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Miyakoshi M. Multilayered regulation of amino acid metabolism in Escherichia coli. Curr Opin Microbiol 2024; 77:102406. [PMID: 38061078 DOI: 10.1016/j.mib.2023.102406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 11/08/2023] [Accepted: 11/09/2023] [Indexed: 02/12/2024]
Abstract
Amino acid metabolism in Escherichia coli has long been studied and has established the basis for regulatory mechanisms at the transcriptional, posttranscriptional, and posttranslational levels. In addition to the classical signal transduction cascade involving posttranslational modifications (PTMs), novel PTMs in the two primary nitrogen assimilation pathways have recently been uncovered. The regulon of the master transcriptional regulator NtrC is further expanded by a small RNA derived from the 3´UTR of glutamine synthetase mRNA, which coordinates central carbon and nitrogen metabolism. Furthermore, recent advances in sequencing technologies have revealed the global regulatory networks of transcriptional and posttranscriptional regulators, Lrp and GcvB. This review provides an update of the multilayered and interconnected regulatory networks governing amino acid metabolism in E. coli.
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Affiliation(s)
- Masatoshi Miyakoshi
- Department of Infection Biology, Institute of Medicine, University of Tsukuba, 305-8575 Ibaraki, Japan.
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2
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Mock J, Schühle K, Linne U, Mock M, Heider J. A Synthetic Pathway for the Production of Benzylsuccinate in Escherichia coli. Molecules 2024; 29:415. [PMID: 38257328 PMCID: PMC10818641 DOI: 10.3390/molecules29020415] [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: 11/30/2023] [Revised: 12/21/2023] [Accepted: 12/26/2023] [Indexed: 01/24/2024] Open
Abstract
(R)-Benzylsuccinate is generated in anaerobic toluene degradation by the radical addition of toluene to fumarate and further degraded to benzoyl-CoA by a β-oxidation pathway. Using metabolic modules for benzoate transport and activation to benzoyl-CoA and the enzymes of benzylsuccinate β-oxidation, we established an artificial pathway for benzylsuccinate production in Escherichia coli, which is based on its degradation pathway running in reverse. Benzoate is supplied to the medium but needs to be converted to benzoyl-CoA by an uptake transporter and a benzoate-CoA ligase or CoA-transferase. In contrast, the second substrate succinate is endogenously produced from glucose under anaerobic conditions, and the constructed pathway includes a succinyl-CoA:benzylsuccinate CoA-transferase that activates it to the CoA-thioester. We present first evidence for the feasibility of this pathway and explore product yields under different growth conditions. Compared to aerobic cultures, the product yield increased more than 1000-fold in anaerobic glucose-fermenting cultures and showed further improvement under fumarate-respiring conditions. An important bottleneck to overcome appears to be product excretion, based on much higher recorded intracellular concentrations of benzylsuccinate, compared to those excreted. While no export system is known for benzylsuccinate, we observed an increased product yield after adding an unspecific mechanosensitive channel to the constructed pathway.
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Affiliation(s)
- Johanna Mock
- Fachbereich Biologe, Philipps-University Marburg, Karl-von-Frisch-Str. 8, 35043 Marburg, Germany
- Synmikro Center Marburg, Karl-von-Frisch-Str. 8, 35043 Marburg, Germany
| | - Karola Schühle
- Fachbereich Biologe, Philipps-University Marburg, Karl-von-Frisch-Str. 8, 35043 Marburg, Germany
| | - Uwe Linne
- Synmikro Center Marburg, Karl-von-Frisch-Str. 8, 35043 Marburg, Germany
- Fachbereich Chemie, Philipps-University Marburg, Hans-Meerwein-Str. 10, 35043 Marburg, Germany
| | - Marco Mock
- Fachbereich Biologe, Philipps-University Marburg, Karl-von-Frisch-Str. 8, 35043 Marburg, Germany
| | - Johann Heider
- Fachbereich Biologe, Philipps-University Marburg, Karl-von-Frisch-Str. 8, 35043 Marburg, Germany
- Synmikro Center Marburg, Karl-von-Frisch-Str. 8, 35043 Marburg, Germany
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3
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Little AS, Younker IT, Schechter MS, Bernardino PN, Méheust R, Stemczynski J, Scorza K, Mullowney MW, Sharan D, Waligurski E, Smith R, Ramanswamy R, Leiter W, Moran D, McMillin M, Odenwald MA, Iavarone AT, Sidebottom AM, Sundararajan A, Pamer EG, Eren AM, Light SH. Dietary- and host-derived metabolites are used by diverse gut bacteria for anaerobic respiration. Nat Microbiol 2024; 9:55-69. [PMID: 38177297 PMCID: PMC11055453 DOI: 10.1038/s41564-023-01560-2] [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: 01/11/2023] [Accepted: 11/14/2023] [Indexed: 01/06/2024]
Abstract
Respiratory reductases enable microorganisms to use molecules present in anaerobic ecosystems as energy-generating respiratory electron acceptors. Here we identify three taxonomically distinct families of human gut bacteria (Burkholderiaceae, Eggerthellaceae and Erysipelotrichaceae) that encode large arsenals of tens to hundreds of respiratory-like reductases per genome. Screening species from each family (Sutterella wadsworthensis, Eggerthella lenta and Holdemania filiformis), we discover 22 metabolites used as respiratory electron acceptors in a species-specific manner. Identified reactions transform multiple classes of dietary- and host-derived metabolites, including bioactive molecules resveratrol and itaconate. Products of identified respiratory metabolisms highlight poorly characterized compounds, such as the itaconate-derived 2-methylsuccinate. Reductase substrate profiling defines enzyme-substrate pairs and reveals a complex picture of reductase evolution, providing evidence that reductases with specificities for related cinnamate substrates independently emerged at least four times. These studies thus establish an exceptionally versatile form of anaerobic respiration that directly links microbial energy metabolism to the gut metabolome.
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Affiliation(s)
- Alexander S Little
- Duchossois Family Institute, University of Chicago, Chicago, IL, USA
- Department of Microbiology, University of Chicago, Chicago, IL, USA
| | - Isaac T Younker
- Duchossois Family Institute, University of Chicago, Chicago, IL, USA
- Department of Microbiology, University of Chicago, Chicago, IL, USA
| | - Matthew S Schechter
- Duchossois Family Institute, University of Chicago, Chicago, IL, USA
- Department of Microbiology, University of Chicago, Chicago, IL, USA
| | - Paola Nol Bernardino
- Duchossois Family Institute, University of Chicago, Chicago, IL, USA
- Department of Microbiology, University of Chicago, Chicago, IL, USA
| | - Raphaël Méheust
- Génomique Métabolique, CEA, Genoscope, Institut François Jacob, Université d'Évry, Université Paris-Saclay, CNRS, Evry, France
| | - Joshua Stemczynski
- Duchossois Family Institute, University of Chicago, Chicago, IL, USA
- Department of Microbiology, University of Chicago, Chicago, IL, USA
| | - Kaylie Scorza
- Duchossois Family Institute, University of Chicago, Chicago, IL, USA
- Department of Microbiology, University of Chicago, Chicago, IL, USA
| | | | - Deepti Sharan
- Duchossois Family Institute, University of Chicago, Chicago, IL, USA
- Department of Microbiology, University of Chicago, Chicago, IL, USA
| | - Emily Waligurski
- Duchossois Family Institute, University of Chicago, Chicago, IL, USA
| | - Rita Smith
- Duchossois Family Institute, University of Chicago, Chicago, IL, USA
| | | | - William Leiter
- Duchossois Family Institute, University of Chicago, Chicago, IL, USA
| | - David Moran
- Duchossois Family Institute, University of Chicago, Chicago, IL, USA
| | - Mary McMillin
- Duchossois Family Institute, University of Chicago, Chicago, IL, USA
| | - Matthew A Odenwald
- Duchossois Family Institute, University of Chicago, Chicago, IL, USA
- Section of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Chicago, Chicago, IL, USA
| | - Anthony T Iavarone
- QB3/Chemistry Mass Spectrometry Facility, University of California, Berkeley, Berkeley, CA, USA
| | | | | | - Eric G Pamer
- Duchossois Family Institute, University of Chicago, Chicago, IL, USA
- Department of Microbiology, University of Chicago, Chicago, IL, USA
- Section of Infectious Diseases & Global Health, Department of Medicine, University of Chicago, Chicago, IL, USA
| | - A Murat Eren
- Helmholtz Institute for Functional Marine Biodiversity, Oldenburg, Germany
- Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, Oldenbug, Germany
| | - Samuel H Light
- Duchossois Family Institute, University of Chicago, Chicago, IL, USA.
- Department of Microbiology, University of Chicago, Chicago, IL, USA.
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Liu B, Jiang L, Liu Y, Sun H, Yan J, Kang C, Yang B. Enterohaemorrhagic E. coli utilizes host- and microbiota-derived L-malate as a signaling molecule for intestinal colonization. Nat Commun 2023; 14:7227. [PMID: 37945607 PMCID: PMC10636207 DOI: 10.1038/s41467-023-43149-7] [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: 09/11/2023] [Accepted: 11/01/2023] [Indexed: 11/12/2023] Open
Abstract
The mammalian gastrointestinal tract is a complex environment that hosts a diverse microbial community. To establish infection, bacterial pathogens must be able to compete with the indigenous microbiota for nutrients, as well as sense the host environment and modulate the expression of genes essential for colonization and virulence. Here, we found that enterohemorrhagic Escherichia coli (EHEC) O157:H7 imports host- and microbiota-derived L-malate using the DcuABC transporters and converts these substrates into fumarate to fuel anaerobic fumarate respiration during infection, thereby promoting its colonization of the host intestine. Moreover, L-malate is important not only for nutrient metabolism but also as a signaling molecule that activates virulence gene expression in EHEC O157:H7. The complete virulence-regulating pathway was elucidated; the DcuS/DcuR two-component system senses high L-malate levels and transduces the signal to the master virulence regulator Ler, which in turn activates locus of enterocyte effacement (LEE) genes to promote EHEC O157:H7 adherence to epithelial cells of the large intestine. Disruption of this virulence-regulating pathway by deleting either dcuS or dcuR significantly reduced colonization by EHEC O157:H7 in the infant rabbit intestinal tract; therefore, targeting these genes and altering physiological aspects of the intestinal environment may offer alternatives for EHEC infection treatment.
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Affiliation(s)
- Bin Liu
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, 300457, P. R. China
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, 300071, P. R. China
| | - Lingyan Jiang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, 300457, P. R. China
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, 300071, P. R. China
| | - Yutao Liu
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, 300457, P. R. China
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, 300071, P. R. China
| | - Hongmin Sun
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, 300457, P. R. China
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, 300071, P. R. China
| | - Jun Yan
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, 300457, P. R. China
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, 300071, P. R. China
| | - Chenbo Kang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, 300457, P. R. China
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, 300071, P. R. China
| | - Bin Yang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin, 300457, P. R. China.
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, 300071, P. R. China.
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Cho YB, Park JW, Unden G, Kim OB. Asuc_0142 of Actinobacillus succinogenes 130Z is the l-aspartate/C4-dicarboxylate exchanger DcuA. MICROBIOLOGY (READING, ENGLAND) 2023; 169:001411. [PMID: 37906508 PMCID: PMC10634366 DOI: 10.1099/mic.0.001411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 10/25/2023] [Indexed: 11/02/2023]
Abstract
Anaerobic bacteria often use antiporters DcuB (malate/succinate antiport) or DcuA (l-aspartate/succinate antiport) for the excretion of succinate during fumarate respiration. The rumen bacterium Actinobacillus succinogenes is able to produce large amounts of succinate by fumarate respiration, using the DcuB-type transporter DcuE for l-malate/succinate antiport. Asuc_0142 was annotated as a second DcuB-type transporter. Deletion of Asuc_0142 decreased the uptake rate for l-[14C]aspartate into A. succinogenes cells. Properties of transport by heterologously expressed Asuc_0142 were investigated in an Escherichia coli mutant deficient of anaerobic C4DC transporters. Expression of Asuc_0142 resulted in high uptake activity for l-[14C]fumarate or l-[14C]aspartate, but the former showed a strong competitive inhibition by l-aspartate. In E. coli loaded with l-[14C]aspartate, [14C]succinate or [14C]fumarate, extracellular C4DCs initiated excretion of the intracellular substrates, with a preference for l-aspartateex/succinatein or l-aspartateex/fumaratein antiport. These findings indicate that Asuc_0142 represents a DcuA-type transporter for l-aspartate uptake and l-aspartateex/C4DCin antiport, differentiating it from the DcuB-type transporter DcuE for l-malateex/succinatein antiport. Sequence analysis and predicted structural characteristics confirm structural similarity of Asuc_0142 to DcuA, and Asuc_0142 was thus re-named as DcuAAs. The bovine rumen fluid contains l-aspartate (99.6 µM), whereas fumarate and l-malate are absent. Therefore, bovine rumen colonisers depend on l-aspartate as an exogenous substrate for fumarate respiration. A. succinogenes encodes HemG (protoporphyrinogen oxidase) and PyrD (dihydroorotate dehydrogenase) for haem and pyrimidine biosynthesis. The enzymes require fumarate as an electron acceptor, suggesting an essential role for l-aspartate, DcuAAs, and fumarate respiration for A. succinogenes growing in the bovine rumen.
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Affiliation(s)
- Young Bin Cho
- Division of EcoScience and Interdisciplinary Program of EcoCreative, Graduate School, Ewha Womans University, Seoul, 03760, Republic of Korea
| | - Ji Won Park
- Division of EcoScience and Interdisciplinary Program of EcoCreative, Graduate School, Ewha Womans University, Seoul, 03760, Republic of Korea
| | - Gottfried Unden
- Institute for Molecular Physiology (IMP), Microbiology and Biotechnology, Johannes Gutenberg-University, Biozentrum II, Hanns-Dieter-Hüsch-Weg 17, 55128 Mainz, Germany
| | - Ok Bin Kim
- Division of EcoScience and Interdisciplinary Program of EcoCreative, Graduate School, Ewha Womans University, Seoul, 03760, Republic of Korea
- Department of Life Science, Ewha Womans University, Seoul, 03760, Republic of Korea
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Turner CB, Blount ZD, Mitchell DH, Lenski RE. Evolution of a cross-feeding interaction following a key innovation in a long-term evolution experiment with Escherichia coli. MICROBIOLOGY (READING, ENGLAND) 2023; 169:001390. [PMID: 37650867 PMCID: PMC10482366 DOI: 10.1099/mic.0.001390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 08/15/2023] [Indexed: 09/01/2023]
Abstract
The evolution of a novel trait can profoundly change an organism's effects on its environment, which can in turn affect the further evolution of that organism and any coexisting organisms. We examine these effects and feedbacks following the evolution of a novel function in the Long-Term Evolution Experiment (LTEE) with Escherichia coli. A characteristic feature of E. coli is its inability to grow aerobically on citrate (Cit-). Nonetheless, a Cit+ variant with this capacity evolved in one LTEE population after 31 000 generations. The Cit+ clade then coexisted stably with another clade that retained the ancestral Cit- phenotype. This coexistence was shaped by the evolution of a cross-feeding relationship based on C4-dicarboxylic acids, particularly succinate, fumarate, and malate, that the Cit+ variants release into the medium. Both the Cit- and Cit+ cells evolved to grow on these excreted resources. The evolution of aerobic growth on citrate thus led to a transition from an ecosystem based on a single limiting resource, glucose, to one with at least five resources that were either shared or partitioned between the two coexisting clades. Our findings show that evolutionary novelties can change environmental conditions in ways that facilitate diversity by altering ecosystem structure and the evolutionary trajectories of coexisting lineages.
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Affiliation(s)
- Caroline B. Turner
- Ecology, Evolution and Behavior Program, Michigan State University, East Lansing, MI, USA
- Present address: Department of Biology, Loyola University Chicago, Chicago, IL, USA
| | - Zachary D. Blount
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA
| | - Daniel H. Mitchell
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA
- Present address: Biological Sciences, University of New Hampshire, Durham, NH, USA
| | - Richard E. Lenski
- Department of Microbiology and Molecular Genetics; and Ecology, Evolution and Behavior Program, Michigan State University, East Lansing, MI, USA
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François-Étienne S, Nicolas L, Eric N, Jaqueline C, Pierre-Luc M, Sidki B, Aleicia H, Danilo B, Luis VA, Nicolas D. Important role of endogenous microbial symbionts of fish gills in the challenging but highly biodiverse Amazonian blackwaters. Nat Commun 2023; 14:3903. [PMID: 37414754 PMCID: PMC10326040 DOI: 10.1038/s41467-023-39461-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 06/09/2023] [Indexed: 07/08/2023] Open
Abstract
Amazonian blackwaters are extremely biodiverse systems containing some of Earth's most naturally acidic, dissolved organic carbon -rich and ion-poor waters. Physiological adaptations of fish facing these ionoregulatory challenges are unresolved but could involve microbially-mediated processes. Here, we characterize the physiological response of 964 fish-microbe systems from four blackwater Teleost species along a natural hydrochemical gradient, using dual RNA-Seq and 16 S rRNA of gill samples. We find that host transcriptional responses to blackwaters are species-specific, but occasionally include the overexpression of Toll-receptors and integrins associated to interkingdom communication. Blackwater gill microbiomes are characterized by a transcriptionally-active betaproteobacterial cluster potentially interfering with epithelial permeability. We explore further blackwater fish-microbe interactions by analyzing transcriptomes of axenic zebrafish larvae exposed to sterile, non-sterile and inverted (non-native bacterioplankton) blackwater. We find that axenic zebrafish survive poorly when exposed to sterile/inverted blackwater. Overall, our results suggest a critical role for endogenous symbionts in blackwater fish physiology.
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Affiliation(s)
- Sylvain François-Étienne
- Institut de Biologie Intégrative et des Systèmes, Université Laval, 1030 avenue de la Médecine, Québec (QC), G1V 0A6, Canada.
- Fisheries and Oceans, Gulf Fisheries Center, 343 University Ave, Moncton, NB, E1C 5K4, Canada.
| | - Leroux Nicolas
- Institut de Biologie Intégrative et des Systèmes, Université Laval, 1030 avenue de la Médecine, Québec (QC), G1V 0A6, Canada
| | - Normandeau Eric
- Institut de Biologie Intégrative et des Systèmes, Université Laval, 1030 avenue de la Médecine, Québec (QC), G1V 0A6, Canada
| | - Custodio Jaqueline
- Instituto Nacional de Pesquisas da Amazônia (INPA), Laboratório de Ecofisiologia e Evolução Molecular, Manaus, AM, 69067-375, Brazil
| | - Mercier Pierre-Luc
- Institut de Biologie Intégrative et des Systèmes, Université Laval, 1030 avenue de la Médecine, Québec (QC), G1V 0A6, Canada
| | - Bouslama Sidki
- Institut de Biologie Intégrative et des Systèmes, Université Laval, 1030 avenue de la Médecine, Québec (QC), G1V 0A6, Canada
| | - Holland Aleicia
- La Trobe University, School of Agriculture, Biomedicine and Environment, Department of Environment and Genetics, Centre for Freshwater Ecosystems, Albury/Wodonga Campus, Vic, Australia
| | - Barroso Danilo
- Instituto Nacional de Pesquisas da Amazônia (INPA), Laboratório de Ecofisiologia e Evolução Molecular, Manaus, AM, 69067-375, Brazil
| | - Val Adalberto Luis
- Instituto Nacional de Pesquisas da Amazônia (INPA), Laboratório de Ecofisiologia e Evolução Molecular, Manaus, AM, 69067-375, Brazil
| | - Derome Nicolas
- Institut de Biologie Intégrative et des Systèmes, Université Laval, 1030 avenue de la Médecine, Québec (QC), G1V 0A6, Canada
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Luo Y, Yan X, Xia Y, Cao Y. Tetracarboxylic acid transporter regulates growth, conidiation, and carbon utilization in Metarhizium acridum. Appl Microbiol Biotechnol 2023; 107:2969-2982. [PMID: 36941435 DOI: 10.1007/s00253-023-12471-x] [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: 12/10/2022] [Revised: 02/25/2023] [Accepted: 02/28/2023] [Indexed: 03/23/2023]
Abstract
Carbon sources and their utilization are vital for fungal growth and development. C4-dicarboxylic acids are important carbon and energy sources that function as intermediate products of the tricarboxylic acid cycle. Transport and regulation of C4-dicarboxylic acid uptake are mainly dependent on tetracarboxylic acid transporters (Dcts) in many microbes, although the roles of Dct genes in fungi have only been partially characterized. Here, we report on the functions of two Dct genes (Dct1 and Dct2) in the entomopathogenic fungus Metarhizium acridum. Our data showed that loss of the MaDct1 gene affected utilization of tetracarboxylic acids and other carbon sources. ΔMaDct1 mutants showed larger colony sizes with extensive mycelial growth but were delayed in conidiation with decreased conidia yield as compared to the wild-type parental strain. On the nutrient-deficient medium, SYA, the wild-type strain produced microcycle conidia, whereas the ΔMaDct1 mutant produced (normal) aerial conidia. In addition, ΔMaDct1 had decreased tolerance to cell wall perturbing agents, but increased tolerances to UV-B radiation and osmotic stress. Insect bioassays indicated that loss of MaDct1 did not affect pathogenicity. In contrast, no distinct phenotypic change was observed for the MaDct2 mutant in terms of growth and biocontrol characteristics. Transcriptomic profiling between wild type and ΔMaDct1 showed that differentially expressed genes were enriched in carbohydrate and amino acid metabolism, transport and catabolism, and signal transduction. These results demonstrate that MaDct1 regulates the conidiation pattern shift and mycelial growth by affecting utilization of carbon sources. These findings are helpful for better understanding the effect of intermediates of carbon metabolism on fungal growth and conidiation. KEY POINTS: • MaDct1 influences fungal growth and conidiation by affecting carbon source utilization. • MaDct1 regulates conidiation pattern shift under nutrient deficiency condition. • MaDct1 is involved in stress tolerance and has no effect on virulence. • MaDct2 has no effect on growth and biocontrol characteristic.
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Affiliation(s)
- Yunxiao Luo
- School of Life Sciences, Chongqing University, Chongqing, 401331, People's Republic of China
- Chongqing Engineering Research Center for Fungal Insecticides, Chongqing, 401331, People's Republic of China
- Key Laboratory of Gene Function and Regulation Technologies Under Chongqing Municipal Education Commission, Chongqing, China
| | - Xi Yan
- School of Life Sciences, Chongqing University, Chongqing, 401331, People's Republic of China
- Chongqing Engineering Research Center for Fungal Insecticides, Chongqing, 401331, People's Republic of China
- Key Laboratory of Gene Function and Regulation Technologies Under Chongqing Municipal Education Commission, Chongqing, China
| | - Yuxian Xia
- School of Life Sciences, Chongqing University, Chongqing, 401331, People's Republic of China.
- Chongqing Engineering Research Center for Fungal Insecticides, Chongqing, 401331, People's Republic of China.
- Key Laboratory of Gene Function and Regulation Technologies Under Chongqing Municipal Education Commission, Chongqing, China.
| | - Yueqing Cao
- School of Life Sciences, Chongqing University, Chongqing, 401331, People's Republic of China.
- Chongqing Engineering Research Center for Fungal Insecticides, Chongqing, 401331, People's Republic of China.
- Key Laboratory of Gene Function and Regulation Technologies Under Chongqing Municipal Education Commission, Chongqing, China.
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9
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Schubert C, Unden G. Fumarate, a central electron acceptor for Enterobacteriaceae beyond fumarate respiration and energy conservation. Adv Microb Physiol 2023; 82:267-299. [PMID: 36948656 DOI: 10.1016/bs.ampbs.2022.10.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
C4-dicarboxylates (C4-DCs) such as fumarate, l-malate and l-aspartate are key substrates for Enterobacteria such as Escherichia coli or Salmonella typhimurium during anaerobic growth. In general, C4-DCs are oxidants during biosynthesis, e.g., of pyrimidine or heme, acceptors for redox balancing, a high-quality nitrogen source (l-aspartate) and electron acceptor for fumarate respiration. Fumarate reduction is required for efficient colonization of the murine intestine, even though the colon contains only small amounts of C4-DCs. However, fumarate can be produced endogenously by central metabolism, allowing autonomous production of an electron acceptor for biosynthesis and redox balancing. Bacteria possess a complex set of transporters for the uptake (DctA), antiport (DcuA, DcuB, TtdT) and excretion (DcuC) of C4-DCs. DctA and DcuB exert regulatory functions and link transport to metabolic control through interaction with regulatory proteins. The sensor kinase DcuS of the C4-DC two-component system DcuS-DcuR forms complexes with DctA (aerobic) or DcuB (anaerobic), representing the functional state of the sensor. Moreover, EIIAGlc from the glucose phospho-transferase system binds to DctA and presumably inhibits C4-DC uptake. Overall, the function of fumarate as an oxidant in biosynthesis and redox balancing explains the pivotal role of fumarate reductase for intestinal colonization, while the role of fumarate in energy conservation (fumarate respiration) is of minor importance.
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Affiliation(s)
- Christopher Schubert
- Institute for Molecular Physiology (IMP), Microbiology and Biotechnology; Johannes Gutenberg-University, Mainz, Germany; Institute of Microbiology, ETH Zurich, Zurich, Switzerland.
| | - Gottfried Unden
- Institute for Molecular Physiology (IMP), Microbiology and Biotechnology; Johannes Gutenberg-University, Mainz, Germany.
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10
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Schubert C, Kim NY, Unden G, Kim OB. C4-dicarboxylate metabolons: interaction of C4-dicarboxylate transporters of Escherichia coli with cytosolic enzymes. FEMS Microbiol Lett 2022; 369:6679557. [PMID: 36044995 DOI: 10.1093/femsle/fnac078] [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: 04/07/2022] [Revised: 05/02/2022] [Accepted: 08/16/2022] [Indexed: 11/13/2022] Open
Abstract
Metabolons represent the structural organization of proteins for metabolic or regulatory pathways. Here the interaction of fumarase FumB, aspartase AspA, and L-tartrate dehydratase TtdAB with the C4-dicarboxylate (C4-DC) transporters DcuA, DcuB, DcuC, and the L-tartrate transporter TtdT of Escherichia coli was tested by a bacterial two-hybrid (BACTH) assay in situ, or by co-chromatography using mSPINE (membrane Streptavidin protein interaction experiment). From the general C4-DC transporters, DcuB interacted with FumB and AspA, DcuA with AspA, whereas DcuC interacted with neither FumB nor AspA. Moreover, TtdT did not interact with TtdAB. The fumB-dcuB, the dcuA-aspA, and the ttdAB-ttdT genes encoding the respective proteins co-localize on the genome and each pair of genes forms co-transcripts whereas the dcuC gene lies alone. The data suggest the formation of DcuB/FumB and DcuB/AspA metabolons for the uptake of L-malate, or L-aspartate, and their conversion to fumarate for fumarate respiration and excretion of the product succinate. The DcuA/AspA metabolon catalyzes uptake and conversion of L-Asp to fumarate coupled to succinate excretion. The DcuA/AspA metabolon provides ammonia at the same time for nitrogen assimilation (ammonia shuttle). On the other hand, TtdT and TtdAB are not organized in a metabolon. Reasons for the formation (DcuA/AspA, DcuB/FumB, DcuB/AspA) or non-formation (DcuC, TtdT and TtdAB) of metabolons are discussed based on their metabolic roles.
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Affiliation(s)
- Christopher Schubert
- Institute for Molecular Physiology, Johannes Gutenberg-University, Mainz, Germany
| | - Nam Yeun Kim
- Department of Life Science, Ewha Womans University, Seoul, Korea
| | - Gottfried Unden
- Institute for Molecular Physiology, Johannes Gutenberg-University, Mainz, Germany
| | - Ok Bin Kim
- Department of Life Science, Ewha Womans University, Seoul, Korea
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Tight Complex Formation of the Fumarate Sensing DcuS-DcuR Two-Component System at the Membrane and Target Promoter Search by Free DcuR Diffusion. mSphere 2022; 7:e0023522. [PMID: 35862816 PMCID: PMC9429925 DOI: 10.1128/msphere.00235-22] [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] [Indexed: 11/30/2022] Open
Abstract
Signaling of two-component systems by phosphoryl transfer requires interaction of the sensor kinase with the response regulator. Interaction of the C4-dicarboxylate-responsive and membrane-integral sensor kinase DcuS with the response regulator DcuR was studied. In vitro, the cytoplasmic part of DcuS (PASC-Kin) was employed. Stable complexes were formed, when either DcuS or DcuR were phosphorylated (Kd 22 ± 11 and 28 ± 7 nM, respectively). The unphosphorylated proteins produced a more labile complex (Kd 1380 ± 395 nM). Bacterial two-hybrid studies confirm interaction of DcuR with DcuS (and PASC-Kin) in vivo. The absolute contents of DcuR (197-979 pmol mg−1 protein) in the bacteria exceeded those of DcuS by more than 1 order of magnitude. According to the Kd values, DcuS exists in complex, with phosphorylated but also unphosphorylated DcuR. In live cell imaging, the predominantly freely diffusing DcuR becomes markedly less mobile after phosphorylation and activation of DcuS by fumarate. Portions of the low mobility fraction accumulated at the cell poles, the preferred location of DcuS, and other portions within the cell, representing phosphorylated DcuR bound to promoters. In the model, acitvation of DcuS increases the affinity toward DcuR, leading to DcuS-P × DcuR formation and phosphorylation of DcuR. The complex is stable enough for phosphate-transfer, but labile enough to allow exchange between DcuR from the cytosol and DcuR-P of the complex. Released DcuR-P diffuses to target promoters and binds. Uncomplexed DcuR-P in the cytosol binds to nonactivated DcuS and becomes dephosphorylated. The lower affinity between DcuR and DcuS avoids blocking of DcuS and allows rapid exchange of DcuR. IMPORTANCE Complex formation of membrane-bound sensor kinases with the response regulators represents an inherent step of signaling from the membrane to the promoters on the DNA. In the C4-dicarboxylate-sensing DcuS-DcuR two-component system, complex formation is strengthened by activation (phosphorylation) in vitro and in vivo, with trapping of the response regulator DcuR at the membrane. Single-molecule tracking of DcuR in the bacterial cell demonstrates two populations of DcuR with decreased mobility in the bacteria after activation: one at the membrane, but a second in the cytosol, likely representing DNA-bound DcuR. The data suggest a model with binding of DcuR to DcuS-P for phosphorylation, and of DcuR-P to DcuS for dephosphorylation, allowing rapid adaptation of the DcuR phosphorylation state. DcuR-P is released and transferred to DNA by 3D diffusion.
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