1
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Brannon JR, Reasoner SA, Bermudez TA, Comer SL, Wiebe MA, Dunigan TL, Beebout CJ, Ross T, Bamidele A, Hadjifrangiskou M. Mapping niche-specific two-component system requirements in uropathogenic Escherichia coli. Microbiol Spectr 2024; 12:e0223623. [PMID: 38385738 PMCID: PMC10986536 DOI: 10.1128/spectrum.02236-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 01/19/2024] [Indexed: 02/23/2024] Open
Abstract
Sensory systems allow pathogens to differentiate between different niches and respond to stimuli within them. A major mechanism through which bacteria sense and respond to stimuli in their surroundings is two-component systems (TCSs). TCSs allow for the detection of multiple stimuli to lead to a highly controlled and rapid change in gene expression. Here, we provide a comprehensive list of TCSs important for the pathogenesis of uropathogenic Escherichia coli (UPEC). UPEC accounts for >75% of urinary tract infections (UTIs) worldwide. UTIs are most prevalent among people assigned female at birth, with the vagina becoming colonized by UPEC in addition to the gut and the bladder. In the bladder, adherence to the urothelium triggers E. coli invasion of bladder cells and an intracellular pathogenic cascade. Intracellular E. coli are safely hidden from host neutrophils, competition from the microbiota, and antibiotics that kill extracellular E. coli. To survive in these intimately connected, yet physiologically diverse niches E. coli must rapidly coordinate metabolic and virulence systems in response to the distinct stimuli encountered in each environment. We hypothesized that specific TCSs allow UPEC to sense these diverse environments encountered during infection with built-in redundant safeguards. Here, we created a library of isogenic TCS deletion mutants that we leveraged to map distinct TCS contributions to infection. We identify-for the first time-a comprehensive panel of UPEC TCSs that are critical for infection of the genitourinary tract and report that the TCSs mediating colonization of the bladder, kidneys, or vagina are distinct.IMPORTANCEWhile two-component system (TCS) signaling has been investigated at depth in model strains of Escherichia coli, there have been no studies to elucidate-at a systems level-which TCSs are important during infection by pathogenic Escherichia coli. Here, we report the generation of a markerless TCS deletion library in a uropathogenic E. coli (UPEC) isolate that can be leveraged for dissecting the role of TCS signaling in different aspects of pathogenesis. We use this library to demonstrate, for the first time in UPEC, that niche-specific colonization is guided by distinct TCS groups.
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Affiliation(s)
- John R. Brannon
- Department of Pathology, Microbiology and Immunology, Division of Molecular Pathogenesis, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Seth A. Reasoner
- Department of Pathology, Microbiology and Immunology, Division of Molecular Pathogenesis, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Tomas A. Bermudez
- Department of Pathology, Microbiology and Immunology, Division of Molecular Pathogenesis, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Sarah L. Comer
- Department of Pathology, Microbiology and Immunology, Division of Molecular Pathogenesis, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Michelle A. Wiebe
- Department of Pathology, Microbiology and Immunology, Division of Molecular Pathogenesis, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Taryn L. Dunigan
- Department of Pathology, Microbiology and Immunology, Division of Molecular Pathogenesis, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Connor J. Beebout
- Department of Pathology, Microbiology and Immunology, Division of Molecular Pathogenesis, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Tamia Ross
- Department of Pathology, Microbiology and Immunology, Division of Molecular Pathogenesis, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Adebisi Bamidele
- Department of Pathology, Microbiology and Immunology, Division of Molecular Pathogenesis, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Maria Hadjifrangiskou
- Department of Pathology, Microbiology and Immunology, Division of Molecular Pathogenesis, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Urology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
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2
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Bermudez TA, Brannon JR, Dudipala N, Reasoner S, Morales G, Wiebe M, Cecala M, DaCosta M, Beebout C, Amir O, Hadjifrangiskou M. Raising the alarm: fosfomycin resistance associated with non-susceptible inner colonies imparts no fitness cost to the primary bacterial uropathogen. Antimicrob Agents Chemother 2024; 68:e0080323. [PMID: 38078906 PMCID: PMC10777853 DOI: 10.1128/aac.00803-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Accepted: 11/11/2023] [Indexed: 01/11/2024] Open
Abstract
IMPORTANCE While fosfomycin resistance is rare, the observation of non-susceptible subpopulations among clinical Escherichia coli isolates is a common phenomenon during antimicrobial susceptibility testing (AST) in American and European clinical labs. Previous evidence suggests that mutations eliciting this phenotype are of high biological cost to the pathogen during infection, leading to current recommendations of neglecting non-susceptible colonies during AST. Here, we report that the most common route to fosfomycin resistance, as well as novel routes described in this work, does not impair virulence in uropathogenic E. coli, the major cause of urinary tract infections, suggesting a re-evaluation of current susceptibility guidelines is warranted.
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Affiliation(s)
- Tomas A. Bermudez
- Department of Pathology, Microbiology & Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - John R. Brannon
- Department of Pathology, Microbiology & Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | | | - Seth Reasoner
- Department of Pathology, Microbiology & Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Grace Morales
- Department of Pathology, Microbiology & Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Michelle Wiebe
- Department of Pathology, Microbiology & Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Mia Cecala
- Vanderbilt University, Nashville, Tennessee, USA
| | | | - Connor Beebout
- Department of Pathology, Microbiology & Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Omar Amir
- Vanderbilt University, Nashville, Tennessee, USA
| | - Maria Hadjifrangiskou
- Department of Pathology, Microbiology & Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Urology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Institute for Infection, Immunology & Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee, USA
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3
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Arcari G, Cecilia F, Oliva A, Polani R, Raponi G, Sacco F, De Francesco A, Pugliese F, Carattoli A. Genotypic Evolution of Klebsiella pneumoniae Sequence Type 512 during Ceftazidime/Avibactam, Meropenem/Vaborbactam, and Cefiderocol Treatment, Italy. Emerg Infect Dis 2023; 29:2266-2274. [PMID: 37877547 PMCID: PMC10617348 DOI: 10.3201/eid2911.230921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2023] Open
Abstract
In February 2022, a critically ill patient colonized with a carbapenem-resistant K. pneumoniae producing KPC-3 and VIM-1 carbapenemases was hospitalized for SARS-CoV-2 in the intensive care unit of Policlinico Umberto I hospital in Rome, Italy. During 95 days of hospitalization, ceftazidime/avibactam, meropenem/vaborbactam, and cefiderocol were administered consecutively to treat 3 respiratory tract infections sustained by different bacterial agents. Those therapies altered the resistome of K. pneumoniae sequence type 512 colonizing or infecting the patient during the hospitalization period. In vivo evolution of the K. pneumoniae sequence type 512 resistome occurred through plasmid loss, outer membrane porin alteration, and a nonsense mutation in the cirA siderophore gene, resulting in high levels of cefiderocol resistance. Cross-selection can occur between K. pneumoniae and treatments prescribed for other infective agents. K. pneumoniae can stably colonize a patient, and antimicrobial-selective pressure can promote progressive K. pneumoniae resistome evolution, indicating a substantial public health threat.
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4
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Melamed S, Zhang A, Jarnik M, Mills J, Silverman A, Zhang H, Storz G. σ 28-dependent small RNA regulation of flagella biosynthesis. eLife 2023; 12:RP87151. [PMID: 37843988 PMCID: PMC10578931 DOI: 10.7554/elife.87151] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2023] Open
Abstract
Flagella are important for bacterial motility as well as for pathogenesis. Synthesis of these structures is energy intensive and, while extensive transcriptional regulation has been described, little is known about the posttranscriptional regulation. Small RNAs (sRNAs) are widespread posttranscriptional regulators, most base pairing with mRNAs to affect their stability and/or translation. Here, we describe four UTR-derived sRNAs (UhpU, MotR, FliX and FlgO) whose expression is controlled by the flagella sigma factor σ28 (fliA) in Escherichia coli. Interestingly, the four sRNAs have varied effects on flagellin protein levels, flagella number and cell motility. UhpU, corresponding to the 3´ UTR of a metabolic gene, likely has hundreds of targets including a transcriptional regulator at the top flagella regulatory cascade connecting metabolism and flagella synthesis. Unlike most sRNAs, MotR and FliX base pair within the coding sequences of target mRNAs and act on ribosomal protein mRNAs connecting ribosome production and flagella synthesis. The study shows how sRNA-mediated regulation can overlay a complex network enabling nuanced control of flagella synthesis.
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Affiliation(s)
- Sahar Melamed
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human DevelopmentBethesdaUnited States
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of JerusalemJerusalemIsrael
| | - Aixia Zhang
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human DevelopmentBethesdaUnited States
| | - Michal Jarnik
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human DevelopmentBethesdaUnited States
| | - Joshua Mills
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human DevelopmentBethesdaUnited States
| | - Aviezer Silverman
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of JerusalemJerusalemIsrael
| | - Hongen Zhang
- Bioinformatics and Scientific Computing Core, Eunice Kennedy Shriver National Institute of Child Health and Human DevelopmentBethesdaUnited States
| | - Gisela Storz
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human DevelopmentBethesdaUnited States
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5
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Brannon JR, Reasoner SA, Bermudez TA, Dunigan TL, Wiebe MA, Beebout CJ, Ross T, Bamidele A, Hadjifrangiskou M. Mapping Niche-specific Two-Component System Requirements in Uropathogenic Escherichia coli. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.23.541942. [PMID: 37292752 PMCID: PMC10245908 DOI: 10.1101/2023.05.23.541942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Sensory systems allow pathogens to differentiate between different niches and respond to stimuli within them. A major mechanism through which bacteria sense and respond to stimuli in their surroundings is two-component systems (TCSs). TCSs allow for the detection of multiple stimuli to lead to a highly controlled and rapid change in gene expression. Here, we provide a comprehensive list of TCSs important for the pathogenesis of uropathogenic Escherichia coli (UPEC). UPEC accounts for >75% of urinary tract infections (UTIs) worldwide. UTIs are most prevalent among people assigned female at birth, with the vagina becoming colonized by UPEC in addition to the gut and the bladder. In the bladder, adherence to the urothelium triggers E. coli invasion of bladder cells and an intracellular pathogenic cascade. Intracellular E. coli are safely hidden from host neutrophils, competition from the microbiota, and antibiotics that kill extracellular E. coli. To survive in these intimately connected, yet physiologically diverse niches E. coli must rapidly coordinate metabolic and virulence systems in response to the distinct stimuli encountered in each environment. We hypothesized that specific TCSs allow UPEC to sense these diverse environments encountered during infection with built-in redundant safeguards. Here, we created a library of isogenic TCS deletion mutants that we leveraged to map distinct TCS contributions to infection. We identify - for the first time - a comprehensive panel of UPEC TCSs that are critical for infection of the genitourinary tract and report that the TCSs mediating colonization of the bladder, kidneys, or vagina are distinct.
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Affiliation(s)
- John R. Brannon
- Department of Pathology, Microbiology & Immunology, Division of Molecular Pathogenesis, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Seth A. Reasoner
- Department of Pathology, Microbiology & Immunology, Division of Molecular Pathogenesis, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Tomas A. Bermudez
- Department of Pathology, Microbiology & Immunology, Division of Molecular Pathogenesis, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Taryn L. Dunigan
- Department of Pathology, Microbiology & Immunology, Division of Molecular Pathogenesis, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Michelle A. Wiebe
- Department of Pathology, Microbiology & Immunology, Division of Molecular Pathogenesis, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Connor J. Beebout
- Department of Pathology, Microbiology & Immunology, Division of Molecular Pathogenesis, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Tamia Ross
- Department of Pathology, Microbiology & Immunology, Division of Molecular Pathogenesis, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Adebisi Bamidele
- Department of Pathology, Microbiology & Immunology, Division of Molecular Pathogenesis, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Maria Hadjifrangiskou
- Department of Pathology, Microbiology & Immunology, Division of Molecular Pathogenesis, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Urology, Vanderbilt University Medical Center, Nashville, TN, USA
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6
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Spencer-Williams I, Balangoda A, Dabundo R, Elliott E, Haig SJ. Exploring the Impacts of Full-Scale Distribution System Orthophosphate Corrosion Control Implementation on the Microbial Ecology of Hydrologically Connected Urban Streams. Microbiol Spectr 2022; 10:e0215822. [PMID: 36321898 PMCID: PMC9769763 DOI: 10.1128/spectrum.02158-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 10/04/2022] [Indexed: 12/24/2022] Open
Abstract
Many cities across the nation are plagued by lead contamination in drinking water. As such, many drinking water utilities have undertaken lead service line (LSL) replacement to prevent further lead contamination. However, given the urgency of lead mitigation, and the socioeconomic challenges associated with LSL replacement, cities have used phosphate-based corrosion inhibitors (i.e., orthophosphate) alongside LSL replacement. While necessary to ensure public health protection from lead contamination, the addition of orthophosphate into an aging and leaking drinking water system may increase the concentration of phosphate leaching into urban streams characterized by century-old failing water infrastructure. Such increases in phosphate availability may cascade into nutrient and microbial community composition shifts. The purpose of this study was to determine how this occurs and to understand whether full-scale distribution system orthophosphate addition impacts the microbial ecology of urban streams. Through monthly collection of water samples from five urban streams before and after orthophosphate addition, significant changes in microbial community composition (16S rRNA amplicon sequencing) and in the relative abundance of typical freshwater taxa were observed. In addition, key microbial phosphorus and nitrogen metabolism genes (e.g., two component regulatory systems) were predicted to change via BugBase. No significant differences in the absolute abundances of total bacteria, Cyanobacteria, and "Candidatus Accumulibacter" were observed. Overall, the findings from this study provide further evidence that urban streams are compromised by unintentional hydrologic connections with drinking water infrastructure. Moreover, our results suggest that infiltration of phosphate-based corrosion inhibitors can impact urban streams and have important, as-yet-overlooked impacts on urban stream microbial communities. IMPORTANCE Elevated lead levels in drinking water supplies are a public health risk. As such, it is imperative for cities to urgently address lead contamination from aging drinking water supplies by way of lead service line replacements and corrosion control methods. However, when applying corrosion control methods, it is also important to consider the chemical and microbiological effects that can occur in natural settings, given that our water infrastructure is aging and more prone to leaks and breaks. Here, we examine the impacts on the microbial ecology of five urban stream systems before and after full-scale distribution system orthophosphate addition. Overall, the results suggest that infiltration of corrosion inhibitors may impact microbial communities; however, future work should be done to ascertain the true impact to protect both public and environmental health.
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Affiliation(s)
- Isaiah Spencer-Williams
- Department of Civil and Environmental Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Anusha Balangoda
- Department of Geology and Environmental Science, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Richard Dabundo
- Department of Geology and Environmental Science, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Emily Elliott
- Department of Geology and Environmental Science, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Sarah-Jane Haig
- Department of Civil and Environmental Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Environmental and Occupational Health, School of Public Health, University of Pittsburgh, Pennsylvania, USA
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7
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The role of sensory kinase proteins in two-component signal transduction. Biochem Soc Trans 2022; 50:1859-1873. [DOI: 10.1042/bst20220848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 11/02/2022] [Accepted: 11/08/2022] [Indexed: 11/19/2022]
Abstract
Two-component systems (TCSs) are modular signaling circuits that regulate diverse aspects of microbial physiology in response to environmental cues. These molecular circuits comprise a sensor histidine kinase (HK) protein that contains a conserved histidine residue, and an effector response regulator (RR) protein with a conserved aspartate residue. HKs play a major role in bacterial signaling, since they perceive specific stimuli, transmit the message across the cytoplasmic membrane, and catalyze their own phosphorylation, and the trans-phosphorylation and dephosphorylation of their cognate response regulator. The molecular mechanisms by which HKs co-ordinate these functions have been extensively analyzed by genetic, biochemical, and structural approaches. Here, we describe the most common modular architectures found in bacterial HKs, and address the operation mode of the individual functional domains. Finally, we discuss the use of these signaling proteins as drug targets or as sensing devices in whole-cell biosensors with medical and biotechnological applications.
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8
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G6P-capturing molecules in the periplasm of Escherichia coli accelerate the shikimate pathway. Metab Eng 2022; 72:68-81. [DOI: 10.1016/j.ymben.2022.03.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 02/17/2022] [Accepted: 03/02/2022] [Indexed: 11/21/2022]
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9
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Cattoir V, Pourbaix A, Magnan M, Chau F, de Lastours V, Felden B, Fantin B, Guérin F. Novel Chromosomal Mutations Responsible for Fosfomycin Resistance in Escherichia coli. Front Microbiol 2020; 11:575031. [PMID: 33193186 PMCID: PMC7607045 DOI: 10.3389/fmicb.2020.575031] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 09/29/2020] [Indexed: 11/13/2022] Open
Abstract
Fosfomycin resistance in Escherichia coli results from chromosomal mutations or acquisition of plasmid-mediated genes. Because these mechanisms may be absent in some resistant isolates, we aimed at decipher the genetic basis of fosfomycin resistance in E. coli. Different groups of isolates were studied: fosfomycin-resistant mutants selected in vitro from E. coli CFT073 (MIC = 1 mg/L) and two groups (wildtype and non-wildtype) of E. coli clinical isolates. Single-nucleotide allelic replacement was performed to confirm the implication of novel mutations into resistance. Induction of uhpT expression by glucose-6-phosphate (G6P) was assessed by RT-qPCR. The genome of all clinical isolates was sequenced by MiSeq (Illumina). Two first-step mutants were obtained in vitro from CFT073 (MICs, 128 mg/L) with single mutations: G469R in uhpB (M3); F384L in uhpC (M4). Second-step mutants (MICs, 256 mg/L) presented additional mutations: R282V in galU (M7 from M3); Q558∗ in lon (M8 from M4). Introduction of uhpB or uhpC mutations by site-directed mutagenesis conferred a 128-fold increase in fosfomycin MICs, whereas single mutations in galU or lon were only responsible for a 2-fold increase. Also, these mutations abolished the induction of uhpT expression by G6P. All 14 fosfomycin-susceptible clinical isolates (MICs, 0.5-8 mg/L) were devoid of any mutation. At least one genetic change was detected in all but one fosfomycin-resistant clinical isolates (MICs, 32 - >256 mg/L) including 8, 17, 18, 5, and 8 in uhpA, uhpB, uhpC, uhpT, and glpT genes, respectively. In conclusion, novel mutations in uhpB and uhpC are associated with fosfomycin resistance in E. coli clinical isolates.
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Affiliation(s)
- Vincent Cattoir
- CHU de Rennes, Service de Bactériologie-Hygiène Hospitalière, Rennes, France.,Centre National de Référence sur la Résistance aux Antibiotiques (laboratoire associé 'Entérocoques'), Rennes, France.,Inserm, Bacterial Regulatory RNAs and Medicine - UMR_S 1230, Rennes, France
| | | | - Mélanie Magnan
- IAME, UMR-1137, Inserm and Université de Paris Diderot, Paris, France
| | - Françoise Chau
- IAME, UMR-1137, Inserm and Université de Paris Diderot, Paris, France
| | - Victoire de Lastours
- IAME, UMR-1137, Inserm and Université de Paris Diderot, Paris, France.,Service de Médecine Interne, Hôpital Beaujon, Assistance Publique - Hôpitaux de Paris, Paris, France
| | - Brice Felden
- Inserm, Bacterial Regulatory RNAs and Medicine - UMR_S 1230, Rennes, France
| | - Bruno Fantin
- IAME, UMR-1137, Inserm and Université de Paris Diderot, Paris, France.,Service de Médecine Interne, Hôpital Beaujon, Assistance Publique - Hôpitaux de Paris, Paris, France
| | - François Guérin
- CHU de Caen, Service de Microbiologie, Caen, France.,Université de Caen Normandie, EA4655, Caen, France
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10
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Interface switch mediates signal transmission in a two-component system. Proc Natl Acad Sci U S A 2020; 117:30433-30440. [PMID: 33199635 DOI: 10.1073/pnas.1912080117] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Two-component systems (TCS), which typically consist of a membrane-embedded histidine kinase and a cytoplasmic response regulator, are the dominant signaling proteins for transduction of environmental stimuli into cellular response pathways in prokaryotic cells. HptRSA is a recently identified TCS consisting of the G6P-associated sensor protein (HptA), transmembrane histidine kinase (HptS), and cytoplasmic effector (HptR). HptRSA mediates glucose-6-phosphate (G6P) uptake to support Staphylococcus aureus growth and multiplication within various host cells. How the mechanism by which HptRSA perceives G6P and triggers a downstream response has remained elusive. Here, we solved the HptA structures in apo and G6P-bound states. G6P binding in the cleft between two HptA domains caused a conformational closing movement. The solved structures of HptA in complex with the periplasmic domain of HptS showed that HptA interacts with HptS through both constitutive and switchable interfaces. The G6P-free form of HptA binds to the membrane-distal side of the HptS periplasmic domain (HptSp), resulting in a parallel conformation of the HptSp protomer pair. However, once HptA associates with G6P, its intramolecular domain closure switches the HptA-HptSp contact region into the membrane-proximal domain, which causes rotation and closure of the C termini of each HptSp protomer. Through biochemical and growth assays of HptA and HptS mutant variants, we proposed a distinct mechanism of interface switch-mediated signaling transduction. Our results provide mechanistic insights into bacterial nutrient sensing and expand our understanding of the activation modes by which TCS communicates external signals.
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11
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Landry BP, Palanki R, Dyulgyarov N, Hartsough LA, Tabor JJ. Phosphatase activity tunes two-component system sensor detection threshold. Nat Commun 2018; 9:1433. [PMID: 29650958 PMCID: PMC5897336 DOI: 10.1038/s41467-018-03929-y] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 03/22/2018] [Indexed: 12/22/2022] Open
Abstract
Two-component systems (TCSs) are the largest family of multi-step signal transduction pathways in biology, and a major source of sensors for biotechnology. However, the input concentrations to which biosensors respond are often mismatched with application requirements. Here, we utilize a mathematical model to show that TCS detection thresholds increase with the phosphatase activity of the sensor histidine kinase. We experimentally validate this result in engineered Bacillus subtilis nitrate and E. coli aspartate TCS sensors by tuning their detection threshold up to two orders of magnitude. We go on to apply our TCS tuning method to recently described tetrathionate and thiosulfate sensors by mutating a widely conserved residue previously shown to impact phosphatase activity. Finally, we apply TCS tuning to engineer B. subtilis to sense and report a wide range of fertilizer concentrations in soil. This work will enable the engineering of tailor-made biosensors for diverse synthetic biology applications. Two-component systems are a major family of signal transduction pathways and a rich source of sensors for biotechnology. Here, the authors develop a general method for rationally tuning two-component system input detection thresholds via specific point mutations in sensor histidine kinase proteins.
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Affiliation(s)
- Brian P Landry
- Department of Bioengineering, Rice University, 6100 Main St., Houston, 77005, TX, USA
| | - Rohan Palanki
- Department of Bioengineering, Rice University, 6100 Main St., Houston, 77005, TX, USA
| | - Nikola Dyulgyarov
- Department of Bioengineering, Rice University, 6100 Main St., Houston, 77005, TX, USA
| | - Lucas A Hartsough
- Department of Bioengineering, Rice University, 6100 Main St., Houston, 77005, TX, USA
| | - Jeffrey J Tabor
- Department of Bioengineering, Rice University, 6100 Main St., Houston, 77005, TX, USA. .,Department of Biosciences, Rice University, 6100 Main St., Houston, 77005, TX, USA.
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12
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Metabolic Adaptations of Intracellullar Bacterial Pathogens and their Mammalian Host Cells during Infection ("Pathometabolism"). Microbiol Spectr 2016; 3. [PMID: 26185075 DOI: 10.1128/microbiolspec.mbp-0002-2014] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Several bacterial pathogens that cause severe infections in warm-blooded animals, including humans, have the potential to actively invade host cells and to efficiently replicate either in the cytosol or in specialized vacuoles of the mammalian cells. The interaction between these intracellular bacterial pathogens and the host cells always leads to multiple physiological changes in both interacting partners, including complex metabolic adaptation reactions aimed to promote proliferation of the pathogen within different compartments of the host cells. In this chapter, we discuss the necessary nutrients and metabolic pathways used by some selected cytosolic and vacuolar intracellular pathogens and--when available--the links between the intracellular bacterial metabolism and the expression of the virulence genes required for the intracellular bacterial replication cycle. Furthermore, we address the growing evidence that pathogen-specific factors may also trigger metabolic responses of the infected mammalian cells affecting the carbon and nitrogen metabolism as well as defense reactions. We also point out that many studies on the metabolic host cell responses induced by the pathogens have to be scrutinized due to the use of established cell lines as model host cells, as these cells are (in the majority) cancer cells that exhibit a dysregulated primary carbon metabolism. As the exact knowledge of the metabolic host cell responses may also provide new concepts for antibacterial therapies, there is undoubtedly an urgent need for host cell models that more closely reflect the in vivo infection conditions.
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13
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Characterization of a novel two-component regulatory system, HptRS, the regulator for the hexose phosphate transport system in Staphylococcus aureus. Infect Immun 2015; 83:1620-8. [PMID: 25644013 DOI: 10.1128/iai.03109-14] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Hexose phosphate is an important carbon source within the cytoplasm of host cells. Bacterial pathogens that invade, survive, and multiply within various host epithelial cells exploit hexose phosphates from the host cytoplasm through the hexose phosphate transport (HPT) system to gain energy and synthesize cellular components. In Escherichia coli, the HPT system consists of a two-component regulatory system (UhpAB) and a phosphate sensor protein (UhpC) that tightly regulate expression of a hexose phosphate transporter (UhpT). Although growing evidence suggests that Staphylococcus aureus also can invade, survive, and multiply within various host epithelial cells, the genetic elements involved in the HPT system in S. aureus have not been characterized yet. In this study, we identified and characterized the HPT system in S. aureus that includes the hptRS (a novel two-component regulatory system), the hptA (a putative phosphate sensor), and the uhpT (a hexose phosphate transporter) genes. The hptA, hptRS, and uhpT markerless deletion mutants were generated by an allelic replacement method using a modified pMAD-CM-GFPuv vector system. We demonstrated that both hptA and hptRS are required to positively regulate transcription of uhpT in response to extracellular phosphates, such as glycerol-3-phosphate (G3P), glucose-6-phosphate (G6P), and fosfomycin. Mutational studies revealed that disruption of the hptA, hptRS, or uhpT gene impaired the growth of bacteria when the available carbon source was limited to G6P, impaired survival/multiplication within various types of host cells, and increased resistance to fosfomycin. The results of this study suggest that the HPT system plays an important role in adaptation of S. aureus within the host cells and could be an important target for developing novel antistaphylococcal therapies.
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Abstract
Beyond fuelling cellular activities with building blocks and energy, metabolism also integrates environmental conditions into intracellular signals. The underlying regulatory network is complex and multifaceted: it ranges from slow interactions, such as changing gene expression, to rapid ones, such as the modulation of protein activity via post-translational modification or the allosteric binding of small molecules. In this Review, we outline the coordination of common metabolic tasks, including nutrient uptake, central metabolism, the generation of energy, the supply of amino acids and protein synthesis. Increasingly, a set of key metabolites is recognized to control individual regulatory circuits, which carry out specific functions of information input and regulatory output. Such a modular view of microbial metabolism facilitates an intuitive understanding of the molecular mechanisms that underlie cellular decision making.
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Carbon metabolism of enterobacterial human pathogens growing in epithelial colorectal adenocarcinoma (Caco-2) cells. PLoS One 2010; 5:e10586. [PMID: 20485672 PMCID: PMC2868055 DOI: 10.1371/journal.pone.0010586] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2010] [Accepted: 04/02/2010] [Indexed: 11/19/2022] Open
Abstract
Analysis of the genome sequences of the major human bacterial pathogens has provided a large amount of information concerning their metabolic potential. However, our knowledge of the actual metabolic pathways and metabolite fluxes occurring in these pathogens under infection conditions is still limited. In this study, we analysed the intracellular carbon metabolism of enteroinvasive Escherichia coli (EIEC HN280 and EIEC 4608-58) and Salmonella enterica Serovar Typhimurium (Stm 14028) replicating in epithelial colorectal adenocarcinoma cells (Caco-2). To this aim, we supplied [U-13C6]glucose to Caco-2 cells infected with the bacterial strains or mutants thereof impaired in the uptake of glucose, mannose and/or glucose 6-phosphate. The 13C-isotopologue patterns of protein-derived amino acids from the bacteria and the host cells were then determined by mass spectrometry. The data showed that EIEC HN280 growing in the cytosol of the host cells, as well as Stm 14028 replicating in the Salmonella-containing vacuole (SCV) utilised glucose, but not glucose 6-phosphate, other phosphorylated carbohydrates, gluconate or fatty acids as major carbon substrates. EIEC 4608-58 used C3-compound(s) in addition to glucose as carbon source. The labelling patterns reflected strain-dependent carbon flux via glycolysis and/or the Entner-Doudoroff pathway, the pentose phosphate pathway, the TCA cycle and anapleurotic reactions between PEP and oxaloacetate. Mutants of all three strains impaired in the uptake of glucose switched to C3-substrate(s) accompanied by an increased uptake of amino acids (and possibly also other anabolic monomers) from the host cell. Surprisingly, the metabolism of the host cells, as judged by the efficiency of 13C-incorporation into host cell amino acids, was not significantly affected by the infection with either of these intracellular pathogens.
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Ninfa AJ. Use of two-component signal transduction systems in the construction of synthetic genetic networks. Curr Opin Microbiol 2010; 13:240-5. [PMID: 20149718 DOI: 10.1016/j.mib.2010.01.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2009] [Revised: 01/04/2010] [Accepted: 01/08/2010] [Indexed: 10/19/2022]
Abstract
Two-component signal transduction systems are a common type of signaling system in prokaryotes; the typical cell has dozens of systems regulating aspects of physiology and controlling responses to environmental conditions. In this review, I consider how these systems may be useful for engineering novel cell functions. Examples of successful incorporation of two-component systems into engineered systems are noted, and features of the systems that favor or hinder potential future use of these signaling systems for synthetic biology applications are discussed. The focus will be on the engineering of novel couplings of sensory functions to signaling outputs. Recent successes in this area are noted, such as the development of light-sensitive transmitter proteins and chemotactic receptors responsive to nitrate.
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Affiliation(s)
- Alexander J Ninfa
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI 48109-0606, USA.
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Buelow DR, Raivio TL. Three (and more) component regulatory systems - auxiliary regulators of bacterial histidine kinases. Mol Microbiol 2009; 75:547-66. [PMID: 19943903 DOI: 10.1111/j.1365-2958.2009.06982.x] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Two-component signal transduction (TCST) is the most prevalent mechanism employed by microbes to sense and respond to environmental changes. It is characterized by the signal-induced transfer of phosphate from a sensor histidine kinase (HK) to a response regulator (RR), resulting in a cellular response. An emerging theme in the field of TCST signalling is the discovery of auxiliary factors, distinct from the HK and RR, which are capable of influencing phosphotransfer. One group of TCST auxiliary proteins accomplishes this task by acting on HKs. Auxiliary regulators of HKs are widespread and have been identified in all cellular compartments, where they can influence HK activity through interactions with the sensing, transmembrane or enzymatic domains of the HK. The effects of an auxiliary regulator are controlled by its regulated expression, modification and/or through ligand binding. Ultimately, auxiliary regulators can connect a given TCST system to other regulatory networks in the cell or result in regulation of the TCST system in response to an expanded range of stimuli. The studies highlighted in this review draw attention to an emerging view of bacterial TCST systems as core signalling units upon which auxiliary factors act.
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Affiliation(s)
- Daelynn R Buelow
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E9
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Sheng X, Huang X, Li J, Xie X, Xu S, Zhang H, Xu H. Regulation of Sulfur Assimilation Pathways in Salmonella enterica Serovar Typhi Upon Up-Shift High Osmotic Treatment: The Role of UhpA Revealed Through Transcriptome Profiling. Curr Microbiol 2009; 59:628-35. [DOI: 10.1007/s00284-009-9487-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2009] [Revised: 08/03/2009] [Accepted: 08/06/2009] [Indexed: 10/20/2022]
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Autophosphorylation and dephosphorylation by soluble forms of the nitrate-responsive sensors NarX and NarQ from Escherichia coli K-12. J Bacteriol 2008; 190:3869-76. [PMID: 18375557 DOI: 10.1128/jb.00092-08] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
NarX-NarL and NarQ-NarP are paralogous two-component regulatory systems that control Escherichia coli gene expression in response to the respiratory oxidants nitrate and nitrite. Nitrate stimulates the autophosphorylation rates of the NarX and NarQ sensors, which then phosphorylate the response regulators NarL and NarP to activate and repress target operon transcription. Here, we investigated both the autophosphorylation and dephosphorylation of soluble sensors in which the maltose binding protein (MBP) has replaced the amino-terminal transmembrane sensory domain. The apparent affinities (K(m)) for ADP were similar for both proteins, about 2 microM, whereas the affinity of MBP-NarQ for ATP was lower, about 23 microM. At a saturating concentration of ATP, the rate constant of MBP-NarX autophosphorylation (about 0.5 x 10(-4) s(-1)) was lower than that observed for MBP-NarQ (about 2.2 x 10(-4) s(-1)). At a saturating concentration of ADP, the rate constant of dephosphorylation was higher than that of autophosphorylation, about 0.03 s(-1) for MBP-NarX and about 0.01 s(-1) for MBP-NarQ. For other studied sensors, the published affinities for ADP range from about 16 microM (KinA) to about 40 microM (NtrB). This suggests that only a small proportion of NarX and NarQ remain phosphorylated in the absence of nitrate, resulting in efficient response regulator dephosphorylation by the remaining unphosphorylated sensors.
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Comparative analysis of the Photorhabdus luminescens and the Yersinia enterocolitica genomes: uncovering candidate genes involved in insect pathogenicity. BMC Genomics 2008; 9:40. [PMID: 18221513 PMCID: PMC2266911 DOI: 10.1186/1471-2164-9-40] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2007] [Accepted: 01/25/2008] [Indexed: 11/24/2022] Open
Abstract
Background Photorhabdus luminescens and Yersinia enterocolitica are both enteric bacteria which are associated with insects. P. luminescens lives in symbiosis with soil nematodes and is highly pathogenic towards insects but not to humans. In contrast, Y. enterocolitica is widely found in the environment and mainly known to cause gastroenteritis in men, but has only recently been shown to be also toxic for insects. It is expected that both pathogens share an overlap of genetic determinants that play a role within the insect host. Results A selective genome comparison was applied. Proteins belonging to the class of two-component regulatory systems, quorum sensing, universal stress proteins, and c-di-GMP signalling have been analysed. The interorganismic synopsis of selected regulatory systems uncovered common and distinct signalling mechanisms of both pathogens used for perception of signals within the insect host. Particularly, a new class of LuxR-like regulators was identified, which might be involved in detecting insect-specific molecules. In addition, the genetic overlap unravelled a two-component system that is unique for the genera Photorhabdus and Yersinia and is therefore suggested to play a major role in the pathogen-insect relationship. Our analysis also highlights factors of both pathogens that are expressed at low temperatures as encountered in insects in contrast to higher (body) temperature, providing evidence that temperature is a yet under-investigated environmental signal for bacterial adaptation to various hosts. Common degradative metabolic pathways are described that might be used to explore nutrients within the insect gut or hemolymph, thus enabling the proliferation of P. luminescens and Y. enterocolitica in their invertebrate hosts. A strikingly higher number of genes encoding insecticidal toxins and other virulence factors in P. luminescens compared to Y. enterocolitica correlates with the higher virulence of P. luminescens towards insects, and suggests a putative broader insect host spectrum of this pathogen. Conclusion A set of factors shared by the two pathogens was identified including those that are involved in the host infection process, in persistence within the insect, or in host exploitation. Some of them might have been selected during the association with insects and then adapted to pathogenesis in mammalian hosts.
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Shulami S, Zaide G, Zolotnitsky G, Langut Y, Feld G, Sonenshein AL, Shoham Y. A two-component system regulates the expression of an ABC transporter for xylo-oligosaccharides in Geobacillus stearothermophilus. Appl Environ Microbiol 2006; 73:874-84. [PMID: 17142383 PMCID: PMC1800775 DOI: 10.1128/aem.02367-06] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Geobacillus stearothermophilus T-6 utilizes an extensive and highly regulated hemicellulolytic system. The genes comprising the xylanolytic system are clustered in a 39.7-kb chromosomal segment. This segment contains a 6-kb transcriptional unit (xynDCEFG) coding for a potential two-component system (xynDC) and an ATP-binding cassette (ABC) transport system (xynEFG). The xynD promoter region contains a 16-bp inverted repeat resembling the operator site for the xylose repressor, XylR. XylR was found to bind specifically to this sequence, and binding was efficiently prevented in vitro in the presence of xylose. The ABC transport system was shown to comprise an operon of three genes (xynEFG) that is transcribed from its own promoter. The nonphosphorylated fused response regulator, His6-XynC, bound to a 220-bp fragment corresponding to the xynE operator. DNase I footprinting analysis showed four protected zones that cover the -53 and the +34 regions and revealed direct repeat sequences of a GAAA-like motif. In vitro transcriptional assays and quantitative reverse transcription-PCR demonstrated that xynE transcription is activated 140-fold in the presence of 1.5 microM XynC. The His6-tagged sugar-binding lipoprotein (XynE) of the ABC transporter interacted with different xylosaccharides, as demonstrated by isothermal titration calorimetry. The change in the heat capacity of binding (DeltaCp) for XynE with xylotriose suggests a stacking interaction in the binding site that can be provided by a single Trp residue and a sugar moiety. Taken together, our data show that XynEFG constitutes an ABC transport system for xylo-oligosaccharides and that its transcription is negatively regulated by XylR and activated by the response regulator XynC, which is part of a two-component sensing system.
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Affiliation(s)
- Smadar Shulami
- Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel
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Bekker M, Teixeira De Mattos MJ, Hellingwerf KJ. The role of two-component regulation systems in the physiology of the bacterial cell. Sci Prog 2006; 89:213-42. [PMID: 17338439 PMCID: PMC10368358 DOI: 10.3184/003685006783238308] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Two-component regulation systems (TCRSs) are the dominant type of signal transduction system in prokaryotes that are used to inform the cellular trancriptional machinery (and additional targets for regulation, like the motility apparatus) about actual changes in the extracellular physicochemical conditions. We now review their molecular structure and enzymatic characteristics, their mutual interactions and its implications, and their role in cellular physiology. Specific emphasis is placed on the ArcB/A system, a representative of the phosphorelay type of TCRS, and a key player in the adjustment of the cellular make-up of enterobacteria in response to alterations in the oxygen availability. Also some applied aspects of the TCRSs are discussed, i.e. their role as a target to develop new anti-bacterials and their application in biotechnology (or: 'synthetic biology').
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Affiliation(s)
| | | | - Klaas J. Hellingwerf
- Laboratory for Microbiology, Swammerdam Institute for Life Sciences, Nieuwe Achtergracht 166, 1018 WV Amsterdam, The Netherlands
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Verhamme DT, Postma PW, Crielaard W, Hellingwerf KJ. Cooperativity in signal transfer through the Uhp system of Escherichia coli. J Bacteriol 2002; 184:4205-10. [PMID: 12107138 PMCID: PMC135205 DOI: 10.1128/jb.184.15.4205-4210.2002] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The UhpABC regulatory system in enterobacteria controls the expression of the hexose phosphate transporter UhpT. Signaling is initiated through sensing of extracellular glucose 6-phosphate by membrane-bound UhpC, which in turn modulates the histidine-protein kinase UhpB. Together with the cytoplasmic response regulator UhpA, they constitute a typical two-component regulatory system based on His-to-Asp phosphoryl transfer. Activated (i.e., phosphorylated) UhpA binds to the promoter region of uhpT, resulting in initiation of transcription. We have investigated the contribution of transmembrane signaling (through UhpBC) and intracellular activation (through UhpA) to the overall Uhp response (UhpT expression) in vivo. UhpA activation could be made independent of transmembrane signaling when (Delta)uhpBC cells were grown on pyruvate. Inorganic phosphate interfered with glucose 6-phosphate-dependent, UhpBC-mediated, as well as pyruvate-mediated activation of UhpA. The relationship between the concentration of inducer (glucose 6-phosphate) and the Uhp induction rate was nonhyperbolic, indicating positive cooperativity. The degree of cooperativity was affected by the carbon or energy source available to the cells for growth. As pyruvate-mediated activation of UhpA in (Delta)uhpBC cells could result in considerably stronger UhpT expression than glucose 6-phosphate-dependent activation through UhpBC, the observed positive cooperativity for the overall pathway in wild-type cells may reflect the previously described cooperative binding of UhpA to the uhpT promoter (J. L. Dahl et al., J. Biol. Chem. 272:1910-1919, 1997).
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Affiliation(s)
- Daniël T Verhamme
- Swammerdam Institute for Life Sciences, BioCentrum Amsterdam, Faculty of Science, University of Amsterdam, Amsterdam, The Netherlands
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Verhamme DT, Arents JC, Postma PW, Crielaard W, Hellingwerf KJ. Investigation of in vivo cross-talk between key two-component systems of Escherichia coli. MICROBIOLOGY (READING, ENGLAND) 2002; 148:69-78. [PMID: 11782500 DOI: 10.1099/00221287-148-1-69] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Intracellular signal transfer in bacteria is dominated by phosphoryl transfer between conserved transmitter and receiver domains in regulatory proteins of so-called two-component systems. Escherichia coli contains 30 such systems, which allow it to modulate gene expression, enzyme activity and the direction of flagellar rotation. The authors have investigated whether, and to what extent, these separate systems form (an) interacting network(s) in vivo, focussing on interactions between four major systems, involved in the responses to the availability of phosphorylated sugars (Uhp), phosphate (Pho), nitrogen (Ntr) and oxygen (Arc). Significant cross-talk was not detectable in wild-type cells. Decreasing expression levels of succinate dehydrogenase (reporting Arc activation), upon activation of the Pho system, appeared to be independent of signalling through PhoR. Cross-talk towards NtrC did occur, however, in a ntrB deletion strain, upon joint activation of Pho, Ntr and Uhp. UhpT expression was demonstrated when cells were grown on pyruvate, through non-cognate phosphorylation of UhpA by acetyl phosphate.
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Affiliation(s)
- Daniël T Verhamme
- Swammerdam Institute for Life Sciences, University of Amsterdam, Nieuwe Achtergracht 166, 1018 WV Amsterdam, The Netherlands1
| | - Jos C Arents
- Swammerdam Institute for Life Sciences, University of Amsterdam, Nieuwe Achtergracht 166, 1018 WV Amsterdam, The Netherlands1
| | - Pieter W Postma
- Swammerdam Institute for Life Sciences, University of Amsterdam, Nieuwe Achtergracht 166, 1018 WV Amsterdam, The Netherlands1
| | - Wim Crielaard
- Swammerdam Institute for Life Sciences, University of Amsterdam, Nieuwe Achtergracht 166, 1018 WV Amsterdam, The Netherlands1
| | - Klaas J Hellingwerf
- Swammerdam Institute for Life Sciences, University of Amsterdam, Nieuwe Achtergracht 166, 1018 WV Amsterdam, The Netherlands1
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