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Sikora F, Budja LVP, Milojevic O, Ziemniewicz A, Dudys P, Görke B. Multiple regulatory inputs including cell envelope stress orchestrate expression of the Escherichia coli rpoN operon. Mol Microbiol 2024; 122:11-28. [PMID: 38770591 DOI: 10.1111/mmi.15280] [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: 12/31/2023] [Revised: 04/21/2024] [Accepted: 05/07/2024] [Indexed: 05/22/2024]
Abstract
The rpoN operon, an important regulatory hub in Enterobacteriaceae, includes rpoN encoding sigma factor σ54, hpf involved in ribosome hibernation, rapZ regulating glucosamine-6-phosphate levels, and two genes encoding proteins of the nitrogen-related phosphotransferase system. Little is known about regulatory mechanisms controlling the abundance of these proteins. This study employs transposon mutagenesis and chemical screens to dissect the complex expression of the rpoN operon. We find that envelope stress conditions trigger read-through transcription into the rpoN operon from a promoter located upstream of the preceding lptA-lptB locus. This promoter is controlled by the envelope stress sigma factor E and response regulator PhoP is required for its full response to a subset of stress signals. σE also stimulates ptsN-rapZ-npr expression using an element downstream of rpoN, presumably by interfering with mRNA processing by RNase E. Additionally, we identify a novel promoter in the 3' end of rpoN that directs transcription of the distal genes in response to ethanol. Finally, we show that translation of hpf and ptsN is individually regulated by the RNA chaperone Hfq, perhaps involving small RNAs. Collectively, our work demonstrates that the rpoN operon is subject to complex regulation, integrating signals related to envelope stress and carbon source quality.
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Affiliation(s)
- Florian Sikora
- Max Perutz Labs, Vienna Biocenter Campus (VBC), Vienna, Austria
- Max Perutz Labs, Department of Microbiology, Immunobiology and Genetics, University of Vienna, Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna BioCenter (VBC), Vienna, Austria
| | - Lara Veronika Perko Budja
- Max Perutz Labs, Vienna Biocenter Campus (VBC), Vienna, Austria
- Max Perutz Labs, Department of Microbiology, Immunobiology and Genetics, University of Vienna, Vienna, Austria
| | - Olja Milojevic
- Max Perutz Labs, Vienna Biocenter Campus (VBC), Vienna, Austria
- Max Perutz Labs, Department of Microbiology, Immunobiology and Genetics, University of Vienna, Vienna, Austria
| | - Amelia Ziemniewicz
- Max Perutz Labs, Vienna Biocenter Campus (VBC), Vienna, Austria
- Max Perutz Labs, Department of Microbiology, Immunobiology and Genetics, University of Vienna, Vienna, Austria
| | - Przemyslaw Dudys
- Max Perutz Labs, Vienna Biocenter Campus (VBC), Vienna, Austria
- Max Perutz Labs, Department of Microbiology, Immunobiology and Genetics, University of Vienna, Vienna, Austria
| | - Boris Görke
- Max Perutz Labs, Vienna Biocenter Campus (VBC), Vienna, Austria
- Max Perutz Labs, Department of Microbiology, Immunobiology and Genetics, University of Vienna, Vienna, Austria
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2
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Calvanese M, D’Angelo C, Tutino ML, Lauro C. Whole-Cell Biosensor for Iron Monitoring as a Potential Tool for Safeguarding Biodiversity in Polar Marine Environments. Mar Drugs 2024; 22:299. [PMID: 39057408 PMCID: PMC11277574 DOI: 10.3390/md22070299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Revised: 06/05/2024] [Accepted: 06/24/2024] [Indexed: 07/28/2024] Open
Abstract
Iron is a key micronutrient essential for various essential biological processes. As a consequence, alteration in iron concentration in seawater can deeply influence marine biodiversity. In polar marine environments, where environmental conditions are characterized by low temperatures, the role of iron becomes particularly significant. While iron limitation can negatively influence primary production and nutrient cycling, excessive iron concentrations can lead to harmful algal blooms and oxygen depletion. Furthermore, the growth of certain phytoplankton species can be increased in high-iron-content environments, resulting in altered balance in the marine food web and reduced biodiversity. Although many chemical/physical methods are established for inorganic iron quantification, the determination of the bio-available iron in seawater samples is more suitably carried out using marine microorganisms as biosensors. Despite existing challenges, whole-cell biosensors offer other advantages, such as real-time detection, cost-effectiveness, and ease of manipulation, making them promising tools for monitoring environmental iron levels in polar marine ecosystems. In this review, we discuss fundamental biosensor designs and assemblies, arranging host features, transcription factors, reporter proteins, and detection methods. The progress in the genetic manipulation of iron-responsive regulatory and reporter modules is also addressed to the optimization of the biosensor performance, focusing on the improvement of sensitivity and specificity.
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Affiliation(s)
- Marzia Calvanese
- Department of Chemical Sciences, University of Naples “Federico II”, Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126 Naples, Italy; (M.C.); (C.D.); (M.L.T.)
- Istituto Nazionale Biostrutture e Biosistemi (I.N.B.B), Viale Medaglie D’Oro 305, 00136 Roma, Italy
| | - Caterina D’Angelo
- Department of Chemical Sciences, University of Naples “Federico II”, Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126 Naples, Italy; (M.C.); (C.D.); (M.L.T.)
| | - Maria Luisa Tutino
- Department of Chemical Sciences, University of Naples “Federico II”, Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126 Naples, Italy; (M.C.); (C.D.); (M.L.T.)
- Istituto Nazionale Biostrutture e Biosistemi (I.N.B.B), Viale Medaglie D’Oro 305, 00136 Roma, Italy
| | - Concetta Lauro
- Department of Chemical Sciences, University of Naples “Federico II”, Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126 Naples, Italy; (M.C.); (C.D.); (M.L.T.)
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Sun B, Tan B, Zhang P, Zhu L, Wei H, Huang T, Li C, Yang W. Iron deficiency anemia: a critical review on iron absorption, supplementation and its influence on gut microbiota. Food Funct 2024; 15:1144-1157. [PMID: 38235788 DOI: 10.1039/d3fo04644c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
Iron deficiency anemia (IDA) caused by micronutrient iron deficiency has attracted global attention due to its adverse health effects. The regulation of iron uptake and metabolism is finely controlled by various transporters and hormones in the body. Dietary iron intake and regulation are essential in maintaining human health and iron requirements. The review aims to investigate literature concerning dietary iron intake and systemic regulation. Besides, recent IDA treatment and dietary iron supplementation are discussed. Considering the importance of the gut microbiome, the interaction between bacteria and micronutrient iron in the gut is also a focus of this review. The iron absorption efficiency varies considerably according to iron type and dietary factors. Iron fortification remains the cost-effective strategy, although challenges exist in developing suitable iron fortificants and food vehicles regarding bioavailability and acceptability. Iron deficiency may alter the microbiome structure and promote the growth of pathogenic bacteria in the gut, affecting immune balance and human health.
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Affiliation(s)
- Bolun Sun
- College of Food and Pharmaceutical Sciences, Key Laboratory of Animal Protein Food Deep Processing Technology of Zhejiang Province, Ningbo University, Ningbo 315211, China.
- School of Nursing, Wenzhou Medical University, Wenzhou 325035, China
| | - Beibei Tan
- School of Agriculture and Food, Faculty of Science, University of Melbourne, Australia
| | - Panxue Zhang
- College of Food and Pharmaceutical Sciences, Key Laboratory of Animal Protein Food Deep Processing Technology of Zhejiang Province, Ningbo University, Ningbo 315211, China.
| | - Lianlian Zhu
- School of Nursing, Wenzhou Medical University, Wenzhou 325035, China
| | - Huamao Wei
- College of Food and Pharmaceutical Sciences, Key Laboratory of Animal Protein Food Deep Processing Technology of Zhejiang Province, Ningbo University, Ningbo 315211, China.
| | - Tao Huang
- College of Food and Pharmaceutical Sciences, Key Laboratory of Animal Protein Food Deep Processing Technology of Zhejiang Province, Ningbo University, Ningbo 315211, China.
| | - Chao Li
- College of Food and Pharmaceutical Sciences, Key Laboratory of Animal Protein Food Deep Processing Technology of Zhejiang Province, Ningbo University, Ningbo 315211, China.
| | - Wenge Yang
- College of Food and Pharmaceutical Sciences, Key Laboratory of Animal Protein Food Deep Processing Technology of Zhejiang Province, Ningbo University, Ningbo 315211, China.
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Verbeelen T, Fernandez CA, Nguyen TH, Gupta S, Aarts R, Tabury K, Leroy B, Wattiez R, Vlaeminck SE, Leys N, Ganigué R, Mastroleo F. Whole transcriptome analysis highlights nutrient limitation of nitrogen cycle bacteria in simulated microgravity. NPJ Microgravity 2024; 10:3. [PMID: 38200027 PMCID: PMC10781756 DOI: 10.1038/s41526-024-00345-z] [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: 09/20/2023] [Accepted: 01/01/2024] [Indexed: 01/12/2024] Open
Abstract
Regenerative life support systems (RLSS) will play a vital role in achieving self-sufficiency during long-distance space travel. Urine conversion into a liquid nitrate-based fertilizer is a key process in most RLSS. This study describes the effects of simulated microgravity (SMG) on Comamonas testosteroni, Nitrosomonas europaea, Nitrobacter winogradskyi and a tripartite culture of the three, in the context of nitrogen recovery for the Micro-Ecological Life Support System Alternative (MELiSSA). Rotary cell culture systems (RCCS) and random positioning machines (RPM) were used as SMG analogues. The transcriptional responses of the cultures were elucidated. For CO2-producing C. testosteroni and the tripartite culture, a PermaLifeTM PL-70 cell culture bag mounted on an in-house 3D-printed holder was applied to eliminate air bubble formation during SMG cultivation. Gene expression changes indicated that the fluid dynamics in SMG caused nutrient and O2 limitation. Genes involved in urea hydrolysis and nitrification were minimally affected, while denitrification-related gene expression was increased. The findings highlight potential challenges for nitrogen recovery in space.
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Affiliation(s)
- Tom Verbeelen
- Nuclear Medical Applications, Belgian Nuclear Research Centre (SCK CEN), Boeretang 200, 2400, Mol, Belgium
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000, Ghent, Belgium
| | - Celia Alvarez Fernandez
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000, Ghent, Belgium
| | - Thanh Huy Nguyen
- Department of Proteomics and Microbiology, University of Mons, Av. Du Champs de Mars 6, 7000, Mons, Belgium
| | - Surya Gupta
- Nuclear Medical Applications, Belgian Nuclear Research Centre (SCK CEN), Boeretang 200, 2400, Mol, Belgium
| | - Raf Aarts
- Nuclear Medical Applications, Belgian Nuclear Research Centre (SCK CEN), Boeretang 200, 2400, Mol, Belgium
| | - Kevin Tabury
- Nuclear Medical Applications, Belgian Nuclear Research Centre (SCK CEN), Boeretang 200, 2400, Mol, Belgium
| | - Baptiste Leroy
- Department of Proteomics and Microbiology, University of Mons, Av. Du Champs de Mars 6, 7000, Mons, Belgium
| | - Ruddy Wattiez
- Department of Proteomics and Microbiology, University of Mons, Av. Du Champs de Mars 6, 7000, Mons, Belgium
| | - Siegfried E Vlaeminck
- Research Group of Sustainable Energy, Air and Water Technology, Department of Bioscience Engineering, University of Antwerp, Groenenborgerlaan 171, 2020, Antwerp, Belgium
- Centre for Advanced Process Technology for Urban REsource Recovery (CAPTURE), Frieda Saeysstraat 1, 9052, Ghent, Belgium
| | - Natalie Leys
- Nuclear Medical Applications, Belgian Nuclear Research Centre (SCK CEN), Boeretang 200, 2400, Mol, Belgium
| | - Ramon Ganigué
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000, Ghent, Belgium
- Centre for Advanced Process Technology for Urban REsource Recovery (CAPTURE), Frieda Saeysstraat 1, 9052, Ghent, Belgium
| | - Felice Mastroleo
- Nuclear Medical Applications, Belgian Nuclear Research Centre (SCK CEN), Boeretang 200, 2400, Mol, Belgium.
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Tang B, Wang B, Xu Z, Hou R, Zhang M, Chen X, Liu Y, Liu F. Iron ions regulate antifungal HSAF biosynthesis in Lysobacter enzymogenes by manipulating the DNA-binding affinity of the ferric uptake regulator (Fur). Microbiol Spectr 2023; 11:e0061723. [PMID: 37737630 PMCID: PMC10581043 DOI: 10.1128/spectrum.00617-23] [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: 02/10/2023] [Accepted: 07/05/2023] [Indexed: 09/23/2023] Open
Abstract
Heat-stable antifungal factor (HSAF), produced by Lysobacter enzymogenes OH11, is regarded as a potential biological pesticide due to its broad-spectrum antifungal activity and novel mode of action. However, the current production of HSAF is low and cannot meet the requirements for large-scale production. Herein, we discovered that iron ions greatly promoted HSAF production, and the ferric uptake regulator (Fur) was involved in this regulatory process. Fur was also found to participate in the regulation of iron homeostasis in OH11 via the classic inhibition mechanism of Holo-Fur. Furthermore, Fur was collectively observed to directly bind to the promoter of the HSAF biosynthesis gene, and its DNA-binding affinity was attenuated by the addition of iron ions in vitro and in vivo. Its regulatory mechanism followed the uncommon inhibition mechanism of Apo-Fur. In summary, Fur exhibited a bidirectional regulatory mechanism in OH11. This study reveals a novel regulatory mechanism whereby Fur upregulates the biosynthesis of secondary metabolites. These findings contribute to the improvement of HSAF production and may guide its development into biological pesticides. IMPORTANCE HSAF possesses potent and broad antifungal activity with a novel mode of action. The HSAF yield is critical for fermentation production. In this study, iron ions were found to increase HSAF production, and the specific mechanism was elaborated. These results provide theoretical support for genetic transformation to improve HSAF yield, supporting its development into biological pesticides.
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Affiliation(s)
- Bao Tang
- Jiangsu Key Laboratory for Food Quality and Safety, State Key Laboratory Cultivation Base of Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, Institute of Plant Protection, Nanjing, Jiangsu, China
- School of Life Sciences, Jiangsu University, Zhengjiang, Jiangsu, China
| | - Bo Wang
- Jiangsu Key Laboratory for Food Quality and Safety, State Key Laboratory Cultivation Base of Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, Institute of Plant Protection, Nanjing, Jiangsu, China
| | - Zhizhou Xu
- Jiangsu Key Laboratory for Food Quality and Safety, State Key Laboratory Cultivation Base of Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, Institute of Plant Protection, Nanjing, Jiangsu, China
- College of Plant Protection, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Rouxian Hou
- Jiangsu Key Laboratory for Food Quality and Safety, State Key Laboratory Cultivation Base of Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, Institute of Plant Protection, Nanjing, Jiangsu, China
- College of Plant Protection, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Min Zhang
- Jiangsu Key Laboratory for Food Quality and Safety, State Key Laboratory Cultivation Base of Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, Institute of Plant Protection, Nanjing, Jiangsu, China
| | - Xian Chen
- Jiangsu Key Laboratory for Food Quality and Safety, State Key Laboratory Cultivation Base of Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, Institute of Plant Protection, Nanjing, Jiangsu, China
| | - Youzhou Liu
- Jiangsu Key Laboratory for Food Quality and Safety, State Key Laboratory Cultivation Base of Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, Institute of Plant Protection, Nanjing, Jiangsu, China
| | - Fengquan Liu
- Jiangsu Key Laboratory for Food Quality and Safety, State Key Laboratory Cultivation Base of Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, Institute of Plant Protection, Nanjing, Jiangsu, China
- College of Plant Protection, Hainan University, Haikou, China
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6
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Steingard CH, Helmann JD. Meddling with Metal Sensors: Fur-Family Proteins as Signaling Hubs. J Bacteriol 2023; 205:e0002223. [PMID: 37010421 PMCID: PMC10127796 DOI: 10.1128/jb.00022-23] [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] [Indexed: 04/04/2023] Open
Abstract
The ferric uptake regulator (Fur) protein is the founding member of the FUR superfamily of metalloregulatory proteins that control metal homeostasis in bacteria. FUR proteins regulate metal homeostasis in response to the binding of iron (Fur), zinc (Zur), manganese (Mur), or nickel (Nur). FUR family proteins are generally dimers in solution, but the DNA-bound complex can involve a single dimer, a dimer-of-dimers, or an extended array of bound protein. Elevated FUR levels due to changes in cell physiology increase DNA occupancy and may also kinetically facilitate protein dissociation. Interactions between FUR proteins and other regulators are commonplace, often including cooperative and competitive DNA-binding interactions within the regulatory region. Further, there are many emerging examples of allosteric regulators that interact directly with FUR family proteins. Here, we focus on newly uncovered examples of allosteric regulation by diverse Fur antagonists (Escherichia coli YdiV/SlyD, Salmonella enterica EIIANtr, Vibrio parahaemolyticus FcrX, Acinetobacter baumannii BlsA, Bacillus subtilis YlaN, and Pseudomonas aeruginosa PacT) as well as one Zur antagonist (Mycobacterium bovis CmtR). Small molecules and metal complexes may also serve as regulatory ligands, with examples including heme binding to Bradyrhizobium japonicum Irr and 2-oxoglutarate binding to Anabaena FurA. How these protein-protein and protein-ligand interactions act in conjunction with regulatory metal ions to facilitate signal integration is an active area of investigation.
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Affiliation(s)
| | - John D. Helmann
- Department of Microbiology, Cornell University, Ithaca, New York, USA
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Confirmation of Glucose Transporters through Targeted Mutagenesis and Transcriptional Analysis in Clostridium acetobutylicum. FERMENTATION 2023. [DOI: 10.3390/fermentation9010064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The solvent-producing bacterium Clostridium acetobutylicum is able to grow on a variety of carbohydrates. The main hexose transport system is the phosphoenolpyruvate-dependent phosphotransferase system (PTS). When the gene glcG that encodes the glucose transporter was inactivated, the resulting mutant glcG::int(1224) grew as well as the wild type, yet its glucose consumption was reduced by 17% in a batch fermentation. Transcriptomics analysis of the phosphate-limited continuous cultures showed that the cellobiose transporter GlcCE was highly up-regulated in the mutant glcG::int(1224). The glcCE mutation did not affect growth and even consumed slightly more glucose during solventogenesis growth compared to wild type, indicating that GlcG is the primary glucose-specific PTS. Poor growth of the double mutant glcG::int(1224)-glcCE::int(193) further revealed that GlcCE was the secondary glucose PTS and that there must be other PTSs capable of glucose uptake. The observations obtained in this study provided a promising foundation to understand glucose transport in C. acetobutylicum.
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Abstract
Iron limitation is a universal strategy of host immunity during bacterial infection. However, the mechanisms by which pathogens antagonize host nutritional immunity have not been fully elucidated. Here, we identified a requirement for the UMPylator YdiU for this process in Salmonella. The expression of YdiU was dramatically induced by the metal starvation signal. The intracellular iron content was much lower in the ΔydiU strain than in wild-type Salmonella, and the ΔydiU strain exhibited severe growth defect under metal deficiency environments. Genome-wide expression analyses revealed significantly decreased expression of iron uptake genes in ΔydiU strain compared with the wild-type strain. Interestingly, YdiU did not affect the expression level of the major iron uptake regulator Fur but directly UMPylated Fur on its H118 residue in vivo and in vitro. UMPylation destroyed the Fur dimer, promoted Fur aggregation, and eliminated the DNA-binding activity of Fur, thus abolishing the ability of Fur to inhibit iron uptake. Restricting Fur to the deUMPylated state dramatically eliminates Salmonella iron uptake in iron deficiency environments. In parallel, YdiU facilitates Salmonella survival within host cells by regulating the iron uptake pathway.
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Bowlin MQ, Long AR, Huffines JT, Gray MJ. The role of nitrogen-responsive regulators in controlling inorganic polyphosphate synthesis in Escherichia coli. MICROBIOLOGY (READING, ENGLAND) 2022; 168:001185. [PMID: 35482529 PMCID: PMC10233264 DOI: 10.1099/mic.0.001185] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 04/10/2022] [Indexed: 12/22/2022]
Abstract
Inorganic polyphosphate (polyP) is synthesized by bacteria under stressful environmental conditions and acts by a variety of mechanisms to promote cell survival. While the kinase that synthesizes polyP (PPK, encoded by the ppk gene) is well known, ppk transcription is not activated by environmental stress and little is understood about how environmental stress signals lead to polyP accumulation. Previous work has shown that the transcriptional regulators DksA, RpoN (σ54) and RpoE (σ24) positively regulate polyP production, but not ppk transcription, in Escherichia coli. In this work, we examine the role of the alternative sigma factor RpoN and nitrogen starvation stress response pathways in controlling polyP synthesis. We show that the RpoN enhancer binding proteins GlnG and GlrR impact polyP production, and uncover a new role for the nitrogen phosphotransferase regulator PtsN (EIIANtr) as a positive regulator of polyP production, acting upstream of DksA, downstream of RpoN and apparently independently of RpoE. However, neither these regulatory proteins nor common nitrogen metabolites appear to act directly on PPK, and the precise mechanism(s) by which polyP production is modulated after stress remain(s) unclear. Unexpectedly, we also found that the genes that impact polyP production vary depending on the composition of the rich media in which the cells were grown before exposure to polyP-inducing stress. These results constitute progress towards deciphering the regulatory networks driving polyP production under stress, and highlight the remarkable complexity of this regulation and its connections to a broad range of stress-sensing pathways.
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Affiliation(s)
- Marvin Q. Bowlin
- Department of Microbiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Abagail Renee Long
- Department of Microbiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Joshua T. Huffines
- Department of Microbiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Michael Jeffrey Gray
- Department of Microbiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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Shao S, Li C, Zhao L, Zhang Y, Yin K, Wang Q. Interplay between ferric uptake regulator Fur and horizontally acquired virulence regulator EsrB coordinates virulence gene expression in Edwardsiella piscicida. Microbiol Res 2021; 253:126892. [PMID: 34673373 DOI: 10.1016/j.micres.2021.126892] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 10/07/2021] [Accepted: 10/09/2021] [Indexed: 12/23/2022]
Abstract
Edwardsiella piscicida mediates hemorrhagic septicemia and is a leading pathogen of fish. E. piscicida invades and colonizes macrophages using type III and VI secretion systems (T3/T6SS) that are controlled by a two-component system (TCS) EsrA-EsrB. Iron acquisition is essential for E. piscicida pathogenesis and coordination between iron and TCS signaling in modulating bacterial virulence is not well understood. Here, we show that iron uptake systems are co-regulated by ferric uptake regulator (Fur) in E. piscicida. Fur bound to 98 genes that harbored conserved Fur-box to globally control the expression of ∼755 genes, including those encoding iron uptake systems, T3/T6SS, and Icc, cAMP phosphodiesterase that represses biofilm formation. Additionally, Fur, in complex with iron, bound to the esrB promoter to repress expression and ultimately attenuated virulence. Conversely, EsrB activated the expression of T3/T6SS and iron uptake systems to mitigate a shortage of intracellular iron during iron scarcity. Furthermore, EsrB directly bound to and activated the fur promoter, leading to Fur-ferrous ion-dependent esrB repression in the presence of iron. Finally, Fur-EsrB interplay was essential for bacterial fitness during in vivo infection and survival in seawater environments. Collectively, we highlight the mechanisms that underlie the reciprocal regulatory networks of iron homeostasis and virulence systems in E. piscicida.
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Affiliation(s)
- Shuai Shao
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China; Shanghai Engineering Research Center of Maricultured Animal Vaccines, Shanghai, China
| | - Chunli Li
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China
| | - Luyao Zhao
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China
| | - Yuanxing Zhang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), 519000, Zhuhai, China; Shanghai Engineering Research Center of Maricultured Animal Vaccines, Shanghai, China
| | - Kaiyu Yin
- School of Hospitality Management, Shanghai Business School, Shanghai, 200235, China.
| | - Qiyao Wang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China; Shanghai Engineering Research Center of Maricultured Animal Vaccines, Shanghai, China.
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11
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Groisman EA, Duprey A, Choi J. How the PhoP/PhoQ System Controls Virulence and Mg 2+ Homeostasis: Lessons in Signal Transduction, Pathogenesis, Physiology, and Evolution. Microbiol Mol Biol Rev 2021; 85:e0017620. [PMID: 34191587 PMCID: PMC8483708 DOI: 10.1128/mmbr.00176-20] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
The PhoP/PhoQ two-component system governs virulence, Mg2+ homeostasis, and resistance to a variety of antimicrobial agents, including acidic pH and cationic antimicrobial peptides, in several Gram-negative bacterial species. Best understood in Salmonella enterica serovar Typhimurium, the PhoP/PhoQ system consists o-regulated gene products alter PhoP-P amounts, even under constant inducing conditions. PhoP-P controls the abundance of hundreds of proteins both directly, by having transcriptional effects on the corresponding genes, and indirectly, by modifying the abundance, activity, or stability of other transcription factors, regulatory RNAs, protease regulators, and metabolites. The investigation of PhoP/PhoQ has uncovered novel forms of signal transduction and the physiological consequences of regulon evolution.
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Affiliation(s)
- Eduardo A. Groisman
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut, USA
- Yale Microbial Sciences Institute, West Haven, Connecticut, USA
| | - Alexandre Duprey
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut, USA
| | - Jeongjoon Choi
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut, USA
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12
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Xu Y, Yang S, You G, Hou J. Antibiotic resistance genes attenuation in anaerobic microorganisms during iron uptake from zero valent iron: An iron-dependent form of homeostasis and roles as regulators. WATER RESEARCH 2021; 195:116979. [PMID: 33690012 DOI: 10.1016/j.watres.2021.116979] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 02/17/2021] [Accepted: 02/24/2021] [Indexed: 06/12/2023]
Abstract
Zero valent iron (ZVI) has been previously documented to attenuate the propagation of antibiotic resistance genes (ARGs) in microbes, while how ZVI affects the evolution of ARGs remains unclear. Herein, we investigated the influences of ZVI on ARGs dissemination in anaerobic bioreactor treating oxytetracycline (tet) containing wastewater, by deciphering the roles of iron homeostasis and regulatory effects. A net reduction of tet gene targets ranging from 0.75 to 1.88 and 0.67 to 2.08 log unit in intracellular and extracellular DNA was achieved at the optimal dosage of 5 g/L ZVI, whereas 20 g/L ZVI made no effects on ARGs reduction. The reduced ARGs abundance by ZVI was directly related to the inhibited horizontal transfer of ARGs and decreased proliferation of resistant strains (mainly Paludibacter and WCHB1-32). The potential mechanisms included the increased antioxidant capacity, the depressed efflux pump system and the weakened energy driving force by Fur regulon in microbes (especially for Cloacibacterium and Dechloromonas). The negligible influence of 20 g/L ZVI on ARGs reduction was ascribed to the iron-catalyzed oxidative damage and reduced physiological activity. This study firstly illustrated the potential relationships among activation of iron uptake regulator leading to protection against oxidative stress, alternation of physiological metabolisms and reduction of ARGs dissemination. This work extents our understanding about the priority of ZVI in mitigating ARGs proliferation and sheds light on its potential application in wastewater treatment plants.
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Affiliation(s)
- Yi Xu
- College of Agricultural Engineering, Hohai University, Nanjing, 210098, PR China; Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, 1 Xikang Road, Nanjing 210098, PR China
| | - Shihong Yang
- College of Agricultural Engineering, Hohai University, Nanjing, 210098, PR China
| | - Guoxiang You
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, 1 Xikang Road, Nanjing 210098, PR China
| | - Jun Hou
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, 1 Xikang Road, Nanjing 210098, PR China.
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13
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Zhang X, Zhou D, Bai H, Liu Q, Xiao XL, Yu YG. Comparative transcriptome analysis of virulence genes of enterohemorrhagic Escherichia coli O157:H7 to acid stress. FOOD BIOTECHNOL 2021. [DOI: 10.1080/08905436.2021.1908345] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Xiaowei Zhang
- School of Food Science and Engineering, South China University of Technology, Guangzhou City, Guangdong Province, China
| | - Donggen Zhou
- Ningbo International Travel Healthcare Center, Ningbo City, Haishu District, China
| | - Hong Bai
- School of Food Science and Engineering, South China University of Technology, Guangzhou City, Guangdong Province, China
| | - Qijun Liu
- School of Food Science and Engineering, South China University of Technology, Guangzhou City, Guangdong Province, China
| | - Xing-Long Xiao
- School of Food Science and Engineering, South China University of Technology, Guangzhou City, Guangdong Province, China
| | - Yi-Gang Yu
- School of Food Science and Engineering, South China University of Technology, Guangzhou City, Guangdong Province, China
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14
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Bradley JM, Svistunenko DA, Wilson MT, Hemmings AM, Moore GR, Le Brun NE. Bacterial iron detoxification at the molecular level. J Biol Chem 2021; 295:17602-17623. [PMID: 33454001 PMCID: PMC7762939 DOI: 10.1074/jbc.rev120.007746] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 10/07/2020] [Indexed: 01/18/2023] Open
Abstract
Iron is an essential micronutrient, and, in the case of bacteria, its availability is commonly a growth-limiting factor. However, correct functioning of cells requires that the labile pool of chelatable "free" iron be tightly regulated. Correct metalation of proteins requiring iron as a cofactor demands that such a readily accessible source of iron exist, but overaccumulation results in an oxidative burden that, if unchecked, would lead to cell death. The toxicity of iron stems from its potential to catalyze formation of reactive oxygen species that, in addition to causing damage to biological molecules, can also lead to the formation of reactive nitrogen species. To avoid iron-mediated oxidative stress, bacteria utilize iron-dependent global regulators to sense the iron status of the cell and regulate the expression of proteins involved in the acquisition, storage, and efflux of iron accordingly. Here, we survey the current understanding of the structure and mechanism of the important members of each of these classes of protein. Diversity in the details of iron homeostasis mechanisms reflect the differing nutritional stresses resulting from the wide variety of ecological niches that bacteria inhabit. However, in this review, we seek to highlight the similarities of iron homeostasis between different bacteria, while acknowledging important variations. In this way, we hope to illustrate how bacteria have evolved common approaches to overcome the dual problems of the insolubility and potential toxicity of iron.
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Affiliation(s)
- Justin M Bradley
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich, United Kingdom.
| | | | - Michael T Wilson
- School of Life Sciences, University of Essex, Colchester, United Kingdom
| | - Andrew M Hemmings
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich, United Kingdom; Centre for Molecular and Structural Biochemistry, School of Biological Sciences, University of East Anglia, Norwich, United Kingdom
| | - Geoffrey R Moore
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich, United Kingdom
| | - Nick E Le Brun
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich, United Kingdom.
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15
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Huang M, Liu M, Liu J, Zhu D, Tang Q, Jia R, Chen S, Zhao X, Yang Q, Wu Y, Zhang S, Huang J, Ou X, Mao S, Gao Q, Sun D, Wang M, Cheng A. Functional characterization of Fur in iron metabolism, oxidative stress resistance and virulence of Riemerella anatipestifer. Vet Res 2021; 52:48. [PMID: 33741064 PMCID: PMC7976709 DOI: 10.1186/s13567-021-00919-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 03/01/2021] [Indexed: 12/11/2022] Open
Abstract
Iron is essential for most bacteria to survive, but excessive iron leads to damage by the Fenton reaction. Therefore, the concentration of intracellular free iron must be strictly controlled in bacteria. Riemerella anatipestifer (R. anatipestifer), a Gram-negative bacterium, encodes the iron uptake system. However, the iron homeostasis mechanism remains largely unknown. In this study, it was shown that compared with the wild type R. anatipestifer CH-1, R. anatipestifer CH-1Δfur was more sensitive to streptonigrin, and this effect was alleviated when the bacteria were cultured in iron-depleted medium, suggesting that the fur mutant led to excess iron accumulation inside cells. Similarly, compared with R. anatipestifer CH-1∆recA, R. anatipestifer CH-1∆recAΔfur was more sensitive to H2O2-induced oxidative stress when the bacteria were grown in iron-rich medium rather than iron-depleted medium. Accordingly, it was shown that R. anatipestifer CH-1∆recAΔfur produced more intracellular ROS than R. anatipestifer CH-1∆recA in iron-rich medium. Electrophoretic mobility shift assays showed that R. anatipestifer CH-1 Fur suppressed the transcription of putative iron uptake genes through binding to their promoter regions. Finally, it was shown that compared with the wild type, R. anatipestifer CH-1Δfur was significantly attenuated in ducklings and that the colonization ability of R. anatipestifer CH-1Δfur in various tissues or organs was decreased. All these results suggested that Fur is important for iron homeostasis in R. anatipestifer and its pathogenic mechanism.
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Affiliation(s)
- Mi Huang
- Institute of Preventive Veterinary Medicine, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Research Centre of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, 611130, Sichuan, China
| | - Mafeng Liu
- Institute of Preventive Veterinary Medicine, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Research Centre of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, 611130, Sichuan, China
| | - Jiajun Liu
- Institute of Preventive Veterinary Medicine, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Research Centre of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, 611130, Sichuan, China
| | - Dekang Zhu
- Research Centre of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, 611130, Sichuan, China
| | - Qianying Tang
- Institute of Preventive Veterinary Medicine, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Research Centre of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, 611130, Sichuan, China
| | - Renyong Jia
- Institute of Preventive Veterinary Medicine, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Research Centre of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, 611130, Sichuan, China
| | - Shun Chen
- Institute of Preventive Veterinary Medicine, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Research Centre of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, 611130, Sichuan, China
| | - Xinxin Zhao
- Institute of Preventive Veterinary Medicine, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Research Centre of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, 611130, Sichuan, China
| | - Qiao Yang
- Institute of Preventive Veterinary Medicine, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Research Centre of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, 611130, Sichuan, China
| | - Ying Wu
- Institute of Preventive Veterinary Medicine, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Research Centre of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, 611130, Sichuan, China
| | - Shaqiu Zhang
- Institute of Preventive Veterinary Medicine, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Research Centre of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, 611130, Sichuan, China
| | - Juan Huang
- Institute of Preventive Veterinary Medicine, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Research Centre of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, 611130, Sichuan, China
| | - Xumin Ou
- Institute of Preventive Veterinary Medicine, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Research Centre of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, 611130, Sichuan, China
| | - Sai Mao
- Institute of Preventive Veterinary Medicine, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Research Centre of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, 611130, Sichuan, China
| | - Qun Gao
- Institute of Preventive Veterinary Medicine, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Research Centre of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, 611130, Sichuan, China
| | - Di Sun
- Institute of Preventive Veterinary Medicine, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Research Centre of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, 611130, Sichuan, China
| | - Mingshu Wang
- Institute of Preventive Veterinary Medicine, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, 611130, Sichuan, China. .,Research Centre of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, 611130, Sichuan, China. .,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, 611130, Sichuan, China.
| | - Anchun Cheng
- Institute of Preventive Veterinary Medicine, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, 611130, Sichuan, China. .,Research Centre of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, 611130, Sichuan, China. .,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, 611130, Sichuan, China.
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16
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Morabe ML, McCarter LL. Vibrio parahaemolyticus FcrX, a Fur-controlled regulator that inhibits repression by Fur. Mol Microbiol 2020; 114:77-92. [PMID: 32096286 DOI: 10.1111/mmi.14497] [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: 06/03/2019] [Revised: 02/20/2020] [Accepted: 02/23/2020] [Indexed: 12/15/2022]
Abstract
Iron is an essential nutrient for most organisms, but its limited availability and inherent toxicity necessitate the strict regulation of iron homeostasis. In bacteria, iron starvation affects a broad range of phenotypes including virulence, motility and biofilm formation. For Vibrio parahaemolyticus, a marine bacterium and pathogen, iron limitation is a signal modulating swarmer cell differentiation. In this work, we show the iron regulation of swarming works through the ferric uptake regulator protein Fur. We identified a new Fur-controlled regulator that is upregulated upon iron starvation. FcrX is a 144-amino acid protein containing a domain of unknown function (DUF2753) with three tetratricopeptide repeats. We found that overexpressing fcrX+ was sufficient to induce swarming, luminescence and iron uptake gene expression in multiple Vibrio species; furthermore, ectopic expression increased the transcription of a Fur-controlled gene in Escherichia coli. FcrX production increased intracellular iron. Thus, the overexpression of fcrX+ phenocopied a fur mutant and may prove a generally useful tool to ectopically derepress the Fur regulon. Both V. parahaemolyticus and E. coli Fur interacted with FcrX, and this interaction was altered by iron availability. These data support a model in which this new regulator of iron homeostasis limits the repressive action of Fur.
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Affiliation(s)
- Maria L Morabe
- Department of Microbiology and Immunology, University of Iowa, Iowa City, IA, USA
| | - Linda L McCarter
- Department of Microbiology and Immunology, University of Iowa, Iowa City, IA, USA
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