YdiV regulates Escherichia coli ferric uptake by manipulating the DNA-binding ability of Fur in a SlyD-dependent manner

Abstract Iron is essential for all bacteria. In most bacteria, intracellular iron homeostasis is tightly regulated by the ferric uptake regulator Fur. However, how Fur activates the iron-uptake system during iron deficiency is not fully elucidated. In this study, we found that YdiV, the flagella gene inhibitor, is involved in iron homeostasis in Escherichia coli. Iron deficiency triggers overexpression of YdiV. High levels of YdiV then transforms Fur into a novel form which does not bind DNA in a peptidyl-prolyl cis-trans isomerase SlyD dependent manner. Thus, the cooperation of YdiV, SlyD and Fur activates the gene expression of iron-uptake systems under conditions of iron deficiency. Bacterial invasion assays also demonstrated that both ydiV and slyD are necessary for the survival and growth of uropathogenic E. coli in bladder epithelial cells. This reveals a mechanism where YdiV not only represses flagella expression to make E. coli invisible to the host immune system, but it also promotes iron acquisition to help E. coli overcome host nutritional immunity.

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Ferric uptake regulator (Fur) reversibly binds a [2Fe-2S] cluster to sense intracellular iron homeostasis in Escherichia coli

Journal of Biological Chemistry ◽

10.1074/jbc.ra120.014814 ◽

2020 ◽

Vol 295 (46) ◽

pp. 15454-15463 ◽

Cited By ~ 1

Author(s):

Chelsey R. Fontenot ◽

Homyra Tasnim ◽

Kathryn A. Valdes ◽

Codrina V. Popescu ◽

Huangen Ding

Keyword(s):

Escherichia Coli ◽

Iron Content ◽

Iron Homeostasis ◽

Ferric Uptake Regulator ◽

Intracellular Iron ◽

Free Iron ◽

E Coli ◽

Genes Encoding ◽

Fur Protein ◽

Mutant Cells

The ferric uptake regulator (Fur) is a global transcription factor that regulates intracellular iron homeostasis in bacteria. The current hypothesis states that when the intracellular “free” iron concentration is elevated, Fur binds ferrous iron, and the iron-bound Fur represses the genes encoding for iron uptake systems and stimulates the genes encoding for iron storage proteins. However, the “iron-bound” Fur has never been isolated from any bacteria. Here we report that the Escherichia coli Fur has a bright red color when expressed in E. coli mutant cells containing an elevated intracellular free iron content because of deletion of the iron–sulfur cluster assembly proteins IscA and SufA. The acid-labile iron and sulfide content analyses in conjunction with the EPR and Mössbauer spectroscopy measurements and the site-directed mutagenesis studies show that the red Fur protein binds a [2Fe-2S] cluster via conserved cysteine residues. The occupancy of the [2Fe-2S] cluster in Fur protein is ∼31% in the E. coli iscA/sufA mutant cells and is decreased to ∼4% in WT E. coli cells. Depletion of the intracellular free iron content using the membrane-permeable iron chelator 2,2´-dipyridyl effectively removes the [2Fe-2S] cluster from Fur in E. coli cells, suggesting that Fur senses the intracellular free iron content via reversible binding of a [2Fe-2S] cluster. The binding of the [2Fe-2S] cluster in Fur appears to be highly conserved, because the Fur homolog from Hemophilus influenzae expressed in E. coli cells also reversibly binds a [2Fe-2S] cluster to sense intracellular iron homeostasis.

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ColV Plasmid-Mediated, Colicin V-Independent Iron Uptake System of Invasive Strains of Escherichia coli

Infection and Immunity ◽

10.1128/iai.29.2.411-416.1980 ◽

1980 ◽

Vol 29 (2) ◽

pp. 411-416

Author(s):

Peter H. Williams ◽

Philip J. Warner

Keyword(s):

Escherichia Coli ◽

Iron Uptake ◽

Chelating Agent ◽

Uptake System ◽

Uptake Mechanism ◽

E Coli ◽

Marked Enhancement ◽

Bacterial Cell Membrane ◽

Colicin V ◽

K 12

Evidence is presented that ColV plasmid-mediated iron uptake, an important component of the virulence of invasive strains of Escherichia coli , is independent of colicin V synthesis and activity. A mutant of E. coli K-12 deficient in the biosynthesis of enterochelin (strain AN1937) was unable to grow on minimal agar containing the chelating agent α,α′-dipyridyl unless it was harboring the plasmid ColV-K30 (strain LG1315). Acquisition of the active plasmid-specified iron sequestering system was accompanied by marked enhancement of pathogenicity in experimental infections of mice. Mutants of strain LG1315 were isolated that were defective in iron uptake due to plasmid mutations. They were unchanged with respect to colicin production, but were significantly less virulent than the parent strain. Conversely, mutants isolated as defective in colicin V synthesis were normal for the plasmid-coded iron uptake mechanism and showed the same lethality for infected mice as did strain LG1315. Furthermore, mutations in strain AN1937 which render it resistant or tolerant to the bactericidal action of colicin V did not influence the uptake of iron into plasmid-carrying strains. Cross-feeding tests involving plasmid mutants defective in iron uptake identified two plasmid-specified components of the system, an extracellular iron-chelating compound and a nondiffusible product allowing transport of iron across the bacterial cell membrane.

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Ferric Citrate Uptake is a Virulence Factor in Uropathogenic Escherichia coli

10.1101/2021.11.12.468464 ◽

2021 ◽

Author(s):

Arwen E Frick-Cheng ◽

Anna Sintsova ◽

Sara N Smith ◽

Ali Pirani ◽

Evan S Snitkin ◽

...

Keyword(s):

Escherichia Coli ◽

Urinary Tract ◽

Iron Acquisition ◽

Uropathogenic Escherichia Coli ◽

Ferric Citrate ◽

Uptake System ◽

Lipocalin 2 ◽

Compensatory Mechanisms ◽

E Coli ◽

Iron Source

More than half of women will experience a urinary tract infection (UTI) with uropathogenic Escherichia coli (UPEC) causing ~80% of uncomplicated cases. Iron acquisition systems are essential for uropathogenesis, and UPEC encode functionally redundant iron acquisition systems, underlining their importance. However, a recent UPEC clinical isolate, HM7 lacks this functional redundancy and instead encodes a sole siderophore, enterobactin. To determine if E. coli HM7 possesses unidentified iron acquisition systems, we performed RNA-sequencing under iron-limiting conditions and demonstrated that the ferric citrate uptake system (fecABCDE and fecIR) was highly upregulated. Importantly, there are high levels of citrate within urine, some of which is bound to iron, and the fec system is highly enriched in UPEC isolates compared to environmental or fecal strains. Therefore, we hypothesized that HM7 and other similar strains use the fec system to acquire iron in the host. Deletion of both enterobactin biosynthesis and ferric citrate uptake (ΔentB/ΔfecA) abrogates use of ferric citrate as an iron source and fecA provides an advantage in human urine in absence of enterobactin. However, in a UTI mouse model, fecA is a fitness factor independent of enterobactin production, likely due to the action of host Lipocalin-2 chelating ferrienterobactin. These findings indicate that ferric citrate uptake is used as an iron source when siderophore efficacy is limited, such as in the host during UTI. Defining these novel compensatory mechanisms and understanding the nutritional hierarchy of preferred iron sources within the urinary tract are important in the search for new approaches to combat UTI.

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Tyrosine phosphorylation-dependent localization of TmaR that controls activity of a major bacterial sugar regulator by polar sequestration

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2016017118 ◽

2020 ◽

Vol 118 (2) ◽

pp. e2016017118

Author(s):

Tamar Szoke ◽

Nitsan Albocher ◽

Sutharsan Govindarajan ◽

Anat Nussbaum-Shochat ◽

Orna Amster-Choder

Keyword(s):

Escherichia Coli ◽

Sugar Uptake ◽

Dependent Manner ◽

Tyrosine Residue ◽

Sugar Consumption ◽

E Coli ◽

Acidic Conditions ◽

Enzyme I ◽

Uptake And Metabolism ◽

Protein Enzyme

The poles of Escherichia coli cells are emerging as hubs for major sensory systems, but the polar determinants that allocate their components to the pole are largely unknown. Here, we describe the discovery of a previously unannotated protein, TmaR, which localizes to the E. coli cell pole when phosphorylated on a tyrosine residue. TmaR is shown here to control the subcellular localization and activity of the general PTS protein Enzyme I (EI) by binding and polar sequestration of EI, thus regulating sugar uptake and metabolism. Depletion or overexpression of TmaR results in EI release from the pole or enhanced recruitment to the pole, which leads to increasing or decreasing the rate of sugar consumption, respectively. Notably, phosphorylation of TmaR is required to release EI and enable its activity. Like TmaR, the ability of EI to be recruited to the pole depends on phosphorylation of one of its tyrosines. In addition to hyperactivity in sugar consumption, the absence of TmaR also leads to detrimental effects on the ability of cells to survive in mild acidic conditions. Our results suggest that this survival defect, which is sugar- and EI-dependent, reflects the difficulty of cells lacking TmaR to enter stationary phase. Our study identifies TmaR as the first, to our knowledge, E. coli protein reported to localize in a tyrosine-dependent manner and to control the activity of other proteins by their polar sequestration and release.

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The yliA, -B, -C, and -D Genes of Escherichia coli K-12 Encode a Novel Glutathione Importer with an ATP-Binding Cassette

Journal of Bacteriology ◽

10.1128/jb.187.17.5861-5867.2005 ◽

2005 ◽

Vol 187 (17) ◽

pp. 5861-5867 ◽

Cited By ~ 61

Author(s):

Hideyuki Suzuki ◽

Takashi Koyanagi ◽

Shunsuke Izuka ◽

Akiko Onishi ◽

Hidehiko Kumagai

Keyword(s):

Escherichia Coli ◽

Atp Binding ◽

Sulfur Source ◽

Dependent Manner ◽

Oxygen Species ◽

E Coli ◽

Living Organisms ◽

K 12 ◽

Atp Binding Cassette

ABSTRACT Glutathione protects cells and organisms from oxygen species and peroxides and is indispensable for aerobically living organisms. Moreover, it acts against xenobiotics and drugs by the formation and excretion of glutathione S conjugates. In this study, we show that the yliA, -B, -C, and -D genes of Escherichia coli K-12 encode a glutathione transporter with the ATP-binding cassette. The transporter imports extracellular glutathione into the cytoplasm in an ATP-dependent manner. This transporter, along with γ-glutamyltranspeptidase, has an important role in E. coli growth with glutathione as a sole sulfur source.

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Complex Iron Uptake by the Putrebactin-Mediated and Feo Systems in Shewanella oneidensis

Applied and Environmental Microbiology ◽

10.1128/aem.01752-18 ◽

2018 ◽

Vol 84 (20) ◽

Cited By ~ 3

Author(s):

Lulu Liu ◽

Shisheng Li ◽

Sijing Wang ◽

Ziyang Dong ◽

Haichun Gao

Keyword(s):

Iron Uptake ◽

Iron Homeostasis ◽

Shewanella Oneidensis ◽

Special Role ◽

Uptake System ◽

Biological Processes ◽

Content Type ◽

Iron Uptake System ◽

Reducing Bacteria ◽

Metal Reducing Bacteria

ABSTRACT Shewanella oneidensis is an extensively studied bacterium capable of respiring minerals, including a variety of iron ores, as terminal electron acceptors (EAs). Although iron plays an essential and special role in iron respiration of S. oneidensis, little has been done to date to investigate the characteristics of iron transport in this bacterium. In this study, we found that all proteins encoded by the pub-putA-putB cluster for putrebactin (S. oneidensis native siderophore) synthesis (PubABC), recognition-transport of Fe3+-putrebactin across the outer membrane (PutA), and reduction of ferric putrebactin (PutB) are essential to putrebactin-mediated iron uptake. Although homologs of PutA are many, none can function as its replacement, but some are able to work with other bacterial siderophores. We then showed that Fe2+-specific Feo is the other primary iron uptake system, based on the synthetical lethal phenotype resulting from the loss of both iron uptake routes. The role of the Feo system in iron uptake appears to be more critical, as growth is significantly impaired by the absence of the system but not of putrebactin. Furthermore, we demonstrate that hydroxyl acids, especially α-types such as lactate, promote iron uptake in a Feo-dependent manner. Overall, our findings underscore the importance of the ferrous iron uptake system in metal-reducing bacteria, providing an insight into iron homeostasis by linking these two biological processes. IMPORTANCE S. oneidensis is among the first- and the best-studied metal-reducing bacteria, with great potential in bioremediation and biotechnology. However, many questions regarding mechanisms closely associated with those applications, such as iron homeostasis, including iron uptake, export, and regulation, remain to be addressed. Here we show that Feo is a primary player in iron uptake in addition to the siderophore-dependent route. The investigation also resolved a few puzzles regarding the unexpected phenotypes of the putA mutant and lactate-dependent iron uptake. By elucidating the physiological roles of these two important iron uptake systems, this work revealed the breadth of the impacts of iron uptake systems on the biological processes.

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Anti-Bacterial Effect of CpG-DNA Involves Enhancement of the Complement Systems

International Journal of Molecular Sciences ◽

10.3390/ijms20143397 ◽

2019 ◽

Vol 20 (14) ◽

pp. 3397 ◽

Cited By ~ 1

Author(s):

Kim ◽

Park ◽

Kim ◽

Gautam ◽

Akauliya ◽

...

Keyword(s):

Escherichia Coli ◽

Immune System ◽

Bacterial Infections ◽

Bacterial Activity ◽

Complement C3 ◽

Host Immune System ◽

Cpg Dna ◽

Functional Roles ◽

E Coli ◽

Bacterial Effect

CpG-DNA activates the host immune system to resist bacterial infections. In this study, we examined the protective effect of CpG-DNA in mice against Escherichia coli (E. coli) K1 infection. Administration of CpG-DNA increased the survival of mice after E. coli K1 infection, which reduces the numbers of bacteria in the organs. Pre-injection of mice with CpG-DNA before E. coli K1 infection increased the levels of the complement C3 but not C3a and C3b. The survival of the mice after E. coli K1 infection was significantly decreased when the mice were pre-injected with the cobra venom factor (CVF) removing the complement compared to the non-CVF-treated mice group. It suggests that the complement has protective roles against E. coli K1 infection. In addition, the survival of complement-depleted mice was increased by CpG-DNA pre-administration before E. coli K1 infection. Therefore, we suggest that CpG-DNA enhances the anti-bacterial activity of the immune system by augmenting the levels of complement systems after E. coli K1 infection and triggering other factors as well. Further studies are required to investigate the functional roles of the CpG-DNA-induced complement regulation and other factors against urgent bacterial infection.

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Genomic Avenue to Avian Colisepticemia

mBio ◽

10.1128/mbio.01681-14 ◽

2015 ◽

Vol 6 (1) ◽

Cited By ~ 27

Author(s):

Sagi Huja ◽

Yaara Oren ◽

Eva Trost ◽

Elzbieta Brzuszkiewicz ◽

Dvora Biran ◽

...

Keyword(s):

Escherichia Coli ◽

Genetic Analysis ◽

Virulence Factors ◽

Iron Uptake ◽

Secretion System ◽

Economic Losses ◽

Content Type ◽

E Coli ◽

Type 3 Secretion System ◽

Type 3

ABSTRACTHere we present an extensive genomic and genetic analysis of Escherichia coli strains of serotype O78 that represent the major cause of avian colisepticemia, an invasive infection caused by avian pathogenicEscherichia coli(APEC) strains. It is associated with high mortality and morbidity, resulting in significant economic consequences for the poultry industry. To understand the genetic basis of the virulence of avian septicemic E. coli, we sequenced the entire genome of a clinical isolate of serotype O78—O78:H19 ST88 isolate 789 (O78-9)—and compared it with three publicly available APEC O78 sequences and one complete genome of APEC serotype O1 strain. Although there was a large variability in genome content between the APEC strains, several genes were conserved, which are potentially critical for colisepticemia. Some of these genes are present in multiple copies per genome or code for gene products with overlapping function, signifying their importance. A systematic deletion of each of these virulence-related genes identified three systems that are conserved in all septicemic strains examined and are critical for serum survival, a prerequisite for septicemia. These are the plasmid-encoded protein, the defective ETT2 (E. colitype 3 secretion system 2) type 3 secretion system ETT2sepsis, and iron uptake systems. Strain O78-9 is the only APEC O78 strain that also carried the regulon coding for yersiniabactin, the iron binding system of theYersiniahigh-pathogenicity island. Interestingly, this system is the only one that cannot be complemented by other iron uptake systems under iron limitation and in serum.IMPORTANCEAvian colisepticemia is a severe systemic disease of birds causing high morbidity and mortality and resulting in severe economic losses. The bacteria associated with avian colisepticemia are highly antibiotic resistant, making antibiotic treatment ineffective, and there is no effective vaccine due to the multitude of serotypes involved. To understand the disease and work out strategies to combat it, we performed an extensive genomic and genetic analysis of Escherichia coli strains of serotype O78, the major cause of the disease. We identified several potential virulence factors, conserved in all the colisepticemic strains examined, and determined their contribution to growth in serum, an absolute requirement for septicemia. These findings raise the possibility that specific vaccines or drugs can be developed against these critical virulence factors to help combat this economically important disease.

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Intracellular Free Iron and Its Potential Role in Ultrahigh-Pressure-Induced Inactivation of Escherichia coli

Applied and Environmental Microbiology ◽

10.1128/aem.02202-12 ◽

2012 ◽

Vol 79 (2) ◽

pp. 722-724 ◽

Cited By ~ 4

Author(s):

Yuan Yan ◽

Joy G. Waite-Cusic ◽

Periannan Kuppusamy ◽

Ahmed E. Yousef

Keyword(s):

Escherichia Coli ◽

Iron Chelator ◽

Ultrahigh Pressure ◽

Dependent Manner ◽

Paramagnetic Resonance ◽

Free Iron ◽

Content Type ◽

E Coli ◽

Electron Paramagnetic ◽

Dose Dependent

ABSTRACTIntracellular free iron ofEscherichia coliwas determined by whole-cell electron paramagnetic resonance spectrometry. Ultrahigh pressure (UHP) increased both intracellular free iron and cell lethality in a pressure-dose-dependent manner. The iron chelator 2,2′-dipyridyl protected cells against UHP treatments. A mutation that produced iron overload conditions sensitizedE. colito UHP treatment.

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Dopamine Is a Siderophore-Like Iron Chelator That PromotesSalmonella entericaSerovar Typhimurium Virulence in Mice

mBio ◽

10.1128/mbio.02624-18 ◽

2019 ◽

Vol 10 (1) ◽

Cited By ~ 7

Author(s):

Stefanie Dichtl ◽

Egon Demetz ◽

David Haschka ◽

Piotr Tymoszuk ◽

Verena Petzer ◽

...

Keyword(s):

Bacterial Growth ◽

Iron Uptake ◽

Iron Homeostasis ◽

Iron Acquisition ◽

Lipocalin 2 ◽

Intracellular Iron ◽

Content Type ◽

Hepcidin Expression

ABSTRACTWe have recently shown that the catecholamine dopamine regulates cellular iron homeostasis in macrophages. As iron is an essential nutrient for microbes, and intracellular iron availability affects the growth of intracellular bacteria, we studied whether dopamine administration impacts the course ofSalmonellainfections. Dopamine was found to promote the growth ofSalmonellaboth in culture and within bone marrow-derived macrophages, which was dependent on increased bacterial iron acquisition. Dopamine administration to mice infected withSalmonella entericaserovar Typhimurium resulted in significantly increased bacterial burdens in liver and spleen, as well as reduced survival. The promotion of bacterial growth by dopamine was independent of the siderophore-binding host peptide lipocalin-2. Rather, dopamine enhancement of iron uptake requires both the histidine sensor kinase QseC and bacterial iron transporters, in particular SitABCD, and may also involve the increased expression of bacterial iron uptake genes. Deletion or pharmacological blockade of QseC reduced but did not abolish the growth-promoting effects of dopamine. Dopamine also modulated systemic iron homeostasis by increasing hepcidin expression and depleting macrophages of the iron exporter ferroportin, which enhanced intracellular bacterial growth.Salmonellalacking all central iron uptake pathways failed to benefit from dopamine treatment. These observations are potentially relevant to critically ill patients, in whom the pharmacological administration of catecholamines to improve circulatory performance may exacerbate the course of infection with siderophilic bacteria.IMPORTANCEHere we show that dopamine increases bacterial iron incorporation and promotesSalmonellaTyphimurium growth bothin vitroandin vivo. These observations suggest the potential hazards of pharmacological catecholamine administration in patients with bacterial sepsis but also suggest that the inhibition of bacterial iron acquisition might provide a useful approach to antimicrobial therapy.

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