraR to cell envelope stress. Our understanding of the TRN in E. coli is thus notably expanded. IMPORTANCE E. coli is a common commensal microbe found in the human gut microenvironment; however, some strains cause diseases like diarrhea, urinary tract infections, and meningitis. E. coli’s two-component systems (TCSs) modulate target gene expression, especially related to virulence, pathogenesis, and antimicrobial peptides, in response to environmental stimuli. Thus, it is of utmost importance to understand the transcriptional regulation of TCSs to infer bacterial environmental adaptation and disease pathogenicity. Utilizing a combinatorial approach integrating RNA sequencing (RNA-seq), independent component analysis, chromatin immunoprecipitation coupled with exonuclease treatment (ChIP-exo), and data mining, we suggest five different modes of TCS transcriptional regulation. Our data further highlight noncognate inducers of TCSs, which emphasizes the cross-regulatory nature of TCSs in E. coli and suggests that TCSs may have a role beyond their cognate functionalities. In summary, these results can lead to an understanding of the metabolic capabilities of bacteria and correctly predict complex phenotype under diverse conditions, especially when further incorporated with genome-scale metabolic models.

scholarly journals Methionine Sulfoxide Reduction and Assimilation in Escherichia coli: New Role for the Biotin Sulfoxide Reductase BisC

2005 ◽  
Vol 187 (1) ◽  
pp. 231-237 ◽  
Author(s):  
Benjamin Ezraty ◽  
Julia Bos ◽  
Frédéric Barras ◽  
Laurent Aussel
Keyword(s):  
Escherichia Coli ◽  
Essential Role ◽  
Reductase Activity ◽  
Methionine Sulfoxide ◽  
Mass Spectrometric ◽  
Methionine Sulfoxide Reductase ◽  
Racemic Mixture ◽  
E Coli ◽  
Methionine Sulfoxide Reductases ◽  
Biotin Sulfoxide Reductase

ABSTRACT Methionine ranks among the amino acids most sensitive to oxidation, which converts it to a racemic mixture of methionine-S-sulfoxide (Met-S-SO) and methionine-R-sulfoxide (Met-R-SO). The methionine sulfoxide reductases MsrA and MsrB reduce free and protein-bound MetSO, MsrA being specific for Met-S-SO and MsrB for Met-R-SO. In the present study, we report that an Escherichia coli metB1 auxotroph lacking both msrA and msrB is still able to use either of the two MetSO enantiomers. This indicates that additional methionine sulfoxide reductase activities occur in E. coli. BisC, a poorly characterized biotin sulfoxide reductase, was identified as one of these new methionine sulfoxide reductases. BisC was purified and found to exhibit reductase activity with free Met-S-SO but not with free Met-R-SO as a substrate. Moreover, a metB1 msrA msrB bisC strain of E. coli was unable to use Met-S-SO for growth, but it retained the ability to use Met-R-SO. Mass spectrometric analyses indicated that BisC is unable to reduce protein-bound Met-S-SO. Hence, this study shows that BisC has an essential role in assimilation of oxidized methionines. Moreover, this work provides the first example of an enzyme that reduces free MetSO while having no activity on peptide-bound MetSO residues.

scholarly journals Elucidation of regulatory modes for five two-component systems in Escherichia coli reveals novel relationships

2020 ◽  
Author(s):  
Kumari Sonal Choudhary ◽  
Julia A. Kleinmanns ◽  
Katherine Decker ◽  
Anand V Sastry ◽  
Ye Gao ◽  
...  
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Transcriptional Regulation ◽  
Independent Component Analysis ◽  
Target Gene ◽  
Target Genes ◽  
E Coli ◽  
Component Systems ◽  
Two Component ◽  
Two Component Systems

AbstractEscherichia coli uses two-component systems (TCSs) to respond to environmental signals. TCSs affect gene expression and are parts of E. coli’s global transcriptional regulatory network (TRN). Here, we identified the regulons of five TCSs in E. coli MG1655: BaeSR and CpxAR, which were stimulated by ethanol stress; KdpDE and PhoRB, induced by limiting potassium and phosphate, respectively; and ZraSR, stimulated by zinc. We analyzed RNA-seq data using independent component analysis (ICA). ChIP-exo data was used to validate condition-specific target gene binding sites. Based on this data we (1) identify the target genes for each TCS; (2) show how the target genes are transcribed in response to stimulus; and (3) reveal novel relationships between TCSs, which indicate non-cognate inducers for various response regulators, such as BaeR to iron starvation, CpxR to phosphate limitation, and PhoB and ZraR to cell envelope stress. Our understanding of the TRN in E. coli is thus notably expanded.ImportanceE. coli is a common commensal microbe found in human gut microenvironment; however, some strains cause diseases like diarrhea, urinary tract infections and meningitis. E. coli’s two-component system (TCS) modulates target gene expression, specially related to virulence, pathogenesis and anti-microbial peptides, in response to environmental stimuli. Thus, it is of utmost importance to understand the transcriptional regulation of the TCSs to infer its environmental adaptation and disease pathogenicity. Utilizing a combinatorial approach integrating RNAseq, independent component analysis, ChIP-exo and data mining, we show that TCSs have five different modes of transcriptional regulation. Our data further highlights non-cognate inducers of TCSs emphasizing cross-regulatory nature of TCSs in E. coli and suggests that TCSs may have a role beyond their cognate functionalities. In summary, these results when further incorporated with genome scale metabolic models can lead to understanding of metabolic capabilities of bacteria and correctly predict complex phenotype under diverse conditions.

scholarly journals A bacterial "shield and sword": A previously uncharacterized two-component system protects uropathogenic Escherichia coli from host-derived oxidative insults and promotes hemolysin-mediated host cell pyroptosis

2021 ◽  
Author(s):  
Hongwei Gu ◽  
Xuwang Cai ◽  
Xinyang Zhang ◽  
Jie Luo ◽  
Xiaoyang Zhang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Virulence Factors ◽  
Bacterial Pathogen ◽  
Methionine Sulfoxide ◽  
Uropathogenic Escherichia Coli ◽  
Methionine Sulfoxide Reductase ◽  
Renal Epithelial Cell ◽  
Two Component ◽  
Tract Infections

Uropathogenic Escherichia coli (UPEC) deploys an array of virulence factors to successfully establish urinary tract infections. Coordinated expression of these various virulence factors is critical for UPEC's overall fitness in the host. Two-component signaling systems (TCSs) are a major mechanism by which bacteria sense environmental cues and initiate adaptive responses. Here, we report a previously uncharacterized TCS encoded on a pathogenicity island in UPEC that directly activates the expression of a putative methionine sulfoxide reductase system (C3566/C3567) and a pore-forming hemolysin in response to host-derived hydrogen peroxide (H2O2) exposure. The TCS increases UPEC resistance to H2O2 in vitro and survival in macrophages in tissue culture via C3566/C3567. Additionally, the TCS mediates hemolysin-induced renal epithelial cell and macrophage death via a pyroptosis pathway. Taken together, our data suggest a paradigm in which this signal transduction system coordinates both bacterial pathogen defensive and offensive traits in the presence of host-derived signals.

scholarly journals A transcriptome study of the QseEF two-component system and the QseG membrane protein in enterohaemorrhagic Escherichia coli O157 : H7

Microbiology ◽  
2010 ◽  
Vol 156 (4) ◽  
pp. 1167-1175 ◽  
Author(s):  
Nicola C. Reading ◽  
David Rasko ◽  
Alfredo G. Torres ◽  
Vanessa Sperandio
Keyword(s):  
Escherichia Coli ◽  
Membrane Protein ◽  
Response Regulator ◽  
Two Component System ◽  
E Coli ◽  
Enterohaemorrhagic Escherichia Coli ◽  
Component Systems ◽  
Two Component ◽  
Two Component Systems ◽  
Type Iii Secretion Effector

QseE is a sensor kinase that responds to epinephrine, sulfate and phosphate. QseE constitutes a two-component signalling system together with the QseF σ 54-dependent response regulator. Encoded within the same operon as qseEF is the qseG gene, which encodes a membrane protein involved in the translocation of a type III secretion effector protein of enterohaemorrhagic Escherichia coli (EHEC) into epithelial cells. The qseEGF genes also form an operon with the glnB gene, which encodes the E. coli nitrogen sensor PII protein. Here we report a transcriptome analysis comparing qseE, qseF andqseG single mutants with the wild-type strain. This study revealed that the proteins encoded by these genes play a modest but significant role in iron uptake. Although QseEFG regulate genes involved in nitrogen utilization, these proteins do not play a notable role in nitrogen metabolism. In addition, QseEFG regulate transcription of the rcsBC and phoPQ two-component systems, linking several signal transduction pathways. The similarity of the microarray profiles of these mutants also indicates that these proteins work together. These data indicate that QseEFG are involved in the regulation of virulence and metabolism in EHEC.

scholarly journals Signal Transduction Cascade between EvgA/EvgS and PhoP/PhoQ Two-Component Systems of Escherichia coli

2004 ◽  
Vol 186 (10) ◽  
pp. 3006-3014 ◽  
Author(s):  
Yoko Eguchi ◽  
Tadashi Okada ◽  
Shu Minagawa ◽  
Taku Oshima ◽  
Hirotada Mori ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Signal Transduction ◽  
Transcriptional Analysis ◽  
Two Component System ◽  
E Coli ◽  
Signal Transduction Networks ◽  
Two Component ◽  
Two Systems ◽  
Enhanced Expression ◽  
Two Component Systems

ABSTRACT Transcriptional analysis of a constitutively active mutant of the EvgA/EvgS two-component system of Escherichia coli resulted in enhanced expression of 13 PhoP/PhoQ-regulated genes, crcA, hemL, mgtA, ompT, phoP, phoQ, proP, rstA, rstB, slyB, ybjG, yrbL, and mgrB. This regulatory network between the two systems also occurred as a result of overproduction of the EvgA regulator; however, enhanced transcription of the phoPQ genes did not further activate expression of the PhoP/PhoQ-regulated genes. These results demonstrated signal transduction from the EvgA/EvgS system to the PhoP/PhoQ system in E. coli and also identified the genes that required the two systems for enhanced expression. This is one example of the intricate signal transduction networks that are posited to exist in E. coli.

One-Step Preparation of Competent E. coli: Transformation and Storage of Bacterial Cells in the Same Solution

2021 ◽  
Vol 2021 (11) ◽  
pp. pdb.prot101212 ◽  
Author(s):  
Michael R. Green ◽  
Joseph Sambrook
Keyword(s):  
Escherichia Coli ◽  
Convenient Method ◽  
Plasmid Dna ◽  
Transformation Efficiency ◽  
Bacterial Cells ◽  
E Coli ◽  
One Step ◽  
And Storage

This protocol describes a convenient method for the preparation, use, and storage of competent Escherichia coli. The reported transformation efficiency of this method is ∼5 × 107 transformants/µg of plasmid DNA.

PBP4 and PBP5 are involved in regulating exopolysaccharide synthesis during Escherichia coli biofilm formation

Microbiology ◽  
2021 ◽  
Vol 167 (3) ◽  
Author(s):  
Sathi Mallick ◽  
Shanti Kiran ◽  
Tapas Kumar Maiti ◽  
Anindya S. Ghosh
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Type Species ◽  
Pentose Phosphate ◽  
Bacterial Cells ◽  
Surface Adhesion ◽  
Content Type ◽  
Penicillin Binding Proteins ◽  
E Coli ◽  
Link Type

Escherichia coli low-molecular-mass (LMM) Penicillin-binding proteins (PBPs) help in hydrolysing the peptidoglycan fragments from their cell wall and recycling them back into the growing peptidoglycan matrix, in addition to their reported involvement in biofilm formation. Biofilms are external slime layers of extra-polymeric substances that sessile bacterial cells secrete to form a habitable niche for themselves. Here, we hypothesize the involvement of Escherichia coli LMM PBPs in regulating the nature of exopolysaccharides (EPS) prevailing in its extra-polymeric substances during biofilm formation. Therefore, this study includes the assessment of physiological characteristics of E. coli CS109 LMM PBP deletion mutants to address biofilm formation abilities, viability and surface adhesion. Finally, EPS from parent CS109 and its ΔPBP4 and ΔPBP5 mutants were purified and analysed for sugars present. Deletions of LMM PBP reduced biofilm formation, bacterial adhesion and their viability in biofilms. Deletions also diminished EPS production by ΔPBP4 and ΔPBP5 mutants, purification of which suggested an increased overall negative charge compared with their parent. Also, EPS analyses from both mutants revealed the appearance of an unusual sugar, xylose, that was absent in CS109. Accordingly, the reason for reduced biofilm formation in LMM PBP mutants may be speculated as the subsequent production of xylitol and a hindrance in the standard flow of the pentose phosphate pathway.

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