1
|
Galvis J, Guyon J, Dartigues B, Hecht H, Grüning B, Specque F, Soueidan H, Karkar S, Daubon T, Nikolski M. DIMet: an open-source tool for differential analysis of targeted isotope-labeled metabolomics data. Bioinformatics 2024; 40:btae282. [PMID: 38656970 PMCID: PMC11109473 DOI: 10.1093/bioinformatics/btae282] [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: 10/26/2023] [Revised: 04/04/2024] [Accepted: 04/23/2024] [Indexed: 04/26/2024] Open
Abstract
MOTIVATION Many diseases, such as cancer, are characterized by an alteration of cellular metabolism allowing cells to adapt to changes in the microenvironment. Stable isotope-resolved metabolomics (SIRM) and downstream data analyses are widely used techniques for unraveling cells' metabolic activity to understand the altered functioning of metabolic pathways in the diseased state. While a number of bioinformatic solutions exist for the differential analysis of SIRM data, there is currently no available resource providing a comprehensive toolbox. RESULTS In this work, we present DIMet, a one-stop comprehensive tool for differential analysis of targeted tracer data. DIMet accepts metabolite total abundances, isotopologue contributions, and isotopic mean enrichment, and supports differential comparison (pairwise and multi-group), time-series analyses, and labeling profile comparison. Moreover, it integrates transcriptomics and targeted metabolomics data through network-based metabolograms. We illustrate the use of DIMet in real SIRM datasets obtained from Glioblastoma P3 cell-line samples. DIMet is open-source, and is readily available for routine downstream analysis of isotope-labeled targeted metabolomics data, as it can be used both in the command line interface or as a complete toolkit in the public Galaxy Europe and Workfow4Metabolomics web platforms. AVAILABILITY AND IMPLEMENTATION DIMet is freely available at https://github.com/cbib/DIMet, and through https://usegalaxy.eu and https://workflow4metabolomics.usegalaxy.fr. All the datasets are available at Zenodo https://zenodo.org/records/10925786.
Collapse
Affiliation(s)
- Johanna Galvis
- University of Bordeaux, CNRS, IBGC UMR 5095, Bordeaux, France
- University of Bordeaux, Bordeaux Bioinformatics Center CBiB, Bordeaux, France
| | - Joris Guyon
- University of Bordeaux, INSERM, BPH U1219, Bordeaux, France
- Medical Pharmacology Department, Bordeaux University Hospital, Bordeaux, France
| | - Benjamin Dartigues
- University of Bordeaux, Bordeaux Bioinformatics Center CBiB, Bordeaux, France
| | - Helge Hecht
- RECETOX, Faculty of Science, Masaryk University, Brno, Czech Republic
- Galaxy Europe, University of Freiburg, Freiburg, Baden-Württemberg, Germany
| | - Björn Grüning
- Galaxy Europe, University of Freiburg, Freiburg, Baden-Württemberg, Germany
- Bioinformatics Group, Department of Computer Science, Albert-Ludwigs-University Freiburg, 79110 Freiburg, Germany
| | - Florian Specque
- University of Bordeaux, CNRS, IBGC UMR 5095, Bordeaux, France
| | - Hayssam Soueidan
- University of Bordeaux, Bordeaux Bioinformatics Center CBiB, Bordeaux, France
| | - Slim Karkar
- University of Bordeaux, CNRS, IBGC UMR 5095, Bordeaux, France
- University of Bordeaux, Bordeaux Bioinformatics Center CBiB, Bordeaux, France
| | - Thomas Daubon
- University of Bordeaux, CNRS, IBGC UMR 5095, Bordeaux, France
| | - Macha Nikolski
- University of Bordeaux, CNRS, IBGC UMR 5095, Bordeaux, France
- University of Bordeaux, Bordeaux Bioinformatics Center CBiB, Bordeaux, France
| |
Collapse
|
2
|
Law RC, Nurwono G, Park JO. A parallel glycolysis provides a selective advantage through rapid growth acceleration. Nat Chem Biol 2024; 20:314-322. [PMID: 37537378 PMCID: PMC10987256 DOI: 10.1038/s41589-023-01395-2] [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: 09/03/2022] [Accepted: 07/06/2023] [Indexed: 08/05/2023]
Abstract
Glycolysis is a universal metabolic process that breaks down glucose to produce adenosine triphosphate (ATP) and biomass precursors. The Entner-Doudoroff (ED) pathway is a glycolytic pathway that parallels textbook glycolysis but yields half as much ATP. Accordingly, in organisms that possess both glycolytic pathways (for example, Escherichia coli), its raison d'être remains a mystery. In this study, we found that the ED pathway provides a selective advantage during growth acceleration. Upon carbon and nitrogen upshifts, E. coli accelerates growth faster with than without the ED pathway. Concurrent isotope tracing reveals that the ED pathway flux increases faster than that of textbook glycolysis. We attribute the fast response time of the ED pathway to its strong thermodynamic driving force and streamlining of glucose import. Intermittent nutrient supply manifests the evolutionary advantage of the parallel glycolysis; thus, the dynamic nature of an ostensibly redundant pathway's role in promoting rapid adaptation constitutes a metabolic design principle.
Collapse
Affiliation(s)
- Richard C Law
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, Los Angeles, CA, USA
| | - Glenn Nurwono
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, USA
| | - Junyoung O Park
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, Los Angeles, CA, USA.
| |
Collapse
|
3
|
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.
Collapse
Affiliation(s)
- Masatoshi Miyakoshi
- Department of Infection Biology, Institute of Medicine, University of Tsukuba, 305-8575 Ibaraki, Japan.
| |
Collapse
|
4
|
Bassett S, Ding Y, Roy MK, Reisz JA, D'Alessandro A, Nagpal P, Chatterjee A. Light-Driven Metabolic Pathways in Non-Photosynthetic Biohybrid Bacteria. Chembiochem 2024; 25:e202300572. [PMID: 37861981 DOI: 10.1002/cbic.202300572] [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: 08/14/2023] [Revised: 10/11/2023] [Accepted: 10/19/2023] [Indexed: 10/21/2023]
Abstract
Biomanufacturing via microorganisms relies on carbon substrates for molecular feedstocks and a source of energy to carry out enzymatic reactions. This creates metabolic bottlenecks and lowers the efficiency for substrate conversion. Nanoparticle biohybridization with proteins and whole cell surfaces can bypass the need for redox cofactor regeneration for improved secondary metabolite production in a non-specific manner. Here we propose using nanobiohybrid organisms (Nanorgs), intracellular protein-nanoparticle hybrids formed through the spontaneous coupling of core-shell quantum dots (QDs) with histidine-tagged enzymes in non-photosynthetic bacteria, for light-mediated control of bacterial metabolism. This proved to eliminate metabolic constrictions and replace glucose with light as the source of energy in Escherichia coli, with an increase in growth by 1.7-fold in 75 % reduced nutrient media. Metabolomic tracking through carbon isotope labeling confirmed flux shunting through targeted pathways, with accumulation of metabolites downstream of respective targets. Finally, application of Nanorgs with the Ehrlich pathway improved isobutanol titers/yield by 3.9-fold in 75 % less sugar from E. coli strains with no genetic alterations. These results demonstrate the promise of Nanorgs for metabolic engineering and low-cost biomanufacturing.
Collapse
Affiliation(s)
- Shane Bassett
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, CO 80303, USA
| | - Yuchen Ding
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, CO 80303, USA
| | - Micaela K Roy
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, 80045, USA
| | - Julie A Reisz
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, 80045, USA
| | - Angelo D'Alessandro
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, 80045, USA
| | - Prashant Nagpal
- ARC Labs, Louisville, CO 80027, USA
- Sachi Bio, Inc., Louisville, CO 80027, USA
| | - Anushree Chatterjee
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, CO 80303, USA
- ARC Labs, Louisville, CO 80027, USA
- Sachi Bio, Inc., Louisville, CO 80027, USA
| |
Collapse
|
5
|
Liu GH, Yang S, Han S, Xie CJ, Liu X, Rensing C, Zhou SG. Nitrogen fixation and transcriptome of a new diazotrophic Geomonas from paddy soils. mBio 2023; 14:e0215023. [PMID: 37855611 PMCID: PMC10746287 DOI: 10.1128/mbio.02150-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 09/07/2023] [Indexed: 10/20/2023] Open
Abstract
IMPORTANCE The ability of Geomonas species to fix nitrogen gas (N2) is an important metabolic feature for its application as a plant growth-promoting rhizobacterium. This research is of great importance as it provides the first comprehensive direct experimental evidence of nitrogen fixation by the genus Geomonas in pure culture. We isolated a number of Geomonas strains from paddy soils and determined that nifH was present in these strains. This study demonstrated that these Geomonas species harbored genes encoding nitrogenase, as do Geobacter and Anaeromyxobacter in the same class of Deltaproteobacteria. We demonstrated N2-dependent growth of Geomonas and determined regulation of gene expression associated with nitrogen fixation. The research establishes and advances our understanding of nitrogen fixation in Geomonas.
Collapse
Affiliation(s)
- Guo-Hong Liu
- Institute of Resources, Environment and Soil Fertilizer, Fujian Academy of Agricultural Sciences, Fuzhou City, Fujian Province, China
| | - Shang Yang
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou City, Fujian Province, China
| | - Shuang Han
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou City, Fujian Province, China
| | - Cheng-Jie Xie
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou City, Fujian Province, China
| | - Xing Liu
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou City, Fujian Province, China
| | - Christopher Rensing
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou City, Fujian Province, China
| | - Shun-Gui Zhou
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou City, Fujian Province, China
| |
Collapse
|
6
|
Li S, You X, Rani A, Özcan E, Sela DA. Bifidobacterium infantis utilizes N-acetylglucosamine-containing human milk oligosaccharides as a nitrogen source. Gut Microbes 2023; 15:2244721. [PMID: 37609905 PMCID: PMC10448974 DOI: 10.1080/19490976.2023.2244721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 07/26/2023] [Accepted: 08/01/2023] [Indexed: 08/24/2023] Open
Abstract
Bifidobacterium longum subsp. infantis (B. infantis) utilizes oligosaccharides secreted in human milk as a carbohydrate source. These human milk oligosaccharides (HMOs) integrate the nitrogenous residue N-acetylglucosamine (NAG), although HMO nitrogen utilization has not been described to date. Herein, we characterize the B. infantis nitrogen utilization phenotype on two NAG-containing HMO species, LNT and LNnT. This was characterized through in vitro growth kinetics, incorporation of isotopically labeled NAG nitrogen into the proteome, as well as modulation of intracellular 2-oxoglutarate levels while utilizing HMO nitrogen. Further support is provided by comparative transcriptomics and proteomics that identified global regulatory networks deployed during HMO nitrogen utilization. The aggregate data demonstrate that B. infantis strains utilize HMO nitrogen with the potential to significantly impact fundamental and clinical studies, as well as enable applications.
Collapse
Affiliation(s)
- Shuqi Li
- Department of Food Science, University of Massachusetts, Amherst, MA, USA
| | - Xiaomeng You
- Department of Food Science, University of Massachusetts, Amherst, MA, USA
| | - Asha Rani
- Department of Food Science, University of Massachusetts, Amherst, MA, USA
| | - Ezgi Özcan
- Department of Food Science, University of Massachusetts, Amherst, MA, USA
| | - David A. Sela
- Department of Food Science, University of Massachusetts, Amherst, MA, USA
- Department of Microbiology, University of Massachusetts Amherst, Amherst, MA, USA
- Department of Nutrition, University of Massachusetts Amherst, Amherst, MA, USA
- Department of Microbiology & Physiological Systems and Center for Microbiome Research, University of Massachusetts Medical School, Worcester, MA, USA
| |
Collapse
|
7
|
Sieradzki ET, Nuccio EE, Pett-Ridge J, Firestone MK. Rhizosphere and detritusphere habitats modulate expression of soil N-cycling genes during plant development. mSystems 2023; 8:e0031523. [PMID: 37754554 PMCID: PMC10654102 DOI: 10.1128/msystems.00315-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 08/07/2023] [Indexed: 09/28/2023] Open
Abstract
IMPORTANCE Plant roots modulate microbial nitrogen (N) cycling by regulating the supply of root-derived carbon and nitrogen uptake. These differences in resource availability cause distinct micro-habitats to develop: soil near living roots, decaying roots, near both, or outside the direct influence of roots. While many environmental factors and genes control the microbial processes involved in the nitrogen cycle, most research has focused on single genes and pathways, neglecting the interactive effects these pathways have on each other. The processes controlled by these pathways determine consumption and production of N by soil microorganisms. We followed the expression of N-cycling genes in four soil microhabitats over a period of active root growth for an annual grass. We found that the presence of root litter and living roots significantly altered gene expression involved in multiple nitrogen pathways, as well as tradeoffs between pathways, which ultimately regulate N availability to plants.
Collapse
Affiliation(s)
- Ella T. Sieradzki
- Department of Environmental Science, Policy and Management, University of California Berkeley, Berkeley, California, USA
| | - Erin E. Nuccio
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California, USA
| | - Jennifer Pett-Ridge
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California, USA
- Life & Environmental Sciences Department, UC Merced, Merced, California, USA
- Innovative Genomics Institute, UC Berkeley, Berkeley, California, USA
| | - Mary K. Firestone
- Department of Environmental Science, Policy and Management, University of California Berkeley, Berkeley, California, USA
| |
Collapse
|
8
|
Sun Y, Zhang Y, Zhao T, Luan Y, Wang Y, Yang C, Shen B, Huang X, Li G, Zhao S, Zhao G, Wang Q. Acetylation coordinates the crosstalk between carbon metabolism and ammonium assimilation in Salmonella enterica. EMBO J 2023; 42:e112333. [PMID: 37183585 PMCID: PMC10308350 DOI: 10.15252/embj.2022112333] [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: 08/09/2022] [Revised: 02/21/2023] [Accepted: 04/28/2023] [Indexed: 05/16/2023] Open
Abstract
Enteric bacteria use up to 15% of their cellular energy for ammonium assimilation via glutamine synthetase (GS)/glutamate synthase (GOGAT) and glutamate dehydrogenase (GDH) in response to varying ammonium availability. However, the sensory mechanisms for effective and appropriate coordination between carbon metabolism and ammonium assimilation have not been fully elucidated. Here, we report that in Salmonella enterica, carbon metabolism coordinates the activities of GS/GDH via functionally reversible protein lysine acetylation. Glucose promotes Pat acetyltransferase-mediated acetylation and activation of adenylylated GS. Simultaneously, glucose induces GDH acetylation to inactivate the enzyme by impeding its catalytic centre, which is reversed upon GDH deacetylation by deacetylase CobB. Molecular dynamics (MD) simulations indicate that adenylylation is required for acetylation-dependent activation of GS. We show that acetylation and deacetylation occur within minutes of "glucose shock" to promptly adapt to ammonium/carbon variation and finely balance glutamine/glutamate synthesis. Finally, in a mouse infection model, reduced S. enterica growth caused by the expression of adenylylation-mimetic GS is rescued by acetylation-mimicking mutations. Thus, glucose-driven acetylation integrates signals from ammonium assimilation and carbon metabolism to fine-tune bacterial growth control.
Collapse
Affiliation(s)
- Yunwei Sun
- Department of Gastroenterology of Ruijin Hospital, Shanghai Institute of ImmunologyShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Yuebin Zhang
- Laboratory of Molecular Modeling and Design, State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalianChina
| | - Tingting Zhao
- Department of Gastroenterology of Ruijin Hospital, Shanghai Institute of ImmunologyShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Yi Luan
- Department of Pharmacology, Vascular Biology and Therapeutic ProgramYale University School of MedicineNew HavenCTUSA
| | - Ying Wang
- Department of Gastroenterology of Ruijin Hospital, Shanghai Institute of ImmunologyShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Chen Yang
- CAS‐Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological SciencesChinese Academy of SciencesShanghaiChina
| | - Bo Shen
- Department of Gastroenterology of Ruijin Hospital, Shanghai Institute of ImmunologyShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Xi Huang
- Department of Gastroenterology of Ruijin Hospital, Shanghai Institute of ImmunologyShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Guohui Li
- Laboratory of Molecular Modeling and Design, State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalianChina
| | - Shimin Zhao
- State Key Lab of Genetic Engineering & Institutes of Biomedical SciencesFudan UniversityShanghaiChina
- Department of Microbiology and Microbial Engineering, School of Life SciencesFudan UniversityShanghaiChina
- Collaborative Innovation Center for Biotherapy, West China HospitalSichuan UniversityChengduChina
| | - Guo‐ping Zhao
- CAS‐Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological SciencesChinese Academy of SciencesShanghaiChina
- State Key Lab of Genetic Engineering & Institutes of Biomedical SciencesFudan UniversityShanghaiChina
- Department of Microbiology and Microbial Engineering, School of Life SciencesFudan UniversityShanghaiChina
- Shanghai‐MOST Key Laboratory of Disease and Health GenomicsChinese National Human Genome Center at ShanghaiShanghaiChina
- Department of Microbiology and Li KaShing Institute of Health SciencesThe Chinese University of Hong Kong, Prince of Wales HospitalShatin, New Territories, Hong Kong SARChina
| | - Qijun Wang
- Department of Gastroenterology of Ruijin Hospital, Shanghai Institute of ImmunologyShanghai Jiao Tong University School of MedicineShanghaiChina
- Department of Pharmacology, Vascular Biology and Therapeutic ProgramYale University School of MedicineNew HavenCTUSA
| |
Collapse
|
9
|
Effects of glutamate oxaloacetate transaminase on reactive oxygen species in Ganoderma lucidum. Appl Microbiol Biotechnol 2023; 107:1845-1861. [PMID: 36754884 DOI: 10.1007/s00253-023-12417-3] [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: 08/05/2022] [Revised: 01/15/2023] [Accepted: 01/22/2023] [Indexed: 02/10/2023]
Abstract
Nitrogen metabolism can regulate mycelial growth and secondary metabolism in Ganoderma lucidum. As an important enzyme in intracellular amino acid metabolism, glutamate oxaloacetate transaminase (GOT) has many physiological functions in animals and plants, but its function in fungi has been less studied. In the present study, two GOT isoenzymes were found in G. lucidum; one is located in the mitochondria (GOT1), and the other is located in the cytoplasm (GOT2). The reactive oxygen species (ROS) level was increased in got1 silenced strains and was approximately 1.5-fold higher than that in the wild-type (WT) strain, while silencing got2 did not affect the ROS level. To explore how GOT affects ROS in G. lucidum, experiments related to the generation and elimination of intracellular ROS were conducted. First, compared with that in the WT strain, the glutamate content, one of the substrates of GOT, decreased when got1 or got2 was knocked down, and the glutathione (l-γ-glutamyl-l-cysteinylglycine) (GSH) content decreased by approximately 38.6%, 19.3%, and 40.1% in got1 silenced strains, got2 silenced strains, and got1/2 co-silenced strains respectively. Second, GOT also affects glucose metabolism. The pyruvate (PA), acetyl-CoA and α-ketoglutarate (α-KG) contents decreased in got1 and got2 silenced strains, and the transcription levels of most genes involved in the glycolytic pathway and the tricarboxylic acid cycle increased. The NADH content was increased in got1 silenced strains and got2 silenced strains, and the NAD+/NADH ratio was decreased, which might result in mitochondrial ROS production. Compared with the WT strain, the mitochondrial ROS level was approximately 1.5-fold higher in the got1 silenced strains. In addition, silencing of got1 or got2 resulted in a decrease in antioxidant enzymes, including superoxide dismutase, catalase, glutathione reductase, and ascorbate peroxidase. Finally, ganoderic acid (GA) was increased by approximately 40% in got1 silenced strains compared with the WT strain, while silencing of got2 resulted in a 10% increase in GA biosynthesis. These findings provide new insights into the effect of GOT on ROS and secondary metabolism in fungi. KEY POINTS: • GOT plays important roles in ROS level in Ganoderma lucidum. • Silencing of got1 resulted in decrease in GSH content and antioxidant enzymes activities, but an increase in mitochondrial ROS level in G. lucidum. • Silencing of got1 and got2 resulted in an increase in ganoderic acid biosynthesis in G. lucidum.
Collapse
|
10
|
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.
Collapse
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.
| |
Collapse
|
11
|
Krysenko S, Wohlleben W. Polyamine and Ethanolamine Metabolism in Bacteria as an Important Component of Nitrogen Assimilation for Survival and Pathogenicity. Med Sci (Basel) 2022; 10:40. [PMID: 35997332 PMCID: PMC9397018 DOI: 10.3390/medsci10030040] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/23/2022] [Accepted: 07/25/2022] [Indexed: 11/16/2022] Open
Abstract
Nitrogen is an essential element required for bacterial growth. It serves as a building block for the biosynthesis of macromolecules and provides precursors for secondary metabolites. Bacteria have developed the ability to use various nitrogen sources and possess two enzyme systems for nitrogen assimilation involving glutamine synthetase/glutamate synthase and glutamate dehydrogenase. Microorganisms living in habitats with changeable availability of nutrients have developed strategies to survive under nitrogen limitation. One adaptation is the ability to acquire nitrogen from alternative sources including the polyamines putrescine, cadaverine, spermidine and spermine, as well as the monoamine ethanolamine. Bacterial polyamine and monoamine metabolism is not only important under low nitrogen availability, but it is also required to survive under high concentrations of these compounds. Such conditions can occur in diverse habitats such as soil, plant tissues and human cells. Strategies of pathogenic and non-pathogenic bacteria to survive in the presence of poly- and monoamines offer the possibility to combat pathogens by using their capability to metabolize polyamines as an antibiotic drug target. This work aims to summarize the knowledge on poly- and monoamine metabolism in bacteria and its role in nitrogen metabolism.
Collapse
Affiliation(s)
- Sergii Krysenko
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), Department of Microbiology and Biotechnology, University of Tübingen, Auf der Morgenstelle 28, 72076 Tübingen, Germany;
- Cluster of Excellence ‘Controlling Microbes to Fight Infections’, University of Tübingen, 72076 Tübingen, Germany
| | - Wolfgang Wohlleben
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), Department of Microbiology and Biotechnology, University of Tübingen, Auf der Morgenstelle 28, 72076 Tübingen, Germany;
- Cluster of Excellence ‘Controlling Microbes to Fight Infections’, University of Tübingen, 72076 Tübingen, Germany
| |
Collapse
|
12
|
Fifani B, Steels S, Helmus C, Delacuvellerie A, Deracinois B, Phalip V, Delvigne F, Jacques P. Coculture of Trichoderma harzianum and Bacillus velezensis Based on Metabolic Cross-Feeding Modulates Lipopeptide Production. Microorganisms 2022; 10:microorganisms10051059. [PMID: 35630500 PMCID: PMC9148127 DOI: 10.3390/microorganisms10051059] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 05/18/2022] [Accepted: 05/18/2022] [Indexed: 01/27/2023] Open
Abstract
Cocultures have been widely explored for their use in deciphering microbial interaction and its impact on the metabolisms of the interacting microorganisms. In this work, we investigate, in different liquid coculture conditions, the compatibility of two microorganisms with the potential for the biocontrol of plant diseases: the fungus Trichoderma harzianum IHEM5437 and the bacterium Bacillus velezensis GA1 (a strong antifungal lipopeptide producing strain). While the Bacillus overgrew the Trichoderma in a rich medium due to its antifungal lipopeptide production, a drastically different trend was observed in a medium in which a nitrogen nutritional dependency was imposed. Indeed, in this minimum medium containing nitrate as the sole nitrogen source, cooperation between the bacterium and the fungus was established. This is reflected by the growth of both species as well as the inhibition of the expression of Bacillus genes encoding lipopeptide synthetases. Interestingly, the growth of the bacterium in the minimum medium was enabled by the amendment of the culture by the fungal supernatant, which, in this case, ensures a high production yield of lipopeptides. These results highlight, for the first time, that Trichoderma harzianum and Bacillus velezensis are able, in specific environmental conditions, to adapt their metabolisms in order to grow together.
Collapse
Affiliation(s)
- Barbara Fifani
- UMR Transfrontalière BioEcoAgro No 1158, University Lille, INRAE, University Liège, UPJV, YNCREA, University Artois, University Littoral Côte d’Opale, TERRA—Teaching and Research Centre, Gembloux Agro-Bio Tech, University Liège, 5030 Gembloux, Belgium; (B.F.); (S.S.); (C.H.); (F.D.)
- UMR Transfrontalière BioEcoAgro No 1158, University Lille, INRAE, University Liège, UPJV, YNCREA, University Artois, University Littoral Côte d’Opale, ICV—Charles Viollette Institute, 59000 Lille, France; (B.D.); (V.P.)
| | - Sebastien Steels
- UMR Transfrontalière BioEcoAgro No 1158, University Lille, INRAE, University Liège, UPJV, YNCREA, University Artois, University Littoral Côte d’Opale, TERRA—Teaching and Research Centre, Gembloux Agro-Bio Tech, University Liège, 5030 Gembloux, Belgium; (B.F.); (S.S.); (C.H.); (F.D.)
| | - Catherine Helmus
- UMR Transfrontalière BioEcoAgro No 1158, University Lille, INRAE, University Liège, UPJV, YNCREA, University Artois, University Littoral Côte d’Opale, TERRA—Teaching and Research Centre, Gembloux Agro-Bio Tech, University Liège, 5030 Gembloux, Belgium; (B.F.); (S.S.); (C.H.); (F.D.)
| | | | - Barbara Deracinois
- UMR Transfrontalière BioEcoAgro No 1158, University Lille, INRAE, University Liège, UPJV, YNCREA, University Artois, University Littoral Côte d’Opale, ICV—Charles Viollette Institute, 59000 Lille, France; (B.D.); (V.P.)
| | - Vincent Phalip
- UMR Transfrontalière BioEcoAgro No 1158, University Lille, INRAE, University Liège, UPJV, YNCREA, University Artois, University Littoral Côte d’Opale, ICV—Charles Viollette Institute, 59000 Lille, France; (B.D.); (V.P.)
| | - Frank Delvigne
- UMR Transfrontalière BioEcoAgro No 1158, University Lille, INRAE, University Liège, UPJV, YNCREA, University Artois, University Littoral Côte d’Opale, TERRA—Teaching and Research Centre, Gembloux Agro-Bio Tech, University Liège, 5030 Gembloux, Belgium; (B.F.); (S.S.); (C.H.); (F.D.)
| | - Philippe Jacques
- UMR Transfrontalière BioEcoAgro No 1158, University Lille, INRAE, University Liège, UPJV, YNCREA, University Artois, University Littoral Côte d’Opale, TERRA—Teaching and Research Centre, Gembloux Agro-Bio Tech, University Liège, 5030 Gembloux, Belgium; (B.F.); (S.S.); (C.H.); (F.D.)
- Correspondence:
| |
Collapse
|
13
|
Pal A, Iyer MS, Srinivasan S, Narain Seshasayee AS, Venkatesh KV. Global pleiotropic effects in adaptively evolved Escherichia coli lacking CRP reveal molecular mechanisms that define the growth physiology. Open Biol 2022; 12:210206. [PMID: 35167766 PMCID: PMC8846999 DOI: 10.1098/rsob.210206] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Evolution facilitates emergence of fitter phenotypes by efficient allocation of cellular resources in conjunction with beneficial mutations. However, system-wide pleiotropic effects that redress the perturbations to the apex node of the transcriptional regulatory networks remain unclear. Here, we elucidate that absence of global transcriptional regulator CRP in Escherichia coli results in alterations in key metabolic pathways under glucose respiratory conditions, favouring stress- or hedging-related functions over growth-enhancing functions. Further, we disentangle the growth-mediated effects from the CRP regulation-specific effects on these metabolic pathways. We quantitatively illustrate that the loss of CRP perturbs proteome efficiency, as evident from metabolic as well as ribosomal proteome fractions, that corroborated with intracellular metabolite profiles. To address how E. coli copes with such systemic defect, we evolved Δcrp mutant in the presence of glucose. Besides acquiring mutations in the promoter of glucose transporter ptsG, the evolved populations recovered the metabolic pathways to their pre-perturbed state coupled with metabolite re-adjustments, which altogether enabled increased growth. By contrast to Δcrp mutant, the evolved strains remodelled their proteome efficiency towards biomass synthesis, albeit at the expense of carbon efficiency. Overall, we comprehensively illustrate the genetic and metabolic basis of pleiotropic effects, fundamental for understanding the growth physiology.
Collapse
Affiliation(s)
- Ankita Pal
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Mahesh S. Iyer
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Sumana Srinivasan
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | | | - K. V. Venkatesh
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| |
Collapse
|
14
|
Miyakoshi M, Morita T, Kobayashi A, Berger A, Takahashi H, Gotoh Y, Hayashi T, Tanaka K. Glutamine synthetase mRNA releases sRNA from its 3'UTR to regulate carbon/nitrogen metabolic balance in Enterobacteriaceae. eLife 2022; 11:82411. [PMID: 36440827 PMCID: PMC9731577 DOI: 10.7554/elife.82411] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 11/27/2022] [Indexed: 11/29/2022] Open
Abstract
Glutamine synthetase (GS) is the key enzyme of nitrogen assimilation induced under nitrogen limiting conditions. The carbon skeleton of glutamate and glutamine, 2-oxoglutarate, is supplied from the TCA cycle, but how this metabolic flow is controlled in response to nitrogen availability remains unknown. We show that the expression of the E1o component of 2-oxoglutarate dehydrogenase, SucA, is repressed under nitrogen limitation in Salmonella enterica and Escherichia coli. The repression is exerted at the post-transcriptional level by an Hfq-dependent sRNA GlnZ generated from the 3'UTR of the GS-encoding glnA mRNA. Enterobacterial GlnZ variants contain a conserved seed sequence and primarily regulate sucA through base-pairing far upstream of the translation initiation region. During growth on glutamine as the nitrogen source, the glnA 3'UTR deletion mutants expressed SucA at higher levels than the S. enterica and E. coli wild-type strains, respectively. In E. coli, the transcriptional regulator Nac also participates in the repression of sucA. Lastly, this study clarifies that the release of GlnZ from the glnA mRNA by RNase E is essential for the post-transcriptional regulation of sucA. Thus, the mRNA coordinates the two independent functions to balance the supply and demand of the fundamental metabolites.
Collapse
Affiliation(s)
- Masatoshi Miyakoshi
- Department of Infection Biology, Faculty of Medicine, University of TsukubaTsukubaJapan,Transborder Medical Research Center, University of TsukubaTsukubaJapan,International Joint Degree Master’s Program in Agro-Biomedical Science in Food and Health (GIP-TRIAD), University of TsukubaTsukubaJapan
| | - Teppei Morita
- Institute for Advanced Biosciences, Keio UniversityTsuruokaJapan,Graduate School of Media and Governance, Keio UniversityFujisawaJapan
| | - Asaki Kobayashi
- Transborder Medical Research Center, University of TsukubaTsukubaJapan
| | - Anna Berger
- International Joint Degree Master’s Program in Agro-Biomedical Science in Food and Health (GIP-TRIAD), University of TsukubaTsukubaJapan
| | | | - Yasuhiro Gotoh
- Department of Bacteriology, Faculty of Medical Sciences, Kyushu UniversityFukuokaJapan
| | - Tetsuya Hayashi
- Department of Bacteriology, Faculty of Medical Sciences, Kyushu UniversityFukuokaJapan
| | - Kan Tanaka
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of TechnologyYokohamaJapan
| |
Collapse
|
15
|
Martien JI, Trujillo EA, Jacobson TB, Tatli M, Hebert AS, Stevenson DM, Coon JJ, Amador-Noguez D. Metabolic Remodeling during Nitrogen Fixation in Zymomonas mobilis. mSystems 2021; 6:e0098721. [PMID: 34783580 PMCID: PMC8594446 DOI: 10.1128/msystems.00987-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 10/06/2021] [Indexed: 11/20/2022] Open
Abstract
Zymomonas mobilis is an ethanologenic bacterium currently being developed for production of advanced biofuels. Recent studies have shown that Z. mobilis can fix dinitrogen gas (N2) as a sole nitrogen source. During N2 fixation, Z. mobilis exhibits increased biomass-specific rates of ethanol production. In order to better understand the physiology of Z. mobilis during N2 fixation and during changes in ammonium (NH4+) availability, we performed liquid chromatography-mass spectrometry (LC-MS)-based targeted metabolomics and shotgun proteomics under three regimes of nitrogen availability: continuous N2 fixation, gradual NH4+ depletion, and acute NH4+ addition to N2-fixing cells. We report dynamic changes in abundance of proteins and metabolites related to nitrogen fixation, motility, ammonium assimilation, amino acid biosynthesis, nucleotide biosynthesis, isoprenoid biosynthesis, and Entner-Doudoroff (ED) glycolysis, providing insight into the regulatory mechanisms that control these processes in Z. mobilis. Our analysis identified potential physiological mechanisms that may contribute to increased specific ethanol production during N2 fixation, including decreased activity of biosynthetic pathways, increased protein abundance of alcohol dehydrogenase (ADHI), and increased thermodynamic favorability of the ED pathway. Of particular relevance to advanced biofuel production, we found that intermediates in the methylerythritol phosphate (MEP) pathway for isoprenoid biosynthesis were depleted during N2 fixation, coinciding with decreased protein abundance of deoxyxylulose 5-phosphate synthase (DXS), the first enzyme in the pathway. This implies that DXS protein abundance serves as a native control point in regulating MEP pathway activity in Z. mobilis. The results of this study will inform metabolic engineering to further develop Z. mobilis as a platform organism for biofuel production. IMPORTANCE Biofuels and bioproducts have the potential to serve as environmentally sustainable replacements for petroleum-derived fuels and commodity molecules. Advanced fuels such as higher alcohols and isoprenoids are more suitable gasoline replacements than bioethanol. Developing microbial systems to generate advanced biofuels requires metabolic engineering to reroute carbon away from ethanol and other native products and toward desired pathways, such as the MEP pathway for isoprenoid biosynthesis. However, rational engineering of microbial metabolism relies on understanding metabolic control points, in terms of both enzyme activity and thermodynamic favorability. In Z. mobilis, the factors that control glycolytic rates, ethanol production, and isoprenoid production are still not fully understood. In this study, we performed metabolomic, proteomic, and thermodynamic analysis of Z. mobilis during N2 fixation. This analysis identified key changes in metabolite levels, enzyme abundance, and glycolytic thermodynamic favorability that occurred during changes in NH4+ availability, helping to inform future efforts in metabolic engineering.
Collapse
Affiliation(s)
- Julia I. Martien
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin–Madison, Madison, Wisconsin, USA
- Department of Bacteriology, University of Wisconsin–Madison, Madison, Wisconsin, USA
| | - Edna A. Trujillo
- Department of Chemistry, University of Wisconsin–Madison, Madison, Wisconsin, USA
- National Center for Quantitative Biology of Complex Systems, University of Wisconsin–Madison, Madison, Wisconsin, USA
| | - Tyler B. Jacobson
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin–Madison, Madison, Wisconsin, USA
- Department of Bacteriology, University of Wisconsin–Madison, Madison, Wisconsin, USA
| | - Mehmet Tatli
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin–Madison, Madison, Wisconsin, USA
- Department of Bacteriology, University of Wisconsin–Madison, Madison, Wisconsin, USA
| | - Alexander S. Hebert
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin–Madison, Madison, Wisconsin, USA
- Department of Chemistry, University of Wisconsin–Madison, Madison, Wisconsin, USA
| | - David M. Stevenson
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin–Madison, Madison, Wisconsin, USA
- Department of Bacteriology, University of Wisconsin–Madison, Madison, Wisconsin, USA
| | - Joshua J. Coon
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin–Madison, Madison, Wisconsin, USA
- Department of Chemistry, University of Wisconsin–Madison, Madison, Wisconsin, USA
- National Center for Quantitative Biology of Complex Systems, University of Wisconsin–Madison, Madison, Wisconsin, USA
- Department of Biomolecular Chemistry, University of Wisconsin–Madison, Madison, Wisconsin, USA
- Morgridge Institute for Research, Madison, Wisconsin, USA
| | - Daniel Amador-Noguez
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin–Madison, Madison, Wisconsin, USA
- Department of Bacteriology, University of Wisconsin–Madison, Madison, Wisconsin, USA
| |
Collapse
|
16
|
Mohd Din ARJ, Suzuki K, Honjo M, Amano K, Nishimura T, Moriuchi R, Dohra H, Ishizawa H, Kimura M, Tashiro Y, Futamata H. Imbalance in Carbon and Nitrogen Metabolism in Comamonas testosteroni R2 Is Caused by Negative Feedback and Rescued by L-arginine. Microbes Environ 2021; 36. [PMID: 34645730 PMCID: PMC8674442 DOI: 10.1264/jsme2.me21050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The collapse of Comamonas testosteroni R2 under chemostat conditions and the aerobic growth of strain R2 under batch conditions with phenol as the sole carbon source were investigated using physiological and transcriptomic techniques. Phenol-/catechol-degrading activities under chemostat conditions gradually decreased, suggesting that metabolites produced from strain R2 accumulated in the culture, which caused negative feedback. The competitive inhibition of phenol hydroxylase and catechol dioxygenase was observed in a crude extract of the supernatant collected from the collapsed culture. Transcriptomic analyses showed that genes related to nitrogen transport were up-regulated; the ammonium transporter amtB was up-regulated approximately 190-fold in the collapsed status, suggesting an increase in the concentration of ammonium in cells. The transcriptional levels of most of the genes related to gluconeogenesis, glycolysis, the pentose phosphate pathway, and the TCA and urea cycles decreased by ~0.7-fold in the stable status, whereas the activities of glutamate synthase and glutamine synthetase increased by ~2-fold. These results suggest that ammonium was assimilated into glutamate and glutamine via 2-oxoglutarate under the limited supply of carbon skeletons, whereas the synthesis of other amino acids and nucleotides was repressed by 0.6-fold. Furthermore, negative feedback appeared to cause an imbalance between carbon and nitrogen metabolism, resulting in collapse. The effects of amino acids on negative feedback were investigated. L-arginine allowed strain R2 to grow normally, even under growth-inhibiting conditions, suggesting that the imbalance was corrected by the stimulation of the urea cycle, resulting in the rescue of strain R2.
Collapse
Affiliation(s)
- Abd Rahman Jabir Mohd Din
- Graduate School of Science and Technology, Shizuoka University.,Innovation Centre in Agritechnology for Advanced Bioprocess, UTM Pagoh Research Center
| | - Kenshi Suzuki
- Microbial Ecotechnology (Social Cooperation Laboratory), Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo
| | - Masahiro Honjo
- Graduate School of Science and Technology, Shizuoka University
| | - Koki Amano
- Department of Applied Chemistry and Biochemical Engineering, Graduate School of Engineering, Shizuoka University
| | - Tomoka Nishimura
- Department of Applied Chemistry and Biochemical Engineering, Graduate School of Engineering, Shizuoka University
| | - Ryota Moriuchi
- Research Institution of Green Science and Technology, Shizuoka University
| | - Hideo Dohra
- Research Institution of Green Science and Technology, Shizuoka University
| | - Hidehiro Ishizawa
- Research Institution of Green Science and Technology, Shizuoka University
| | - Motohiko Kimura
- Department of Applied Chemistry and Biochemical Engineering, Graduate School of Engineering, Shizuoka University
| | - Yosuke Tashiro
- Graduate School of Science and Technology, Shizuoka University.,Department of Applied Chemistry and Biochemical Engineering, Graduate School of Engineering, Shizuoka University
| | - Hiroyuki Futamata
- Graduate School of Science and Technology, Shizuoka University.,Department of Applied Chemistry and Biochemical Engineering, Graduate School of Engineering, Shizuoka University.,Research Institution of Green Science and Technology, Shizuoka University
| |
Collapse
|
17
|
Schulz C, Kumelj T, Karlsen E, Almaas E. Genome-scale metabolic modelling when changes in environmental conditions affect biomass composition. PLoS Comput Biol 2021; 17:e1008528. [PMID: 34029317 PMCID: PMC8177628 DOI: 10.1371/journal.pcbi.1008528] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 06/04/2021] [Accepted: 04/27/2021] [Indexed: 11/29/2022] Open
Abstract
Genome-scale metabolic modeling is an important tool in the study of metabolism by enhancing the collation of knowledge, interpretation of data, and prediction of metabolic capabilities. A frequent assumption in the use of genome-scale models is that the in vivo organism is evolved for optimal growth, where growth is represented by flux through a biomass objective function (BOF). While the specific composition of the BOF is crucial, its formulation is often inherited from similar organisms due to the experimental challenges associated with its proper determination. A cell’s macro-molecular composition is not fixed and it responds to changes in environmental conditions. As a consequence, initiatives for the high-fidelity determination of cellular biomass composition have been launched. Thus, there is a need for a mathematical and computational framework capable of using multiple measurements of cellular biomass composition in different environments. Here, we propose two different computational approaches for directly addressing this challenge: Biomass Trade-off Weighting (BTW) and Higher-dimensional-plane InterPolation (HIP). In lieu of experimental data on biomass composition-variation in response to changing nutrient environment, we assess the properties of BTW and HIP using three hypothetical, yet biologically plausible, BOFs for the Escherichia coli genome-scale metabolic model iML1515. We find that the BTW and HIP formulations have a significant impact on model performance and phenotypes. Furthermore, the BTW method generates larger growth rates in all environments when compared to HIP. Using acetate secretion and the respiratory quotient as proxies for phenotypic changes, we find marked differences between the methods as HIP generates BOFs more similar to a reference BOF than BTW. We conclude that the presented methods constitute a conceptual step in developing genome-scale metabolic modelling approaches capable of addressing the inherent dependence of cellular biomass composition on nutrient environments. Changes in the environment promote changes in an organism’s metabolism. To achieve balanced growth states for near-optimal function, cells respond through metabolic rearrangements, which may influence the biosynthesis of metabolic precursors for building a cell’s molecular constituents. Therefore, it is necessary to take the dependence of biomass composition on environmental conditions into consideration. While measuring the biomass composition for some environments is possible, and should be done, it cannot be completed for all possible environments. In this work, we propose two main approaches, BTW and HIP, for addressing the challenge of estimating biomass composition in response to environmental changes. We evaluate the phenotypic consequences of BTW and HIP by characterizing their effect on growth, secretion potential, respiratory efficiency, and gene essentiality of a cell. Our work constitutes a first conceptual step in accounting for the influence of growth conditions on biomass composition, and in turn the biomass composition’s effect on metabolic phenotypic traits, within constraint-based modelling. As such, we believe it will improve the relevance of constraint-based methods in metabolic engineering and drug discovery, since the biosynthetic potential of microbes for generating industrially relevant products or drugs often is closely linked to their biomass composition.
Collapse
Affiliation(s)
- Christian Schulz
- Department of Biotechnology and Food Science, NTNU - Norwegian University of Science and Technology, Trondheim, Norway
| | - Tjasa Kumelj
- Department of Biotechnology and Food Science, NTNU - Norwegian University of Science and Technology, Trondheim, Norway
| | - Emil Karlsen
- Department of Biotechnology and Food Science, NTNU - Norwegian University of Science and Technology, Trondheim, Norway
| | - Eivind Almaas
- Department of Biotechnology and Food Science, NTNU - Norwegian University of Science and Technology, Trondheim, Norway
- K.G. Jebsen Center for Genetic Epidemiology, Department of Public Health and General Practice, NTNU - Norwegian University of Science and Technology, Trondheim, Norway
- * E-mail:
| |
Collapse
|
18
|
Rapid Response of Nitrogen Cycling Gene Transcription to Labile Carbon Amendments in a Soil Microbial Community. mSystems 2021; 6:6/3/e00161-21. [PMID: 33975966 PMCID: PMC8125072 DOI: 10.1128/msystems.00161-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A large portion of activity in soil microbial communities occurs in short time frames in response to an increase in C availability, affecting the biogeochemical cycling of nitrogen. These changes are of particular importance as nitrogen represents both a limiting nutrient for terrestrial plants as well as a potential pollutant. Episodic inputs of labile carbon (C) to soil can rapidly stimulate nitrogen (N) immobilization by soil microorganisms. However, the transcriptional patterns that underlie this process remain unclear. In order to better understand the regulation of N cycling in soil microbial communities, we conducted a 48-h laboratory incubation with agricultural soil where we stimulated the uptake of inorganic N by amending the soil with glucose. We analyzed the metagenome and metatranscriptome of the microbial communities at four time points that corresponded with changes in N availability. The relative abundances of genes remained largely unchanged throughout the incubation. In contrast, glucose addition rapidly increased the transcription of genes encoding ammonium and nitrate transporters, enzymes responsible for N assimilation into biomass, and genes associated with the N regulatory network. This upregulation coincided with an increase in transcripts associated with glucose breakdown and oxoglutarate production, demonstrating a connection between C and N metabolism. When concentrations of ammonium were low, we observed a transient upregulation of genes associated with the nitrogen-fixing enzyme nitrogenase. Transcripts for nitrification and denitrification were downregulated throughout the incubation, suggesting that dissimilatory transformations of N may be suppressed in response to labile C inputs in these soils. These results demonstrate that soil microbial communities can respond rapidly to changes in C availability by drastically altering the transcription of N cycling genes. IMPORTANCE A large portion of activity in soil microbial communities occurs in short time frames in response to an increase in C availability, affecting the biogeochemical cycling of nitrogen. These changes are of particular importance as nitrogen represents both a limiting nutrient for terrestrial plants as well as a potential pollutant. However, we lack a full understanding of the short-term effects of labile carbon inputs on the metabolism of microbes living in soil. Here, we found that soil microbial communities responded to labile carbon addition by rapidly transcribing genes encoding proteins and enzymes responsible for inorganic nitrogen acquisition, including nitrogen fixation. This work demonstrates that soil microbial communities respond within hours to carbon inputs through altered gene expression. These insights are essential for an improved understanding of the microbial processes governing soil organic matter production, decomposition, and nutrient cycling in natural and agricultural ecosystems.
Collapse
|
19
|
Kochanowski K, Okano H, Patsalo V, Williamson J, Sauer U, Hwa T. Global coordination of metabolic pathways in Escherichia coli by active and passive regulation. Mol Syst Biol 2021; 17:e10064. [PMID: 33852189 PMCID: PMC8045939 DOI: 10.15252/msb.202010064] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 03/04/2021] [Accepted: 03/09/2021] [Indexed: 12/15/2022] Open
Abstract
Microorganisms adjust metabolic activity to cope with diverse environments. While many studies have provided insights into how individual pathways are regulated, the mechanisms that give rise to coordinated metabolic responses are poorly understood. Here, we identify the regulatory mechanisms that coordinate catabolism and anabolism in Escherichia coli. Integrating protein, metabolite, and flux changes in genetically implemented catabolic or anabolic limitations, we show that combined global and local mechanisms coordinate the response to metabolic limitations. To allocate proteomic resources between catabolism and anabolism, E. coli uses a simple global gene regulatory program. Surprisingly, this program is largely implemented by a single transcription factor, Crp, which directly activates the expression of catabolic enzymes and indirectly reduces the expression of anabolic enzymes by passively sequestering cellular resources needed for their synthesis. However, metabolic fluxes are not controlled by this regulatory program alone; instead, fluxes are adjusted mostly through passive changes in the local metabolite concentrations. These mechanisms constitute a simple but effective global regulatory program that coarsely partitions resources between different parts of metabolism while ensuring robust coordination of individual metabolic reactions.
Collapse
Affiliation(s)
- Karl Kochanowski
- Institute of Molecular Systems BiologyETH ZurichZurichSwitzerland
- Life Science Zurich PhD Program on Systems BiologyZurichSwitzerland
| | - Hiroyuki Okano
- Department of PhysicsUniversity of California at San DiegoLa JollaCAUSA
| | - Vadim Patsalo
- Department of Integrative Structural and Computational Biology, and The Skaggs Institute for Chemical BiologyThe Scripps Research InstituteLa JollaCAUSA
| | - James Williamson
- Department of Integrative Structural and Computational Biology, and The Skaggs Institute for Chemical BiologyThe Scripps Research InstituteLa JollaCAUSA
| | - Uwe Sauer
- Institute of Molecular Systems BiologyETH ZurichZurichSwitzerland
| | - Terence Hwa
- Department of PhysicsUniversity of California at San DiegoLa JollaCAUSA
- Institute for Theoretical ScienceETH ZurichZurichSwitzerland
| |
Collapse
|
20
|
Iyer MS, Pal A, Srinivasan S, Somvanshi PR, Venkatesh KV. Global Transcriptional Regulators Fine-Tune the Translational and Metabolic Efficiency for Optimal Growth of Escherichia coli. mSystems 2021; 6:e00001-21. [PMID: 33785570 PMCID: PMC8546960 DOI: 10.1128/msystems.00001-21] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Accepted: 02/25/2021] [Indexed: 12/13/2022] Open
Abstract
Global transcriptional regulators coordinate complex genetic interactions that bestow better adaptability for an organism against external and internal perturbations. These transcriptional regulators are known to control an enormous array of genes with diverse functionalities. However, regulator-driven molecular mechanisms that underpin precisely tuned translational and metabolic processes conducive for rapid exponential growth remain obscure. Here, we comprehensively reveal the fundamental role of global transcriptional regulators FNR, ArcA, and IHF in sustaining translational and metabolic efficiency under glucose fermentative conditions in Escherichia coli By integrating high-throughput gene expression profiles and absolute intracellular metabolite concentrations, we illustrate that these regulators are crucial in maintaining nitrogen homeostasis, govern expression of otherwise unnecessary or hedging genes, and exert tight control on metabolic bottleneck steps. Furthermore, we characterize changes in expression and activity profiles of other coregulators associated with these dysregulated metabolic pathways, determining the regulatory interactions within the transcriptional regulatory network. Such systematic findings emphasize their importance in optimizing the proteome allocation toward metabolic enzymes as well as ribosomes, facilitating condition-specific phenotypic outcomes. Consequentially, we reveal that disruption of this inherent trade-off between ribosome and metabolic proteome economy due to the loss of regulators resulted in lowered growth rates. Moreover, our findings reinforce that the accumulations of intracellular metabolites in the event of proteome repartitions negatively affects the glucose uptake. Overall, by extending the three-partition proteome allocation theory concordant with multi-omics measurements, we elucidate the physiological consequences of loss of global regulators on central carbon metabolism restraining the organism to attain maximal biomass synthesis.IMPORTANCE Cellular proteome allocation in response to environmental or internal perturbations governs their eventual phenotypic outcome. This entails striking an effective balance between amino acid biosynthesis by metabolic proteins and its consumption by ribosomes. However, the global transcriptional regulator-driven molecular mechanisms that underpin their coordination remains unexplored. Here, we emphasize that global transcriptional regulators, known to control expression of a myriad of genes, are fundamental for precisely tuning the translational and metabolic efficiencies that define the growth optimality. Towards this, we systematically characterized the single deletion effect of FNR, ArcA, and IHF regulators of Escherichia coli on exponential growth under anaerobic glucose fermentative conditions. Their absence disrupts the stringency of proteome allocation, which manifests as impairment in key metabolic processes and an accumulation of intracellular metabolites. Furthermore, by incorporating an extension to the empirical growth laws, we quantitatively demonstrate the general design principles underlying the existence of these regulators in E. coli.
Collapse
Affiliation(s)
- Mahesh S Iyer
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, India
| | - Ankita Pal
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, India
| | - Sumana Srinivasan
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, India
| | - Pramod R Somvanshi
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, India
| | - K V Venkatesh
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, India
| |
Collapse
|
21
|
Renick PJ, Mulgaonkar A, Co CM, Wu CY, Zhou N, Velazquez A, Pennington J, Sherwood A, Dong H, Castellino L, Öz OK, Tang L, Sun X. Imaging of Actively Proliferating Bacterial Infections by Targeting the Bacterial Metabolic Footprint with d-[5- 11C]-Glutamine. ACS Infect Dis 2021; 7:347-361. [PMID: 33476123 DOI: 10.1021/acsinfecdis.0c00617] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Since most d-amino acids (DAAs) are utilized by bacterial cells but not by mammalian eukaryotic hosts, recently DAA-based molecular imaging strategies have been extensively explored for noninvasively differentiating bacterial infections from the host's inflammatory responses. Given glutamine's pivotal role in bacterial survival, cell growth, biofilm formation, and even virulence, here we report a new positron emission tomography (PET) imaging approach using d-5-[11C]glutamine (d-[5-11C]-Gln) for potential clinical assessment of bacterial infection through a comparative study with its l-isomer counterpart, l-[5-11C]-Gln. In both control and infected mice, l-[5-11C]-Gln had substantially higher uptake levels than d-[5-11C]-Gln in most organs except the kidneys, showing the expected higher use of l-[5-11C]-Gln by mammalian tissues and more efficient renal excretion of d-[5-11C]-Gln. Importantly, our work demonstrates that PET imaging with d-[5-11C]-Gln is capable of detecting infections induced by both Escherichia coli (E. coli) and methicillin-resistant Staphylococcus aureus (MRSA) in a dual-infection murine myositis model with significantly higher infection-to-background contrast than with l-[5-11C]-Gln (in E. coli, 1.64; in MRSA, 2.62, p = 0.0004). This can be attributed to the fact that d-[5-11C]-Gln is utilized by bacteria while being more efficiently cleared from the host tissues. We confirmed the bacterial infection imaging specificity of d-[5-11C]-Gln by comparing its uptake in active bacterial infections versus sterile inflammation and with 2-deoxy-2-[18F]fluoroglucose ([18F]FDG). These results together demonstrate the translational potential of PET imaging with d-[5-11C]-Gln for the noninvasive detection of bacterial infectious diseases in humans.
Collapse
|
22
|
Jiang L, Pang J, Yang L, Li W, Duan L, Zhang G, Luo Y. Engineering endogenous l-proline biosynthetic pathway to boost trans-4-hydroxy-l-proline production in Escherichia coli. J Biotechnol 2021; 329:104-117. [PMID: 33539894 DOI: 10.1016/j.jbiotec.2021.01.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 01/11/2021] [Accepted: 01/13/2021] [Indexed: 11/16/2022]
Abstract
Non-proteinogenic trans-4-hydroxy-l-proline (t4HYP), a crucial naturally occurred amino acid, is present in most organisms. t4HYP is a regio- and stereo-selectively hydroxylated product of l-proline and a valuable building block for pharmaceutically important intermediates/ingredients synthesis. Microbial production of t4HYP has aroused extensive investigations because of its low-cost and environmentally benign features. Herein, we reported metabolic engineering of endogenous l-proline biosynthetic pathway to enhance t4HYP production in trace l-proline-producing Escherichia coli BL21(DE3) (21-S0). The genes responsible for by-product formation from l-proline, pyruvate, acetyl-CoA, and isocitrate in the biosynthetic network of 21-S0 were knocked out to channel the metabolic flux towards l-proline biosynthesis. PdhR was knocked out to remove its negative regulation and aceK was deleted to ensure isocitrate dehydrogenase's activity and to increase NADPH/NADP+ level. The other genes for l-proline biosynthesis were enhanced by integration of strong promoters and 5'-untranslated regions. The resulting engineered E. coli strains 21-S1 ∼ 21-S9 harboring a codon-optimized proline 4-hydroxylase-encoding gene (P4H) were grown and fermented. A titer of 4.82 g/L of t4HYP production in 21-S6 overexpressing P4H was obtained at conical flask level, comparing with the starting 21-S0 (26 mg/L). The present work paves an efficient metabolic engineering way for higher t4HYP production in E. coli.
Collapse
Affiliation(s)
- Liangzhen Jiang
- Center for Natural Products Research, Chengdu Institute of Biology, Chinese Academy of Sciences, 9 Section 4, Renmin Road South, Chengdu 610041, People's Republic of China; College of Pharmacy and Biological Engineering, Chengdu University, 2025 Chengluo Avenue, Chengdu 610106, People's Republic of China
| | - Jing Pang
- Center for Natural Products Research, Chengdu Institute of Biology, Chinese Academy of Sciences, 9 Section 4, Renmin Road South, Chengdu 610041, People's Republic of China; University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, People's Republic of China
| | - Lixia Yang
- Center for Natural Products Research, Chengdu Institute of Biology, Chinese Academy of Sciences, 9 Section 4, Renmin Road South, Chengdu 610041, People's Republic of China
| | - Wei Li
- Center for Natural Products Research, Chengdu Institute of Biology, Chinese Academy of Sciences, 9 Section 4, Renmin Road South, Chengdu 610041, People's Republic of China
| | - Lili Duan
- College of Food Science and Technology, Sichuan Tourism University, 459 Hongling Road, Chengdu 610100, People's Republic of China
| | - Guolin Zhang
- Center for Natural Products Research, Chengdu Institute of Biology, Chinese Academy of Sciences, 9 Section 4, Renmin Road South, Chengdu 610041, People's Republic of China
| | - Yinggang Luo
- Center for Natural Products Research, Chengdu Institute of Biology, Chinese Academy of Sciences, 9 Section 4, Renmin Road South, Chengdu 610041, People's Republic of China; State Key Laboratory of Bioorganic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, People's Republic of China.
| |
Collapse
|
23
|
An ion-pair free LC-MS/MS method for quantitative metabolite profiling of microbial bioproduction systems. Talanta 2021; 222:121625. [DOI: 10.1016/j.talanta.2020.121625] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 08/31/2020] [Accepted: 09/02/2020] [Indexed: 11/23/2022]
|
24
|
Xu C, Weston BR, Tyson JJ, Cao Y. Cell cycle control and environmental response by second messengers in Caulobacter crescentus. BMC Bioinformatics 2020; 21:408. [PMID: 32998723 PMCID: PMC7526171 DOI: 10.1186/s12859-020-03687-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Background Second messengers, c-di-GMP and (p)ppGpp, are vital regulatory molecules in bacteria, influencing cellular processes such as biofilm formation, transcription, virulence, quorum sensing, and proliferation. While c-di-GMP and (p)ppGpp are both synthesized from GTP molecules, they play antagonistic roles in regulating the cell cycle. In C. crescentus, c-di-GMP works as a major regulator of pole morphogenesis and cell development. It inhibits cell motility and promotes S-phase entry by inhibiting the activity of the master regulator, CtrA. Intracellular (p)ppGpp accumulates under starvation, which helps bacteria to survive under stressful conditions through regulating nucleotide levels and halting proliferation. (p)ppGpp responds to nitrogen levels through RelA-SpoT homolog enzymes, detecting glutamine concentration using a nitrogen phosphotransferase system (PTS Ntr). This work relates the guanine nucleotide-based second messenger regulatory network with the bacterial PTS Ntr system and investigates how bacteria respond to nutrient availability. Results We propose a mathematical model for the dynamics of c-di-GMP and (p)ppGpp in C. crescentus and analyze how the guanine nucleotide-based second messenger system responds to certain environmental changes communicated through the PTS Ntr system. Our mathematical model consists of seven ODEs describing the dynamics of nucleotides and PTS Ntr enzymes. Our simulations are consistent with experimental observations and suggest, among other predictions, that SpoT can effectively decrease c-di-GMP levels in response to nitrogen starvation just as well as it increases (p)ppGpp levels. Thus, the activity of SpoT (or its homologues in other bacterial species) can likely influence the cell cycle by influencing both c-di-GMP and (p)ppGpp. Conclusions In this work, we integrate current knowledge and experimental observations from the literature to formulate a novel mathematical model. We analyze the model and demonstrate how the PTS Ntr system influences (p)ppGpp, c-di-GMP, GMP and GTP concentrations. While this model does not consider all aspects of PTS Ntr signaling, such as cross-talk with the carbon PTS system, here we present our first effort to develop a model of nutrient signaling in C. crescentus.
Collapse
Affiliation(s)
- Chunrui Xu
- Genetics, Bioinformatics, and Computational Biology, Virginia Tech, Blacksburg, 24061, VA, USA
| | - Bronson R Weston
- Genetics, Bioinformatics, and Computational Biology, Virginia Tech, Blacksburg, 24061, VA, USA
| | - John J Tyson
- Department of Biological Sciences, Virginia Tech, Blacksburg, 24061, VA, USA
| | - Yang Cao
- Department of Computer Science, Virginia Tech, Blacksburg, 24061, VA, USA.
| |
Collapse
|
25
|
Aspartate aminotransferase Rv3722c governs aspartate-dependent nitrogen metabolism in Mycobacterium tuberculosis. Nat Commun 2020; 11:1960. [PMID: 32327655 PMCID: PMC7181641 DOI: 10.1038/s41467-020-15876-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 03/31/2020] [Indexed: 01/01/2023] Open
Abstract
Gene rv3722c of Mycobacterium tuberculosis is essential for in vitro growth, and encodes a putative pyridoxal phosphate-binding protein of unknown function. Here we use metabolomic, genetic and structural approaches to show that Rv3722c is the primary aspartate aminotransferase of M. tuberculosis, and mediates an essential but underrecognized role in metabolism: nitrogen distribution. Rv3722c deficiency leads to virulence attenuation in macrophages and mice. Our results identify aspartate biosynthesis and nitrogen distribution as potential species-selective drug targets in M. tuberculosis.
Collapse
|
26
|
Millard P, Schmitt U, Kiefer P, Vorholt JA, Heux S, Portais JC. ScalaFlux: A scalable approach to quantify fluxes in metabolic subnetworks. PLoS Comput Biol 2020; 16:e1007799. [PMID: 32287281 PMCID: PMC7182278 DOI: 10.1371/journal.pcbi.1007799] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 04/24/2020] [Accepted: 03/19/2020] [Indexed: 01/01/2023] Open
Abstract
13C-metabolic flux analysis (13C-MFA) allows metabolic fluxes to be quantified in living organisms and is a major tool in biotechnology and systems biology. Current 13C-MFA approaches model label propagation starting from the extracellular 13C-labeled nutrient(s), which limits their applicability to the analysis of pathways close to this metabolic entry point. Here, we propose a new approach to quantify fluxes through any metabolic subnetwork of interest by modeling label propagation directly from the metabolic precursor(s) of this subnetwork. The flux calculations are thus purely based on information from within the subnetwork of interest, and no additional knowledge about the surrounding network (such as atom transitions in upstream reactions or the labeling of the extracellular nutrient) is required. This approach, termed ScalaFlux for SCALAble metabolic FLUX analysis, can be scaled up from individual reactions to pathways to sets of pathways. ScalaFlux has several benefits compared with current 13C-MFA approaches: greater network coverage, lower data requirements, independence from cell physiology, robustness to gaps in data and network information, better computational efficiency, applicability to rich media, and enhanced flux identifiability. We validated ScalaFlux using a theoretical network and simulated data. We also used the approach to quantify fluxes through the prenyl pyrophosphate pathway of Saccharomyces cerevisiae mutants engineered to produce phytoene, using a dataset for which fluxes could not be calculated using existing approaches. A broad range of metabolic systems can be targeted with minimal cost and effort, making ScalaFlux a valuable tool for the analysis of metabolic fluxes.
Collapse
Affiliation(s)
- Pierre Millard
- TBI, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
| | - Uwe Schmitt
- Scientific IT Services, ETH Zurich, Zurich, Switzerland
| | - Patrick Kiefer
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Julia A. Vorholt
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Stéphanie Heux
- TBI, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
| | - Jean-Charles Portais
- TBI, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
- MetaboHUB-MetaToul, National infrastructure of metabolomics and fluxomics, Toulouse, France
- STROMALab, Université de Toulouse, INSERM U1031, EFS, INP-ENVT, UPS, Toulouse, France
- * E-mail:
| |
Collapse
|
27
|
Santos ARS, Gerhardt ECM, Parize E, Pedrosa FO, Steffens MBR, Chubatsu LS, Souza EM, Passaglia LMP, Sant'Anna FH, de Souza GA, Huergo LF, Forchhammer K. NAD + biosynthesis in bacteria is controlled by global carbon/nitrogen levels via PII signaling. J Biol Chem 2020; 295:6165-6176. [PMID: 32179648 PMCID: PMC7196632 DOI: 10.1074/jbc.ra120.012793] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 03/10/2020] [Indexed: 01/01/2023] Open
Abstract
NAD+ is a central metabolite participating in core metabolic redox reactions. The prokaryotic NAD synthetase enzyme NadE catalyzes the last step of NAD+ biosynthesis, converting nicotinic acid adenine dinucleotide (NaAD) to NAD+. Some members of the NadE family use l-glutamine as a nitrogen donor and are named NadEGln. Previous gene neighborhood analysis has indicated that the bacterial nadE gene is frequently clustered with the gene encoding the regulatory signal transduction protein PII, suggesting a functional relationship between these proteins in response to the nutritional status and the carbon/nitrogen ratio of the bacterial cell. Here, using affinity chromatography, bioinformatics analyses, NAD synthetase activity, and biolayer interferometry assays, we show that PII and NadEGln physically interact in vitro, that this complex relieves NadEGln negative feedback inhibition by NAD+. This mechanism is conserved in distantly related bacteria. Of note, the PII protein allosteric effector and cellular nitrogen level indicator 2-oxoglutarate (2-OG) inhibited the formation of the PII-NadEGln complex within a physiological range. These results indicate an interplay between the levels of ATP, ADP, 2-OG, PII-sensed glutamine, and NAD+, representing a metabolic hub that may balance the levels of core nitrogen and carbon metabolites. Our findings support the notion that PII proteins act as a dissociable regulatory subunit of NadEGln, thereby enabling the control of NAD+ biosynthesis according to the nutritional status of the bacterial cell.
Collapse
Affiliation(s)
- Adrian Richard Schenberger Santos
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná (UFPR), Curitiba, Paraná, CEP: 81531-980 Brazil; Interfakultäres Institut für Mikrobiologie und Infektionsmedizin der Eberhard-Karls Universität Tübingen, Auf der Morgenstelle 28, Tübingen 72076, Germany
| | | | - Erick Parize
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná (UFPR), Curitiba, Paraná, CEP: 81531-980 Brazil
| | - Fabio Oliveira Pedrosa
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná (UFPR), Curitiba, Paraná, CEP: 81531-980 Brazil
| | - Maria Berenice Reynaud Steffens
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná (UFPR), Curitiba, Paraná, CEP: 81531-980 Brazil
| | - Leda Satie Chubatsu
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná (UFPR), Curitiba, Paraná, CEP: 81531-980 Brazil
| | - Emanuel Maltempi Souza
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná (UFPR), Curitiba, Paraná, CEP: 81531-980 Brazil
| | - Luciane Maria Pereira Passaglia
- Departamento de Genética, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, CEP:91501-970 CP 15053 Brazil
| | - Fernando Hayashi Sant'Anna
- Departamento de Genética, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, CEP:91501-970 CP 15053 Brazil
| | - Gustavo Antônio de Souza
- Departamento de Bioquímica, Universidade Federal do Rio Grande do Norte, Natal/RN, CEP: 59072-970 Brazil
| | - Luciano Fernandes Huergo
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná (UFPR), Curitiba, Paraná, CEP: 81531-980 Brazil; Interfakultäres Institut für Mikrobiologie und Infektionsmedizin der Eberhard-Karls Universität Tübingen, Auf der Morgenstelle 28, Tübingen 72076, Germany; Setor Litoral, UFPR, Matinhos, Paraná, CEP: 83260-000 Brazil.
| | - Karl Forchhammer
- Interfakultäres Institut für Mikrobiologie und Infektionsmedizin der Eberhard-Karls Universität Tübingen, Auf der Morgenstelle 28, Tübingen 72076, Germany.
| |
Collapse
|
28
|
Nitrogen Metabolism in Cancer and Immunity. Trends Cell Biol 2020; 30:408-424. [PMID: 32302552 DOI: 10.1016/j.tcb.2020.02.005] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 02/03/2020] [Accepted: 02/11/2020] [Indexed: 12/16/2022]
Abstract
As one of the fundamental requirements for cell growth and proliferation, nitrogen acquisition and utilization must be tightly regulated. Nitrogen can be generated from amino acids (AAs) and utilized for biosynthetic processes through transamination and deamination reactions. Importantly, limitations of nitrogen availability in cells can disrupt the synthesis of proteins, nucleic acids, and other important nitrogen-containing compounds. Rewiring cellular metabolism to support anabolic processes is a feature common to both cancer and proliferating immune cells. In this review, we discuss how nitrogen is utilized in biosynthetic pathways and highlight different metabolic and oncogenic programs that alter the flow of nitrogen to sustain biomass production and growth, an important emerging feature of cancer and immune cell proliferation.
Collapse
|
29
|
Near-equilibrium glycolysis supports metabolic homeostasis and energy yield. Nat Chem Biol 2019; 15:1001-1008. [PMID: 31548693 PMCID: PMC10184052 DOI: 10.1038/s41589-019-0364-9] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 07/26/2019] [Indexed: 01/31/2023]
Abstract
Glycolysis plays a central role in producing ATP and biomass. Its control principles, however, remain incompletely understood. Here, we develop a method that combines 2H and 13C tracers to determine glycolytic thermodynamics. Using this method, we show that, in conditions and organisms with relatively slow fluxes, multiple steps in glycolysis are near to equilibrium, reflecting spare enzyme capacity. In Escherichia coli, nitrogen or phosphorus upshift rapidly increases the thermodynamic driving force, deploying the spare enzyme capacity to increase flux. Similarly, respiration inhibition in mammalian cells rapidly increases both glycolytic flux and the thermodynamic driving force. The thermodynamic shift allows flux to increase with only small metabolite concentration changes. Finally, we find that the cellulose-degrading anaerobe Clostridium cellulolyticum exhibits slow, near-equilibrium glycolysis due to the use of pyrophosphate rather than ATP for fructose-bisphosphate production, resulting in enhanced per-glucose ATP yield. Thus, near-equilibrium steps of glycolysis promote both rapid flux adaptation and energy efficiency.
Collapse
|
30
|
Klähn S, Bolay P, Wright PR, Atilho RM, Brewer KI, Hagemann M, Breaker RR, Hess WR. A glutamine riboswitch is a key element for the regulation of glutamine synthetase in cyanobacteria. Nucleic Acids Res 2019; 46:10082-10094. [PMID: 30085248 PMCID: PMC6212724 DOI: 10.1093/nar/gky709] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 07/25/2018] [Indexed: 12/19/2022] Open
Abstract
As the key enzyme of bacterial nitrogen assimilation, glutamine synthetase (GS) is tightly regulated. In cyanobacteria, GS activity is controlled by the interaction with inactivating protein factors IF7 and IF17 encoded by the genes gifA and gifB, respectively. We show that a glutamine-binding aptamer within the gifB 5′ UTR of Synechocystis sp. PCC 6803 is critical for the expression of IF17. Binding of glutamine induced structural re-arrangements in this RNA element leading to enhanced protein synthesis in vivo and characterizing it as a riboswitch. Mutagenesis showed the riboswitch mechanism to contribute at least as much to the control of gene expression as the promoter-mediated transcriptional regulation. We suggest this and a structurally related but distinct element, to be designated type 1 and type 2 glutamine riboswitches. Extended biocomputational searches revealed that glutamine riboswitches are exclusively but frequently found in cyanobacterial genomes, where they are primarily associated with gifB homologs. Hence, this RNA-based sensing mechanism is common in cyanobacteria and establishes a regulatory feedback loop that couples the IF17-mediated GS inactivation to the intracellular glutamine levels. Together with the previously described sRNA NsiR4, these results show that non-coding RNA is an indispensable component in the control of nitrogen assimilation in cyanobacteria.
Collapse
Affiliation(s)
- Stephan Klähn
- Genetics & Experimental Bioinformatics, Faculty of Biology, University of Freiburg, Freiburg, Germany.,Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA.,Department of Solar Materials, Helmholtz-Centre for Environmental Research, Leipzig, Germany
| | - Paul Bolay
- Genetics & Experimental Bioinformatics, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Patrick R Wright
- Bioinformatics, Technical Faculty, University of Freiburg, Freiburg, Germany
| | - Ruben M Atilho
- Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Kenneth I Brewer
- Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Martin Hagemann
- Department of Plant Physiology, Institute of Biological Sciences, University of Rostock, Rostock, Germany
| | - Ronald R Breaker
- Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA.,Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA.,Howard Hughes Medical Institute, Yale University, New Haven, CT, USA
| | - Wolfgang R Hess
- Genetics & Experimental Bioinformatics, Faculty of Biology, University of Freiburg, Freiburg, Germany.,Freiburg Institute for Advanced Studies, University of Freiburg, Germany
| |
Collapse
|
31
|
Maeda K, Westerhoff HV, Kurata H, Boogerd FC. Ranking network mechanisms by how they fit diverse experiments and deciding on E. coli's ammonium transport and assimilation network. NPJ Syst Biol Appl 2019; 5:14. [PMID: 30993002 PMCID: PMC6461619 DOI: 10.1038/s41540-019-0091-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 03/12/2019] [Indexed: 11/17/2022] Open
Abstract
The complex ammonium transport and assimilation network of E. coli involves the ammonium transporter AmtB, the regulatory proteins GlnK and GlnB, and the central N-assimilating enzymes together with their highly complex interactions. The engineering and modelling of such a complex network seem impossible because functioning depends critically on a gamut of data known at patchy accuracy. We developed a way out of this predicament, which employs: (i) a constrained optimization-based technology for the simultaneous fitting of models to heterogeneous experimental data sets gathered through diverse experimental set-ups, (ii) a 'rubber band method' to deal with different degrees of uncertainty, both in experimentally determined or estimated parameter values and in measured transient or steady-state variables (training data sets), (iii) integration of human expertise to decide on accuracies of both parameters and variables, (iv) massive computation employing a fast algorithm and a supercomputer, (v) an objective way of quantifying the plausibility of models, which makes it possible to decide which model is the best and how much better that model is than the others. We applied the new technology to the ammonium transport and assimilation network, integrating recent and older data of various accuracies, from different expert laboratories. The kinetic model objectively ranked best, has E. coli's AmtB as an active transporter of ammonia to be assimilated with GlnK minimizing the futile cycling that is an inevitable consequence of intracellular ammonium accumulation. It is 130 times better than a model with facilitated passive transport of ammonia.
Collapse
Affiliation(s)
- Kazuhiro Maeda
- Frontier Research Academy for Young Researchers, Kyushu Institute of Technology, Kitakyushu, Fukuoka, Japan
- Department of Bioscience and Bioinformatics, Kyushu Institute of Technology, Iizuka, Fukuoka Japan
| | - Hans V. Westerhoff
- Department of Molecular Cell Biology, Faculty of Science, VU University Amsterdam, O|2 building, Amsterdam, Netherlands
- Manchester Centre for Integrative Systems Biology, Manchester Interdisciplinary Biocentre, School of Chemical Engineering and Analytical Science, The University of Manchester, Manchester, UK
- Synthetic Systems Biology and Nuclear Organization, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, Netherlands
| | - Hiroyuki Kurata
- Department of Bioscience and Bioinformatics, Kyushu Institute of Technology, Iizuka, Fukuoka Japan
- Biomedical Informatics R&D Center, Kyushu Institute of Technology, Iizuka, Fukuoka Japan
| | - Fred C. Boogerd
- Department of Molecular Cell Biology, Faculty of Science, VU University Amsterdam, O|2 building, Amsterdam, Netherlands
| |
Collapse
|
32
|
Biosensors-Based In Vivo Quantification of 2-Oxoglutarate in Cyanobacteria and Proteobacteria. Life (Basel) 2018; 8:life8040051. [PMID: 30373229 PMCID: PMC6315671 DOI: 10.3390/life8040051] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Revised: 10/24/2018] [Accepted: 10/25/2018] [Indexed: 01/12/2023] Open
Abstract
2-oxoglutarate (α-ketoglutarate; 2-OG) is an intermediate of the Krebs cycle, and constitutes the carbon skeleton for nitrogen assimilation and the synthesis of a variety of compounds. In addition to being an important metabolite, 2-OG is a signaling molecule with a broad regulatory repertoire in a variety of organisms, including plants, animals, and bacteria. Although challenging, measuring the levels and variations of metabolic signals in vivo is critical to better understand how cells control specific processes. To measure cellular 2-OG concentrations and dynamics, we designed a set of biosensors based on the fluorescence resonance energy transfer (FRET) technology that can be used in vivo in different organisms. For this purpose, we took advantage of the conformational changes of two cyanobacterial proteins induced by 2-OG binding. We show that these biosensors responded immediately and specifically to different 2-OG levels, and hence allowed to measure 2-OG variations in function of environmental modifications in the proteobacterium Escherichia coli and in the cyanobacterium Anabaena sp. PCC 7120. Our results pave the way to study 2-OG dynamics at the cellular level in uni- and multi-cellular organisms.
Collapse
|
33
|
Trautwein K, Hensler M, Wiegmann K, Skorubskaya E, Wöhlbrand L, Wünsch D, Hinrichs C, Feenders C, Müller C, Schell K, Ruppersberg H, Vagts J, Koßmehl S, Steinbüchel A, Schmidt-Kopplin P, Wilkes H, Hillebrand H, Blasius B, Schomburg D, Rabus R. The marine bacterium Phaeobacter inhibens secures external ammonium by rapid buildup of intracellular nitrogen stocks. FEMS Microbiol Ecol 2018; 94:5074353. [PMID: 30124819 PMCID: PMC6122490 DOI: 10.1093/femsec/fiy154] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Accepted: 08/13/2018] [Indexed: 11/27/2022] Open
Abstract
Reduced nitrogen species are key nutrients for biological productivity in the oceans. Ammonium is often present in low and growth-limiting concentrations, albeit peaks occur during collapse of algal blooms or via input from deep sea upwelling and riverine inflow. Autotrophic phytoplankton exploit ammonium peaks by storing nitrogen intracellularly. In contrast, the strategy of heterotrophic bacterioplankton to acquire ammonium is less well understood. This study revealed the marine bacterium Phaeobacter inhibens DSM 17395, a Roseobacter group member, to have already depleted the external ammonium when only ∼⅓ of the ultimately attained biomass is formed. This was paralleled by a three-fold increase in cellular nitrogen levels and rapid buildup of various nitrogen-containing intracellular metabolites (and enzymes for their biosynthesis) and biopolymers (DNA, RNA and proteins). Moreover, nitrogen-rich cells secreted potential RTX proteins and the antibiotic tropodithietic acid, perhaps to competitively secure pulses of external ammonium and to protect themselves from predation. This complex response may ensure growing cells and their descendants exclusive provision with internal nitrogen stocks. This nutritional strategy appears prevalent also in other roseobacters from distant geographical provenances and could provide a new perspective on the distribution of reduced nitrogen in marine environments, i.e. temporary accumulation in bacterioplankton cells.
Collapse
Affiliation(s)
- Kathleen Trautwein
- General and Molecular Microbiology, Institute for Chemistry and Biology of the Marine Environment (ICBM), University Oldenburg, Carl-von-Ossietzky Str. 9-11, Oldenburg 26111, Germany
| | - Michael Hensler
- Bioinformatics and Biochemistry, Institute for Biochemistry and Biotechnology, Technische Universität Braunschweig, Rebenring 56, Braunschweig 38106, Germany
| | - Katharina Wiegmann
- General and Molecular Microbiology, Institute for Chemistry and Biology of the Marine Environment (ICBM), University Oldenburg, Carl-von-Ossietzky Str. 9-11, Oldenburg 26111, Germany
| | - Ekaterina Skorubskaya
- General and Molecular Microbiology, Institute for Chemistry and Biology of the Marine Environment (ICBM), University Oldenburg, Carl-von-Ossietzky Str. 9-11, Oldenburg 26111, Germany
| | - Lars Wöhlbrand
- General and Molecular Microbiology, Institute for Chemistry and Biology of the Marine Environment (ICBM), University Oldenburg, Carl-von-Ossietzky Str. 9-11, Oldenburg 26111, Germany
| | - Daniel Wünsch
- General and Molecular Microbiology, Institute for Chemistry and Biology of the Marine Environment (ICBM), University Oldenburg, Carl-von-Ossietzky Str. 9-11, Oldenburg 26111, Germany
| | - Christina Hinrichs
- General and Molecular Microbiology, Institute for Chemistry and Biology of the Marine Environment (ICBM), University Oldenburg, Carl-von-Ossietzky Str. 9-11, Oldenburg 26111, Germany
| | - Christoph Feenders
- Mathematical Modelling, Institute for Chemistry and Biology of the Marine Environment (ICBM), University Oldenburg, Carl-von-Ossietzky Str. 9-11, Oldenburg 26111, Germany
| | - Constanze Müller
- Analytical BioGeoChemistry, HelmholtzZentrum München, German Research Centre for Environmental Health, Ingolstädter Landstr. 1, Neuherberg 85764, Germany
| | - Kristina Schell
- General and Molecular Microbiology, Institute for Chemistry and Biology of the Marine Environment (ICBM), University Oldenburg, Carl-von-Ossietzky Str. 9-11, Oldenburg 26111, Germany
| | - Hanna Ruppersberg
- General and Molecular Microbiology, Institute for Chemistry and Biology of the Marine Environment (ICBM), University Oldenburg, Carl-von-Ossietzky Str. 9-11, Oldenburg 26111, Germany
| | - Jannes Vagts
- General and Molecular Microbiology, Institute for Chemistry and Biology of the Marine Environment (ICBM), University Oldenburg, Carl-von-Ossietzky Str. 9-11, Oldenburg 26111, Germany
| | - Sebastian Koßmehl
- General and Molecular Microbiology, Institute for Chemistry and Biology of the Marine Environment (ICBM), University Oldenburg, Carl-von-Ossietzky Str. 9-11, Oldenburg 26111, Germany
| | - Alexander Steinbüchel
- Institute for Molecular Microbiology and Biotechnology, WWU Münster, Corrensstr. 3, Münster 48149, Germany
| | - Philippe Schmidt-Kopplin
- Analytical BioGeoChemistry, HelmholtzZentrum München, German Research Centre for Environmental Health, Ingolstädter Landstr. 1, Neuherberg 85764, Germany
| | - Heinz Wilkes
- Organic Geochemistry, Institute for Chemistry and Biology of the Marine Environment (ICBM), University Oldenburg, Carl-von-Ossietzky Str. 9-11, Oldenburg 26111, Germany
| | - Helmut Hillebrand
- Planktology, Institute for Chemistry and Biology of the Marine Environment (ICBM), University Oldenburg, Carl-von-Ossietzky Str. 9-11, Oldenburg 26111, Germany
- Helmholtz Institute for Functional Marine Biodiversity at the University of Oldenburg (HIFMB), Ammerländer Heerstr. 231, Oldenburg 23129, Germany
| | - Bernd Blasius
- Mathematical Modelling, Institute for Chemistry and Biology of the Marine Environment (ICBM), University Oldenburg, Carl-von-Ossietzky Str. 9-11, Oldenburg 26111, Germany
| | - Dietmar Schomburg
- Bioinformatics and Biochemistry, Institute for Biochemistry and Biotechnology, Technische Universität Braunschweig, Rebenring 56, Braunschweig 38106, Germany
| | - Ralf Rabus
- General and Molecular Microbiology, Institute for Chemistry and Biology of the Marine Environment (ICBM), University Oldenburg, Carl-von-Ossietzky Str. 9-11, Oldenburg 26111, Germany
| |
Collapse
|
34
|
Wirth R, Kádár G, Kakuk B, Maróti G, Bagi Z, Szilágyi Á, Rákhely G, Horváth J, Kovács KL. The Planktonic Core Microbiome and Core Functions in the Cattle Rumen by Next Generation Sequencing. Front Microbiol 2018; 9:2285. [PMID: 30319585 PMCID: PMC6165872 DOI: 10.3389/fmicb.2018.02285] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 09/07/2018] [Indexed: 12/31/2022] Open
Abstract
The cow rumen harbors a great variety of diverse microbes, which form a complex, organized community. Understanding the behavior of this multifarious network is crucial in improving ruminant nutrient use efficiency. The aim of this study was to expand our knowledge by examining 10 Holstein dairy cow rumen fluid fraction whole metagenome and transcriptome datasets. DNA and mRNA sequence data, generated by Ion Torrent, was subjected to quality control and filtering before analysis for core elements. The taxonomic core microbiome consisted of 48 genera belonging to Bacteria (47) and Archaea (1). The genus Prevotella predominated the planktonic core community. Core functional groups were identified using co-occurrence analysis and resulted in 587 genes, from which 62 could be assigned to metabolic functions. Although this was a minimal functional core, it revealed key enzymes participating in various metabolic processes. A diverse and rich collection of enzymes involved in carbohydrate metabolism and other functions were identified. Transcripts coding for enzymes active in methanogenesis made up 1% of the core functions. The genera associated with the core enzyme functions were also identified. Linking genera to functions showed that the main metabolic pathways are primarily provided by Bacteria and several genera may serve as a “back-up” team for the central functions. The key actors in most essential metabolic routes belong to the genus Prevotella. Confirming earlier studies, the genus Methanobrevibacter carries out the overwhelming majority of rumen methanogenesis and therefore methane emission mitigation seems conceivable via targeting the hydrogenotrophic methanogenesis.
Collapse
Affiliation(s)
- Roland Wirth
- Department of Biotechnology, University of Szeged, Szeged, Hungary
| | | | - Balázs Kakuk
- Department of Biotechnology, University of Szeged, Szeged, Hungary
| | - Gergely Maróti
- Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, Szeged, Hungary
| | - Zoltán Bagi
- Department of Biotechnology, University of Szeged, Szeged, Hungary
| | - Árpád Szilágyi
- Department of Biotechnology, University of Szeged, Szeged, Hungary
| | - Gábor Rákhely
- Department of Biotechnology, University of Szeged, Szeged, Hungary.,Institute of Biophysics, Biological Research Center, Hungarian Academy of Sciences, Szeged, Hungary
| | - József Horváth
- Faculty of Agriculture, University of Szeged, Hódmezövásárhely, Hungary
| | - Kornél L Kovács
- Department of Biotechnology, University of Szeged, Szeged, Hungary.,Institute of Biophysics, Biological Research Center, Hungarian Academy of Sciences, Szeged, Hungary.,Department of Oral Biology and Experimental Dental Research, University of Szeged, Szeged, Hungary
| |
Collapse
|
35
|
Li SHJ, Li Z, Park JO, King CG, Rabinowitz JD, Wingreen NS, Gitai Z. Escherichia coli translation strategies differ across carbon, nitrogen and phosphorus limitation conditions. Nat Microbiol 2018; 3:939-947. [PMID: 30038306 DOI: 10.1038/s41564-018-0199-2] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Accepted: 06/15/2018] [Indexed: 11/09/2022]
Abstract
For cells to grow faster they must increase their protein production rate. Microorganisms have traditionally been thought to accomplish this increase by producing more ribosomes to enhance protein synthesis capacity, leading to the linear relationship between ribosome level and growth rate observed under most growth conditions previously examined. Past studies have suggested that this linear relationship represents an optimal resource allocation strategy for each growth rate, independent of any specific nutrient state. Here we investigate protein production strategies in continuous cultures limited for carbon, nitrogen and phosphorus, which differentially impact substrate supply for protein versus nucleic acid metabolism. Unexpectedly, we find that at slow growth rates, Escherichia coli achieves the same protein production rate using three different strategies under the three different nutrient limitations. Under phosphorus (P) limitation, translation is slow due to a particularly low abundance of ribosomes, which are RNA-rich and thus particularly costly for phosphorous-limited cells. Under nitrogen (N) limitation, translation elongation is slowed by processes including ribosome stalling at glutamine codons. Under carbon (C) limitation, translation is slowed by accumulation of inactive ribosomes not bound to messenger RNA. These extra ribosomes enable rapid growth acceleration during nutrient upshift. Thus, bacteria tune ribosome usage across different limiting nutrients to enable balanced nutrient-limited growth while also preparing for future nutrient upshifts.
Collapse
Affiliation(s)
| | - Zhiyuan Li
- Princeton Center for Theoretical Science, Princeton University, Princeton, NJ, USA
| | - Junyoung O Park
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA.,Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, USA.,Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, CA, USA
| | | | - Joshua D Rabinowitz
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA.,Department of Chemistry, Princeton University, Princeton, NJ, USA
| | - Ned S Wingreen
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA. .,Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA.
| | - Zemer Gitai
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA.
| |
Collapse
|
36
|
Liu L, Su X, Quinn WJ, Hui S, Krukenberg K, Frederick DW, Redpath P, Zhan L, Chellappa K, White E, Migaud M, Mitchison TJ, Baur JA, Rabinowitz JD. Quantitative Analysis of NAD Synthesis-Breakdown Fluxes. Cell Metab 2018; 27:1067-1080.e5. [PMID: 29685734 PMCID: PMC5932087 DOI: 10.1016/j.cmet.2018.03.018] [Citation(s) in RCA: 347] [Impact Index Per Article: 57.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 11/11/2017] [Accepted: 03/26/2018] [Indexed: 01/23/2023]
Abstract
The redox cofactor nicotinamide adenine dinucleotide (NAD) plays a central role in metabolism and is a substrate for signaling enzymes including poly-ADP-ribose-polymerases (PARPs) and sirtuins. NAD concentration falls during aging, which has triggered intense interest in strategies to boost NAD levels. A limitation in understanding NAD metabolism has been reliance on concentration measurements. Here, we present isotope-tracer methods for NAD flux quantitation. In cell lines, NAD was made from nicotinamide and consumed largely by PARPs and sirtuins. In vivo, NAD was made from tryptophan selectively in the liver, which then excreted nicotinamide. NAD fluxes varied widely across tissues, with high flux in the small intestine and spleen and low flux in the skeletal muscle. Intravenous administration of nicotinamide riboside or mononucleotide delivered intact molecules to multiple tissues, but the same agents given orally were metabolized to nicotinamide in the liver. Thus, flux analysis can reveal tissue-specific NAD metabolism.
Collapse
Affiliation(s)
- Ling Liu
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08540, USA; Department of Chemistry, Princeton University, Princeton, NJ 08540, USA; Diabetes Research Center, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Xiaoyang Su
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08540, USA; Department of Medicine, Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ 08904, USA
| | - William J Quinn
- Department of Physiology and Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Sheng Hui
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08540, USA
| | - Kristin Krukenberg
- Department of System Biology, Harvard Medical School, Boston, MA 02115, USA; Shire, Lexington, MA 02421, USA
| | - David W Frederick
- Department of Physiology and Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Philip Redpath
- School of Pharmacy, Queen's University Belfast, Belfast, Northern Ireland BT9 7BL, UK
| | - Le Zhan
- Rutgers Cancer Institute of New Jersey, New Brunswick, NJ 08903, USA
| | - Karthikeyani Chellappa
- Department of Physiology and Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Eileen White
- Rutgers Cancer Institute of New Jersey, New Brunswick, NJ 08903, USA
| | - Marie Migaud
- School of Pharmacy, Queen's University Belfast, Belfast, Northern Ireland BT9 7BL, UK; Mitchell Cancer Institute, University of South Alabama, Mobile, AL 36604, USA
| | - Timothy J Mitchison
- Department of System Biology, Harvard Medical School, Boston, MA 02115, USA.
| | - Joseph A Baur
- Department of Physiology and Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - Joshua D Rabinowitz
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08540, USA; Department of Chemistry, Princeton University, Princeton, NJ 08540, USA; Diabetes Research Center, University of Pennsylvania, Philadelphia, PA 19104, USA.
| |
Collapse
|
37
|
Santos ARS, Gerhardt ECM, Moure VR, Pedrosa FO, Souza EM, Diamanti R, Högbom M, Huergo LF. Kinetics and structural features of dimeric glutamine-dependent bacterial NAD + synthetases suggest evolutionary adaptation to available metabolites. J Biol Chem 2018; 293:7397-7407. [PMID: 29581233 DOI: 10.1074/jbc.ra118.002241] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 03/11/2018] [Indexed: 01/09/2023] Open
Abstract
NADH (NAD+) and its reduced form NADH serve as cofactors for a variety of oxidoreductases that participate in many metabolic pathways. NAD+ also is used as substrate by ADP-ribosyl transferases and by sirtuins. NAD+ biosynthesis is one of the most fundamental biochemical pathways in nature, and the ubiquitous NAD+ synthetase (NadE) catalyzes the final step in this biosynthetic route. Two different classes of NadE have been described to date: dimeric single-domain ammonium-dependent NadENH3 and octameric glutamine-dependent NadEGln, and the presence of multiple NadE isoforms is relatively common in prokaryotes. Here, we identified a novel dimeric group of NadEGln in bacteria. Substrate preferences and structural analyses suggested that dimeric NadEGln enzymes may constitute evolutionary intermediates between dimeric NadENH3 and octameric NadEGln The characterization of additional NadE isoforms in the diazotrophic bacterium Azospirillum brasilense along with the determination of intracellular glutamine levels in response to an ammonium shock led us to propose a model in which these different NadE isoforms became active accordingly to the availability of nitrogen. These data may explain the selective pressures that support the coexistence of multiple isoforms of NadE in some prokaryotes.
Collapse
Affiliation(s)
| | | | | | | | | | - Riccardo Diamanti
- Department of Biochemistry and Biophysics, Stockholm University, 106 91 Stockholm, Sweden
| | - Martin Högbom
- Department of Biochemistry and Biophysics, Stockholm University, 106 91 Stockholm, Sweden
| | - Luciano Fernandes Huergo
- Department of Biochemistry and Molecular Biology, Curitiba, PR, 512 Brazil; Setor Litoral, Universidade Federal do Paraná (UFPR), Curitiba, PR, 512 Brazil.
| |
Collapse
|
38
|
de Oliveira Viana J, Scotti MT, Scotti L. Molecular Docking Studies in Multitarget Antitubercular Drug Discovery. METHODS IN PHARMACOLOGY AND TOXICOLOGY 2018. [DOI: 10.1007/7653_2018_28] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
|
39
|
Sacomboio ENM, Kim EYS, Ruchaud Correa HL, Bonato P, de Oliveira Pedrosa F, de Souza EM, Chubatsu LS, Müller-Santos M. The transcriptional regulator NtrC controls glucose-6-phosphate dehydrogenase expression and polyhydroxybutyrate synthesis through NADPH availability in Herbaspirillum seropedicae. Sci Rep 2017; 7:13546. [PMID: 29051509 PMCID: PMC5648810 DOI: 10.1038/s41598-017-12649-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 09/12/2017] [Indexed: 11/09/2022] Open
Abstract
The NTR system is the major regulator of nitrogen metabolism in Bacteria. Despite its broad and well-known role in the assimilation, biosynthesis and recycling of nitrogenous molecules, little is known about its role in carbon metabolism. In this work, we present a new facet of the NTR system in the control of NADPH concentration and the biosynthesis of molecules dependent on reduced coenzyme in Herbaspirillum seropedicae SmR1. We demonstrated that a ntrC mutant strain accumulated high levels of polyhydroxybutyrate (PHB), reaching levels up to 2-fold higher than the parental strain. In the absence of NtrC, the activity of glucose-6-phosphate dehydrogenase (encoded by zwf) increased by 2.8-fold, consequently leading to a 2.1-fold increase in the NADPH/NADP+ ratio. A GFP fusion showed that expression of zwf is likewise controlled by NtrC. The increase in NADPH availability stimulated the production of polyhydroxybutyrate regardless the C/N ratio in the medium. The mutant ntrC was more resistant to H2O2 exposure and controlled the propagation of ROS when facing the oxidative condition, a phenotype associated with the increase in PHB content.
Collapse
Affiliation(s)
- Euclides Nenga Manuel Sacomboio
- Department of Biochemistry and Molecular Biology, Laboratory of Nitrogen Fixation, Federal University of Paraná (UFPR), Curitiba, Brazil
| | - Edson Yu Sin Kim
- Department of Biochemistry and Molecular Biology, Laboratory of Nitrogen Fixation, Federal University of Paraná (UFPR), Curitiba, Brazil
| | - Henrique Leonardo Ruchaud Correa
- Department of Biochemistry and Molecular Biology, Laboratory of Nitrogen Fixation, Federal University of Paraná (UFPR), Curitiba, Brazil
| | - Paloma Bonato
- Department of Biochemistry and Molecular Biology, Laboratory of Nitrogen Fixation, Federal University of Paraná (UFPR), Curitiba, Brazil
| | - Fabio de Oliveira Pedrosa
- Department of Biochemistry and Molecular Biology, Laboratory of Nitrogen Fixation, Federal University of Paraná (UFPR), Curitiba, Brazil
| | - Emanuel Maltempi de Souza
- Department of Biochemistry and Molecular Biology, Laboratory of Nitrogen Fixation, Federal University of Paraná (UFPR), Curitiba, Brazil
| | - Leda Satie Chubatsu
- Department of Biochemistry and Molecular Biology, Laboratory of Nitrogen Fixation, Federal University of Paraná (UFPR), Curitiba, Brazil
| | - Marcelo Müller-Santos
- Department of Biochemistry and Molecular Biology, Laboratory of Nitrogen Fixation, Federal University of Paraná (UFPR), Curitiba, Brazil.
| |
Collapse
|
40
|
An LC-MS Approach to Quantitative Measurement of Ammonia Isotopologues. Sci Rep 2017; 7:10304. [PMID: 28871132 PMCID: PMC5583358 DOI: 10.1038/s41598-017-09993-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 08/01/2017] [Indexed: 11/22/2022] Open
Abstract
Ammonia is a fundamental aspect of metabolism spanning all of phylogeny. Metabolomics, including metabolic tracing studies, are an integral part of elucidating the role of ammonia in these systems. However, current methods for measurement of ammonia are spectrophotometric, and cannot distinguish isotopologues of ammonia, significantly limiting metabolic tracing studies. Here, we describe a novel LC-MS-based method that quantitatively assesses both 14N-and 15N-isotopologues of ammonia in polar metabolite extracts. This assay (1) quantitatively measures the concentration of ammonia in polar metabolite isolates used for metabolomic studies, and (2) accurately determines the percent isotope abundance of 15N-ammonia in a cell lysate for 15N-isotope tracing studies. We apply this assay to quantitatively measure glutamine-derived ammonia in lung cancer cell lines with differential expression of glutaminase.
Collapse
|
41
|
GlnK Facilitates the Dynamic Regulation of Bacterial Nitrogen Assimilation. Biophys J 2017; 112:2219-2230. [PMID: 28538158 PMCID: PMC5448240 DOI: 10.1016/j.bpj.2017.04.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 04/10/2017] [Accepted: 04/14/2017] [Indexed: 11/29/2022] Open
Abstract
Ammonium assimilation in Escherichia coli is regulated by two paralogous proteins (GlnB and GlnK), which orchestrate interactions with regulators of gene expression, transport proteins, and metabolic pathways. Yet how they conjointly modulate the activity of glutamine synthetase, the key enzyme for nitrogen assimilation, is poorly understood. We combine experiments and theory to study the dynamic roles of GlnB and GlnK during nitrogen starvation and upshift. We measure time-resolved in vivo concentrations of metabolites, total and posttranslationally modified proteins, and develop a concise biochemical model of GlnB and GlnK that incorporates competition for active and allosteric sites, as well as functional sequestration of GlnK. The model predicts the responses of glutamine synthetase, GlnB, and GlnK under time-varying external ammonium level in the wild-type and two genetic knock-outs. Our results show that GlnK is tightly regulated under nitrogen-rich conditions, yet it is expressed during ammonium run-out and starvation. This suggests a role for GlnK as a buffer of nitrogen shock after starvation, and provides a further functional link between nitrogen and carbon metabolisms.
Collapse
|
42
|
Sporer AJ, Kahl LJ, Price-Whelan A, Dietrich LE. Redox-Based Regulation of Bacterial Development and Behavior. Annu Rev Biochem 2017; 86:777-797. [DOI: 10.1146/annurev-biochem-061516-044453] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Abigail J. Sporer
- Department of Biological Sciences, Columbia University, New York, NY 10027
| | - Lisa J. Kahl
- Department of Biological Sciences, Columbia University, New York, NY 10027
| | - Alexa Price-Whelan
- Department of Biological Sciences, Columbia University, New York, NY 10027
| | - Lars E.P. Dietrich
- Department of Biological Sciences, Columbia University, New York, NY 10027
| |
Collapse
|
43
|
Diazotrophic Growth Allows Azotobacter vinelandii To Overcome the Deleterious Effects of a glnE Deletion. Appl Environ Microbiol 2017; 83:AEM.00808-17. [PMID: 28432097 DOI: 10.1128/aem.00808-17] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 04/10/2017] [Indexed: 11/20/2022] Open
Abstract
Overcoming the inhibitory effects of excess environmental ammonium on nitrogenase synthesis or activity and preventing ammonium assimilation have been considered strategies to increase the amount of fixed nitrogen transferred from bacterial to plant partners in associative or symbiotic plant-diazotroph relationships. The GlnE adenylyltransferase/adenylyl-removing enzyme catalyzes reversible adenylylation of glutamine synthetase (GS), thereby affecting the posttranslational regulation of ammonium assimilation that is critical for the appropriate coordination of carbon and nitrogen assimilation. Since GS is key to the sole ammonium assimilation pathway of Azotobacter vinelandii, attempts to obtain deletion mutants in the gene encoding GS (glnA) have been unsuccessful. We have generated a glnE deletion strain, thus preventing posttranslational regulation of GS. The resultant strain containing constitutively active GS is unable to grow well on ammonium-containing medium, as previously observed in other organisms, and can be cultured only at low ammonium concentrations. This phenotype is caused by the lack of downregulation of GS activity, resulting in high intracellular glutamine levels and severe perturbation of the ratio of glutamine to 2-oxoglutarate under excess-nitrogen conditions. Interestingly, the mutant can grow diazotrophically at rates comparable to those of the wild type. This observation suggests that the control of nitrogen fixation-specific gene expression at the transcriptional level in response to 2-oxoglutarate via NifA is sufficiently tight to alone regulate ammonium production at levels appropriate for optimal carbon and nitrogen balance.IMPORTANCE In this study, the characterization of the glnE knockout mutant of the model diazotroph Azotobacter vinelandii provides significant insights into the integration of the regulatory mechanisms of ammonium production and ammonium assimilation during nitrogen fixation. The work reveals the profound fidelity of nitrogen fixation regulation in providing ammonium sufficient for maximal growth but constraining energetically costly excess production. A detailed fundamental understanding of the interplay between the regulation of ammonium production and assimilation is of paramount importance in exploiting existing and potentially engineering new plant-diazotroph relationships for improved agriculture.
Collapse
|
44
|
Lüddecke J, Francois L, Spät P, Watzer B, Chilczuk T, Poschet G, Hell R, Radlwimmer B, Forchhammer K. P II Protein-Derived FRET Sensors for Quantification and Live-Cell Imaging of 2-Oxoglutarate. Sci Rep 2017; 7:1437. [PMID: 28469248 PMCID: PMC5431102 DOI: 10.1038/s41598-017-01440-w] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 03/30/2017] [Indexed: 12/21/2022] Open
Abstract
The citric acid cycle intermediate 2-oxoglutarate (2-OG, a.k.a. alpha-ketoglutarate) links the carbon and nitrogen metabolic pathways and can provide information on the metabolic status of cells. In recent years, it has become exceedingly clear that 2-OG also acts as a master regulator of diverse biologic processes in all domains of life. Consequently, there is a great demand for time-resolved data on 2-OG fluctuations that can’t be adequately addressed using established methods like mass spectrometry-based metabolomics analysis. Therefore, we set out to develop a novel intramolecular 2-OG FRET sensor based on the signal transduction protein PII from Synechococcus elongatus PCC 7942. We created two variants of the sensor, with a dynamic range for 2-OG from 0.1 µM to 0.1 mM or from 10 µM to 10 mM. As proof of concept, we applied the sensors to determine in situ glutamine:2-oxoglutarate aminotransferase (GOGAT) activity in Synechococcus elongatus PCC 7942 cells and measured 2-OG concentrations in cell extracts from Escherichia coli in vitro. Finally, we could show the sensors’ functionality in living human cell lines, demonstrating their potential in the context of mechanistic studies and drug screening.
Collapse
Affiliation(s)
- Jan Lüddecke
- Interfaculty Institute for Microbiology and Infection Medicine, Division Organismic Interactions, University of Tübingen, Tübingen, Germany
| | - Liliana Francois
- Division of Molecular Genetics, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Philipp Spät
- Interfaculty Institute for Microbiology and Infection Medicine, Division Organismic Interactions, University of Tübingen, Tübingen, Germany
| | - Björn Watzer
- Interfaculty Institute for Microbiology and Infection Medicine, Division Organismic Interactions, University of Tübingen, Tübingen, Germany
| | - Tomasz Chilczuk
- Interfaculty Institute for Microbiology and Infection Medicine, Division Organismic Interactions, University of Tübingen, Tübingen, Germany
| | - Gernot Poschet
- Centre for Organismal Studies Heidelberg, Rupprecht-Karls-Universität Heidelberg, Heidelberg, Germany
| | - Rüdiger Hell
- Centre for Organismal Studies Heidelberg, Rupprecht-Karls-Universität Heidelberg, Heidelberg, Germany
| | - Bernhard Radlwimmer
- Division of Molecular Genetics, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Karl Forchhammer
- Interfaculty Institute for Microbiology and Infection Medicine, Division Organismic Interactions, University of Tübingen, Tübingen, Germany.
| |
Collapse
|
45
|
Rydzak T, Garcia D, Stevenson DM, Sladek M, Klingeman DM, Holwerda EK, Amador-Noguez D, Brown SD, Guss AM. Deletion of Type I glutamine synthetase deregulates nitrogen metabolism and increases ethanol production in Clostridium thermocellum. Metab Eng 2017; 41:182-191. [PMID: 28400329 DOI: 10.1016/j.ymben.2017.04.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 03/27/2017] [Accepted: 04/07/2017] [Indexed: 12/25/2022]
Abstract
Clostridium thermocellum rapidly deconstructs cellulose and ferments resulting hydrolysis products into ethanol and other products, and is thus a promising platform organism for the development of cellulosic biofuel production via consolidated bioprocessing. While recent metabolic engineering strategies have targeted eliminating canonical fermentation products (acetate, lactate, formate, and H2), C. thermocellum also secretes amino acids, which has limited ethanol yields in engineered strains to approximately 70% of the theoretical maximum. To investigate approaches to decrease amino acid secretion, we attempted to reduce ammonium assimilation by deleting the Type I glutamine synthetase (glnA) in an essentially wild type strain of C. thermocellum. Deletion of glnA reduced levels of secreted valine and total amino acids by 53% and 44% respectively, and increased ethanol yields by 53%. RNA-seq analysis revealed that genes encoding the RNF-complex were more highly expressed in ΔglnA and may have a role in improving NADH-availability for ethanol production. While a significant up-regulation of genes involved in nitrogen assimilation and urea uptake suggested that deletion of glnA induces a nitrogen starvation response, metabolomic analysis showed an increase in intracellular glutamine levels indicative of nitrogen-rich conditions. We propose that deletion of glnA causes deregulation of nitrogen metabolism, leading to overexpression of nitrogen metabolism genes and, in turn, elevated glutamine levels. Here we demonstrate that perturbation of nitrogen assimilation is a promising strategy to redirect flux from the production of nitrogenous compounds toward biofuels in C. thermocellum.
Collapse
Affiliation(s)
- Thomas Rydzak
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States; BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - David Garcia
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States; BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - David M Stevenson
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, United States
| | - Margaret Sladek
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States; BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Dawn M Klingeman
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States; BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Evert K Holwerda
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States; Thayer School of Engineering at Dartmouth College, Hanover, NH, United States
| | - Daniel Amador-Noguez
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, United States
| | - Steven D Brown
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States; BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Adam M Guss
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States; BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States.
| |
Collapse
|
46
|
Metabolic regulation is sufficient for global and robust coordination of glucose uptake, catabolism, energy production and growth in Escherichia coli. PLoS Comput Biol 2017; 13:e1005396. [PMID: 28187134 PMCID: PMC5328398 DOI: 10.1371/journal.pcbi.1005396] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 02/27/2017] [Accepted: 02/03/2017] [Indexed: 11/23/2022] Open
Abstract
The metabolism of microorganisms is regulated through two main mechanisms: changes of enzyme capacities as a consequence of gene expression modulation (“hierarchical control”) and changes of enzyme activities through metabolite-enzyme interactions. An increasing body of evidence indicates that hierarchical control is insufficient to explain metabolic behaviors, but the system-wide impact of metabolic regulation remains largely uncharacterized. To clarify its role, we developed and validated a detailed kinetic model of Escherichia coli central metabolism that links growth to environment. Metabolic control analyses confirm that the control is widely distributed across the network and highlight strong interconnections between all the pathways. Exploration of the model solution space reveals that several robust properties emerge from metabolic regulation, from the molecular level (e.g. homeostasis of total metabolite pool) to the overall cellular physiology (e.g. coordination of carbon uptake, catabolism, energy and redox production, and growth), while allowing a large degree of flexibility at most individual metabolic steps. These properties have important physiological implications for E. coli and significantly expand the self-regulating capacities of its metabolism. Metabolism is a fundamental biochemical process that enables cells to operate and grow by converting nutrients into ‘building blocks’ and energy. Metabolism happens through the work of enzymes, which are encoded by genes. Thus, genes and their regulation are often thought of controlling metabolism, somewhat at the top of a hierarchical control system. However, an increasing body of evidence indicates that metabolism plays an active role in the control of its own operation via a dense network of metabolite-enzyme interactions. The system-wide role of metabolic regulation is hard to dissect and so far remains largely uncharacterized. To better understand its role, we constructed a detailed kinetic model of the carbon and energy metabolism of the bacterium Escherichia coli, a model organism in Systems and Synthetic biology. Model simulations indicate that kinetic considerations of metabolism alone can explain data from hundreds of experiments, without needing to invoke regulation of gene expression. In particular, metabolic regulation is sufficient to coordinate carbon utilization, redox and energy production, and growth, while maintaining local flexibility at individual metabolic steps. These findings indicate that the self-regulating capacities of E. coli metabolism are far more significant than previously expected, and improve our understanding on how cells work.
Collapse
|
47
|
Sanchuki HBS, Gravina F, Rodrigues TE, Gerhardt ECM, Pedrosa FO, Souza EM, Raittz RT, Valdameri G, de Souza GA, Huergo LF. Dynamics of the Escherichia coli proteome in response to nitrogen starvation and entry into the stationary phase. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2016; 1865:344-352. [PMID: 27939605 DOI: 10.1016/j.bbapap.2016.12.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 12/02/2016] [Accepted: 12/06/2016] [Indexed: 01/31/2023]
Abstract
Nitrogen is needed for the biosynthesis of biomolecules including proteins and nucleic acids. In the absence of fixed nitrogen prokaryotes such as E. coli immediately ceases growth. Ammonium is the preferred nitrogen source for E. coli supporting the fastest growth rates. Under conditions of ammonium limitation, E. coli can use alternative nitrogen sources to supply ammonium ions and this reprogramming is led by the induction of the NtrC regulon. Here we used label free proteomics to determine the dynamics of E. coli proteins expression in response to ammonium starvation in both the short (30min) and the longer (60min) starvation. Protein abundances and post-translational modifications confirmed that activation of the NtrC regulon acts as the first line of defense against nitrogen starvation. The ribosome inactivating protein Rmf was induced shortly after ammonium exhaustion and this was preceded by induction of other ribosome inactivating proteins such as Hpf and RaiA supporting the hypothesis that ribosome shut-down is a key process during nitrogen limitation stress. The proteomic data revealed that growth arrest due to nitrogen starvation correlates with the accumulation of proteins involved in DNA condensation, RNA and protein catabolism and ribosome hibernation. Collectively, these proteome adaptations will result in metabolic inactive cells which are likely to exhibit multidrug tolerance.
Collapse
Affiliation(s)
| | - Fernanda Gravina
- Departamento de Bioquímica e Biologia Molecular, UFPR, Curitiba, PR, Brazil
| | - Thiago E Rodrigues
- Departamento de Bioquímica e Biologia Molecular, UFPR, Curitiba, PR, Brazil
| | | | - Fábio O Pedrosa
- Departamento de Bioquímica e Biologia Molecular, UFPR, Curitiba, PR, Brazil
| | - Emanuel M Souza
- Departamento de Bioquímica e Biologia Molecular, UFPR, Curitiba, PR, Brazil
| | - Roberto T Raittz
- Setor de Educação Profissional e Tecnológica, UFPR, Curitiba, PR, Brazil
| | - Glaucio Valdameri
- Departamento de Bioquímica e Biologia Molecular, UFPR, Curitiba, PR, Brazil; Departamento de Análises Clínicas, UFPR, Curitiba, PR, Brazil
| | - Gustavo A de Souza
- Department of Immunology, University of Oslo and Oslo University Hospital, The Proteomics Core Facility, Rikshospitalet, Oslo, Norway; Instituto do Cérebro, UFRN, Natal, RN, Brazil
| | - Luciano F Huergo
- Departamento de Bioquímica e Biologia Molecular, UFPR, Curitiba, PR, Brazil; Setor Litoral, UFPR, Matinhos, PR, Brazil.
| |
Collapse
|
48
|
Jahan N, Maeda K, Matsuoka Y, Sugimoto Y, Kurata H. Development of an accurate kinetic model for the central carbon metabolism of Escherichia coli. Microb Cell Fact 2016; 15:112. [PMID: 27329289 PMCID: PMC4915146 DOI: 10.1186/s12934-016-0511-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 06/08/2016] [Indexed: 01/17/2023] Open
Abstract
Background A kinetic model provides insights into the dynamic response of biological systems and predicts how their complex metabolic and gene regulatory networks generate particular functions. Of many biological systems, Escherichia coli metabolic pathways have been modeled extensively at the enzymatic and genetic levels, but existing models cannot accurately reproduce experimental behaviors in a batch culture, due to the inadequate estimation of a specific cell growth rate and a large number of unmeasured parameters. Results In this study, we developed a detailed kinetic model for the central carbon metabolism of E. coli in a batch culture, which includes the glycolytic pathway, tricarboxylic acid cycle, pentose phosphate pathway, Entner-Doudoroff pathway, anaplerotic pathway, glyoxylate shunt, oxidative phosphorylation, phosphotransferase system (Pts), non-Pts and metabolic gene regulations by four protein transcription factors: cAMP receptor, catabolite repressor/activator, pyruvate dehydrogenase complex repressor and isocitrate lyase regulator. The kinetic parameters were estimated by a constrained optimization method on a supercomputer. The model estimated a specific growth rate based on reaction kinetics and accurately reproduced the dynamics of wild-type E. coli and multiple genetic mutants in a batch culture. Conclusions This model overcame the intrinsic limitations of existing kinetic models in a batch culture, predicted the effects of multilayer regulations (allosteric effectors and gene expression) on central carbon metabolism and proposed rationally designed fast-growing cells based on understandings of molecular processes. Electronic supplementary material The online version of this article (doi:10.1186/s12934-016-0511-x) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Nusrat Jahan
- Department of Bioscience and Bioinformatics, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka, Fukuoka, 820-8502, Japan
| | - Kazuhiro Maeda
- Frontier Research Academy for Young Researchers, Kyushu Institute of Technology, 1-1 Sensui-cho, Tobata, Kitakyushu, Fukuoka, 804-8550, Japan.,Biomedical Informatics R&D Center, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka, Fukuoka, 820-8502, Japan
| | - Yu Matsuoka
- Department of Bioscience and Bioinformatics, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka, Fukuoka, 820-8502, Japan
| | - Yurie Sugimoto
- Department of Bioscience and Bioinformatics, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka, Fukuoka, 820-8502, Japan
| | - Hiroyuki Kurata
- Department of Bioscience and Bioinformatics, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka, Fukuoka, 820-8502, Japan. .,Biomedical Informatics R&D Center, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka, Fukuoka, 820-8502, Japan.
| |
Collapse
|
49
|
Bren A, Park JO, Towbin BD, Dekel E, Rabinowitz JD, Alon U. Glucose becomes one of the worst carbon sources for E.coli on poor nitrogen sources due to suboptimal levels of cAMP. Sci Rep 2016; 6:24834. [PMID: 27109914 PMCID: PMC4843011 DOI: 10.1038/srep24834] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 04/05/2016] [Indexed: 12/20/2022] Open
Abstract
In most conditions, glucose is the best carbon source for E. coli: it provides faster growth than other sugars, and is consumed first in sugar mixtures. Here we identify conditions in which E. coli strains grow slower on glucose than on other sugars, namely when a single amino acid (arginine, glutamate, or proline) is the sole nitrogen source. In sugar mixtures with these nitrogen sources, E. coli still consumes glucose first, but grows faster rather than slower after exhausting glucose, generating a reversed diauxic shift. We trace this counterintuitive behavior to a metabolic imbalance: levels of TCA-cycle metabolites including α-ketoglutarate are high, and levels of the key regulatory molecule cAMP are low. Growth rates were increased by experimentally increasing cAMP levels, either by adding external cAMP, by genetically perturbing the cAMP circuit or by inhibition of glucose uptake. Thus, the cAMP control circuitry seems to have a ‘bug’ that leads to slow growth under what may be an environmentally rare condition.
Collapse
Affiliation(s)
- Anat Bren
- Dept. of Molecular Cell Biology, Weizmann Institute of Science, Rehovot Israel 76100
| | - Junyoung O Park
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA.,Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Benjamin D Towbin
- Dept. of Molecular Cell Biology, Weizmann Institute of Science, Rehovot Israel 76100
| | - Erez Dekel
- Dept. of Molecular Cell Biology, Weizmann Institute of Science, Rehovot Israel 76100
| | - Joshua D Rabinowitz
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA.,Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Uri Alon
- Dept. of Molecular Cell Biology, Weizmann Institute of Science, Rehovot Israel 76100
| |
Collapse
|
50
|
Abstract
The metabolite 2-oxoglutarate (also known as α-ketoglutarate, 2-ketoglutaric acid, or oxoglutaric acid) lies at the intersection between the carbon and nitrogen metabolic pathways. This compound is a key intermediate of one of the most fundamental biochemical pathways in carbon metabolism, the tricarboxylic acid (TCA) cycle. In addition, 2-oxoglutarate also acts as the major carbon skeleton for nitrogen-assimilatory reactions. Experimental data support the conclusion that intracellular levels of 2-oxoglutarate fluctuate according to nitrogen and carbon availability. This review summarizes how nature has capitalized on the ability of 2-oxoglutarate to reflect cellular nutritional status through evolution of a variety of 2-oxoglutarate-sensing regulatory proteins. The number of metabolic pathways known to be regulated by 2-oxoglutarate levels has increased significantly in recent years. The signaling properties of 2-oxoglutarate are highlighted by the fact that this metabolite regulates the synthesis of the well-established master signaling molecule, cyclic AMP (cAMP), in Escherichia coli.
Collapse
|