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Zhang Q, Alter T, Fleischmann S. Non-O1/Non-O139 Vibrio cholerae-An Underestimated Foodborne Pathogen? An Overview of Its Virulence Genes and Regulatory Systems Involved in Pathogenesis. Microorganisms 2024; 12:818. [PMID: 38674762 PMCID: PMC11052320 DOI: 10.3390/microorganisms12040818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 04/05/2024] [Accepted: 04/15/2024] [Indexed: 04/28/2024] Open
Abstract
In recent years, the number of foodborne infections with non-O1 and non-O139 Vibrio cholerae (NOVC) has increased worldwide. These have ranged from sporadic infection cases to localized outbreaks. The majority of case reports describe self-limiting gastroenteritis. However, severe gastroenteritis and even cholera-like symptoms have also been described. All reported diarrheal cases can be traced back to the consumption of contaminated seafood. As climate change alters the habitats and distribution patterns of aquatic bacteria, there is a possibility that the number of infections and outbreaks caused by Vibrio spp. will further increase, especially in countries where raw or undercooked seafood is consumed or clean drinking water is lacking. Against this background, this review article focuses on a possible infection pathway and how NOVC can survive in the human host after oral ingestion, colonize intestinal epithelial cells, express virulence factors causing diarrhea, and is excreted by the human host to return to the environment.
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Affiliation(s)
| | | | - Susanne Fleischmann
- Institute of Food Safety and Food Hygiene, School of Veterinary Medicine, Freie Universität Berlin, Königsweg 69, 14163 Berlin, Germany; (Q.Z.); (T.A.)
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2
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Tian Z, Xiang F, Peng K, Qin Z, Feng Y, Huang B, Ouyang P, Huang X, Chen D, Lai W, Geng Y. The cAMP Receptor Protein (CRP) of Vibrio mimicus Regulates Its Bacterial Growth, Type II Secretion System, Flagellum Formation, Adhesion Genes, and Virulence. Animals (Basel) 2024; 14:437. [PMID: 38338079 PMCID: PMC10854923 DOI: 10.3390/ani14030437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 01/12/2024] [Accepted: 01/22/2024] [Indexed: 02/12/2024] Open
Abstract
Vibrio mimicus is a serious pathogen in aquatic animals, resulting in significant economic losses. The cAMP receptor protein (CRP) often acts as a central regulator in highly pathogenic pathogens. V. mimicus SCCF01 is a highly pathogenic strain isolated from yellow catfish; the crp gene deletion strain (Δcrp) was constructed by natural transformation to determine whether this deletion affects the virulence phenotypes. Their potential molecular connections were revealed by qRT-PCR analysis. Our results showed that the absence of the crp gene resulted in bacterial and colony morphological changes alongside decreases in bacterial growth, hemolytic activity, biofilm formation, enzymatic activity, motility, and cell adhesion. A cell cytotoxicity assay and animal experiments confirmed that crp contributes to V. mimicus pathogenicity, as the LD50 of the Δcrp strain was 73.1-fold lower compared to the WT strain. Moreover, qRT-PCR analysis revealed the inhibition of type II secretion system genes, flagellum genes, adhesion genes, and metalloproteinase genes in the deletion strain. This resulted in the virulence phenotype differences described above. Together, these data demonstrate that the crp gene plays a core regulatory role in V. mimicus virulence and pathogenicity.
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Affiliation(s)
- Ziqi Tian
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; (Z.T.); (F.X.); (K.P.); (Z.Q.); (Y.F.); (B.H.); (P.O.); (W.L.)
| | - Fei Xiang
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; (Z.T.); (F.X.); (K.P.); (Z.Q.); (Y.F.); (B.H.); (P.O.); (W.L.)
- Agricultural and Rural Bureau of Zhongjiang County, Deyang 618100, China
| | - Kun Peng
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; (Z.T.); (F.X.); (K.P.); (Z.Q.); (Y.F.); (B.H.); (P.O.); (W.L.)
| | - Zhenyang Qin
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; (Z.T.); (F.X.); (K.P.); (Z.Q.); (Y.F.); (B.H.); (P.O.); (W.L.)
| | - Yang Feng
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; (Z.T.); (F.X.); (K.P.); (Z.Q.); (Y.F.); (B.H.); (P.O.); (W.L.)
| | - Bowen Huang
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; (Z.T.); (F.X.); (K.P.); (Z.Q.); (Y.F.); (B.H.); (P.O.); (W.L.)
| | - Ping Ouyang
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; (Z.T.); (F.X.); (K.P.); (Z.Q.); (Y.F.); (B.H.); (P.O.); (W.L.)
| | - Xiaoli Huang
- Department of Aquaculture, Sichuan Agricultural University, Chengdu 611130, China; (X.H.); (D.C.)
| | - Defang Chen
- Department of Aquaculture, Sichuan Agricultural University, Chengdu 611130, China; (X.H.); (D.C.)
| | - Weimin Lai
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; (Z.T.); (F.X.); (K.P.); (Z.Q.); (Y.F.); (B.H.); (P.O.); (W.L.)
| | - Yi Geng
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China; (Z.T.); (F.X.); (K.P.); (Z.Q.); (Y.F.); (B.H.); (P.O.); (W.L.)
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3
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Flores E, Dutta S, Bosserman R, van Hoof A, Krachler AM. Colonization of larval zebrafish ( Danio rerio) with adherent-invasive Escherichia coli prevents recovery of the intestinal mucosa from drug-induced enterocolitis. mSphere 2023; 8:e0051223. [PMID: 37971273 PMCID: PMC10732064 DOI: 10.1128/msphere.00512-23] [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: 09/05/2023] [Accepted: 10/07/2023] [Indexed: 11/19/2023] Open
Abstract
IMPORTANCE Although inflammatory bowel diseases are on the rise, what factors influence IBD risk and severity, and the underlying mechanisms remain to be fully understood. Although host genetics, microbiome, and environmental factors have all been shown to correlate with the development of IBD, cause and effect are difficult to disentangle in this context. For example, AIEC is a known pathobiont found in IBD patients, but it remains unclear if gut inflammation during IBD facilitates colonization with AIEC, or if AIEC colonization makes the host more susceptible to pro-inflammatory stimuli. It is critical to understand the mechanisms that contribute to AIEC infections in a susceptible host in order to develop successful therapeutics. Here, we show that the larval zebrafish model recapitulates key features of AIEC infections in other animal models and can be utilized to address these gaps in knowledge.
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Affiliation(s)
- Erika Flores
- Microbiology and Infectious Diseases Program, MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, University of Texas, Houston, Texas, USA
- Department of Microbiology and Molecular Genetics, The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Soumita Dutta
- Department of Microbiology and Molecular Genetics, The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Rachel Bosserman
- Department of Microbiology and Molecular Genetics, The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Ambro van Hoof
- Microbiology and Infectious Diseases Program, MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, University of Texas, Houston, Texas, USA
- Department of Microbiology and Molecular Genetics, The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Anne-Marie Krachler
- Microbiology and Infectious Diseases Program, MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, University of Texas, Houston, Texas, USA
- Department of Microbiology and Molecular Genetics, The University of Texas Health Science Center at Houston, Houston, Texas, USA
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4
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Schnoor SB, Neubauer P, Gimpel M. Recent insights into the world of dual-function bacterial sRNAs. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023:e1824. [PMID: 38039556 DOI: 10.1002/wrna.1824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 10/20/2023] [Accepted: 10/23/2023] [Indexed: 12/03/2023]
Abstract
Dual-function sRNAs refer to a small subgroup of small regulatory RNAs that merges base-pairing properties of antisense RNAs with peptide-encoding properties of mRNA. Both functions can be part of either same or in another metabolic pathway. Here, we want to update the knowledge of to the already known dual-function sRNAs and review the six new sRNAs found since 2017 regarding their structure, functional mechanisms, evolutionary conservation, and role in the regulation of distinct biological/physiological processes. The increasing identification of dual-function sRNAs through bioinformatics approaches, RNomics and RNA-sequencing and the associated increase in regulatory understanding will likely continue to increase at the same rate in the future. This may improve our understanding of the physiology, virulence and resistance of bacteria, as well as enable their use in technical applications. This article is categorized under: Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs.
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Affiliation(s)
| | - Peter Neubauer
- Department of Bioprocess Engineering, Technische Universitat Berlin, Berlin, Germany
| | - Matthias Gimpel
- Department of Bioprocess Engineering, Technische Universitat Berlin, Berlin, Germany
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5
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Wang K, Lu H, Zou M, Wang G, Zhao J, Huang X, Ren F, Hu H, Huang J, Min X. DegS protease regulates antioxidant capacity and adaptability to oxidative stress environment in Vibrio cholerae. Front Cell Infect Microbiol 2023; 13:1290508. [PMID: 38053530 PMCID: PMC10694293 DOI: 10.3389/fcimb.2023.1290508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 11/06/2023] [Indexed: 12/07/2023] Open
Abstract
Adaptation to oxidative stress is critical for survival of Vibrio cholerae in aquatic ecosystems and hosts. DegS activates the σE envelope stress response. We have previously revealed that DegS may be involved in regulating the oxidative stress response. In this study, we demonstrated that deletion of the degS gene attenuates the antioxidant capacity of V. cholerae. In addition, our results further revealed that the regulation of antioxidant capacity by DegS in V. cholerae could involve the cAMP-CRP complex, which regulates rpoS. XthA is an exonuclease that repairs oxidatively damaged cells and affects the bacterial antioxidant capacity. qRT-PCR showed that DegS, σE, cAMP, CRP, and RpoS positively regulate xthA gene transcription. XthA overexpression partially compensates for antioxidant deficiency in the degS mutant. These results suggest that DegS affects the antioxidant capacity of V.cholerae by regulating xthA expression via the cAMP-CRP-RpoS pathway. In a mouse intestinal colonization experiment, our data showed that V.cholerae degS, rpoE, and rpoS gene deletions were associated with significantly reduced resistance to oxidative stress and the ability to colonize the mouse intestine. In conclusion, these findings provide new insights into the regulation of antioxidant activity by V.cholerae DegS.
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Affiliation(s)
- Kaiying Wang
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China
- School of Laboratory Medicine, Zunyi Medical University, Zunyi, Guizhou, China
| | - Huifang Lu
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China
- School of Laboratory Medicine, Zunyi Medical University, Zunyi, Guizhou, China
| | - Mei Zou
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China
- School of Laboratory Medicine, Zunyi Medical University, Zunyi, Guizhou, China
| | - Guangli Wang
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China
- School of Laboratory Medicine, Zunyi Medical University, Zunyi, Guizhou, China
| | - Jiajun Zhao
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China
- School of Laboratory Medicine, Zunyi Medical University, Zunyi, Guizhou, China
| | - Xiaoyu Huang
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China
- School of Laboratory Medicine, Zunyi Medical University, Zunyi, Guizhou, China
| | - Fangyu Ren
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China
- School of Laboratory Medicine, Zunyi Medical University, Zunyi, Guizhou, China
| | - Huaqin Hu
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China
- School of Laboratory Medicine, Zunyi Medical University, Zunyi, Guizhou, China
| | - Jian Huang
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China
- School of Laboratory Medicine, Zunyi Medical University, Zunyi, Guizhou, China
| | - Xun Min
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China
- School of Laboratory Medicine, Zunyi Medical University, Zunyi, Guizhou, China
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6
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Yoon CK, Lee SH, Zhang J, Lee HY, Kim MK, Seok YJ. HPr prevents FruR-mediated facilitation of RNA polymerase binding to the fru promoter in Vibrio cholerae. Nucleic Acids Res 2023; 51:5432-5448. [PMID: 36987873 PMCID: PMC10287919 DOI: 10.1093/nar/gkad220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 02/17/2023] [Accepted: 03/15/2023] [Indexed: 03/30/2023] Open
Abstract
Phosphorylation state-dependent interactions of the phosphoenolpyruvate (PEP):carbohydrate phosphotransferase system (PTS) components with transcription factors play a key role in carbon catabolite repression (CCR) by glucose in bacteria. Glucose inhibits the PTS-dependent transport of fructose and is preferred over fructose in Vibrio cholerae, but the mechanism is unknown. We have recently shown that, contrary to Escherichia coli, the fructose-dependent transcriptional regulator FruR acts as an activator of the fru operon in V. cholerae and binding of the FruR-fructose 1-phosphate (F1P) complex to an operator facilitates RNA polymerase (RNAP) binding to the fru promoter. Here we show that, in the presence of glucose, dephosphorylated HPr, a general PTS component, binds to FruR. Whereas HPr does not affect DNA-binding affinity of FruR, regardless of the presence of F1P, it prevents the FruR-F1P complex from facilitating the binding of RNAP to the fru promoter. Structural and biochemical analyses of the FruR-HPr complex identify key residues responsible for the V. cholerae-specific FruR-HPr interaction not observed in E. coli. Finally, we reveal how the dephosphorylated HPr interacts with FruR in V. cholerae, whereas the phosphorylated HPr binds to CcpA, which is a global regulator of CCR in Bacillus subtilis and shows structural similarity to FruR.
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Affiliation(s)
- Chang-Kyu Yoon
- School of Biological Sciences and Institute of Microbiology, Seoul National University, Seoul, 08826, Korea
- Research Institute of Basic Science, Seoul National University, Seoul, 08826, Korea
| | - Seung-Hwan Lee
- School of Biological Sciences and Institute of Microbiology, Seoul National University, Seoul, 08826, Korea
| | - Jing Zhang
- Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup, 56212, Korea
| | - Hye-Young Lee
- School of Biological Sciences and Institute of Microbiology, Seoul National University, Seoul, 08826, Korea
- Research Institute of Basic Science, Seoul National University, Seoul, 08826, Korea
| | - Min-Kyu Kim
- Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup, 56212, Korea
| | - Yeong-Jae Seok
- School of Biological Sciences and Institute of Microbiology, Seoul National University, Seoul, 08826, Korea
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7
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Ghandour R, Papenfort K. Small regulatory RNAs in Vibrio cholerae. MICROLIFE 2023; 4:uqad030. [PMID: 37441523 PMCID: PMC10335731 DOI: 10.1093/femsml/uqad030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 06/02/2023] [Accepted: 06/13/2023] [Indexed: 07/15/2023]
Abstract
Vibrio cholerae is a major human pathogen causing the diarrheal disease, cholera. Regulation of virulence in V. cholerae is a multifaceted process involving gene expression changes at the transcriptional and post-transcriptional level. Whereas various transcription factors have been reported to modulate virulence in V. cholerae, small regulatory RNAs (sRNAs) have now been established to also participate in virulence control and the regulation of virulence-associated processes, such as biofilm formation, quorum sensing, stress response, and metabolism. In most cases, these sRNAs act by base-pairing with multiple target transcripts and this process typically requires the aid of an RNA-binding protein, such as the widely conserved Hfq protein. This review article summarizes the functional roles of sRNAs in V. cholerae, their underlying mechanisms of gene expression control, and how sRNAs partner with transcription factors to modulate complex regulatory programs. In addition, we will discuss regulatory principles discovered in V. cholerae that not only apply to other Vibrio species, but further extend into the large field of RNA-mediated gene expression control in bacteria.
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Affiliation(s)
- Rabea Ghandour
- Friedrich Schiller University Jena, Institute of Microbiology, 07745 Jena, Germany
| | - Kai Papenfort
- Corresponding author. Institute of Microbiology, General Microbiology, Friedrich Schiller University Jena, Winzerlaer Straße 2, 07745 Jena, Germany. Tel: +49-3641-949-311; E-mail:
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8
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Krol E, Werel L, Essen LO, Becker A. Structural and functional diversity of bacterial cyclic nucleotide perception by CRP proteins. MICROLIFE 2023; 4:uqad024. [PMID: 37223727 PMCID: PMC10187061 DOI: 10.1093/femsml/uqad024] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 04/07/2023] [Accepted: 04/28/2023] [Indexed: 05/25/2023]
Abstract
Cyclic AMP (cAMP) is a ubiquitous second messenger synthesized by most living organisms. In bacteria, it plays highly diverse roles in metabolism, host colonization, motility, and many other processes important for optimal fitness. The main route of cAMP perception is through transcription factors from the diverse and versatile CRP-FNR protein superfamily. Since the discovery of the very first CRP protein CAP in Escherichia coli more than four decades ago, its homologs have been characterized in both closely related and distant bacterial species. The cAMP-mediated gene activation for carbon catabolism by a CRP protein in the absence of glucose seems to be restricted to E. coli and its close relatives. In other phyla, the regulatory targets are more diverse. In addition to cAMP, cGMP has recently been identified as a ligand of certain CRP proteins. In a CRP dimer, each of the two cyclic nucleotide molecules makes contacts with both protein subunits and effectuates a conformational change that favors DNA binding. Here, we summarize the current knowledge on structural and physiological aspects of E. coli CAP compared with other cAMP- and cGMP-activated transcription factors, and point to emerging trends in metabolic regulation related to lysine modification and membrane association of CRP proteins.
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Affiliation(s)
- Elizaveta Krol
- Department of Biology, Philipps-Universität Marburg, Karl-von-Frisch-Straße 8, 35043 Marburg, Germany
- Center for Synthetic Microbiology (SYNMIKRO), Philipps-Universität Marburg, Karl-von-Frisch-Str. 14, 35043 Marburg, Germany
| | - Laura Werel
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany
| | - Lars Oliver Essen
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany
| | - Anke Becker
- Corresponding author. Center for Synthetic Microbiology (SYNMIKRO), Philipps-Universität Marburg, Karl-von-Frisch-Str. 14, 35043 Marburg. E-mail:
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Walker LM, Haycocks JR, van Kessel JC, Dalia TN, Dalia AB, Grainger DC. A simple mechanism for integration of quorum sensing and cAMP signalling in V. cholerae. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.08.527633. [PMID: 36798193 PMCID: PMC9934648 DOI: 10.1101/2023.02.08.527633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Many bacteria use quorum sensing to control changes in lifestyle. The process is regulated by microbially derived "autoinducer" signalling molecules, that accumulate in the local environment. Individual cells sense autoinducer abundance, to infer population density, and alter their behaviour accordingly. In Vibrio cholerae , quorum sensing signals are transduced by phosphorelay to the transcription factor LuxO. Unphosphorylated LuxO permits expression of HapR, which alters global gene expression patterns. In this work, we have mapped the genome-wide distribution of LuxO and HapR in V. cholerae . Whilst LuxO has a small regulon, HapR targets 32 loci. Many HapR targets coincide with sites for the cAMP receptor protein (CRP) that regulates the transcriptional response to carbon starvation. This overlap, also evident in other Vibrio species, results from similarities in the DNA sequence bound by each factor. At shared sites, HapR and CRP simultaneously contact the double helix and binding is stabilised by direct interaction of the two factors. Importantly, this involves a CRP surface that usually contacts RNA polymerase to stimulate transcription. As a result, HapR can block transcription activation by CRP. Thus, by interacting at shared sites, HapR and CRP integrate information from quorum sensing and cAMP signalling to control gene expression.
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Affiliation(s)
- Lucas M. Walker
- School of Biosciences, University of Birmingham, Edgbaston B15 2TT, UK
| | | | | | - Triana N. Dalia
- Department of Biology, Indiana University, Bloomington, Indiana, USA
| | - Ankur B. Dalia
- Department of Biology, Indiana University, Bloomington, Indiana, USA
| | - David C. Grainger
- School of Biosciences, University of Birmingham, Edgbaston B15 2TT, UK,for correspondence: , Tel: +44 (0)121 414 5437
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Zou M, Wang K, Zhao J, Lu H, Yang H, Huang M, Wang L, Wang G, Huang J, Min X. DegS protease regulates the motility, chemotaxis, and colonization of Vibrio cholerae. Front Microbiol 2023; 14:1159986. [PMID: 37089576 PMCID: PMC10113495 DOI: 10.3389/fmicb.2023.1159986] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 03/14/2023] [Indexed: 04/25/2023] Open
Abstract
In bacteria, DegS protease functions as an activating factor of the σE envelope stress response system, which ultimately activates the transcription of stress response genes in the cytoplasm. On the basis of high-throughput RNA sequencing, we have previously found that degS knockout inhibits the expression of flagellum synthesis- and chemotaxis-related genes, thereby indicating that DegS may be involved in the regulation of V. cholerae motility. In this study, we examined the relationships between DegS and motility in V. cholerae. Swimming motility and chemotaxis assays revealed that degS or rpoE deletion promotes a substantial reduction in the motility and chemotaxis of V. cholerae, whereas these activities were restored in ΔdegS::degS and ΔdegSΔrseA strains, indicating that DegS is partially dependent on σE to positively regulate V. cholerae activity. Gene-act network analysis revealed that the cAMP-CRP-RpoS signaling pathway, which plays an important role in flagellar synthesis, is significantly inhibited in ΔdegS mutants, whereas in response to the overexpression of cyaA/crp and rpoS in the ΔdegS strain, the motility and chemotaxis of the ΔdegS + cyaA/crp and ΔdegS + rpoS strains were partially restored compared with the ΔdegS strain. We further demonstrated that transcription levels of the flagellar regulatory gene flhF are regulated by DegS via the cAMP-CRP-RpoS signaling pathway. Overexpression of the flhF gene in the ΔdegS strain partially restored motility and chemotaxis. In addition, suckling mouse intestinal colonization experiments indicated that the ΔdegS and ΔrpoE strains were characterized by the poor colonization of mouse intestines, whereas colonization efficacy was restored in the ΔdegSΔrseA, ΔdegS + cyaA/crp, ΔdegS + rpoS, and ΔdegS + flhF strains. Collectively, our findings indicate that DegS regulates the motility and chemotaxis of V. cholerae via the cAMP-CRP-RpoS-FlhF pathway, thereby influencing the colonization of suckling mouse intestines.
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Affiliation(s)
- Mei Zou
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China
- School of Laboratory Medicine, Zunyi Medical University, Zunyi, Guizhou, China
| | - Kaiying Wang
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China
- School of Laboratory Medicine, Zunyi Medical University, Zunyi, Guizhou, China
| | - Jiajun Zhao
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China
- School of Laboratory Medicine, Zunyi Medical University, Zunyi, Guizhou, China
| | - Huifang Lu
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China
- School of Laboratory Medicine, Zunyi Medical University, Zunyi, Guizhou, China
| | - Hui Yang
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China
- School of Laboratory Medicine, Zunyi Medical University, Zunyi, Guizhou, China
| | - Meirong Huang
- School of Laboratory Medicine, Zunyi Medical University, Zunyi, Guizhou, China
- Department of Blood Transfusion, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China
| | - Lu Wang
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China
- School of Laboratory Medicine, Zunyi Medical University, Zunyi, Guizhou, China
| | - Guangli Wang
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China
- School of Laboratory Medicine, Zunyi Medical University, Zunyi, Guizhou, China
| | - Jian Huang
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China
- School of Laboratory Medicine, Zunyi Medical University, Zunyi, Guizhou, China
| | - Xun Min
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China
- School of Laboratory Medicine, Zunyi Medical University, Zunyi, Guizhou, China
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11
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Gibson JA, Gebhardt MJ, Santos RERS, Dove SL, Watnick PI. Sequestration of a dual function DNA-binding protein by Vibrio cholerae CRP. Proc Natl Acad Sci U S A 2022; 119:e2210115119. [PMID: 36343262 PMCID: PMC9674212 DOI: 10.1073/pnas.2210115119] [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: 06/17/2022] [Accepted: 10/04/2022] [Indexed: 11/09/2022] Open
Abstract
Although the mechanism by which the cyclic AMP receptor protein (CRP) regulates global gene transcription has been intensively studied for decades, new discoveries remain to be made. Here, we report that, during rapid growth, CRP associates with both the well-conserved, dual-function DNA-binding protein peptidase A (PepA) and the cell membrane. These interactions are not present under nutrient-limited growth conditions, due to post-translational modification of three lysines on a single face of CRP. Although coincident DNA binding is rare, dissociation from CRP results in increased PepA occupancy at many chromosomal binding sites and differential regulation of hundreds of genes, including several encoding cyclic dinucleotide phosphodiesterases. We show that PepA represses biofilm formation and activates motility/chemotaxis. We propose a model in which membrane-bound CRP interferes with PepA DNA binding. Under nutrient limitation, PepA is released. Together, CRP and free PepA activate a transcriptional response that impels the bacterium to seek a more hospitable environment. This work uncovers a function for CRP in the sequestration of a regulatory protein. More broadly, it describes a paradigm of bacterial transcriptome modulation through metabolically regulated association of transcription factors with the cell membrane.
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Affiliation(s)
- Jacob A. Gibson
- Division of Infectious Diseases, Boston Children’s Hospital, Boston, MA 02115
- Biological and Biomedical Sciences Program, Harvard Medical School, Boston, MA 02115
| | - Michael J. Gebhardt
- Division of Infectious Diseases, Boston Children’s Hospital, Boston, MA 02115
- Department of Pediatrics, Harvard Medical School, Boston, MA 02115
| | - Renato E. R. S. Santos
- Division of Infectious Diseases, Boston Children’s Hospital, Boston, MA 02115
- Department of Pediatrics, Harvard Medical School, Boston, MA 02115
| | - Simon L. Dove
- Division of Infectious Diseases, Boston Children’s Hospital, Boston, MA 02115
- Department of Pediatrics, Harvard Medical School, Boston, MA 02115
| | - Paula I. Watnick
- Division of Infectious Diseases, Boston Children’s Hospital, Boston, MA 02115
- Department of Pediatrics, Harvard Medical School, Boston, MA 02115
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12
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A mannose-sensing AraC-type transcriptional activator regulates cell–cell aggregation of Vibrio cholerae. NPJ Biofilms Microbiomes 2022; 8:65. [PMID: 35987769 PMCID: PMC9392796 DOI: 10.1038/s41522-022-00331-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 08/03/2022] [Indexed: 11/18/2022] Open
Abstract
In addition to catalyzing coupled transport and phosphorylation of carbohydrates, the phosphoenolpyruvate:carbohydrate phosphotransferase system (PTS) regulates various physiological processes in most bacteria. Therefore, the transcription of genes encoding the PTS is precisely regulated by transcriptional regulators depending on substrate availability. As the distribution of the mannose-specific PTS (PTSMan) is limited to animal-associated bacteria, it has been suggested to play an important role in host-bacteria interactions. In Vibrio cholerae, mannose is known to inhibit biofilm formation. During host infection, the transcription level of the V. cholerae gene encoding the putative PTSMan (hereafter referred to as manP) significantly increases, and mutations in this gene increase host survival rate. Herein, we show that an AraC-type transcriptional regulator (hereafter referred to as ManR) acts as a transcriptional activator of the mannose operon and is responsible for V. cholerae growth and biofilm inhibition on a mannose or fructose-supplemented medium. ManR activates mannose operon transcription by facilitating RNA polymerase binding to the promoter in response to mannose 6-phosphate and, to a lesser extent, to fructose 1-phosphate. When manP or manR is impaired, the mannose-induced inhibition of biofilm formation was reversed and intestinal colonization was significantly reduced in a Drosophila melanogaster infection model. Our results show that ManR recognizes mannose and fructose in the environment and facilitates V. cholerae survival in the host.
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13
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Yan L, Jin Y, Zhang B, Xu Y, Peng X, Qin S, Chen L. Diverse Aquatic Animal Matrices Play a Key Role in Survival and Potential Virulence of Non-O1/O139 Vibrio cholerae Isolates. Front Microbiol 2022; 13:896767. [PMID: 35801116 PMCID: PMC9255913 DOI: 10.3389/fmicb.2022.896767] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 05/04/2022] [Indexed: 11/13/2022] Open
Abstract
Vibrio cholerae can cause pandemic cholera in humans. The waterborne bacterium is frequently isolated from aquatic products worldwide. However, current literature on the impact of aquatic product matrices on the survival and pathogenicity of cholerae is rare. In this study, the growth of eleven non-O1/0O139 V. cholerae isolates recovered from eight species of commonly consumed fish and shellfish was for the first time determined in the eight aquatic animal matrices, most of which highly increased the bacterial biomass when compared with routine trypsin soybean broth (TSB) medium. Secretomes of the V. cholerae isolates (draft genome size: 3,852,021–4,144,013 bp) were determined using two-dimensional gel electrophoresis (2DE-GE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) techniques. Comparative secretomic analyses revealed 74 differential extracellular proteins, including several virulence- and resistance-associated proteins secreted by the V. cholerae isolates when grown in the eight matrices. Meanwhile, a total of 8,119 intracellular proteins were identified, including 83 virulence- and 8 resistance-associated proteins, of which 61 virulence-associated proteins were absent from proteomes of these isolates when grown in the TSB medium. Additionally, comparative genomic and proteomic analyses also revealed several strain-specific proteins with unknown functions in the V. cholerae isolates. Taken, the results in this study demonstrate that distinct secretomes and proteomes induced by the aquatic animal matrices facilitate V. cholerae resistance in the edible aquatic animals and enhance the pathogenicity of the leading waterborne pathogen worldwide.
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Affiliation(s)
- Lili Yan
- Key Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture and Rural Affairs of the People's Republic of China, Shanghai, China
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Yinzhe Jin
- Key Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture and Rural Affairs of the People's Republic of China, Shanghai, China
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Beiyu Zhang
- Key Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture and Rural Affairs of the People's Republic of China, Shanghai, China
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Yingwei Xu
- Key Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture and Rural Affairs of the People's Republic of China, Shanghai, China
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Xu Peng
- Department of Biology, Archaea Centre, University of Copenhagen, Copenhagen, Denmark
| | - Si Qin
- Key Laboratory for Food Science and Biotechnology of Hunan Province, College of Food Science and Technology, Hunan Agricultural University, Changsha, China
- *Correspondence: Si Qin
| | - Lanming Chen
- Key Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture and Rural Affairs of the People's Republic of China, Shanghai, China
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
- Lanming Chen
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14
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Homologs of the Escherichia coli F Element Protein TraR, Including Phage Lambda Orf73, Directly Reprogram Host Transcription. mBio 2022; 13:e0095222. [PMID: 35583320 PMCID: PMC9239242 DOI: 10.1128/mbio.00952-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Bacterial cells and their associated plasmids and bacteriophages encode numerous small proteins of unknown function. One example, the 73-amino-acid protein TraR, is encoded by the transfer operon of the conjugative F plasmid of Escherichia coli. TraR is a distant homolog of DksA, a protein found in almost all proteobacterial species that is required for ppGpp to regulate transcription during the stringent response. TraR and DksA increase or decrease transcription initiation depending on the kinetic features of the promoter by binding directly to RNA polymerase without binding to DNA. Unlike DksA, whose full activity requires ppGpp as a cofactor, TraR is fully active by itself and unaffected by ppGpp. TraR belongs to a family of divergent proteins encoded by proteobacterial bacteriophages and other mobile elements. Here, we experimentally addressed whether other members of the TraR family function like the F element-encoded TraR. Purified TraR and all 5 homologs that were examined bound to RNA polymerase, functioned at lower concentrations than DksA, and complemented a dksA-null strain for growth on minimal medium. One of the homologs, λ Orf73, encoded by bacteriophage lambda, was examined in greater detail. λ Orf73 slowed host growth and increased phage burst size. Mutational analysis suggested that λ Orf73 and TraR have a similar mechanism for inhibiting rRNA and r-protein promoters. We suggest that TraR and its homologs regulate host transcription to divert cellular resources to phage propagation or conjugation without induction of ppGpp and a stringent response.
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15
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Hoque MM, Noorian P, Espinoza-Vergara G, Manuneedhi Cholan P, Kim M, Rahman MH, Labbate M, Rice SA, Pernice M, Oehlers SH, McDougald D. Adaptation to an amoeba host drives selection of virulence-associated traits in Vibrio cholerae. THE ISME JOURNAL 2022; 16:856-867. [PMID: 34654895 PMCID: PMC8857207 DOI: 10.1038/s41396-021-01134-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 09/20/2021] [Accepted: 09/29/2021] [Indexed: 12/02/2022]
Abstract
Predation by heterotrophic protists drives the emergence of adaptive traits in bacteria, and often these traits lead to altered interactions with hosts and persistence in the environment. Here we studied adaptation of the cholera pathogen, Vibrio cholerae during long-term co-incubation with the protist host, Acanthamoeba castellanii. We determined phenotypic and genotypic changes associated with long-term intra-amoebal host adaptation and how this impacts pathogen survival and fitness. We showed that adaptation to the amoeba host leads to temporal changes in multiple phenotypic traits in V. cholerae that facilitate increased survival and competitive fitness in amoeba. Genome sequencing and mutational analysis revealed that these altered lifestyles were linked to non-synonymous mutations in conserved regions of the flagellar transcriptional regulator, flrA. Additionally, the mutations resulted in enhanced colonisation in zebrafish, establishing a link between adaptation of V. cholerae to amoeba predation and enhanced environmental persistence. Our results show that pressure imposed by amoeba on V. cholerae selects for flrA mutations that serves as a key driver for adaptation. Importantly, this study provides evidence that adaptive traits that evolve in pathogens in response to environmental predatory pressure impact the colonisation of eukaryotic organisms by these pathogens.
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Affiliation(s)
- M. Mozammel Hoque
- grid.117476.20000 0004 1936 7611The iThree Institute, University of Technology Sydney, Sydney, NSW Australia
| | - Parisa Noorian
- grid.117476.20000 0004 1936 7611The iThree Institute, University of Technology Sydney, Sydney, NSW Australia
| | - Gustavo Espinoza-Vergara
- grid.117476.20000 0004 1936 7611The iThree Institute, University of Technology Sydney, Sydney, NSW Australia
| | - Pradeep Manuneedhi Cholan
- grid.1013.30000 0004 1936 834XTuberculosis Research Program at the Centenary Institute, The University of Sydney, Camperdown, NSW Australia ,grid.1013.30000 0004 1936 834XFaculty of Medicine and Health & Marie Bashir Institute, The University of Sydney, Camperdown, NSW Australia
| | - Mikael Kim
- grid.117476.20000 0004 1936 7611Climate Change Cluster, University of Technology Sydney, Sydney, NSW Australia
| | - Md Hafizur Rahman
- grid.117476.20000 0004 1936 7611School of Life Sciences, Faculty of Science, University of Technology Sydney, Sydney, NSW Australia
| | - Maurizio Labbate
- grid.117476.20000 0004 1936 7611School of Life Sciences, Faculty of Science, University of Technology Sydney, Sydney, NSW Australia
| | - Scott A. Rice
- grid.117476.20000 0004 1936 7611The iThree Institute, University of Technology Sydney, Sydney, NSW Australia ,grid.59025.3b0000 0001 2224 0361Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Mathieu Pernice
- grid.117476.20000 0004 1936 7611Climate Change Cluster, University of Technology Sydney, Sydney, NSW Australia
| | - Stefan H. Oehlers
- grid.1013.30000 0004 1936 834XTuberculosis Research Program at the Centenary Institute, The University of Sydney, Camperdown, NSW Australia ,grid.1013.30000 0004 1936 834XFaculty of Medicine and Health & Marie Bashir Institute, The University of Sydney, Camperdown, NSW Australia
| | - Diane McDougald
- grid.117476.20000 0004 1936 7611The iThree Institute, University of Technology Sydney, Sydney, NSW Australia ,grid.59025.3b0000 0001 2224 0361Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
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16
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Li Y, Yan J, Guo X, Wang X, Liu F, Cao B. The global regulators ArcA and CytR collaboratively modulate Vibrio cholerae motility. BMC Microbiol 2022; 22:22. [PMID: 35021992 PMCID: PMC8753867 DOI: 10.1186/s12866-022-02435-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Accepted: 01/05/2022] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Vibrio cholerae, a Gram-negative bacterium, is highly motile owing to the presence of a single polar flagellum. The global anaerobiosis response regulator, ArcA regulates the expression of virulence factors and enhance biofilm formation in V. cholerae. However, the function of ArcA for the motility of V. cholerae is yet to be elucidated. CytR, which represses nucleoside uptake and catabolism, is known to play a chief role in V. cholerae pathogenesis and flagellar synthesis but the mechanism that CytR influences motility is unclear.
Results
In this study, we found that the ΔarcA mutant strain exhibited higher motility than the WT strain due to ArcA directly repressed flrA expression. We further discovered that CytR directly enhanced fliK expression, which explained why the ΔcytR mutant strain was retarded in motility. On the other hand, cytR was a direct ArcA target and cytR expression was directly repressed by ArcA. As expected, cytR expression was down-regulated.
Conclusions
Overall, ArcA plays a critical role in V. cholerae motility by regulating flrA expression directly and fliK indirectly in the manner of cytR.
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17
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Guest T, Haycocks JRJ, Warren GZL, Grainger DC. Genome-wide mapping of Vibrio cholerae VpsT binding identifies a mechanism for c-di-GMP homeostasis. Nucleic Acids Res 2021; 50:149-159. [PMID: 34908143 PMCID: PMC8754643 DOI: 10.1093/nar/gkab1194] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 11/16/2021] [Accepted: 11/18/2021] [Indexed: 11/13/2022] Open
Abstract
Many bacteria use cyclic dimeric guanosine monophosphate (c-di-GMP) to control changes in lifestyle. The molecule, synthesized by proteins having diguanylate cyclase activity, is often a signal to transition from motile to sedentary behaviour. In Vibrio cholerae, c-di-GMP can exert its effects via the transcription factors VpsT and VpsR. Together, these proteins activate genes needed for V. cholerae to form biofilms. In this work, we have mapped the genome-wide distribution of VpsT in a search for further regulatory roles. We show that VpsT binds 23 loci and recognises a degenerate DNA palindrome having the consensus 5'-W-5R-4[CG]-3Y-2W-1W+1R+2[GC]+3Y+4W+5-3'. Most genes targeted by VpsT encode functions related to motility, biofilm formation, or c-di-GMP metabolism. Most notably, VpsT activates expression of the vpvABC operon that encodes a diguanylate cyclase. This creates a positive feedback loop needed to maintain intracellular levels of c-di-GMP. Mutation of the key VpsT binding site, upstream of vpvABC, severs the loop and c-di-GMP levels fall accordingly. Hence, as well as relaying the c-di-GMP signal, VpsT impacts c-di-GMP homeostasis.
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Affiliation(s)
- Thomas Guest
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - James R J Haycocks
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Gemma Z L Warren
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - David C Grainger
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
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18
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Lang M, Krin E, Korlowski C, Sismeiro O, Varet H, Coppée JY, Mazel D, Baharoglu Z. Sleeping ribosomes: Bacterial signaling triggers RaiA mediated persistence to aminoglycosides. iScience 2021; 24:103128. [PMID: 34611612 PMCID: PMC8476650 DOI: 10.1016/j.isci.2021.103128] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 09/07/2021] [Accepted: 09/09/2021] [Indexed: 12/19/2022] Open
Abstract
Indole is a molecule proposed to be involved in bacterial signaling. We find that indole secretion is induced by sublethal tobramycin concentrations and increases persistence to aminoglycosides in V. cholerae. Indole transcriptomics showed increased expression of raiA, a ribosome associated factor. Deletion of raiA abolishes the appearance of indole dependent persisters to aminoglycosides, although its overexpression leads to 100-fold increase of persisters, and a reduction in lag phase, evocative of increased active 70S ribosome content, confirmed by sucrose gradient analysis. We propose that, under stress conditions, RaiA-bound inactive 70S ribosomes are stored as “sleeping ribosomes”, and are rapidly reactivated upon stress relief. Our results point to an active process of persister formation through ribosome protection during translational stress (e.g., aminoglycoside treatment) and reactivation upon antibiotic removal. Translation is a universal process, and these results could help elucidate a mechanism of persistence formation in a controlled, thus inducible way. Indole is produced under sub-MIC tobramycin stress in V. cholerae and upregulates raiA RaiA is involved in indole-dependent formation of aminoglycoside specific persisters RaiA overexpression allows faster growth restart and increases 70S ribosome content RaiA-bound inactive 70S ribosomes form intact and reactivable sleeping ribosome pools
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Affiliation(s)
- Manon Lang
- Département Génomes et Génétique, Institut Pasteur, UMR3525, CNRS, Unité Plasticité du Génome Bactérien, 75015 Paris, France
- Sorbonne Université, Collège Doctoral, 75005 Paris, France
| | - Evelyne Krin
- Département Génomes et Génétique, Institut Pasteur, UMR3525, CNRS, Unité Plasticité du Génome Bactérien, 75015 Paris, France
| | - Chloé Korlowski
- Département Génomes et Génétique, Institut Pasteur, UMR3525, CNRS, Unité Plasticité du Génome Bactérien, 75015 Paris, France
| | - Odile Sismeiro
- Biomics Technological Platform, Center for Technological Resources and Research, Institut Pasteur, 75015 Paris, France
| | - Hugo Varet
- Biomics Technological Platform, Center for Technological Resources and Research, Institut Pasteur, 75015 Paris, France
- Bioinformatics and Biostatistics Hub, Department of Computational Biology, USR 3756 CNRS, Institut Pasteur, 75015 Paris, France
| | - Jean-Yves Coppée
- Biomics Technological Platform, Center for Technological Resources and Research, Institut Pasteur, 75015 Paris, France
| | - Didier Mazel
- Département Génomes et Génétique, Institut Pasteur, UMR3525, CNRS, Unité Plasticité du Génome Bactérien, 75015 Paris, France
- Corresponding author
| | - Zeynep Baharoglu
- Département Génomes et Génétique, Institut Pasteur, UMR3525, CNRS, Unité Plasticité du Génome Bactérien, 75015 Paris, France
- Corresponding author
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19
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Venkat K, Hoyos M, Haycocks JR, Cassidy L, Engelmann B, Rolle-Kampczyk U, von Bergen M, Tholey A, Grainger DC, Papenfort K. A dual-function RNA balances carbon uptake and central metabolism in Vibrio cholerae. EMBO J 2021; 40:e108542. [PMID: 34612526 PMCID: PMC8672173 DOI: 10.15252/embj.2021108542] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 08/31/2021] [Accepted: 09/02/2021] [Indexed: 11/22/2022] Open
Abstract
Bacterial small RNAs (sRNAs) are well known to modulate gene expression by base pairing with trans‐encoded transcripts and are typically non‐coding. However, several sRNAs have been reported to also contain an open reading frame and thus are considered dual‐function RNAs. In this study, we discovered a dual‐function RNA from Vibrio cholerae, called VcdRP, harboring a 29 amino acid small protein (VcdP), as well as a base‐pairing sequence. Using a forward genetic screen, we identified VcdRP as a repressor of cholera toxin production and link this phenotype to the inhibition of carbon transport by the base‐pairing segment of the regulator. By contrast, we demonstrate that the VcdP small protein acts downstream of carbon transport by binding to citrate synthase (GltA), the first enzyme of the citric acid cycle. Interaction of VcdP with GltA results in increased enzyme activity and together VcdR and VcdP reroute carbon metabolism. We further show that transcription of vcdRP is repressed by CRP allowing us to provide a model in which VcdRP employs two different molecular mechanisms to synchronize central metabolism in V. cholerae.
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Affiliation(s)
- Kavyaa Venkat
- Institute of Microbiology, Friedrich Schiller University, Jena, Germany
| | - Mona Hoyos
- Institute of Microbiology, Friedrich Schiller University, Jena, Germany
| | - James Rj Haycocks
- Institute of Microbiology and Infection, University of Birmingham, Birmingham, UK
| | - Liam Cassidy
- Systematic Proteome Research & Bioanalytics, University of Kiel, Kiel, Germany
| | | | | | | | - Andreas Tholey
- Systematic Proteome Research & Bioanalytics, University of Kiel, Kiel, Germany
| | - David C Grainger
- Institute of Microbiology and Infection, University of Birmingham, Birmingham, UK
| | - Kai Papenfort
- Institute of Microbiology, Friedrich Schiller University, Jena, Germany.,Microverse Cluster, Friedrich Schiller University Jena, Jena, Germany
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20
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Liu Y, Liu B, Xu T, Wang Q, Li W, Wu J, Zheng X, Liu B, Liu R, Liu X, Guo X, Feng L, Wang L. A fructose/H + symporter controlled by a LacI-type regulator promotes survival of pandemic Vibrio cholerae in seawater. Nat Commun 2021; 12:4649. [PMID: 34330925 PMCID: PMC8324912 DOI: 10.1038/s41467-021-24971-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 07/13/2021] [Indexed: 02/07/2023] Open
Abstract
The bacterium Vibrio cholerae can colonize the human intestine and cause cholera, but spends much of its life cycle in seawater. The pathogen must adapt to substantial environmental changes when moving between seawater and the human intestine, including different availability of carbon sources such as fructose. Here, we use in vitro experiments as well as mouse intestinal colonization assays to study the mechanisms used by pandemic V. cholerae to adapt to these environmental changes. We show that a LacI-type regulator (FruI) and a fructose/H+ symporter (FruT) are important for fructose uptake at low fructose concentrations, as those found in seawater. FruT is downregulated by FruI, which is upregulated when O2 concentrations are low (as in the intestine) by ArcAB, a two-component system known to respond to changes in oxygen levels. As a result, the bacteria predominantly use FruT for fructose uptake under seawater conditions (low fructose, high O2), and use a known fructose phosphotransferase system (PTS, Fpr) for fructose uptake under conditions found in the intestine. PTS activity leads to reduced levels of intracellular cAMP, which in turn upregulate virulence genes. Our results indicate that the FruT/FruI system may be important for survival of pandemic V. cholerae in seawater.
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Affiliation(s)
- Yutao Liu
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, P. R. China
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, P. R. China
- Tianjin Key Laboratory of Microbial Functional Genomics, Tianjin, P.R. China
| | - Bin Liu
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, P. R. China
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, P. R. China
- Tianjin Key Laboratory of Microbial Functional Genomics, Tianjin, P.R. China
| | - Tingting Xu
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, P. R. China
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, P. R. China
- Tianjin Key Laboratory of Microbial Functional Genomics, Tianjin, P.R. China
- Shenzhen Institute of Respiratory Diseases, Second Clinical Medical College (Shenzhen People's Hospital), Jinan University, Shenzhen, P. R. China
| | - Qian Wang
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, P. R. China
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, P. R. China
- Tianjin Key Laboratory of Microbial Functional Genomics, Tianjin, P.R. China
| | - Wendi Li
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, P. R. China
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, P. R. China
- Tianjin Key Laboratory of Microbial Functional Genomics, Tianjin, P.R. China
| | - Jialin Wu
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, P. R. China
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, P. R. China
- Tianjin Key Laboratory of Microbial Functional Genomics, Tianjin, P.R. China
| | - Xiaoyu Zheng
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, P. R. China
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, P. R. China
- Tianjin Key Laboratory of Microbial Functional Genomics, Tianjin, P.R. China
| | - Bin Liu
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, P. R. China
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, P. R. China
- Tianjin Key Laboratory of Microbial Functional Genomics, Tianjin, P.R. China
| | - Ruiying Liu
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, P. R. China
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, P. R. China
- Tianjin Key Laboratory of Microbial Functional Genomics, Tianjin, P.R. China
| | - Xingmei Liu
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, P. R. China
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, P. R. China
- Tianjin Key Laboratory of Microbial Functional Genomics, Tianjin, P.R. China
| | - Xi Guo
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, P. R. China
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, P. R. China
- Tianjin Key Laboratory of Microbial Functional Genomics, Tianjin, P.R. China
| | - Lu Feng
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, P. R. China.
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, P. R. China.
- Tianjin Key Laboratory of Microbial Functional Genomics, Tianjin, P.R. China.
| | - Lei Wang
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, P. R. China.
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, P. R. China.
- Tianjin Key Laboratory of Microbial Functional Genomics, Tianjin, P.R. China.
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, P. R. China.
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21
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Henrique C, Falcão MAP, De Araújo Pimenta L, Maleski ALA, Lima C, Mitsunari T, Sampaio SC, Lopes-Ferreira M, Piazza RMF. Heat-Labile Toxin from Enterotoxigenic Escherichia coli Causes Systemic Impairment in Zebrafish Model. Toxins (Basel) 2021; 13:419. [PMID: 34204819 PMCID: PMC8231604 DOI: 10.3390/toxins13060419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 05/05/2021] [Accepted: 05/10/2021] [Indexed: 11/20/2022] Open
Abstract
Heat-labile toxin I (LT-I), produced by strains of enterotoxigenic Escherichia coli (ETEC), causes profuse watery diarrhea in humans. Different in vitro and in vivo models have already elucidated the mechanism of action of this toxin; however, their use does not always allow for more specific studies on how the LT-I toxin acts in systemic tracts and intestinal cell lines. In the present work, zebrafish (Danio rerio) and human intestinal cells (Caco-2) were used as models to study the toxin LT-I. Caco-2 cells were used, in the 62nd passage, at different cell concentrations. LT-I was conjugated to FITC to visualize its transport in cells, as well as microinjected into the caudal vein of zebrafish larvae, in order to investigate its effects on survival, systemic traffic, and morphological formation. The internalization of LT-I was visualized in 3 × 104 Caco-2 cells, being associated with the cell membrane and nucleus. The systemic traffic of LT-I in zebrafish larvae showed its presence in the cardiac cavity, yolk, and regions of the intestine, as demonstrated by cardiac edema (100%), the absence of a swimming bladder (100%), and yolk edema (80%), in addition to growth limitation in the larvae, compared to the control group. There was a reduction in heart rate during the assessment of larval survival kinetics, demonstrating the cardiotoxic effect of LT-I. Thus, in this study, we provide essential new depictions of the features of LT-I.
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Affiliation(s)
- Camila Henrique
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo 05503-900, SP, Brazil; (C.H.); (T.M.)
| | - Maria Alice Pimentel Falcão
- Laboratório de Toxinologia Aplicada, Instituto Butantan, São Paulo 05503-900, SP, Brazil; (M.A.P.F.); (A.L.A.M.); (C.L.)
| | - Luciana De Araújo Pimenta
- Laboratório de Fisiopatologia, Instituto Butantan, São Paulo 05503-900, SP, Brazil; (L.D.A.P.); (S.C.S.)
| | - Adolfo Luís Almeida Maleski
- Laboratório de Toxinologia Aplicada, Instituto Butantan, São Paulo 05503-900, SP, Brazil; (M.A.P.F.); (A.L.A.M.); (C.L.)
| | - Carla Lima
- Laboratório de Toxinologia Aplicada, Instituto Butantan, São Paulo 05503-900, SP, Brazil; (M.A.P.F.); (A.L.A.M.); (C.L.)
| | - Thais Mitsunari
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo 05503-900, SP, Brazil; (C.H.); (T.M.)
| | - Sandra Coccuzzo Sampaio
- Laboratório de Fisiopatologia, Instituto Butantan, São Paulo 05503-900, SP, Brazil; (L.D.A.P.); (S.C.S.)
| | - Mônica Lopes-Ferreira
- Laboratório de Toxinologia Aplicada, Instituto Butantan, São Paulo 05503-900, SP, Brazil; (M.A.P.F.); (A.L.A.M.); (C.L.)
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22
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Choi G, Kim D, Im H, Choi SH. A Nitric Oxide-Responsive Transcriptional Regulator NsrR Cooperates With Lrp and CRP to Tightly Control the hmpA Gene in Vibrio vulnificus. Front Microbiol 2021; 12:681196. [PMID: 34093504 PMCID: PMC8175989 DOI: 10.3389/fmicb.2021.681196] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 04/23/2021] [Indexed: 12/12/2022] Open
Abstract
Nitric oxide (NO) is an important antimicrobial effector produced by the host innate immune system to counteract invading pathogens. To survive and establish a successful infection, a fulminating human pathogen Vibrio vulnificus expresses the hmpA gene encoding an NO dioxygenase in an NO-responsive manner. In this study, we identified an Rrf2-family transcriptional regulator NsrR that is predicted to contain the Fe-S cluster coordinated by three cysteine residues. Transcriptome analysis showed that NsrR controls the expression of multiple genes potentially involved in nitrosative stress responses. Particularly, NsrR acts as a strong repressor of hmpA transcription and relieves the repression of hmpA upon exposure to NO. Notably, nsrR and hmpA are transcribed divergently, and their promoter regions overlap with each other. Molecular biological analyses revealed that NsrR directly binds to this overlapping promoter region, which is alleviated by loss of the Fe-S cluster, leading to the subsequent derepression of hmpA under nitrosative stress. We further found that a leucine-responsive regulatory protein (Lrp) negatively regulates hmpA in an NsrR-dependent manner by directly binding to the promoter region, presumably resulting in a DNA conformation change to support the repression by NsrR. Meanwhile, a cyclic AMP receptor protein (CRP) positively regulates hmpA probably through repression of nsrR and lrp by directly binding to each promoter region in a sequential cascade. Altogether, this collaborative regulation of NsrR along with Lrp and CRP enables an elaborate control of hmpA transcription, contributing to survival under host-derived nitrosative stress and thereby the pathogenesis of V. vulnificus.
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Affiliation(s)
- Garam Choi
- National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
- Center for Food and Bioconvergence, Seoul National University, Seoul, South Korea
| | - Dukyun Kim
- National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
| | - Hanhyeok Im
- National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
- Center for Food and Bioconvergence, Seoul National University, Seoul, South Korea
| | - Sang Ho Choi
- National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
- Center for Food and Bioconvergence, Seoul National University, Seoul, South Korea
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23
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Yoon CK, Kang D, Kim MK, Seok YJ. Vibrio cholerae FruR facilitates binding of RNA polymerase to the fru promoter in the presence of fructose 1-phosphate. Nucleic Acids Res 2021; 49:1397-1410. [PMID: 33476373 PMCID: PMC7897506 DOI: 10.1093/nar/gkab013] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 12/31/2020] [Accepted: 01/06/2021] [Indexed: 12/25/2022] Open
Abstract
In most bacteria, efficient use of carbohydrates is primarily mediated by the phosphoenolpyruvate (PEP):carbohydrate phosphotransferase system (PTS), which concomitantly phosphorylates the substrates during import. Therefore, transcription of the PTS-encoding genes is precisely regulated by transcriptional regulators, depending on the availability of the substrate. Fructose is transported mainly through the fructose-specific PTS (PTSFru) and simultaneously converted into fructose 1-phosphate (F1P). In Gammaproteobacteria such as Escherichia coli and Pseudomonas putida, transcription of the fru operon encoding two PTSFru components, FruA and FruB, and the 1-phosphofructokinase FruK is repressed by FruR in the absence of the inducer F1P. Here, we show that, contrary to the case in other Gammaproteobacteria, FruR acts as a transcriptional activator of the fru operon and is indispensable for the growth of Vibrio cholerae on fructose. Several lines of evidence suggest that binding of the FruR-F1P complex to an operator which is located between the –35 and –10 promoter elements changes the DNA structure to facilitate RNA polymerase binding to the promoter. We discuss the mechanism by which the highly conserved FruR regulates the expression of its target operon encoding the highly conserved PTSFru and FruK in a completely opposite direction among closely related families of bacteria.
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Affiliation(s)
- Chang-Kyu Yoon
- School of Biological Sciences and Institute of Microbiology, Seoul National University, Seoul 08826, Korea
| | - Deborah Kang
- School of Biological Sciences and Institute of Microbiology, Seoul National University, Seoul 08826, Korea
| | - Min-Kyu Kim
- Radiation Research Division, Korea Atomic Energy Research Institute, Jeongeup 56212, Korea
| | - Yeong-Jae Seok
- School of Biological Sciences and Institute of Microbiology, Seoul National University, Seoul 08826, Korea
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24
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Cho JY, Liu R, Macbeth JC, Hsiao A. The Interface of Vibrio cholerae and the Gut Microbiome. Gut Microbes 2021; 13:1937015. [PMID: 34180341 PMCID: PMC8244777 DOI: 10.1080/19490976.2021.1937015] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 05/18/2021] [Accepted: 05/24/2021] [Indexed: 02/04/2023] Open
Abstract
The bacterium Vibrio cholerae is the etiologic agent of the severe human diarrheal disease cholera. The gut microbiome, or the native community of microorganisms found in the human gastrointestinal tract, is increasingly being recognized as a factor in driving susceptibility to infection, in vivo fitness, and host interactions of this pathogen. Here, we review a subset of the emerging studies in how gut microbiome structure and microbial function are able to drive V. cholerae virulence gene regulation, metabolism, and modulate host immune responses to cholera infection and vaccination. Improved mechanistic understanding of commensal-pathogen interactions offers new perspectives in the design of prophylactic and therapeutic approaches for cholera control.
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Affiliation(s)
- Jennifer Y. Cho
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA, USA
- Department of Biochemistry, University of California, Riverside, California, USA
| | - Rui Liu
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA, USA
- Graduate Program in Genetics, Genomics, and Bioinformatics, University of California, Riverside, California, USA
| | - John C. Macbeth
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA, USA
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, California, USA
| | - Ansel Hsiao
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA, USA
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25
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Hsiao A, Zhu J. Pathogenicity and virulence regulation of Vibrio cholerae at the interface of host-gut microbiome interactions. Virulence 2020; 11:1582-1599. [PMID: 33172314 PMCID: PMC7671094 DOI: 10.1080/21505594.2020.1845039] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 10/27/2020] [Accepted: 10/28/2020] [Indexed: 12/12/2022] Open
Abstract
The Gram-negative bacterium Vibrio cholerae is responsible for the severe diarrheal pandemic disease cholera, representing a major global public health concern. This pathogen transitions from aquatic reservoirs into epidemics in human populations, and has evolved numerous mechanisms to sense this transition in order to appropriately regulate its gene expression for infection. At the intersection of pathogen and host in the gastrointestinal tract lies the community of native gut microbes, the gut microbiome. It is increasingly clear that the diversity of species and biochemical activities within the gut microbiome represents a driver of infection outcome, through their ability to manipulate the signals used by V. cholerae to regulate virulence and fitness in vivo. A better mechanistic understanding of how commensal microbial action interacts with V. cholerae pathogenesis may lead to novel prophylactic and therapeutic interventions for cholera. Here, we review a subset of this burgeoning field of research.
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Affiliation(s)
- Ansel Hsiao
- Department of Microbiology & Plant Pathology, University of California Riverside, Riverside, CA, USA
| | - Jun Zhu
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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26
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Abstract
Vibrio is a large and diverse genus of bacteria, of which most are nonpathogenic species found in the aquatic environment. However, a subset of the Vibrio genus includes several species that are highly pathogenic, either to humans or to aquatic animals. In recent years, Danio rerio, commonly known as the zebrafish, has emerged as a major animal model used for studying nearly every aspect of biology, including infectious diseases. Zebrafish are especially useful because the embryos are transparent, larvae are small and facilitate imaging studies, and numerous transgenic fish strains have been constructed. Zebrafish models for several pathogenic Vibrio species have been described, and indeed a fish model is highly relevant for the study of aquatic bacterial pathogens. Here, we summarize the zebrafish models that have been used to study pathogenic Vibrio species to date.
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Affiliation(s)
- Dhrubajyoti Nag
- Department of Biochemistry, Microbiology, and Immunology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Dustin A Farr
- Department of Biochemistry, Microbiology, and Immunology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Madison G Walton
- Department of Biochemistry, Microbiology, and Immunology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Jeffrey H Withey
- Department of Biochemistry, Microbiology, and Immunology, Wayne State University School of Medicine, Detroit, Michigan, USA
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27
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Hsieh ML, Waters CM, Hinton DM. VpsR Directly Activates Transcription of Multiple Biofilm Genes in Vibrio cholerae. J Bacteriol 2020; 202:e00234-20. [PMID: 32661076 PMCID: PMC7925080 DOI: 10.1128/jb.00234-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 06/25/2020] [Indexed: 01/05/2023] Open
Abstract
Vibrio cholerae biofilm biogenesis, which is important for survival, dissemination, and persistence, requires multiple genes in the Vibrio polysaccharides (vps) operons I and II as well as the cluster of ribomatrix (rbm) genes. Transcriptional control of these genes is a complex process that requires several activators/repressors and the ubiquitous signaling molecule, cyclic di-GMP (c-di-GMP). Previously, we demonstrated that VpsR directly activates RNA polymerase containing σ70 (σ70-RNAP) at the vpsL promoter (P vpsL ), which precedes the vps-II operon, in a c-di-GMP-dependent manner by stimulating formation of the transcriptionally active, open complex. Using in vitro transcription, electrophoretic mobility shift assays, and DNase I footprinting, we show here that VpsR also directly activates σ70-RNAP transcription from other promoters within the biofilm formation cluster, including P vpsU , at the beginning of the vps-I operon, P rbmA , at the start of the rbm cluster, and P rbmF , which lies upstream of the divergent rbmF and rbmE genes. In this capacity, we find that VpsR is able to behave both as a class II activator, which functions immediately adjacent/overlapping the core promoter sequence (P vpsL and P vpsU ), and as a class I activator, which functions farther upstream (P rbmA and P rbmF ). Because these promoters vary in VpsR-DNA binding affinity in the absence and presence of c-di-GMP, we speculate that VpsR's mechanism of activation is dependent on both the concentration of VpsR and the level of c-di-GMP to increase transcription, resulting in finely tuned regulation.IMPORTANCEVibrio cholerae, the bacterial pathogen that is responsible for the disease cholera, uses biofilms to aid in survival, dissemination, and persistence. VpsR, which directly senses the second messenger c-di-GMP, is a major regulator of this process. Together with c-di-GMP, VpsR directly activates transcription by RNA polymerase containing σ70 from the vpsL biofilm biogenesis promoter. Using biochemical methods, we demonstrate for the first time that VpsR/c-di-GMP directly activates σ70-RNA polymerase at the first genes of the vps and ribomatrix operons. In this regard, it functions as either a class I or class II activator. Our results broaden the mechanism of c-di-GMP-dependent transcription activation and the specific role of VpsR in biofilm formation.
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Affiliation(s)
- Meng-Lun Hsieh
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA
- Gene Expression and Regulation Section, Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Christopher M Waters
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Deborah M Hinton
- Gene Expression and Regulation Section, Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
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28
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Spatiotemporal Regulation of Vibrio Exotoxins by HlyU and Other Transcriptional Regulators. Toxins (Basel) 2020; 12:toxins12090544. [PMID: 32842612 PMCID: PMC7551375 DOI: 10.3390/toxins12090544] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 08/17/2020] [Accepted: 08/19/2020] [Indexed: 02/06/2023] Open
Abstract
After invading a host, bacterial pathogens secrete diverse protein toxins to disrupt host defense systems. To ensure successful infection, however, pathogens must precisely regulate the expression of those exotoxins because uncontrolled toxin production squanders energy. Furthermore, inappropriate toxin secretion can trigger host immune responses that are detrimental to the invading pathogens. Therefore, bacterial pathogens use diverse transcriptional regulators to accurately regulate multiple exotoxin genes based on spatiotemporal conditions. This review covers three major exotoxins in pathogenic Vibrio species and their transcriptional regulation systems. When Vibrio encounters a host, genes encoding cytolysin/hemolysin, multifunctional-autoprocessing repeats-in-toxin (MARTX) toxin, and secreted phospholipases are coordinately regulated by the transcriptional regulator HlyU. At the same time, however, they are distinctly controlled by a variety of other transcriptional regulators. How this coordinated but distinct regulation of exotoxins makes Vibrio species successful pathogens? In addition, anti-virulence strategies that target the coordinating master regulator HlyU and related future research directions are discussed.
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29
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A MARTX Toxin rtxA Gene Is Controlled by Host Environmental Signals through a CRP-Coordinated Regulatory Network in Vibrio vulnificus. mBio 2020; 11:mBio.00723-20. [PMID: 32723914 PMCID: PMC7387792 DOI: 10.1128/mbio.00723-20] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
A MARTX toxin, RtxA, is an essential virulence factor of many pathogens, including Vibrio species. H-NS and HlyU repress and derepress, respectively, rtxA expression of a life-threatening pathogen, Vibrio vulnificus. We found that Lrp directly activates rtxA independently of H-NS and HlyU, and leucine inhibits the Lrp-mediated activation of rtxA. Furthermore, we demonstrated that CRP represses rtxA but derepresses in the presence of exogenous glucose. CRP represses rtxA not only directly by binding to upstream of rtxA but also indirectly by repressing lrp and hlyU. This is the first report of a regulatory network comprising CRP, Lrp, H-NS, and HlyU, which coordinates the rtxA expression in response to environmental signals such as leucine and glucose during infection. This elaborate regulatory network will enhance the fitness of V. vulnificus and contribute to its successful infection within the host. A multifunctional autoprocessing repeats-in-toxin (MARTX) toxin plays an essential role in the virulence of many pathogens, including a fulminating human pathogen Vibrio vulnificus. H-NS and HlyU repress and derepress expression of the MARTX toxin gene rtxA in V. vulnificus, respectively. However, little is known about other regulatory proteins and environmental signals involved in rtxA regulation. In this study, we found that a leucine-responsive regulatory protein (Lrp) activates rtxA by binding directly and specifically to the rtxA promoter, PrtxA. Phased hypersensitivity resulting from DNase I cleavage of the PrtxA regulatory region suggests that Lrp probably induces DNA bending in PrtxA. Lrp activates PrtxA independently of H-NS and HlyU, and leucine inhibits Lrp binding to PrtxA and reduces the Lrp-mediated activation. Furthermore, a cyclic AMP receptor protein (CRP) represses PrtxA, and exogenous glucose relieves the CRP-mediated repression. Biochemical and mutational analyses demonstrated that CRP binds directly and specifically to the upstream region of PrtxA, which presumably alters the DNA conformation in PrtxA and thus represses rtxA. Moreover, CRP represses expression of lrp and hlyU by binding directly to their upstream regions, forming coherent feed-forward loops with Lrp and HlyU. In conclusion, expression of rtxA is controlled by a regulatory network comprising CRP, Lrp, H-NS, and HlyU in response to changes in host environmental signals such as leucine and glucose. This collaborative regulation enables the elaborate expression of rtxA, thereby enhancing the fitness and pathogenesis of V. vulnificus during the course of infection.
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Abstract
Cholera is a devastating illness that kills tens of thousands of people annually. Vibrio cholerae, the causative agent of cholera, is an important model organism to investigate both bacterial pathogenesis and the impact of horizontal gene transfer on the emergence and dissemination of new virulent strains. Despite the importance of this pathogen, roughly one-third of V. cholerae genes are functionally unannotated, leaving large gaps in our understanding of this microbe. Through coexpression network analysis of existing RNA sequencing data, this work develops an approach to uncover novel gene-gene relationships and contextualize genes with no known function, which will advance our understanding of V. cholerae virulence and evolution. Research into the evolution and pathogenesis of Vibrio cholerae has benefited greatly from the generation of high-throughput sequencing data to drive molecular analyses. The steady accumulation of these data sets now provides a unique opportunity for in silico hypothesis generation via coexpression analysis. Here, we leverage all published V. cholerae RNA sequencing data, in combination with select data from other platforms, to generate a gene coexpression network that validates known gene interactions and identifies novel genetic partners across the entire V. cholerae genome. This network provides direct insights into genes influencing pathogenicity, metabolism, and transcriptional regulation, further clarifies results from previous sequencing experiments in V. cholerae (e.g., transposon insertion sequencing [Tn-seq] and chromatin immunoprecipitation sequencing [ChIP-seq]), and expands upon microarray-based findings in related Gram-negative bacteria. IMPORTANCE Cholera is a devastating illness that kills tens of thousands of people annually. Vibrio cholerae, the causative agent of cholera, is an important model organism to investigate both bacterial pathogenesis and the impact of horizontal gene transfer on the emergence and dissemination of new virulent strains. Despite the importance of this pathogen, roughly one-third of V. cholerae genes are functionally unannotated, leaving large gaps in our understanding of this microbe. Through coexpression network analysis of existing RNA sequencing data, this work develops an approach to uncover novel gene-gene relationships and contextualize genes with no known function, which will advance our understanding of V. cholerae virulence and evolution.
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31
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Khannpnavar B, Mehta V, Qi C, Korkhov V. Structure and function of adenylyl cyclases, key enzymes in cellular signaling. Curr Opin Struct Biol 2020; 63:34-41. [PMID: 32334344 DOI: 10.1016/j.sbi.2020.03.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 03/01/2020] [Accepted: 03/06/2020] [Indexed: 12/19/2022]
Abstract
The adenylyl cyclases (ACs) catalyze the production of the ubiquitous second messenger, cAMP, which in turns acts on a number of effectors and thus regulates a plethora of cellular functions. As the key enzymes in the highly evolutionarily conserved cAMP pathway, the ACs control the physiology of the cells, tissues, organs and organisms in health and disease. A comprehensive understanding of the specific role of the ACs in these processes of life requires a deep mechanistic understanding of structure and mechanisms of action of these enzymes. Here we highlight the exciting recent reports on the biochemistry and structure and higher order organization of the ACs and their signaling complexes. These studies have provided the glimpses into the principles of the AC-mediated homeostatic control of cellular physiology.
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Affiliation(s)
- Basavraj Khannpnavar
- Institute of Biochemistry, ETH Zurich, Switzerland; Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen 5232, Switzerland
| | - Ved Mehta
- Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen 5232, Switzerland
| | - Chao Qi
- Institute of Biochemistry, ETH Zurich, Switzerland; Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen 5232, Switzerland
| | - Volodymyr Korkhov
- Institute of Biochemistry, ETH Zurich, Switzerland; Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen 5232, Switzerland.
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32
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O'Boyle N, Turner NCA, Roe AJ, Connolly JPR. Plastic Circuits: Regulatory Flexibility in Fine Tuning Pathogen Success. Trends Microbiol 2020; 28:360-371. [PMID: 32298614 DOI: 10.1016/j.tim.2020.01.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 01/07/2020] [Accepted: 01/16/2020] [Indexed: 12/30/2022]
Abstract
Bacterial pathogens employ diverse fitness and virulence mechanisms to gain an advantage in competitive niches. These lifestyle-specific traits require integration into the regulatory network of the cell and are often controlled by pre-existing transcription factors. In this review, we highlight recent advances that have been made in characterizing this regulatory flexibility in prominent members of the Enterobacteriaceae. We focus on the direct global interactions between transcription factors and their target genes in pathogenic Escherichia coli and Salmonella revealed using chromatin immunoprecipitation coupled with next-generation sequencing. Furthermore, the implications and advantages of such regulatory adaptations in benefiting distinct pathogenic lifestyles are discussed.
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Affiliation(s)
- Nicky O'Boyle
- Institute of Infection, Immunity, and Inflammation, University of Glasgow, Glasgow, G12 8TA, UK
| | - Natasha C A Turner
- Institute of Infection, Immunity, and Inflammation, University of Glasgow, Glasgow, G12 8TA, UK
| | - Andrew J Roe
- Institute of Infection, Immunity, and Inflammation, University of Glasgow, Glasgow, G12 8TA, UK.
| | - James P R Connolly
- Institute of Infection, Immunity, and Inflammation, University of Glasgow, Glasgow, G12 8TA, UK; Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle-upon-Tyne, NE2 4HH, UK.
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33
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Flores EM, Nguyen AT, Odem MA, Eisenhoffer GT, Krachler AM. The zebrafish as a model for gastrointestinal tract-microbe interactions. Cell Microbiol 2020; 22:e13152. [PMID: 31872937 DOI: 10.1111/cmi.13152] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 11/07/2019] [Accepted: 12/19/2019] [Indexed: 02/06/2023]
Abstract
The zebrafish (Danio rerio) has become a widely used vertebrate model for bacterial, fungal, viral, and protozoan infections. Due to its genetic tractability, large clutch sizes, ease of manipulation, and optical transparency during early life stages, it is a particularly useful model to address questions about the cellular microbiology of host-microbe interactions. Although its use as a model for systemic infections, as well as infections localised to the hindbrain and swimbladder having been thoroughly reviewed, studies focusing on host-microbe interactions in the zebrafish gastrointestinal tract have been neglected. Here, we summarise recent findings regarding the developmental and immune biology of the gastrointestinal tract, drawing parallels to mammalian systems. We discuss the use of adult and larval zebrafish as models for gastrointestinal infections, and more generally, for studies of host-microbe interactions in the gut.
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Affiliation(s)
- Erika M Flores
- Department of Microbiology and Molecular Genetics, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas.,M.D. Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, Texas
| | - Anh T Nguyen
- Department of Microbiology and Molecular Genetics, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas.,M.D. Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, Texas
| | - Max A Odem
- Department of Microbiology and Molecular Genetics, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas
| | - George T Eisenhoffer
- M.D. Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, Texas.,Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Anne Marie Krachler
- Department of Microbiology and Molecular Genetics, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas.,M.D. Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, Texas
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Abstract
Vibrio cholerae, the causative agent of the diarrheal disease cholera, benefits from a sessile biofilm lifestyle that enhances survival outside the host but also contributes to host colonization and infectivity. The bacterial second messenger c-di-GMP has been identified as a central regulator of biofilm formation, including in V. cholerae; however, our understanding of the pathways that contribute to this process is incomplete. Here, we define a conserved signaling system that controls the stability of large adhesion proteins at the cell surface of V. cholerae, which are important for cell attachment and biofilm formation. Insight into the regulatory circuit underlying biofilm formation may inform targeted strategies to interfere with a process that renders this bacterium remarkably adaptable to changing environments. The dinucleotide second messenger c-di-GMP has emerged as a central regulator of reversible cell attachment during bacterial biofilm formation. A prominent cell adhesion mechanism first identified in pseudomonads combines two c-di-GMP-mediated processes: transcription of a large adhesin and its cell surface display via posttranslational proteolytic control. Here, we characterize an orthologous c-di-GMP effector system and show that it is operational in Vibrio cholerae, where it regulates two distinct classes of adhesins. Through structural analyses, we reveal a conserved autoinhibition mechanism of the c-di-GMP receptor that controls adhesin proteolysis and present a structure of a c-di-GMP-bound receptor module. We further establish functionality of the periplasmic protease controlled by the receptor against the two adhesins. Finally, transcription and functional assays identify physiological roles of both c-di-GMP-regulated adhesins in surface attachment and biofilm formation. Together, our studies highlight the conservation of a highly efficient signaling effector circuit for the control of cell surface adhesin expression and its versatility by revealing strain-specific variations.
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The quorum sensing transcription factor AphA directly regulates natural competence in Vibrio cholerae. PLoS Genet 2019; 15:e1008362. [PMID: 31658256 PMCID: PMC6855506 DOI: 10.1371/journal.pgen.1008362] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 11/14/2019] [Accepted: 10/16/2019] [Indexed: 01/30/2023] Open
Abstract
Many bacteria use population density to control gene expression via quorum sensing. In Vibrio cholerae, quorum sensing coordinates virulence, biofilm formation, and DNA uptake by natural competence. The transcription factors AphA and HapR, expressed at low and high cell density respectively, play a key role. In particular, AphA triggers the entire virulence cascade upon host colonisation. In this work we have mapped genome-wide DNA binding by AphA. We show that AphA is versatile, exhibiting distinct modes of DNA binding and promoter regulation. Unexpectedly, whilst HapR is known to induce natural competence, we demonstrate that AphA also intervenes. Most notably, AphA is a direct repressor of tfoX, the master activator of competence. Hence, production of AphA markedly suppressed DNA uptake; an effect largely circumvented by ectopic expression of tfoX. Our observations suggest dual regulation of competence. At low cell density AphA is a master repressor whilst HapR activates the process at high cell density. Thus, we provide deep mechanistic insight into the role of AphA and highlight how V. cholerae utilises this regulator for diverse purposes. Cholera remains a devastating diarrhoeal disease responsible for millions of cases, thousands of deaths, and a $3 billion financial burden every year. Although notorious for causing human disease, the microorganism responsible for cholera is predominantly a resident of aquatic environments. Here, the organism survives in densely packed communities on the surfaces of crustaceans. Remarkably, in this situation, the microbe can feast on neighbouring cells and acquire their DNA. This provides a useful food source and an opportunity to obtain new genetic information. In this paper, we have investigated how acquisition of DNA from the local environment is regulated. We show that a “switch” within the microbial cell, known to activate disease processes in the human host, also controls DNA uptake. Our results explain why DNA scavenging only occurs in suitable environments and illustrates how interactions between common regulatory switches affords precise control of microbial behaviours.
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Li J, Lu S, Kan B, Liang W. Serotype-shifting gene rfbT is a direct transcriptional target of cAMP receptor protein (CRP) in V. cholerae O1. Biochem Biophys Res Commun 2019; 519:874-879. [PMID: 31563325 DOI: 10.1016/j.bbrc.2019.09.080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 09/19/2019] [Indexed: 11/26/2022]
Abstract
Ogawa and Inaba are two main serotypes of O1 V. cholerae and alternate among cholera epidemics. The rfbT gene encodes a methyltransferase and is required for Ogawa serotype. The Inaba serotype is the consequence of genetic alterations in rfbT gene which results in loss-of-function enzyme product. However, the expression and regulation of rfbT has not been understood yet. Here we demonstrated that a global regulator, cAMP receptor protein (CRP), positively regulates rfbT transcription through a non-canonical CRP binding site (CBS) in its promoter region. This finding is supported by the analyses of rfbT mRNA abundance, rfbT-lacZ fusions and electrophoretic mobility shift assay (EMSA). The analyses of rfbT mRNA level in wild type (WT), Δcrp, and lower or higher level of cAMP backgrounds revealed that CRP is required for rfbT expression in response to intracellular cAMP level. Subsequent rfbT-lacZ fusions and EMSA collectively displayed that cAMP-CRP complex transcriptionally activates rfbT through directly binding to CBS in rfbT promoter region. Consistently, serological microagglutination test showed that crp deletion resulted in at least 4-fold decrease in titer of Ogawa serum compared to its WT. These results expanded our knowledge of understanding the genetic determinants and probable regulatory mechanism of V. cholerae O1 serotype shift between Ogawa and Inaba.
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Affiliation(s)
- Jing Li
- National Institute for Communicable Disease Control and Prevention, and State Key Laboratory for Infectious Disease Prevention and Control, Chinese Centre for Disease Control and Prevention, Changping, Beijing, China
| | - Shan Lu
- National Institute for Communicable Disease Control and Prevention, and State Key Laboratory for Infectious Disease Prevention and Control, Chinese Centre for Disease Control and Prevention, Changping, Beijing, China.
| | - Biao Kan
- National Institute for Communicable Disease Control and Prevention, and State Key Laboratory for Infectious Disease Prevention and Control, Chinese Centre for Disease Control and Prevention, Changping, Beijing, China; Collaborative Innovation Centre for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Weili Liang
- National Institute for Communicable Disease Control and Prevention, and State Key Laboratory for Infectious Disease Prevention and Control, Chinese Centre for Disease Control and Prevention, Changping, Beijing, China; Collaborative Innovation Centre for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China.
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Malaiyan J, Balakrishnan A, Nasimuddin S, Mohan K, Meenakshi-Sundaram P, Mamandur-Devarajan S, Gnanadesikan S, Kandasamy M, Jayakumar N, Elumalai D, Ra GG. Novel gas producing Vibrio cholerae: a case report of gastroenteritis with acute kidney injury. Access Microbiol 2019; 1:e000005. [PMID: 32974506 PMCID: PMC7470351 DOI: 10.1099/acmi.0.000005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 01/10/2019] [Indexed: 11/21/2022] Open
Abstract
Background Bacterial characterization is important in clinical and epidemiological studies. We herein report the first case of gas-producing Vibrio cholera gastroenteritis with acute kidney injury. Case presentation A 30-year-old female presented to the emergency department with complaints of about ten episodes of watery diarrhea, four episodes of vomiting and elevated serum urea/creatinine levels. Although the bacteria were first misidentified as Vibrio furnissii by gas production on carbohydrate fermentation and triple sugar iron agar, it was later confirmed as Vibrio cholerae by 16 S rRNA gene sequencing and specific PCR. The treatment regimen was followed as for Vibrio species with intravenous fluids, ciprofloxacin and doxycycline. The patient recovered without relapse. Conclusions Literature survey from the PubMed database shows no gas-producing Vibrio cholerae isolate being reported in the world. Further, genotype studies are warranted to look into the gas production of Vibrio cholerae.
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Affiliation(s)
- Jeevan Malaiyan
- Department of Microbiology, Sri Muthukumaran Medical College Hospital and Research Institute, Affiliated to The Tamil Nadu Dr. M.G.R. Medical University, Chikkarayapuram, Chennai 600 069, India
| | - Anandan Balakrishnan
- Department of Genetics, Dr. ALM Post Graduate Institute of Basic Medical Sciences, University of Madras, Taramani campus, Chennai 600113, India
| | - Sowmya Nasimuddin
- Department of Microbiology, Sri Muthukumaran Medical College Hospital and Research Institute, Affiliated to The Tamil Nadu Dr. M.G.R. Medical University, Chikkarayapuram, Chennai 600 069, India
| | - Kamalraj Mohan
- Department of Microbiology, Sri Muthukumaran Medical College Hospital and Research Institute, Affiliated to The Tamil Nadu Dr. M.G.R. Medical University, Chikkarayapuram, Chennai 600 069, India
| | - PradeepRaj Meenakshi-Sundaram
- Department of General Medicine, Sri Muthukumaran Medical College Hospital and Research Institute, Affiliated to The Tamil Nadu Dr. M.G.R. Medical University, Chikkarayapuram, Chennai 600 069, India
| | - Selvam Mamandur-Devarajan
- Department of General Medicine, Sri Muthukumaran Medical College Hospital and Research Institute, Affiliated to The Tamil Nadu Dr. M.G.R. Medical University, Chikkarayapuram, Chennai 600 069, India
| | - Sumathi Gnanadesikan
- Department of Microbiology, Sri Muthukumaran Medical College Hospital and Research Institute, Affiliated to The Tamil Nadu Dr. M.G.R. Medical University, Chikkarayapuram, Chennai 600 069, India
| | - Mohanakrishnan Kandasamy
- Department of Microbiology, Sri Muthukumaran Medical College Hospital and Research Institute, Affiliated to The Tamil Nadu Dr. M.G.R. Medical University, Chikkarayapuram, Chennai 600 069, India
| | - Nithyalakshmi Jayakumar
- Department of Microbiology, Sri Muthukumaran Medical College Hospital and Research Institute, Affiliated to The Tamil Nadu Dr. M.G.R. Medical University, Chikkarayapuram, Chennai 600 069, India
| | - Dhevahi Elumalai
- Department of Microbiology, Sri Muthukumaran Medical College Hospital and Research Institute, Affiliated to The Tamil Nadu Dr. M.G.R. Medical University, Chikkarayapuram, Chennai 600 069, India
| | - Gokul G Ra
- Department of General Medicine, Sri Muthukumaran Medical College Hospital and Research Institute, Affiliated to The Tamil Nadu Dr. M.G.R. Medical University, Chikkarayapuram, Chennai 600 069, India
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A Putative Acetylation System in Vibrio cholerae Modulates Virulence in Arthropod Hosts. Appl Environ Microbiol 2018; 84:AEM.01113-18. [PMID: 30143508 DOI: 10.1128/aem.01113-18] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 08/19/2018] [Indexed: 12/16/2022] Open
Abstract
Acetylation is a broadly conserved mechanism of covalently modifying the proteome to precisely control protein activity. In bacteria, central metabolic enzymes and regulatory proteins, including those involved in virulence, can be targeted for acetylation. In this study, we directly link a putative acetylation system to metabolite-dependent virulence in the pathogen Vibrio cholerae We demonstrate that the cobB and yfiQ genes, which encode homologs of a deacetylase and an acetyltransferase, respectively, modulate V. cholerae metabolism of acetate, a bacterially derived short-chain fatty acid with important physiological roles in a diversity of host organisms. In Drosophila melanogaster, a model arthropod host for V. cholerae infection, the pathogen consumes acetate within the gastrointestinal tract, which contributes to fly mortality. We show that deletion of cobB impairs growth on acetate minimal medium, delays the consumption of acetate from rich medium, and reduces virulence of V. cholerae toward Drosophila These impacts can be reversed by complementing cobB or by introducing a deletion of yfiQ into the ΔcobB background. We further show that cobB controls the accumulation of triglycerides in the Drosophila midgut, which suggests that cobB directly modulates metabolite levels in vivo In Escherichia coli K-12, yfiQ is upregulated by cAMP-cAMP receptor protein (CRP), and we identified a similar pattern of regulation in V. cholerae, arguing that the system is activated in response to similar environmental cues. In summary, we demonstrate that proteins likely involved in acetylation can modulate the outcome of infection by regulating metabolite exchange between pathogens and their colonized hosts.IMPORTANCE The bacterium Vibrio cholerae causes severe disease in humans, and strains can persist in the environment in association with a wide diversity of host species. By investigating the molecular mechanisms that underlie these interactions, we can better understand constraints affecting the ecology and evolution of this global pathogen. The Drosophila model of Vibrio cholerae infection has revealed that bacterial regulation of acetate and other small metabolites from within the fly gastrointestinal tract is crucial for its virulence. Here, we demonstrate that genes that may modify the proteome of V. cholerae affect virulence toward Drosophila, most likely by modulating central metabolic pathways that control the consumption of acetate as well as other small molecules. These findings further highlight the many layers of regulation that tune bacterial metabolism to alter the trajectory of interactions between bacteria and their hosts.
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