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Gao C, Ding HT, Li K, Cao HY, Wang N, Gu ZT, Wang Q, Sun ML, Chen XL, Chen Y, Zhang YZ, Fu HH, Li CY. Structural basis of a microbial trimethylamine transporter. mBio 2025; 16:e0191424. [PMID: 39576113 PMCID: PMC11708041 DOI: 10.1128/mbio.01914-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2024] [Accepted: 10/30/2024] [Indexed: 01/11/2025] Open
Abstract
Trimethylamine (TMA), a simple trace biogenic amine resulting from the decomposition of proteins and other macromolecules, is ubiquitous in nature. It is found in the human gut as well as in various terrestrial and marine ecosystems. While the role of TMA in promoting cardiovascular diseases and depolarizing olfactory sensory neurons in humans has only recently been explored, many microbes are well known for their ability to utilize TMA as a carbon, nitrogen, and energy source. Here, we report the first structure of a TMA transporter, TmaT, originally identified from a marine bacterium. TmaT is a member of the betaine-choline-carnitine transporter family, and we show that TmaT is an Na+/TMA symporter, which possessed high specificity and binding affinity toward TMA. Furthermore, the structures of TmaT and two TmaT-TMA complexes were solved by cryo-EM. TmaT forms a homotrimer structure in solution. Each TmaT monomer has 12 transmembrane helices, and the TMA transport channel is formed by a four-helix bundle. TMA can move between different aromatic boxes, which provides the structural basis of TmaT importing TMA. When TMA is bound in location I, residues Trp146, Trp151, Tyr154, and Trp326 form an aromatic box to accommodate TMA. Moreover, Met105 also plays an important role in the binding of TMA. When TMA is transferred to location II, it is bound in the aromatic box formed by Trp325, Trp326, and Trp329. Based on our results, we proposed the TMA transport mechanism by TmaT. This study provides novel insights into TMA transport across biological membranes. IMPORTANCE The volatile trimethylamine (TMA) plays an important role in promoting cardiovascular diseases and depolarizing olfactory sensory neurons in humans and serves as a key nutrient source for a variety of ubiquitous marine microbes. While the TMA transporter TmaT has been identified from a marine bacterium, the structure of TmaT and the molecular mechanism involved in TMA transport remain unclear. In this study, we elucidated the high-resolution cryo-EM structures of TmaT and TmaT-TMA complexes and revealed the TMA binding and transport mechanisms by structural and biochemical analyses. The results advance our understanding of the TMA transport processes across biological membranes.
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Affiliation(s)
- Chao Gao
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, China
- MOE Key Laboratory of Evolution and Marine Biodiversity, Frontiers Science Center for Deep Ocean Multispheres and Earth System & College of Marine Life Sciences, Ocean University of China, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao, China
- Joint Research Center for Marine Microbial Science and Technology, Shandong University and Ocean University of China, Qingdao, China
| | - Hai-Tao Ding
- Antarctic Great Wall Ecology National Observation and Research Station, Polar Research Institute of China, Ministry of Natural Resources, Shanghai, China
| | - Kang Li
- MOE Key Laboratory of Evolution and Marine Biodiversity, Frontiers Science Center for Deep Ocean Multispheres and Earth System & College of Marine Life Sciences, Ocean University of China, Qingdao, China
- Joint Research Center for Marine Microbial Science and Technology, Shandong University and Ocean University of China, Qingdao, China
| | - Hai-Yan Cao
- MOE Key Laboratory of Evolution and Marine Biodiversity, Frontiers Science Center for Deep Ocean Multispheres and Earth System & College of Marine Life Sciences, Ocean University of China, Qingdao, China
- Joint Research Center for Marine Microbial Science and Technology, Shandong University and Ocean University of China, Qingdao, China
| | - Ning Wang
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, China
- MOE Key Laboratory of Evolution and Marine Biodiversity, Frontiers Science Center for Deep Ocean Multispheres and Earth System & College of Marine Life Sciences, Ocean University of China, Qingdao, China
- Joint Research Center for Marine Microbial Science and Technology, Shandong University and Ocean University of China, Qingdao, China
| | - Zeng-Tian Gu
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, China
| | - Qing Wang
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, China
| | - Mei-Ling Sun
- MOE Key Laboratory of Evolution and Marine Biodiversity, Frontiers Science Center for Deep Ocean Multispheres and Earth System & College of Marine Life Sciences, Ocean University of China, Qingdao, China
- Joint Research Center for Marine Microbial Science and Technology, Shandong University and Ocean University of China, Qingdao, China
| | - Xiu-Lan Chen
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao, China
- Joint Research Center for Marine Microbial Science and Technology, Shandong University and Ocean University of China, Qingdao, China
| | - Yin Chen
- MOE Key Laboratory of Evolution and Marine Biodiversity, Frontiers Science Center for Deep Ocean Multispheres and Earth System & College of Marine Life Sciences, Ocean University of China, Qingdao, China
- School of Life Sciences, University of Warwick, Coventry, United Kingdom
| | - Yu-Zhong Zhang
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, China
- MOE Key Laboratory of Evolution and Marine Biodiversity, Frontiers Science Center for Deep Ocean Multispheres and Earth System & College of Marine Life Sciences, Ocean University of China, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao, China
- Joint Research Center for Marine Microbial Science and Technology, Shandong University and Ocean University of China, Qingdao, China
| | - Hui-Hui Fu
- MOE Key Laboratory of Evolution and Marine Biodiversity, Frontiers Science Center for Deep Ocean Multispheres and Earth System & College of Marine Life Sciences, Ocean University of China, Qingdao, China
- Joint Research Center for Marine Microbial Science and Technology, Shandong University and Ocean University of China, Qingdao, China
| | - Chun-Yang Li
- MOE Key Laboratory of Evolution and Marine Biodiversity, Frontiers Science Center for Deep Ocean Multispheres and Earth System & College of Marine Life Sciences, Ocean University of China, Qingdao, China
- Joint Research Center for Marine Microbial Science and Technology, Shandong University and Ocean University of China, Qingdao, China
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Borodina I, Kenny LC, McCarthy CM, Paramasivan K, Pretorius E, Roberts TJ, van der Hoek SA, Kell DB. The biology of ergothioneine, an antioxidant nutraceutical. Nutr Res Rev 2020; 33:190-217. [PMID: 32051057 PMCID: PMC7653990 DOI: 10.1017/s0954422419000301] [Citation(s) in RCA: 119] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 11/20/2019] [Accepted: 11/25/2019] [Indexed: 02/07/2023]
Abstract
Ergothioneine (ERG) is an unusual thio-histidine betaine amino acid that has potent antioxidant activities. It is synthesised by a variety of microbes, especially fungi (including in mushroom fruiting bodies) and actinobacteria, but is not synthesised by plants and animals who acquire it via the soil and their diet, respectively. Animals have evolved a highly selective transporter for it, known as solute carrier family 22, member 4 (SLC22A4) in humans, signifying its importance, and ERG may even have the status of a vitamin. ERG accumulates differentially in various tissues, according to their expression of SLC22A4, favouring those such as erythrocytes that may be subject to oxidative stress. Mushroom or ERG consumption seems to provide significant prevention against oxidative stress in a large variety of systems. ERG seems to have strong cytoprotective status, and its concentration is lowered in a number of chronic inflammatory diseases. It has been passed as safe by regulatory agencies, and may have value as a nutraceutical and antioxidant more generally.
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Affiliation(s)
- Irina Borodina
- The Novo Nordisk Foundation Center for Biosustainability, Building 220, Chemitorvet 200, Technical University of Denmark, 2800Kongens Lyngby, Denmark
| | - Louise C. Kenny
- Department of Women’s and Children’s Health, Institute of Translational Medicine, University of Liverpool, Crown Street, LiverpoolL8 7SS, UK
| | - Cathal M. McCarthy
- Irish Centre for Fetal and Neonatal Translational Research (INFANT), Cork University Maternity Hospital, Cork, Republic of Ireland
- Department of Pharmacology and Therapeutics, Western Gateway Building, University College Cork, Cork, Republic of Ireland
| | - Kalaivani Paramasivan
- The Novo Nordisk Foundation Center for Biosustainability, Building 220, Chemitorvet 200, Technical University of Denmark, 2800Kongens Lyngby, Denmark
| | - Etheresia Pretorius
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, Private Bag X1 Matieland, 7602, South Africa
| | - Timothy J. Roberts
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, Private Bag X1 Matieland, 7602, South Africa
- Department of Biochemistry, Institute of Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Crown Street, LiverpoolL69 7ZB, UK
| | - Steven A. van der Hoek
- The Novo Nordisk Foundation Center for Biosustainability, Building 220, Chemitorvet 200, Technical University of Denmark, 2800Kongens Lyngby, Denmark
| | - Douglas B. Kell
- The Novo Nordisk Foundation Center for Biosustainability, Building 220, Chemitorvet 200, Technical University of Denmark, 2800Kongens Lyngby, Denmark
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, Private Bag X1 Matieland, 7602, South Africa
- Department of Biochemistry, Institute of Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Crown Street, LiverpoolL69 7ZB, UK
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Investigations of Dimethylglycine, Glycine Betaine, and Ectoine Uptake by a Betaine-Carnitine-Choline Transporter Family Transporter with Diverse Substrate Specificity in Vibrio Species. J Bacteriol 2020; 202:JB.00314-20. [PMID: 32817090 DOI: 10.1128/jb.00314-20] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 08/06/2020] [Indexed: 01/08/2023] Open
Abstract
Fluctuations in osmolarity are one of the most prevalent stresses to which bacteria must adapt, both hypo- and hyperosmotic conditions. Most bacteria cope with high osmolarity by accumulating compatible solutes (osmolytes) in the cytoplasm to maintain the turgor pressure of the cell. Vibrio parahaemolyticus, a halophile, utilizes at least six compatible solute transporters for the uptake of osmolytes: two ABC family ProU transporters and four betaine-carnitine-choline transporter (BCCT) family transporters. The full range of compatible solutes transported by this species has yet to be determined. Using an osmolyte phenotypic microarray plate for growth analyses, we expanded the known osmolytes used by V. parahaemolyticus to include N,N-dimethylglycine (DMG), among others. Growth pattern analysis of four triple-bccT mutants, possessing only one functional BCCT, indicated that BccT1 (VP1456), BccT2 (VP1723), and BccT3 (VP1905) transported DMG. BccT1 was unusual in that it could take up both compounds with methylated head groups (glycine betaine [GB], choline, and DMG) and cyclic compounds (ectoine and proline). Bioinformatics analysis identified the four coordinating amino acid residues for GB in the BccT1 protein. In silico modeling analysis demonstrated that GB, DMG, and ectoine docked in the same binding pocket in BccT1. Using site-directed mutagenesis, we showed that a strain with all four residues mutated resulted in the loss of uptake of GB, DMG, and ectoine. We showed that three of the four residues were essential for ectoine uptake, whereas only one of the residues was important for GB uptake. Overall, we have demonstrated that DMG is a highly effective compatible solute for Vibrio species and have elucidated the amino acid residues in BccT1 that are important for the coordination of GB, DMG, and ectoine transport.IMPORTANCE Vibrio parahaemolyticus possesses at least six osmolyte transporters, which allow the bacterium to adapt to high-salinity conditions. In this study, we identified several additional osmolytes that were utilized by V. parahaemolyticus We demonstrated that the compound DMG, which is present in the marine environment, was a highly effective osmolyte for Vibrio species. We determined that DMG is transported via BCCT family carriers, which have not been shown previously to take up this compound. BccT1 was a carrier for GB, DMG, and ectoine, and we identified the amino acid residues essential for the coordination of these compounds. The data suggest that for BccT1, GB is more easily accommodated than ectoine in the transporter binding pocket.
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Pérez-García F, Brito LF, Wendisch VF. Function of L-Pipecolic Acid as Compatible Solute in Corynebacterium glutamicum as Basis for Its Production Under Hyperosmolar Conditions. Front Microbiol 2019; 10:340. [PMID: 30858843 PMCID: PMC6397837 DOI: 10.3389/fmicb.2019.00340] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 02/08/2019] [Indexed: 12/20/2022] Open
Abstract
Pipecolic acid or L-PA is a cyclic amino acid derived from L-lysine which has gained interest in the recent years within the pharmaceutical and chemical industries. L-PA can be produced efficiently using recombinant Corynebacterium glutamicum strains by expanding the natural L-lysine biosynthetic pathway. L-PA is a six-membered ring homolog of the five-membered ring amino acid L-proline, which serves as compatible solute in C. glutamicum. Here, we show that de novo synthesized or externally added L-PA partially is beneficial for growth under hyper-osmotic stress conditions. C. glutamicum cells accumulated L-PA under elevated osmotic pressure and released it after an osmotic down shock. In the absence of the mechanosensitive channel YggB intracellular L-PA concentrations increased and its release after osmotic down shock was slower. The proline permease ProP was identified as a candidate L-PA uptake system since RNAseq analysis revealed increased proP RNA levels upon L-PA production. Under hyper-osmotic conditions, a ΔproP strain showed similar growth behavior than the parent strain when L-proline was added externally. By contrast, the growth impairment of the ΔproP strain under hyper-osmotic conditions could not be alleviated by addition of L-PA unless proP was expressed from a plasmid. This is commensurate with the view that L-proline can be imported into the C. glutamicum cell by ProP and other transporters such as EctP and PutP, while ProP appears of major importance for L-PA uptake under hyper-osmotic stress conditions.
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Affiliation(s)
- Fernando Pérez-García
- Genetics of Prokaryotes, Faculty of Biology - CeBiTec, Bielefeld University, Bielefeld, Germany
| | - Luciana F Brito
- Genetics of Prokaryotes, Faculty of Biology - CeBiTec, Bielefeld University, Bielefeld, Germany
| | - Volker F Wendisch
- Genetics of Prokaryotes, Faculty of Biology - CeBiTec, Bielefeld University, Bielefeld, Germany
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Pérez-García F, Max Risse J, Friehs K, Wendisch VF. Fermentative production of L-pipecolic acid from glucose and alternative carbon sources. Biotechnol J 2017; 12. [DOI: 10.1002/biot.201600646] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2016] [Revised: 01/28/2017] [Accepted: 02/06/2017] [Indexed: 12/18/2022]
Affiliation(s)
- Fernando Pérez-García
- Genetics of Prokaryotes; Faculty of Biology & Center for Biotechnology; Bielefeld University; Bielefeld Germany
| | - Joe Max Risse
- Fermentation Technology; Technical Faculty & Center for Biotechnology; Bielefeld University; Bielefeld Germany
| | - Karl Friehs
- Fermentation Technology; Technical Faculty & Center for Biotechnology; Bielefeld University; Bielefeld Germany
| | - Volker F. Wendisch
- Genetics of Prokaryotes; Faculty of Biology & Center for Biotechnology; Bielefeld University; Bielefeld Germany
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6
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Nguyen AQD, Schneider J, Reddy GK, Wendisch VF. Fermentative production of the diamine putrescine: system metabolic engineering of corynebacterium glutamicum. Metabolites 2015; 5:211-31. [PMID: 25919117 PMCID: PMC4495370 DOI: 10.3390/metabo5020211] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Revised: 04/08/2015] [Accepted: 04/13/2015] [Indexed: 11/16/2022] Open
Abstract
Corynebacterium glutamicum shows great potential for the production of the glutamate-derived diamine putrescine, a monomeric compound of polyamides. A genome-scale stoichiometric model of a C. glutamicum strain with reduced ornithine transcarbamoylase activity, derepressed arginine biosynthesis, and an anabolic plasmid-addiction system for heterologous expression of E. coli ornithine decarboxylase gene speC was investigated by flux balance analysis with respect to its putrescine production potential. Based on these simulations, enhancing glycolysis and anaplerosis by plasmid-borne overexpression of the genes for glyceraldehyde 3-phosphate dehydrogenase and pyruvate carboxylase as well as reducing 2-oxoglutarate dehydrogenase activity were chosen as targets for metabolic engineering. Changing the translational start codon of the chromosomal gene for 2-oxoglutarate dehydrogenase subunit E1o to the less preferred TTG and changing threonine 15 of OdhI to alanine reduced 2-oxoglutarate dehydrogenase activity about five fold and improved putrescine titers by 28%. Additional engineering steps improved further putrescine production with the largest contributions from preventing the formation of the by-product N-acetylputrescine by deletion of spermi(di)ne N-acetyltransferase gene snaA and from overexpression of the gene for a feedback-resistant N-acetylglutamate kinase variant. The resulting C. glutamicum strain NA6 obtained by systems metabolic engineering accumulated two fold more putrescine than the base strain, i.e., 58.1 ± 0.2 mM, and showed a specific productivity of 0.045 g·g-1·h-1 and a yield on glucose of 0.26 g·g-1.
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Affiliation(s)
- Anh Q D Nguyen
- Chair of Genetics of Prokaryotes, Faculty of Biology & CeBiTec, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany.
| | - Jens Schneider
- Chair of Genetics of Prokaryotes, Faculty of Biology & CeBiTec, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany.
| | - Gajendar Komati Reddy
- Chair of Genetics of Prokaryotes, Faculty of Biology & CeBiTec, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany.
| | - Volker F Wendisch
- Chair of Genetics of Prokaryotes, Faculty of Biology & CeBiTec, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany.
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Membrane transporter engineering in industrial biotechnology and whole cell biocatalysis. Trends Biotechnol 2015; 33:237-46. [DOI: 10.1016/j.tibtech.2015.02.001] [Citation(s) in RCA: 145] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Revised: 01/15/2015] [Accepted: 02/02/2015] [Indexed: 02/06/2023]
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Becker J, Schäfer R, Kohlstedt M, Harder BJ, Borchert NS, Stöveken N, Bremer E, Wittmann C. Systems metabolic engineering of Corynebacterium glutamicum for production of the chemical chaperone ectoine. Microb Cell Fact 2013; 12:110. [PMID: 24228689 PMCID: PMC4225761 DOI: 10.1186/1475-2859-12-110] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Accepted: 11/05/2013] [Indexed: 11/14/2022] Open
Abstract
Background The stabilizing and function-preserving effects of ectoines have attracted considerable biotechnological interest up to industrial scale processes for their production. These rely on the release of ectoines from high-salinity-cultivated microbial producer cells upon an osmotic down-shock in rather complex processor configurations. There is growing interest in uncoupling the production of ectoines from the typical conditions required for their synthesis, and instead design strains that naturally release ectoines into the medium without the need for osmotic changes, since the use of high-salinity media in the fermentation process imposes notable constraints on the costs, design, and durability of fermenter systems. Results Here, we used a Corynebacterium glutamicum strain as a cellular chassis to establish a microbial cell factory for the biotechnological production of ectoines. The implementation of a mutant aspartokinase enzyme ensured efficient supply of L-aspartate-beta-semialdehyde, the precursor for ectoine biosynthesis. We further engineered the genome of the basic C. glutamicum strain by integrating a codon-optimized synthetic ectABCD gene cluster under expressional control of the strong and constitutive C. glutamicum tuf promoter. The resulting recombinant strain produced ectoine and excreted it into the medium; however, lysine was still found as a by-product. Subsequent inactivation of the L-lysine exporter prevented the undesired excretion of lysine while ectoine was still exported. Using the streamlined cell factory, a fed-batch process was established that allowed the production of ectoine with an overall productivity of 6.7 g L-1 day-1 under growth conditions that did not rely on the use of high-salinity media. Conclusions The present study describes the construction of a stable microbial cell factory for recombinant production of ectoine. We successfully applied metabolic engineering strategies to optimize its synthetic production in the industrial workhorse C. glutamicum and thereby paved the way for further improvements in ectoine yield and biotechnological process optimization.
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Affiliation(s)
- Judith Becker
- Institute of Biochemical Engineering, Technische Universität Braunschweig, Braunschweig, Germany.
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Trötschel C, Albaum SP, Poetsch A. Proteome turnover in bacteria: current status for Corynebacterium glutamicum and related bacteria. Microb Biotechnol 2013; 6:708-19. [PMID: 23425033 PMCID: PMC3815937 DOI: 10.1111/1751-7915.12035] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2012] [Revised: 01/03/2013] [Accepted: 01/05/2013] [Indexed: 11/28/2022] Open
Abstract
With the advent of high-resolution mass spectrometry together with sophisticated data analysis and interpretation algorithms, determination of protein synthesis and degradation rates (i.e. protein turnover) on a proteome-wide scale by employing stable isotope-labelled amino acids has become feasible. These dynamic data provide a deeper understanding of protein homeostasis and stress response mechanisms in microorganisms than well-established ‘steady state’ proteomics approaches. In this article, we summarize the technological challenges and solutions both on the biochemistry/mass spectrometry and bioinformatics level for turnover proteomics with a focus on chromatographic techniques. Although the number of available case studies for Corynebacterium glutamicum and related actinobacteria is still very limited, our review illustrates the potential of protein turnover studies for an improved understanding of questions in the area of biotechnology and biomedicine. Here, new insights from investigations of growth phase transition and different stress dynamics including iron, acid and heat stress for pathogenic but also for industrial actinobacteria are presented. Finally, we will comment on the advantages of integrated software solutions for biologists and briefly discuss the remaining technical challenges and upcoming possibilities for protein turnover analysis.
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Affiliation(s)
- Christian Trötschel
- Department of Plant Biochemistry, Ruhr-University Bochum, 44780, Bochum, Germany
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Osmotic stress response in C. glutamicum: impact of channel- and transporter-mediated potassium accumulation. Arch Microbiol 2011; 193:787-96. [PMID: 21614527 DOI: 10.1007/s00203-011-0717-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Revised: 05/06/2011] [Accepted: 05/09/2011] [Indexed: 10/18/2022]
Abstract
Potassium accumulation is an essential aspect of bacterial response to diverse stress situations; consequently its uptake plays a pivotal role. Here, we show that the Gram-positive soil bacterium Corynebacterium glutamicum which is employed for the large-scale industrial production of amino acids requires potassium under conditions of ionic and non-ionic osmotic stress. Besides the accumulation of high concentrations of potassium contributing significantly to the osmotic potential of the cytoplasm, we demonstrate that glutamate is not the counter ion for potassium under these conditions. Interestingly, potassium is required for the activation of osmotic stress-dependent expression of the genes betP and proP. The Kup-type potassium transport system which is present in C. glutamicum in addition to the potassium channel CglK does not contribute to potassium uptake at conditions of hyperosmotic stress. Furthermore, we established a secondary carrier of the KtrAB type from C. jeikeium in C. glutamicum thus providing an experimental comparison of channel- and carrier-mediated potassium uptake under osmotic stress. While at low potassium availability, the presence of the KtrAB transporter improves both potassium accumulation and growth of C. glutamicum upon osmotic stress, at proper potassium supply, the channel CglK is sufficient.
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Ziegler C, Bremer E, Krämer R. The BCCT family of carriers: from physiology to crystal structure. Mol Microbiol 2011; 78:13-34. [PMID: 20923416 DOI: 10.1111/j.1365-2958.2010.07332.x] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Increases in the environmental osmolarity are key determinants for the growth of microorganisms. To ensure a physiologically acceptable level of cellular hydration and turgor at high osmolarity, many bacteria accumulate compatible solutes. Osmotically controlled uptake systems allow the scavenging of these compounds from scarce environmental sources as effective osmoprotectants. A number of these systems belong to the BCCT family (betaine-choline-carnitine-transporter), sodium- or proton-coupled transporters (e.g. BetP and BetT respectively) that are ubiquitous in microorganisms. The BCCT family also contains CaiT, an L-carnitine/γ-butyrobetaine antiporter that is not involved in osmotic stress responses. The glycine betaine transporter BetP from Corynebacterium glutamicum is a representative for osmoregulated symporters of the BCCT family and functions both as an osmosensor and osmoregulator. The crystal structure of BetP in an occluded conformation in complex with its substrate glycine betaine and two crystal structures of CaiT in an inward-facing open conformation in complex with L-carnitine and γ-butyrobetaine were reported recently. These structures and the wealth of biochemical data on the activity control of BetP in response to osmotic stress enable a correlation between the sensing of osmotic stress by a transporter protein with the ensuing regulation of transport activity. Molecular determinants governing the high-affinity binding of the compatible solutes by BetP and CaiT, the coupling in symporters and antiporters, and the osmoregulatory properties are discussed in detail for BetP and various BCCT carriers.
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Affiliation(s)
- Christine Ziegler
- Max-Planck Institute for Biophysics, Max-von-Laue Street 3, D-60438 Frankfurt, Germany
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Fränzel B, Poetsch A, Trötschel C, Persicke M, Kalinowski J, Wolters DA. Quantitative proteomic overview on the Corynebacterium glutamicum l-lysine producing strain DM1730. J Proteomics 2010; 73:2336-53. [DOI: 10.1016/j.jprot.2010.07.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2010] [Revised: 06/16/2010] [Accepted: 07/07/2010] [Indexed: 11/15/2022]
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Fränzel B, Trötschel C, Rückert C, Kalinowski J, Poetsch A, Wolters DA. Adaptation of Corynebacterium glutamicum to salt-stress conditions. Proteomics 2010; 10:445-57. [PMID: 19950167 DOI: 10.1002/pmic.200900482] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Corynebacterium glutamicum is one of the biotechnologically most important microorganisms because of its ability to enrich amino acids extracellularly. Hence, C. glutamicum requires effective adaptation strategies against both hypo- and hyperosmotic stress. We give a comprehensive and coherent outline about the quantitative dynamics of C. glutamicum during adaptation to hyperosmotic stress at the transcript and protein levels. The osmolyte carrier ProP, playing a pivotal role in hyperosmotic stress defence, exhibits the strongest up-regulation of all proteins. A conspicuously regulated group comprises proteins involved in lipid biosynthesis of the cell envelope. This is in accordance with our observation of a more viscous and stickier cell envelope, which is supported by the findings of an altered lipid composition. Together with our results, showing that several transporters were down-regulated, this membrane adaptation appears to be one of C. glutamicum's major protection strategies against hyperosmotic stress. In addition, we demonstrate that no oxidative stress and no iron limitation occur during salt stress contrary to former postulations. Ultimately, it is remarkable that various proteins with divergent mRNA-protein dynamics and regulation have been observed. This leads to the assumption that there are still unknown mechanisms in between the bacterial transcription, translation and post-translation and that these are waiting to be unravelled.
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Affiliation(s)
- Benjamin Fränzel
- Department of Analytical Chemistry, University of Bochum, Bochum, Germany
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Fränzel B, Fischer F, Trötschel C, Poetsch A, Wolters D. The two-phase partitioning system--a powerful technique to purify integral membrane proteins of Corynebacterium glutamicum for quantitative shotgun analysis. Proteomics 2009; 9:2263-72. [PMID: 19322788 DOI: 10.1002/pmic.200800766] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
We established a single consecutive strategy which assigned the most comprehensive number of integral membrane proteins from Gram-positive bacteria to date. For this purpose, we adapted a biphasic partitioning system for the biotechnologically intensively used Corynebacterium glutamicum and proved for the first time that such a system is well suited for quantitative comparison. 297 integral membrane proteins were identified by our integrated approach, which depletes stringently cytosolic proteins. In combination with our previously developed SIMPLE strategy, our data comprise 61% (374 integral membrane proteins) of the entire membrane proteome, which aims towards an almost comprehensive coverage. Wild type and a production strain of C. glutamicum were compared by (15)N metabolic labelling and quantitation was obtained by spectral counting and peak areas. Both quantification strategies display a consistent trend in up or downregulation of proteins. Nevertheless, spectral counting often provides results indicating a much stronger regulation compared to ProRata values. Either spectral counting seems to exaggerate protein regulation or ProRata tends to attenuate the information about the regulation level. We highlight some of the biologically relevant candidates, which prove that our approach helps to give a deeper quantitative insight towards the understanding of transport and other membrane associated processes, important for strain development of C. glutamicum.
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Affiliation(s)
- Benjamin Fränzel
- Department of Analytical Chemistry, Ruhr-University Bochum, Bochum, Germany
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