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Perpetuini G, Rossetti AP, Rapagnetta A, Arfelli G, Prete R, Tofalo R. Wine Barrel Biofilm as a Source of Yeasts with Non-Conventional Properties. Microorganisms 2024; 12:880. [PMID: 38792710 PMCID: PMC11123285 DOI: 10.3390/microorganisms12050880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Revised: 04/18/2024] [Accepted: 04/24/2024] [Indexed: 05/26/2024] Open
Abstract
This study investigated the main microbial groups characterizing the interior surface of oak barrels from different years (1890, 1895, 1920, 1975, 2008) used in the production of vino cotto. The yeasts were characterized for the following properties: γ-aminobutyric acid (GABA) production, antioxidant activity, air-liquid interfacial biofilm formation, and anthocyanin adsorption capacity. Community-level physiological profile analysis revealed that the microbial communities inside the barrels used the tested carbon sources in different manners. The following yeast species were identified: Millerozyma farinosa, Zygosaccharomyces bisporus, Wickerhamiella versatilis, Zygosaccharomyces bailii, Starmerella lactis-condensi, and Zygosaccharomyces rouxii. All the strains were able to produce GABA, and S. lactis-condensi, Z. bisporus and Z. rouxii were the highest producers (more than 600 mg/L). The Z. rouxii and Z. bailii strains showed the highest antioxidant activity. Only seven strains out of ten M. farinosa formed air-liquid interfacial biofilm. None of the M. farinosa strains adsorbed anthocyanins on their cell wall. The other strains adsorbed anthocyanins in a strain-dependent way, and the highest adsorption was observed for the W. versatilis strains. The yeasts isolated in this study could be used to increase the functional properties and the quality of fermented foods and beverages.
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Affiliation(s)
- Giorgia Perpetuini
- Department of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Via Balzarini 1, 64100 Teramo, Italy; (A.P.R.); (A.R.); (G.A.); (R.P.)
| | | | | | | | | | - Rosanna Tofalo
- Department of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Via Balzarini 1, 64100 Teramo, Italy; (A.P.R.); (A.R.); (G.A.); (R.P.)
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2
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Yılmaz C, Ecem Berk Ş, Gökmen V. Effect of different stress conditions on the formation of amino acid derivatives by Brewer's and Baker's yeast during fermentation. Food Chem 2024; 435:137513. [PMID: 37774628 DOI: 10.1016/j.foodchem.2023.137513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 09/11/2023] [Accepted: 09/15/2023] [Indexed: 10/01/2023]
Abstract
The effects of environmental stresses on the formation of amino acid derivatives by Saccharomyces cerevisiae NCYC 88 and Saccharomyces cerevisiae NCYC 79 were investigated. Fermentation was performed in model systems under different temperature, pH, alcohol, phenolic, and osmotic stress conditions, as well as in beer and dough. According to stress response molecules, yeasts were more affected by osmotic, temperature, and alcohol stresses. Both yeast strains increased the formation of kynurenic acid, tryptophan ethyl ester, tryptophol, and gamma-aminobutyric acid under osmotic stress conditions in model systems. Indole-3-acetic acid was found to be higher in the ferulic acid stress dough (262 µg/kg dry weight, d.w.) compared to the control dough (132 µg/kg d.w.) at the end of the fermentation. The results may enable the development of new strategies for designing novel foods with a desired composition of bioactive amino acid derivatives.
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Affiliation(s)
- Cemile Yılmaz
- Food Quality and Safety (FoQuS) Research Group, Department of Food Engineering, Hacettepe University, 06800 Beytepe, Ankara, Turkiye
| | - Şenel Ecem Berk
- Food Quality and Safety (FoQuS) Research Group, Department of Food Engineering, Hacettepe University, 06800 Beytepe, Ankara, Turkiye
| | - Vural Gökmen
- Food Quality and Safety (FoQuS) Research Group, Department of Food Engineering, Hacettepe University, 06800 Beytepe, Ankara, Turkiye.
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3
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Johnston EJ, Tallis J, Cunningham-Oakes E, Moses T, Moore SJ, Hosking S, Rosser SJ. Yeast lacking the sterol C-5 desaturase Erg3 are tolerant to the anti-inflammatory triterpenoid saponin escin. Sci Rep 2023; 13:13617. [PMID: 37604855 PMCID: PMC10442444 DOI: 10.1038/s41598-023-40308-0] [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: 05/10/2023] [Accepted: 08/08/2023] [Indexed: 08/23/2023] Open
Abstract
Escin is a mixture of over 30 glycosylated triterpenoid (saponin) structures, extracted from the dried fruit of horse chestnuts. Escin is currently used as an anti-inflammatory, and has potential applications in the treatment of arthritis and cancer. Engineered yeast would enable production of specific bioactive components of escin at industrial scale, however many saponins have been shown to be toxic to yeast. Here we report that a Saccharomyces cerevisiae strain specifically lacking the sterol C-5 desaturase gene ERG3, exhibits striking enhanced tolerance to escin treatment. Transcriptome analyses, as well as pre-mixing of escin with sterols, support the hypothesis that escin interacts directly with ergosterol, but not as strongly with the altered sterols present in erg3Δ. A diverse range of saponins are of commercial interest, and this research highlights the value of screening lipidome mutants to identify appropriate hosts for engineering the industrial production of saponins.
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Affiliation(s)
- Emily J Johnston
- Centre for Engineering Biology, University of Edinburgh, Edinburgh, EH9 3BD, UK.
| | - Jess Tallis
- Centre for Engineering Biology, University of Edinburgh, Edinburgh, EH9 3BD, UK
| | - Edward Cunningham-Oakes
- Department of Infection Biology and Microbiomes, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Tessa Moses
- EdinOmics, RRID:SCR_021838, University of Edinburgh, Max Born Crescent, Edinburgh, EH9 3BF, UK
| | - Simon J Moore
- Genetic Science Division, Thermo Fisher Scientific, 7 Kingsland Grange, Warrington, Cheshire, WA1 4SR, UK
| | - Sarah Hosking
- Unilever R&D Port Sunlight, Quarry Road East, Bebington, Wirral, CH63 3JW, UK
| | - Susan J Rosser
- Centre for Engineering Biology, University of Edinburgh, Edinburgh, EH9 3BD, UK.
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4
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Tate JJ, Rai R, Cooper TG. TorC1 and nitrogen catabolite repression control of integrated GABA shunt and retrograde pathway gene expression. Yeast 2023; 40:318-332. [PMID: 36960709 PMCID: PMC10518031 DOI: 10.1002/yea.3849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 03/10/2023] [Accepted: 03/14/2023] [Indexed: 03/25/2023] Open
Abstract
Despite our detailed understanding of how the lower GABA shunt and retrograde genes are regulated, there is a paucity of validated information concerning control of GAD1, the glutamate decarboxylase gene which catalyzes the first reaction of the GABA shunt. Further, integration of glutamate degradation via the GABA shunt has not been investigated. Here, we show that while GAD1 shares a response to rapamycin-inhibition of the TorC1 kinase, it does so independently of the Gln3 and Gat1 NCR-sensitive transcriptional activators that mediate transcription of the lower GABA shunt genes. We also show that GABA shunt gene expression increases dramatically in response to nickel ions. The α-ketoglutarate needed for the GABA shunt to cycle, thereby producing reduced pyridine nucleotides, derives from the retrograde pathway as shown by a similar high increase in the retrograde reporter, CIT2 when nickel is present in the medium. These observations demonstrate high integration of the GABA shunt, retrograde, peroxisomal glyoxylate cycle, and β-oxidation pathways.
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Affiliation(s)
- Jennifer J. Tate
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, TN 38163, U.S.A
| | - Rajendra Rai
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, TN 38163, U.S.A
| | - Terrance G. Cooper
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, TN 38163, U.S.A
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5
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Wen Q, Zhao H, Shao Y, Li J, Hu Y, Qi Y, Wang F, Shen J. Heat stress and excessive maturity of fruiting bodies suppress GABA accumulation by modulating GABA metabolism in Pleurotus ostreatus (Jacq. ex Fr.) P. Kumm. Food Res Int 2023; 165:112549. [PMID: 36869537 DOI: 10.1016/j.foodres.2023.112549] [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: 11/29/2022] [Revised: 01/26/2023] [Accepted: 01/29/2023] [Indexed: 02/05/2023]
Abstract
GABA is a health-promoting bioactive substance. Here, the GABA biosynthetic pathways were investigated, and then the dynamic quantitative changes in GABA and the expression levels of genes related to GABA metabolism under heat stress or at different developmental stages of fruiting bodies in Pleurotus ostreatus (Jacq. ex Fr.) P. Kumm were determined. We found that the polyamine degradation pathway was the main route of GABA production under growth normal condition. The accumulation of GABA and the expression of most genes related to GABA biosynthesis, including genes encoding glutamate decarboxylase (PoGAD-2), polyamine oxidase (PoPAO-1), diamine oxidase (PoDAO) and aminoaldehyde dehydrogenase (PoAMADH-1 and PoAMADH-2), were significantly suppressed by heat stress and the excessive maturity of fruiting bodies. Finally, the effects of GABA on the mycelial growth, heat tolerance and the morphogenesis and development of fruiting bodies were studied, the results showed that the deficiency of endogenous GABA inhibited the mycelial growth and primordial formation and aggravated heat damage, whereas exogenous application of GABA could improve thermotolerance and promote the development of fruiting bodies.
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Affiliation(s)
- Qing Wen
- College of Life Sciences, Henan Agricultural University, Henan, Zhengzhou 450002, PR China.
| | - Haoyang Zhao
- College of Life Sciences, Henan Agricultural University, Henan, Zhengzhou 450002, PR China
| | - Yanhong Shao
- College of Life Sciences, Henan Agricultural University, Henan, Zhengzhou 450002, PR China
| | - Jiatao Li
- College of Life Sciences, Henan Agricultural University, Henan, Zhengzhou 450002, PR China
| | - Yanru Hu
- College of Life Sciences, Henan Agricultural University, Henan, Zhengzhou 450002, PR China
| | - Yuancheng Qi
- College of Life Sciences, Henan Agricultural University, Henan, Zhengzhou 450002, PR China
| | - Fengqin Wang
- College of Life Sciences, Henan Agricultural University, Henan, Zhengzhou 450002, PR China
| | - Jinwen Shen
- College of Life Sciences, Henan Agricultural University, Henan, Zhengzhou 450002, PR China.
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6
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Exploring the feasibility of biotransforming salted soy whey into a soy sauce-like condiment using wine yeast Torulaspora delbrueckii and soy sauce yeasts Zygosaccharomyces rouxii and Candida versatilis as single starter cultures. Food Res Int 2022; 156:111350. [DOI: 10.1016/j.foodres.2022.111350] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 04/30/2022] [Accepted: 05/03/2022] [Indexed: 11/24/2022]
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7
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Yeasts Inhabiting Extreme Environments and Their Biotechnological Applications. Microorganisms 2022; 10:microorganisms10040794. [PMID: 35456844 PMCID: PMC9028089 DOI: 10.3390/microorganisms10040794] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 04/06/2022] [Accepted: 04/06/2022] [Indexed: 11/17/2022] Open
Abstract
Yeasts are microscopic fungi inhabiting all Earth environments, including those inhospitable for most life forms, considered extreme environments. According to their habitats, yeasts could be extremotolerant or extremophiles. Some are polyextremophiles, depending on their growth capacity, tolerance, and survival in the face of their habitat’s physical and chemical constitution. The extreme yeasts are relevant for the industrial production of value-added compounds, such as biofuels, lipids, carotenoids, recombinant proteins, enzymes, among others. This review calls attention to the importance of yeasts inhabiting extreme environments, including metabolic and adaptive aspects to tolerate conditions of cold, heat, water availability, pH, salinity, osmolarity, UV radiation, and metal toxicity, which are relevant for biotechnological applications. We explore the habitats of extreme yeasts, highlighting key species, physiology, adaptations, and molecular identification. Finally, we summarize several findings related to the industrially-important extremophilic yeasts and describe current trends in biotechnological applications that will impact the bioeconomy.
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8
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Abstract
The tight association of Candida albicans with the human host has driven the evolution of mechanisms that permit metabolic flexibility. Amino acids, present in a free or peptide-bound form, are abundant carbon and nitrogen sources in many host niches. In C. albicans, the capacity to utilize certain amino acids, like proline, is directly connected to fungal morphogenesis and virulence. Yet the precise nature of proline sensing and uptake in this pathogenic fungus has not been investigated. Since C. albicans encodes 10 putative orthologs of the four Saccharomyces cerevisiae proline transporters, we tested deletion strains of the respective genes and identified Gnp2 (CR_09920W) as the main C. albicans proline permease. In addition, we found that this specialization of Gnp2 was reflected in its transcriptional regulation and further assigned distinct substrate specificities for the other orthologs, indicating functional differences of the C. albicans amino acid permeases compared to the model yeast. The physiological relevance of proline uptake is exemplified by the findings that strains lacking GNP2 were unable to filament in response to extracellular proline and had a reduced capacity to damage macrophages and impaired survival following phagocytosis. Furthermore, GNP2 deletion rendered the cells more sensitive to oxidative stress, illustrating new connections between amino acid uptake and stress adaptation in C. albicans. IMPORTANCE The utilization of various nutrients is of paramount importance for the ability of Candida albicans to successfully colonize and infect diverse host niches. In this context, amino acids are of special interest due to their ubiquitous availability, relevance for fungal growth, and direct influence on virulence traits like filamentation. In this study, we identify a specialized proline transporter in C. albicans encoded by GNP2. The corresponding amino acid permease is essential for proline-induced filamentation, oxidative stress resistance, and fungal survival following interaction with macrophages. Altogether, this work highlights the importance of amino acid uptake for metabolic and stress adaptation in this fungus.
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9
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Márquez D, Escalera-Fanjul X, El Hafidi M, Aguirre-López B, Riego-Ruiz L, González A. Alanine Represses γ-Aminobutyric Acid Utilization and Induces Alanine Transaminase Required for Mitochondrial Function in Saccharomyces cerevisiae. Front Microbiol 2021; 12:695382. [PMID: 34421848 PMCID: PMC8371705 DOI: 10.3389/fmicb.2021.695382] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 07/05/2021] [Indexed: 11/24/2022] Open
Abstract
The γ-aminobutyric acid (GABA) shunt constitutes a conserved metabolic route generating nicotinamide adenine dinucleotide phosphate (NADPH) and regulating stress response in most organisms. Here we show that in the presence of GABA, Saccharomyces cerevisiae produces glutamate and alanine through the irreversible action of Uga1 transaminase. Alanine induces expression of alanine transaminase (ALT1) gene. In an alt1Δ mutant grown on GABA, alanine accumulation leads to repression of the GAD1, UGA1, and UGA2 genes, involved in the GABA shunt, which could result in growth impairment. Induced ALT1 expression and negative modulation of the GABA shunt by alanine constitute a novel regulatory circuit controlling both alanine biosynthesis and catabolism. Consistent with this, the GABA shunt and the production of NADPH are repressed in a wild-type strain grown in alanine, as compared to those detected in the wild-type strain grown on GABA. We also show that heat shock induces alanine biosynthesis and ALT1, UGA1, UGA2, and GAD1 gene expression, whereas an uga1Δ mutant shows heat sensitivity and reduced NADPH pools, as compared with those observed in the wild-type strain. Additionally, an alt1Δ mutant shows an unexpected alanine-independent phenotype, displaying null expression of mitochondrial COX2, COX3, and ATP6 genes and a notable decrease in mitochondrial/nuclear DNA ratio, as compared to a wild-type strain, which results in a petite phenotype. Our results uncover a new negative role of alanine in stress defense, repressing the transcription of the GABA shunt genes, and support a novel Alt1 moonlighting function related to the maintenance of mitochondrial DNA integrity and mitochondrial gene expression.
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Affiliation(s)
- Dariel Márquez
- Departamento de Bioquímica y Biología Estructural, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico, Mexico
| | | | - Mohammed El Hafidi
- Departamento de Biomedicina Cardiovascular, Instituto Nacional de Cardiología Ignacio Chávez, Mexico, Mexico
| | - Beatriz Aguirre-López
- Departamento de Bioquímica y Biología Estructural, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico, Mexico
| | - Lina Riego-Ruiz
- División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica (IPICYT), San Luis Potosí, México
| | - Alicia González
- Departamento de Bioquímica y Biología Estructural, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico, Mexico
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10
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Liboro K, Yu SR, Lim J, So YS, Bahn YS, Eoh H, Park H. Transcriptomic and Metabolomic Analysis Revealed Roles of Yck2 in Carbon Metabolism and Morphogenesis of Candida albicans. Front Cell Infect Microbiol 2021; 11:636834. [PMID: 33796481 PMCID: PMC8008151 DOI: 10.3389/fcimb.2021.636834] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 02/08/2021] [Indexed: 12/05/2022] Open
Abstract
Candida albicans is a part of the normal microbiome of human mucosa and is able to thrive in a wide range of host environments. As an opportunistic pathogen, the virulence of C. albicans is tied to its ability to switch between yeast and hyphal morphologies in response to various environmental cues, one of which includes nutrient availability. Thus, metabolic flexibility plays an important role in the virulence of the pathogen. Our previous study has shown that C. albicans Yeast Casein Kinase 2 (CaYck2) regulates the yeast-to-hyphal switch, but its regulatory mechanisms remain unknown. This study further elucidated the role of Yck2 in governing morphology and carbon metabolism by analyzing the transcriptome and metabolome of the C. albicans YCK2 deletion mutant strain (yck2Δ strain) in comparison to the wild type strain. Our study revealed that loss of CaYck2 perturbs carbon metabolism, leading to a transcriptional response that resembles a transcriptional response to glucose starvation with coinciding intracellular accumulation of glucose and depletion of TCA cycle metabolites. This shift in the metabolome is likely mediated by derepression of glucose-repressed genes in the Mig1/2-mediated glucose sensing pathway and by downregulation of glycolytic genes, possibly through the Rgt1-mediated SRR pathway. In addition, genes involved in beta-oxidation, glyoxylate cycle, oxidative stress response, and arginine biosynthesis were upregulated in the yck2Δ strain, which is highly reminiscent of C. albicans engulfment by macrophages. This coincides with an increase in arginine degradation intermediates in the yck2Δ strain, suggesting arginine catabolism as a potential mechanism of CaYck2-mediated filamentation as seen during C. albicans escape from macrophages. Transcriptome analysis also shows differential expression of hyphal transcriptional regulators Nrg1 and Ume6. This suggests dysregulation of hyphal initiation and elongation in the yck2Δ strain which may lead to the constitutive pseudohyphal phenotype of this strain. Metabolome analysis also detected a high abundance of methyl citrate cycle intermediates in the yck2Δ strain, suggesting the importance of CaYck2 in this pathway. Taken together, we discovered that CaYck2 is an integral piece of carbon metabolism and morphogenesis of C. albicans.
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Affiliation(s)
- Karl Liboro
- Department of Biological Sciences, California State University, Los Angeles, CA, United States
| | - Seong-Ryong Yu
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul, South Korea
| | - Juhyeon Lim
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Yee-Seul So
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul, South Korea
| | - Yong-Sun Bahn
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul, South Korea
| | - Hyungjin Eoh
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Hyunsook Park
- Department of Biological Sciences, California State University, Los Angeles, CA, United States
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11
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Luo H, Liu Z, Xie F, Bilal M, Liu L, Yang R, Wang Z. Microbial production of gamma-aminobutyric acid: applications, state-of-the-art achievements, and future perspectives. Crit Rev Biotechnol 2021; 41:491-512. [PMID: 33541153 DOI: 10.1080/07388551.2020.1869688] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Gamma-aminobutyric acid (GABA) is an important non-protein amino acid with wide-ranging applications. Currently, GABA can be produced by a variety of methods, including chemical synthesis, plant enrichment, enzymatic methods, and microbial production. Among these methods, microbial production has gained increasing attention to meet the strict requirements of an additive in the fields of food, pharmaceutical, and livestock. In addition, renewable and abundant resources, such as glucose and lignocellulosic biomass can also be used for GABA microbial production under mild and environmentally friendly processing conditions. In this review, the applications, metabolic pathways and physiological functions of GABA in different microorganisms were firstly discussed. A comprehensive overview of the current status of process engineering strategies for enhanced GABA production, including fermentation optimization and whole-cell conversion from different feedstocks by various host strains is also provided. We also presented the state-of-the-art achievements in strain development strategies for industrial lactic acid bacteria (LAB), Corynebacterium glutamicum and Escherichia coli to enhance the performance of GABA bioproduction. In order to use bio-based GABA in the fields of food and pharmaceutical, some Generally Recognized as Safe (GRAS) strains such as LAB and C. glutamicum will be the promising chassis hosts. Toward the end of this review, current challenges and valuable research directions/strategies on the improvements of process and strain engineering for economic microbial production of GABA are also suggested.
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Affiliation(s)
- Hongzhen Luo
- School of Life Science and Food Engineering, Huaiyin Institute of Technology, Huaian, China
| | - Zheng Liu
- School of Life Science and Food Engineering, Huaiyin Institute of Technology, Huaian, China
| | - Fang Xie
- School of Life Science and Food Engineering, Huaiyin Institute of Technology, Huaian, China
| | - Muhammad Bilal
- School of Life Science and Food Engineering, Huaiyin Institute of Technology, Huaian, China
| | - Lina Liu
- School of Life Science and Food Engineering, Huaiyin Institute of Technology, Huaian, China
| | - Rongling Yang
- School of Life Science and Food Engineering, Huaiyin Institute of Technology, Huaian, China
| | - Zhaoyu Wang
- School of Life Science and Food Engineering, Huaiyin Institute of Technology, Huaian, China
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12
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Knott EL, Leidenheimer NJ. A Targeted Bioinformatics Assessment of Adrenocortical Carcinoma Reveals Prognostic Implications of GABA System Gene Expression. Int J Mol Sci 2020; 21:ijms21228485. [PMID: 33187258 PMCID: PMC7697095 DOI: 10.3390/ijms21228485] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 11/05/2020] [Accepted: 11/09/2020] [Indexed: 12/12/2022] Open
Abstract
Adrenocortical carcinoma (ACC) is a rare but deadly cancer for which few treatments exist. Here, we have undertaken a targeted bioinformatics study of The Cancer Genome Atlas (TCGA) ACC dataset focusing on the 30 genes encoding the γ-aminobutyric acid (GABA) system—an under-studied, evolutionarily-conserved system that is an emerging potential player in cancer progression. Our analysis identified a subset of ACC patients whose tumors expressed a distinct GABA system transcriptome. Transcript levels of ABAT (encoding a key GABA shunt enzyme), were upregulated in over 40% of tumors, and this correlated with several favorable clinical outcomes including patient survival; while enrichment and ontology analysis implicated two cancer-related biological pathways involved in metastasis and immune response. The phenotype associated with ABAT upregulation revealed a potential metabolic heterogeneity among ACC tumors associated with enhanced mitochondrial metabolism. Furthermore, many GABAA receptor subunit-encoding transcripts were expressed, including two (GABRB2 and GABRD) prognostic for patient survival. Transcripts encoding GABAB receptor subunits and GABA transporters were also ubiquitously expressed. The GABA system transcriptome of ACC tumors is largely mirrored in the ACC NCI-H295R cell line, suggesting that this cell line may be appropriate for future functional studies investigating the role of the GABA system in ACC cell growth phenotypes and metabolism.
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13
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Zajic DE, Podrabsky JE. GABA metabolism is crucial for long-term survival of anoxia in annual killifish embryos. J Exp Biol 2020; 223:jeb229716. [PMID: 32859669 DOI: 10.1242/jeb.229716] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 08/24/2020] [Indexed: 08/25/2023]
Abstract
In most vertebrates, a lack of oxygen quickly leads to irreparable damages to vital organs, such as the brain and heart. However, there are some vertebrates that have evolved mechanisms to survive periods of no oxygen (anoxia). The annual killifish (Austrofundulus limnaeus) survives in ephemeral ponds in the coastal deserts of Venezuela and their embryos have the remarkable ability to tolerate anoxia for months. When exposed to anoxia, embryos of A. limnaeus respond by producing significant amounts of γ-aminobutyric acid (GABA). This study aims to understand the role of GABA in supporting the metabolic response to anoxia. To explore this, we investigated four developmentally distinct stages of A. limnaeus embryos that vary in their anoxia tolerance. We measured GABA and lactate concentrations across development in response to anoxia and aerobic recovery. We then inhibited enzymes responsible for the production and degradation of GABA and observed GABA and lactate concentrations, as well as embryo mortality. Here, we show for the first time that GABA metabolism affects anoxia tolerance in A. limnaeus embryos. Inhibition of enzymes responsible for GABA production (glutamate decarboxylase) and degradation (GABA-transaminase and succinic acid semialdehyde dehydrogenase) led to increased mortality, supporting a role for GABA as an intermediate product and not a metabolic end-product. We propose multiple roles for GABA during anoxia and aerobic recovery in A. limnaeus embryos, serving as a neurotransmitter, an energy source, and an anti-oxidant.
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Affiliation(s)
- Daniel E Zajic
- Department of Biology, Portland State University, PO Box 751, Portland, OR 97207, USA
- Health, Human Performance, and Athletics Department, Linfield University, 900 SE Baker, McMinnville, OR 97128, USA
| | - Jason E Podrabsky
- Department of Biology, Portland State University, PO Box 751, Portland, OR 97207, USA
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14
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Lv X, Liu G, Fan X, Qiao Y, Zhang A, Zhao X, Lin Y, Feng Z. Effects of NaCl and ethanol stresses on γ-aminobutyric acid synthesis in Kocuria kristinae. FOOD BIOSCI 2020. [DOI: 10.1016/j.fbio.2020.100702] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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15
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Mendes Ferreira A, Mendes-Faia A. The Role of Yeasts and Lactic Acid Bacteria on the Metabolism of Organic Acids during Winemaking. Foods 2020; 9:E1231. [PMID: 32899297 PMCID: PMC7555314 DOI: 10.3390/foods9091231] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 08/25/2020] [Accepted: 08/27/2020] [Indexed: 12/31/2022] Open
Abstract
The main role of acidity and pH is to confer microbial stability to wines. No less relevant, they also preserve the color and sensory properties of wines. Tartaric and malic acids are generally the most prominent acids in wines, while others such as succinic, citric, lactic, and pyruvic can exist in minor concentrations. Multiple reactions occur during winemaking and processing, resulting in changes in the concentration of these acids in wines. Two major groups of microorganisms are involved in such modifications: the wine yeasts, particularly strains of Saccharomyces cerevisiae, which carry out alcoholic fermentation; and lactic acid bacteria, which commonly conduct malolactic fermentation. This review examines various such modifications that occur in the pre-existing acids of grape berries and in others that result from this microbial activity as a means to elucidate the link between microbial diversity and wine composition.
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Affiliation(s)
- Ana Mendes Ferreira
- University of Trás-os-Montes and Alto Douro, 5001-801 Vila Real, Portugal;
- WM&B—Wine Microbiology & Biotechnology Laboratory, Department of Biology and Environment, UTAD, 5001-801 Vila Real, Portugal
- BioISI—Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisboa, 1749-016 Lisboa, Portugal
| | - Arlete Mendes-Faia
- University of Trás-os-Montes and Alto Douro, 5001-801 Vila Real, Portugal;
- WM&B—Wine Microbiology & Biotechnology Laboratory, Department of Biology and Environment, UTAD, 5001-801 Vila Real, Portugal
- BioISI—Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisboa, 1749-016 Lisboa, Portugal
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16
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Zajic DE, Podrabsky JE. Metabolomics analysis of annual killifish ( Austrofundulus limnaeus) embryos during aerial dehydration stress. Physiol Genomics 2020; 52:408-422. [PMID: 32776802 DOI: 10.1152/physiolgenomics.00072.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The annual killifish, Austrofundulus limnaeus, survives in ephemeral ponds in the coastal deserts of Venezuela. Persistence through the dry season is dependent on drought-resistant eggs embedded in the pond sediments during the rainy season. The ability of these embryos to enter drastic metabolic dormancy (diapause) during normal development enables A. limnaeus to survive conditions lethal to most other aquatic vertebrates; critical to the survival of the species is the ability of embryos to survive months and perhaps years without access to liquid water. Little is known about the molecular mechanisms that aid in survival of the dry season. This study aims to gain insight into the mechanisms facilitating survival of dehydration stress due to aerial exposure by examining metabolite profiles of dormant and developing embryos. There is strong evidence for unique metabolic profiles based on developmental stage and length of aerial exposure. Actively developing embryos exhibit more robust changes; however, dormant embryos respond in an active manner and significantly alter their metabolic profile. A number of metabolites accumulate in aerial-exposed embryos that may play an important role in survival, including the identification of known antioxidants and neuroprotectants. In addition, a number of unique metabolites not yet discussed in the dehydration literature are identified, such as lanthionine and 2-hydroxyglutarate. Despite high oxygen availability, embryos accumulate the anaerobic end product lactate. This paper offers an overview of the metabolic changes occurring that may support embryonic survival during dehydration stress due to aerial incubation, which can be functionally tested using genetic and pharmacological approaches.
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Affiliation(s)
- Daniel E Zajic
- Department of Biology, Portland State University, Portland, Oregon.,Health, Human Performance, and Athletics Department, Linfield University, McMinnville, Oregon
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17
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Perpetuini G, Tittarelli F, Battistelli N, Suzzi G, Tofalo R. γ‐aminobutyric acid production by
Kluyveromyces marxianus
strains. J Appl Microbiol 2020; 129:1609-1619. [DOI: 10.1111/jam.14736] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 05/26/2020] [Accepted: 05/31/2020] [Indexed: 12/24/2022]
Affiliation(s)
- G. Perpetuini
- Faculty of BioScience and Technology for Food, Agriculture and Environment University of Teramo Teramo Italy
| | - F. Tittarelli
- Faculty of BioScience and Technology for Food, Agriculture and Environment University of Teramo Teramo Italy
| | - N. Battistelli
- Faculty of BioScience and Technology for Food, Agriculture and Environment University of Teramo Teramo Italy
| | - G. Suzzi
- Faculty of BioScience and Technology for Food, Agriculture and Environment University of Teramo Teramo Italy
| | - R. Tofalo
- Faculty of BioScience and Technology for Food, Agriculture and Environment University of Teramo Teramo Italy
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18
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Durán-Viseras A, Andrei AŞ, Vera-Gargallo B, Ghai R, Sánchez-Porro C, Ventosa A. Culturomics-based genomics sheds light on the ecology of the new haloarchaeal genus Halosegnis. Environ Microbiol 2020; 23:3418-3434. [PMID: 32410366 DOI: 10.1111/1462-2920.15082] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 05/10/2020] [Accepted: 05/11/2020] [Indexed: 12/22/2022]
Abstract
The development of culture-independent techniques has revolutionized our understanding of microbial ecology, especially through the illustration of the vast gap between the environmentally abundant microbial diversity and that accessible through cultivation. However, culture-based approaches are not only crucial for understanding the evolutionary, metabolic and ecological milieu of microbial diversity but also for the development of novel biotechnological applications. In this study, we used a culturomics-based approach in order to isolate novel microbial taxa from hypersaline environments (i.e. Isla Cristina and Isla Bacuta salterns in Huelva, Spain). We managed to obtain axenic cultures of four haloarchaeal strains that belong to a new haloarchaeal genus and to obtain their genomic sequences. The phylogenomic and phylogenetic analyses (together with AAI, ANI and digital DDH indices) showed that the isolates constitute two new species, for which we propose the names Halosegnis longus sp. nov. and Halosegnis rubeus sp. nov. The genomic-based metabolic reconstructions indicated that members of this new haloarchaeal genus have photoheterotrophic aerobic lifestyle with a typical salt-in signature. 16S rRNA gene sequence reads abundance profiles and genomic recruitment analyses revealed that the Halosegnis genus has a worldwide geographical distribution, reaching high abundance (up to 8%) in habitats with intermediate salinities.
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Affiliation(s)
- Ana Durán-Viseras
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, Sevilla, 41012, Spain
| | - Adrian-Ştefan Andrei
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre of the Czech Academy of Sciences, České Budějovice, 370 05, Czech Republic
| | - Blanca Vera-Gargallo
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, Sevilla, 41012, Spain
| | - Rohit Ghai
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre of the Czech Academy of Sciences, České Budějovice, 370 05, Czech Republic
| | - Cristina Sánchez-Porro
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, Sevilla, 41012, Spain
| | - Antonio Ventosa
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, Sevilla, 41012, Spain
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19
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Cao W, Wang G, Lu H, Ouyang L, Chu J, Sui Y, Zhuang Y. Improving cytosolic aspartate biosynthesis increases glucoamylase production in Aspergillus niger under oxygen limitation. Microb Cell Fact 2020; 19:81. [PMID: 32245432 PMCID: PMC7118866 DOI: 10.1186/s12934-020-01340-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 03/24/2020] [Indexed: 01/27/2023] Open
Abstract
Background Glucoamylase is one of the most industrially applied enzymes, produced by Aspergillus species, like Aspergillus niger. Compared to the traditional ways of process optimization, the metabolic engineering strategies to improve glucoamylase production are relatively scarce. Results In the previous study combined multi-omics integrative analysis and amino acid supplementation experiment, we predicted four amino acids (alanine, glutamate, glycine and aspartate) as the limited precursors for glucoamylase production in A. niger. To further verify this, five mutants namely OE-ala, OE-glu, OE-gly, OE-asp1 and OE-asp2, derived from the parental strain A. niger CBS 513.88, were constructed respectively for the overexpression of five genes responsible for the biosynthesis of the four kinds of amino acids (An11g02620, An04g00990, An05g00410, An04g06380 and An16g05570). Real-time quantitative PCR revealed that all these genes were successfully overexpressed at the mRNA level while the five mutants exhibited different performance in glucoamylase production in shake flask cultivation. Notably, the results demonstrated that mutant OE-asp2 which was constructed for reinforcing cytosolic aspartate synthetic pathway, exhibited significantly increased glucoamylase activity by 23.5% and 60.3% compared to CBS 513.88 in the cultivation of shake flask and the 5 L fermentor, respectively. Compared to A. niger CBS 513.88, mutant OE-asp2 has a higher intracellular amino acid pool, in particular, alanine, leucine, glycine and glutamine, while the pool of glutamate was decreased. Conclusion Our study combines the target prediction from multi-omics analysis with the experimental validation and proves the possibility of increasing glucoamylase production by enhancing limited amino acid biosynthesis. In short, this systematically conducted study will surely deepen the understanding of resources allocation in cell factory and provide new strategies for the rational design of enzyme production strains.
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Affiliation(s)
- Weiqiang Cao
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, People's Republic of China
| | - Guan Wang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, People's Republic of China
| | - Hongzhong Lu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, People's Republic of China
| | - Liming Ouyang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, People's Republic of China.
| | - Ju Chu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, People's Republic of China
| | - Yufei Sui
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, People's Republic of China
| | - Yingping Zhuang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, People's Republic of China.
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20
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Yuan H, Zhang W, Xiao G, Zhan J. Efficient production of gamma-aminobutyric acid by engineered Saccharomyces cerevisiae with glutamate decarboxylases from Streptomyces. Biotechnol Appl Biochem 2019; 67:240-248. [PMID: 31625206 DOI: 10.1002/bab.1840] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 08/10/2019] [Indexed: 01/27/2023]
Abstract
Gamma-aminobutyric acid (GABA) is an industrially valuable natural product. This study was aimed to establish an efficient food-grade production process of GABA by engineering Saccharomyces cerevisiae that is generally recognized as safe (GRAS). GABA can be produced by catalytic decarboxylation of l-glutamate (l-Glu) by glutamate decarboxylase (GAD, EC4.1.1.15). Two GADs, SsGAD from Streptomyces sp. MJ654-NF4 and ScGAD from Streptomyces chromofuscus ATCC 49982, were heterologously expressed in S. cerevisiae BJ5464. The engineered yeast strains were used as whole-cell biocatalysts for GABA production. S. cerevisiae BJ5464/SsGAD exhibited significantly higher efficient catalytic activity than that of S. cerevisiae BJ5464/ScGAD. The optimal bioconversion system consisted of a cell density of OD600 30, 0.1 M l-Glu, and 0.28 mM pyridoxal phosphate in 0.2 M Na2 HPO4 -citric acid buffer with pH 5.4, and the reactions were performed at 50 °C for 12 H. S. cerevisiae BJ5464/SsGAD cells can be reused, and the accumulated GABA titer reached 62.6 g/L after 10 batches with an overall molar conversion rate of 60.8 mol%. This work thus provides an effective production process of GABA using engineered yeast for food and pharmaceutical applications.
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Affiliation(s)
- Haina Yuan
- School of Biological and Chemical Engineering, Zhejiang Provincial Collaborative Innovation Center of Agricultural Biological Resources Biochemical Manufacturing, Zhejiang Provincial Key Lab for Chem&Bio Processing Technology of Farm Produces, Zhejiang University of Science and Technology, Hangzhou, Zhejiang, China.,Department of Biological Engineering, Utah State University, Logan, UT, USA
| | - Wei Zhang
- Hangzhou Viablife Biotech Co., Ltd., Liangzhu University Science Park, Hangzhou, Zhejiang, 311113, China
| | - Gongnian Xiao
- School of Biological and Chemical Engineering, Zhejiang Provincial Collaborative Innovation Center of Agricultural Biological Resources Biochemical Manufacturing, Zhejiang Provincial Key Lab for Chem&Bio Processing Technology of Farm Produces, Zhejiang University of Science and Technology, Hangzhou, Zhejiang, China
| | - Jixun Zhan
- Department of Biological Engineering, Utah State University, Logan, UT, USA
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21
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Babele PK, Singh AK, Srivastava A. Bio-Inspired Silver Nanoparticles Impose Metabolic and Epigenetic Toxicity to Saccharomyces cerevisiae. Front Pharmacol 2019; 10:1016. [PMID: 31572189 PMCID: PMC6751407 DOI: 10.3389/fphar.2019.01016] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 08/09/2019] [Indexed: 01/01/2023] Open
Abstract
Silver nanoparticles (AgNPs) have many applications in various fields, including biomedical applications. Due to the broad range of applications, they are considered as the leading fraction of manufactured nanoparticles. AgNPs are synthesized by different types of chemical and biological (green) methods. Previously, biologically synthesized AgNPs were considered safe for the environment and humans. However, new toxicity evidence have initiated a more careful assessment to delineate the toxicity mechanisms associated with these nanoparticles. This study demonstrates the use of aqueous gooseberry extract for AgNP preparation in a time- and cost-effective way. Ultraviolet-visible spectroscopy, X-ray diffraction, transmission electron microscopy, and dynamic light scattering confirm the formation of AgNPs, with an average size between 50 and 100 nm. Untargeted 1H-nuclear magnetic resonance-based metabolomics revealed manyfold up- and down-regulation in the concentration of 55 different classes of annotated metabolites in AgNP-exposed yeast Saccharomyces cerevisiae cells. Based on their chemical nature and cellular functions, these metabolites are classified into amino acids, glycolysis and the tricarboxylic acid (TCA) cycle, organic acids, nucleotide metabolism, urea cycle, and lipid metabolism. Transcriptome analysis revealed that the genes involved in oxidative stress mitigation maintain their expression levels, whereas the genes of the TCA cycle and lipid metabolism show drastic down-regulation upon AgNP exposure. Moreover, they can induce alteration in histone epigenetic marks by altering the methylation and acetylation of selected histone H3 and H4 proteins. Altogether, we conclude that the selected dose of biologically synthesized AgNPs impose toxicity by modulating the transcriptome, epigenome, and metabolome of eukaryotic cells, which eventually cause disequilibrium in cellular metabolism leading to toxicity.
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Affiliation(s)
- Piyoosh Kumar Babele
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal, India
| | | | - Amit Srivastava
- Department of Physics, TDPG College, VBS Purvanchal University, Jaunpur, India
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22
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Sen NE, Canet-Pons J, Halbach MV, Arsovic A, Pilatus U, Chae WH, Kaya ZE, Seidel K, Rollmann E, Mittelbronn M, Meierhofer D, De Zeeuw CI, Bosman LWJ, Gispert S, Auburger G. Generation of an Atxn2-CAG100 knock-in mouse reveals N-acetylaspartate production deficit due to early Nat8l dysregulation. Neurobiol Dis 2019; 132:104559. [PMID: 31376479 DOI: 10.1016/j.nbd.2019.104559] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 07/16/2019] [Accepted: 07/30/2019] [Indexed: 12/13/2022] Open
Abstract
Spinocerebellar ataxia type 2 (SCA2) is an autosomal dominant neurodegenerative disorder caused by CAG-expansion mutations in the ATXN2 gene, mainly affecting motor neurons in the spinal cord and Purkinje neurons in the cerebellum. While the large expansions were shown to cause SCA2, the intermediate length expansions lead to increased risk for several atrophic processes including amyotrophic lateral sclerosis and Parkinson variants, e.g. progressive supranuclear palsy. Intense efforts to pioneer a neuroprotective therapy for SCA2 require longitudinal monitoring of patients and identification of crucial molecular pathways. The ataxin-2 (ATXN2) protein is mainly involved in RNA translation control and regulation of nutrient metabolism during stress periods. The preferential mRNA targets of ATXN2 are yet to be determined. In order to understand the molecular disease mechanism throughout different prognostic stages, we generated an Atxn2-CAG100-knock-in (KIN) mouse model of SCA2 with intact murine ATXN2 expression regulation. Its characterization revealed somatic mosaicism of the expansion, with shortened lifespan, a progressive spatio-temporal pattern of pathology with subsequent phenotypes, and anomalies of brain metabolites such as N-acetylaspartate (NAA), all of which mirror faithfully the findings in SCA2 patients. Novel molecular analyses from stages before the onset of motor deficits revealed a strong selective effect of ATXN2 on Nat8l mRNA which encodes the enzyme responsible for NAA synthesis. This metabolite is a prominent energy store of the brain and a well-established marker for neuronal health. Overall, we present a novel authentic rodent model of SCA2, where in vivo magnetic resonance imaging was feasible to monitor progression and where the definition of earliest transcriptional abnormalities was possible. We believe that this model will not only reveal crucial insights regarding the pathomechanism of SCA2 and other ATXN2-associated disorders, but will also aid in developing gene-targeted therapies and disease prevention.
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Affiliation(s)
- Nesli-Ece Sen
- Experimental Neurology, Goethe University Medical School, 60590 Frankfurt am Main, Germany
| | - Júlia Canet-Pons
- Experimental Neurology, Goethe University Medical School, 60590 Frankfurt am Main, Germany
| | - Melanie V Halbach
- Experimental Neurology, Goethe University Medical School, 60590 Frankfurt am Main, Germany
| | - Aleksandar Arsovic
- Experimental Neurology, Goethe University Medical School, 60590 Frankfurt am Main, Germany
| | - Ulrich Pilatus
- Institute of Neuroradiology, Goethe University Medical School, 60590 Frankfurt am Main, Germany
| | - Woon-Hyung Chae
- Georg-Speyer-Haus, Institute for Tumor Biology and Experimental Therapy, 60596 Frankfurt am Main, Germany
| | - Zeynep-Ece Kaya
- Experimental Neurology, Goethe University Medical School, 60590 Frankfurt am Main, Germany; Department of Neurology, Cerrahpasa School of Medicine, Istanbul University, 34098 Istanbul, Turkey
| | - Kay Seidel
- Department of Anatomy II, Institute of Clinical Neuroanatomy, Goethe University, 60590 Frankfurt am Main, Germany
| | - Ewa Rollmann
- Experimental Neurology, Goethe University Medical School, 60590 Frankfurt am Main, Germany
| | - Michel Mittelbronn
- Neurological Institute (Edinger Institute), Goethe University, 60590 Frankfurt am Main, Germany; Luxembourg Centre of Neuropathology (LCNP), Luxembourg; Department of Pathology, Laboratoire National de Santé (LNS), Dudelange, Luxembourg; Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Esch-sur-Alzette, Luxembourg; Department of Oncology, NORLUX Neuro-Oncology Laboratory, Luxembourg Institute of Health (LIH), Luxembourg
| | - David Meierhofer
- Max Planck Institute for Molecular Genetics, 14195 Berlin, Germany
| | - Chris I De Zeeuw
- Netherlands Institute for Neuroscience, Royal Academy of Arts and Sciences, 1105 BA Amsterdam, the Netherlands; Department of Neuroscience, Erasmus Medical Center, 3000 CA Rotterdam, the Netherlands
| | - Laurens W J Bosman
- Department of Neuroscience, Erasmus Medical Center, 3000 CA Rotterdam, the Netherlands
| | - Suzana Gispert
- Experimental Neurology, Goethe University Medical School, 60590 Frankfurt am Main, Germany
| | - Georg Auburger
- Experimental Neurology, Goethe University Medical School, 60590 Frankfurt am Main, Germany.
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23
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Trehalose induced by reactive oxygen species relieved the radial growth defects of Pleurotus ostreatus under heat stress. Appl Microbiol Biotechnol 2019; 103:5379-5390. [PMID: 31069486 DOI: 10.1007/s00253-019-09834-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 03/27/2019] [Accepted: 04/04/2019] [Indexed: 10/26/2022]
Abstract
Trehalose is a nonreducing disaccharide, and it plays an intracellular protective role in organisms under various stress conditions. In this study, the trehalose synthesis and its protective role in Pleurotus ostreatus were investigated. As a signal in metabolic regulation, reactive oxygen species (ROS) accumulated in the mycelia of P. ostreatus under heat stress (HS). Furthermore, mycelial growth was significantly inhibited, and the malondialdehyde (MDA) level significantly increased under HS. First, exogenous addition of H2O2 inhibited mycelial growth and elevated the MDA level, while N-acetyl cysteine (NAC) and vitamin C (VC) reduced the MDA level and recovered mycelial growth under HS by scavenging ROS. These results indicated that the mycelial radial growth defect under HS might be partly caused by ROS accumulation. Second, adding NAC and VC to the media resulted in rescued trehalose accumulation, which indicated that ROS has an effect on inducing trehalose synthesis. Third, the mycelial growth was recovered by addition of trehalose to the media after HS, and the MDA level was reduced. This effect was further verified by the overexpression of genes for trehalose-6-phosphate synthase (TPS) and neutral trehalase (NTH), which led to increased and reduced trehalose content, respectively. In addition, adding validamycin A (NTH inhibitor) to the media promoted trehalose accumulation and the recovered mycelial growth after HS. In conclusion, trehalose production was partly induced by ROS accumulation in the mycelia under HS, and the accumulated trehalose could promote the recovery of growth after HS, partly by reducing the MDA level in the mycelia.
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24
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Zhang MM, Xiong L, Tang YJ, Mehmood MA, Zhao ZK, Bai FW, Zhao XQ. Enhanced acetic acid stress tolerance and ethanol production in Saccharomyces cerevisiae by modulating expression of the de novo purine biosynthesis genes. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:116. [PMID: 31168321 PMCID: PMC6509782 DOI: 10.1186/s13068-019-1456-1] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 05/02/2019] [Indexed: 05/08/2023]
Abstract
BACKGROUND Yeast strains that are tolerant to multiple environmental stresses are highly desired for various industrial applications. Despite great efforts in identifying key genes involved in stress tolerance of budding yeast Saccharomyces cerevisiae, the effects of de novo purine biosynthesis genes on yeast stress tolerance are still not well explored. Our previous studies showed that zinc sulfate addition improved yeast acetic acid tolerance, and key genes involved in yeast stress tolerance were further investigated in this study. RESULTS Three genes involved in de novo purine biosynthesis, namely, ADE1, ADE13, and ADE17, showed significantly increased transcription levels by zinc sulfate supplementation under acetic acid stress, and overexpression of these genes in S. cerevisiae BY4741 enhanced cell growth under various stress conditions. Meanwhile, ethanol productivity was also improved by overexpression of the three ADE genes under stress conditions, among which the highest improvement attained 158.39% by ADE17 overexpression in the presence of inhibitor mixtures derived from lignocellulosic biomass. Elevated levels of adenine-nucleotide pool "AXP" ([ATP] + [ADP] + [AMP]) and ATP content were observed by overexpression of ADE17, both under control condition and under acetic acid stress, and is consistent with the better growth of the recombinant yeast strain. The global intracellular amino acid profiles were also changed by overexpression of the ADE genes. Among the changed amino acids, significant increase of the stress protectant γ-aminobutyric acid (GABA) was revealed by overexpression of the ADE genes under acetic acid stress, suggesting that overexpression of the ADE genes exerts control on both purine biosynthesis and amino acid biosynthesis to protect yeast cells against the stress. CONCLUSION We proved that the de novo purine biosynthesis genes are useful targets for metabolic engineering of yeast stress tolerance. The engineered strains developed in this study with improved tolerance against multiple inhibitors can be employed for efficient lignocellulosic biorefinery to produce biofuels and biochemicals.
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Affiliation(s)
- Ming-Ming Zhang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240 China
| | - Liang Xiong
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian, 116024 China
| | - Ya-Jie Tang
- Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan, 430068 China
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237 China
| | - Muhammad Aamer Mehmood
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240 China
- Department of Bioinformatics & Biotechnology, Government College University Faisalabad, Faisalabad, 38000 Pakistan
| | - Zongbao Kent Zhao
- Department of Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023 China
| | - Feng-Wu Bai
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240 China
| | - Xin-Qing Zhao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240 China
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25
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Transcriptome and metabolome analyses reveal global behaviour of a genetically engineered methanol-independent Pichia pastoris strain. Process Biochem 2019. [DOI: 10.1016/j.procbio.2018.10.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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26
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Kumar Babele P. Zinc oxide nanoparticles impose metabolic toxicity by de-regulating proteome and metabolome in Saccharomyces cerevisiae. Toxicol Rep 2018; 6:64-73. [PMID: 30581761 PMCID: PMC6297892 DOI: 10.1016/j.toxrep.2018.12.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2018] [Revised: 11/28/2018] [Accepted: 12/05/2018] [Indexed: 12/31/2022] Open
Abstract
Untargeted proteomic and metabolic approaches provide complete toxicity assessment. ZnO-NPs de-regulate the proteome and metabolome of S. cerevisiae. ZnO-NPs affect the key metabolites of central metabolic pathways. Protein and/or metabolite can be used as biomarker specific to the ZnO-NPs induced toxicity.
As zinc oxide nanoparticles are being increasingly used in various applications, it is important to assess their potential toxic implications. Stress responses and adaptations are primarily controlled by modulation in cellular proteins (enzyme) and concentration of metabolites. To date proteomics or metabolomics applications in nanotoxicity assessment have been applied to a restricted extent. Here we utilized 2DE and 1H NMR based proteomics and metabolomics respectively to delineate the toxicity mechanism of zinc oxide nanoparticles (ZnO-NPs) in budding yeast S. cerevisiae. We found that the physiological and metabolic processes were altered in the S. cerevisiae upon ZnO-NPs exposure. Almost 40% proteins were down-regulated in ZnO-NPs (10 mg L−1) exposed cell as compared to control. Metabolomics and system biology based pathway analysis, revealed that ZnO-NPs repressed a wide range of key metabolites involved in central carbon metabolism, cofactors synthesis, amino acid and fatty acid biosynthesis, purines and pyrimidines, nucleoside and nucleotide biosynthetic pathways. These metabolic changes may be associated with the energy metabolism, antioxidation, DNA and protein damage and membrane stability. We concluded that untargeted proteomic and metabolic approaches provide more complete measurements and suggest probable molecular mechanisms of nanomaterials toxicity.
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Affiliation(s)
- Piyoosh Kumar Babele
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhauri, Bhopal, 462066, Madhya Pradesh, India
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27
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Ji H, Lu X, Zong H, Zhuge B. γ-aminobutyric acid accumulation enhances the cell growth of Candida glycerinogenes under hyperosmotic conditions. J GEN APPL MICROBIOL 2018. [PMID: 29526924 DOI: 10.2323/jgam.2017.08.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
γ-aminobutyric acid (GABA) is an important non-protein amino acid involved in the response to various environmental stresses in plant cells. The objectives of this study was to test the hypothesis that intracellular accumulation of GABA improves osmotic tolerance in the unconventional yeast Candida glycerinogenes. In C. glycerinogenes, the expression of UGA4 encoding GABA-specific permease is highly induced by hyperosmotic stress. Exogenous GABA application enhanced intracellular GABA accumulation and promoted cell growth under hyperosmotic conditions. Overexpression of the glutamate decarboxylase gene GAD1 resulted in an increased intracellular GABA and improvement in cell growth under hyperosmotic conditions. These results indicated that improving intracellular GABA accumulation of C. glycerinogenes, either through exogenous application or cellular synthesis, is available for improving the tolerance to hyperosmotic stress. We demonstrate that GABA accumulation plays an important role in osmotic stress resistance of the unconventional yeast C. glycerinogenes.
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Affiliation(s)
- Hao Ji
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University.,The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University
| | - Xinyao Lu
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University.,The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University
| | - Hong Zong
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University.,The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University
| | - Bin Zhuge
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University.,The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University
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28
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Liu R, Zhang X, Ren A, Shi DK, Shi L, Zhu J, Yu HS, Zhao MW. Heat stress-induced reactive oxygen species participate in the regulation of HSP expression, hyphal branching and ganoderic acid biosynthesis in Ganoderma lucidum. Microbiol Res 2018; 209:43-54. [PMID: 29580621 DOI: 10.1016/j.micres.2018.02.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 01/30/2018] [Accepted: 02/17/2018] [Indexed: 11/28/2022]
Abstract
Heat stress (HS) is an important environmental factor that affects the growth and metabolism of edible fungi, but the molecular mechanism of the heat stress response (HSR) remains unclear. We previously reported that HS treatment increased the length between two hyphal branches and induced the accumulation of ganoderic acid biosynthesis and the gene expression of heat shock proteins (HSPs) in Ganoderma lucidum. In this study, we found that HS induced a significant increase in the cytosolic ROS concentration, and exogenously added ROS scavengers NAC, VC and NADPH oxidase (Nox) inhibitor DPI reduce the cytosolic ROS accumulation in G. lucidum. In addition, the phenomena of the increased gene expression and increased length between the two hyphal branches and the accumulation of GA biosynthesis induced by HS were mitigated. Furthermore, we investigated the effects of HS on Nox-silenced strains (NoxABi-10, NoxABi-11 and NoxRi-4, NoxRi-7) and found that the level of ROS concentration was lower than that in wild-type (WT) strains treated with HS. Additionally, Nox silenced strains reduced the HS-induced increase in HSP expression, the length between two hyphal branches and GA biosynthesis compared with the WT strain. These data indicate that HS-induced ROS participate in the regulation of HSP expression, hyphal branching and ganoderic acid biosynthesis in G. lucidum. In addition, these findings identified potential pathways linking ROS networks to HSR, physiological and metabolic processes in fungi and provide a valuable reference for studying the role of ROS in HSR, mycelium growth and secondary metabolites.
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Affiliation(s)
- Rui Liu
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Microbiology Department, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, Jiangsu, People's Republic of China
| | - Xue Zhang
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Microbiology Department, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, Jiangsu, People's Republic of China
| | - Ang Ren
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Microbiology Department, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, Jiangsu, People's Republic of China
| | - Deng-Ke Shi
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Microbiology Department, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, Jiangsu, People's Republic of China
| | - Liang Shi
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Microbiology Department, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, Jiangsu, People's Republic of China
| | - Jing Zhu
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Microbiology Department, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, Jiangsu, People's Republic of China
| | - Han-Shou Yu
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Microbiology Department, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, Jiangsu, People's Republic of China
| | - Ming-Wen Zhao
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Microbiology Department, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, Jiangsu, People's Republic of China.
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29
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Yun EJ, Oh EJ, Liu JJ, Yu S, Kim DH, Kwak S, Kim KH, Jin YS. Promiscuous activities of heterologous enzymes lead to unintended metabolic rerouting in Saccharomyces cerevisiae engineered to assimilate various sugars from renewable biomass. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:140. [PMID: 29785207 PMCID: PMC5950193 DOI: 10.1186/s13068-018-1135-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2018] [Accepted: 04/28/2018] [Indexed: 05/08/2023]
Abstract
BACKGROUND Understanding the global metabolic network, significantly perturbed upon promiscuous activities of foreign enzymes and different carbon sources, is crucial for systematic optimization of metabolic engineering of yeast Saccharomyces cerevisiae. Here, we studied the effects of promiscuous activities of overexpressed enzymes encoded by foreign genes on rerouting of metabolic fluxes of an engineered yeast capable of assimilating sugars from renewable biomass by profiling intracellular and extracellular metabolites. RESULTS Unbiased metabolite profiling of the engineered S. cerevisiae strain EJ4 revealed promiscuous enzymatic activities of xylose reductase and xylitol dehydrogenase on galactose and galactitol, respectively, resulting in accumulation of galactitol and tagatose during galactose fermentation. Moreover, during glucose fermentation, a trisaccharide consisting of glucose accumulated outside of the cells probably owing to the promiscuous and transglycosylation activity of β-glucosidase expressed for hydrolyzing cellobiose. Meanwhile, higher accumulation of fatty acids and secondary metabolites was observed during xylose and cellobiose fermentations, respectively. CONCLUSIONS The heterologous enzymes functionally expressed in S. cerevisiae showed promiscuous activities that led to unintended metabolic rerouting in strain EJ4. Such metabolic rerouting could result in a low yield and productivity of a final product due to the formation of unexpected metabolites. Furthermore, the global metabolic network can be significantly regulated by carbon sources, thus yielding different patterns of metabolite production. This metabolomic study can provide useful information for yeast strain improvement and systematic optimization of yeast metabolism to manufacture bio-based products.
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Affiliation(s)
- Eun Ju Yun
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA
- Department of Biotechnology, Graduate School, Korea University, Seoul, 02841 South Korea
| | - Eun Joong Oh
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA
| | - Jing-Jing Liu
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA
| | - Sora Yu
- Department of Biotechnology, Graduate School, Korea University, Seoul, 02841 South Korea
| | - Dong Hyun Kim
- Department of Biotechnology, Graduate School, Korea University, Seoul, 02841 South Korea
| | - Suryang Kwak
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA
| | - Kyoung Heon Kim
- Department of Biotechnology, Graduate School, Korea University, Seoul, 02841 South Korea
| | - Yong-Su Jin
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA
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30
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Tambellini NP, Zaremberg V, Krishnaiah S, Turner RJ, Weljie AM. Primary Metabolism and Medium-Chain Fatty Acid Alterations Precede Long-Chain Fatty Acid Changes Impacting Neutral Lipid Metabolism in Response to an Anticancer Lysophosphatidylcholine Analogue in Yeast. J Proteome Res 2017; 16:3741-3752. [PMID: 28849941 DOI: 10.1021/acs.jproteome.7b00430] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The nonmetabolizable lysophosphatidylcholine (LysoPC) analogue edelfosine is the prototype of a class of compounds being investigated for their potential as selective chemotherapeutic agents. Edelfosine targets membranes, disturbing cellular homeostasis. Is not clear at this point how membrane alterations are communicated between intracellular compartments leading to growth inhibition and eventual cell death. In the present study, a combined metabolomics/lipidomics approach for the unbiased identification of metabolic pathways altered in yeast treated with sublethal concentrations of the LysoPC analogue was employed. Mass spectrometry of polar metabolites, fatty acids, and lipidomic profiling was used to study the effects of edelfosine on yeast metabolism. Amino acid and sugar metabolism, the Krebs cycle, and fatty acid profiles were most disrupted, with polar metabolites and short-medium chain fatty acid changes preceding long and very long-chain fatty acid variations. Initial increases in metabolites such as trehalose, proline, and γ-amino butyric acid with a concomitant decrease in metabolites of the Krebs cycle, citrate and fumarate, are interpreted as a cellular attempt to offset oxidative stress in response to mitochondrial dysfunction induced by the treatment. Notably, alanine, inositol, and myristoleic acid showed a steady increase during the period analyzed (2, 4, and 6 h after treatment). Of importance was the finding that edelfosine induced significant alterations in neutral glycerolipid metabolism resulting in a significant increase in the signaling lipid diacylglycerol.
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Affiliation(s)
- Nicolas P Tambellini
- Department of Biological Sciences, University of Calgary , Calgary, Alberta T2N 1N4, Canada.,Metabolomics Research Centre, University of Calgary , Calgary, Alberta T2N 1N4, Canada
| | - Vanina Zaremberg
- Department of Biological Sciences, University of Calgary , Calgary, Alberta T2N 1N4, Canada
| | - Saikumari Krishnaiah
- Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania Perelman School of Medicine , Philadelphia, Pennsylvania 19104-5158, United States of America
| | - Raymond J Turner
- Department of Biological Sciences, University of Calgary , Calgary, Alberta T2N 1N4, Canada
| | - Aalim M Weljie
- Department of Biological Sciences, University of Calgary , Calgary, Alberta T2N 1N4, Canada.,Metabolomics Research Centre, University of Calgary , Calgary, Alberta T2N 1N4, Canada.,Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania Perelman School of Medicine , Philadelphia, Pennsylvania 19104-5158, United States of America
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31
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Norvienyeku J, Zhong Z, Lin L, Dang X, Chen M, Lin X, Zhang H, Anjago WM, Lin L, Abdul W, Wang Z. Methylmalonate-semialdehyde dehydrogenase mediated metabolite homeostasis essentially regulate conidiation, polarized germination and pathogenesis in Magnaporthe oryzae. Environ Microbiol 2017; 19:4256-4277. [PMID: 28799697 DOI: 10.1111/1462-2920.13888] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 06/22/2017] [Accepted: 08/05/2017] [Indexed: 11/28/2022]
Abstract
Plants generate multitude of aldehydes under abiotic and biotic stress conditions. Ample demonstrations have shown that rice-derived aldehydes enhance the resistance of rice against the rice-blast fungus Magnaporthe oryzae. However, how the fungal pathogen nullifies the inhibitory effects of host aldehydes to establish compatible interaction remains unknown. Here we identified and evaluated the in vivo transcriptional activities of M. oryzae aldehyde dehydrogenase (ALDH) genes. Transcriptional analysis of M. oryzae ALDH genes revealed that the acetylating enzyme Methylmalonate-Semialdehyde Dehydrogenase (MoMsdh/MoMmsdh) elevated activities during host invasion and colonization of the fungus. We further examined the pathophysiological importance of MoMSDH by deploying integrated functional genetics, and biochemical approaches. MoMSDH deletion mutant ΔMomsdh exhibited germination defect, hyper-branching of germ tube and failed to form appressoria on hydrophobic and hydrophilic surface. The MoMSDH disruption caused accumulation of small branch-chain amino acids, pyridoxine and AMP/cAMP in the ΔMomsdh mutant and altered Spitzenkörper organization in the conidia. We concluded that MoMSDH contribute significantly to the pathogenesis of M. oryzae by regulating the mobilization of Spitzenkörper during germ tube morphogenesis, appressoria formation by acting as metabolic switch regulating small branch-chain amino acids, inositol, pyridoxine and AMP/cAMP homeostasis.
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Affiliation(s)
- Justice Norvienyeku
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China.,Fujian-Taiwan Joint Center for Ecological Control of Crop Pests and College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Zhenhui Zhong
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China.,Fujian-Taiwan Joint Center for Ecological Control of Crop Pests and College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Lili Lin
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China.,Fujian-Taiwan Joint Center for Ecological Control of Crop Pests and College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Xie Dang
- Fujian-Taiwan Joint Center for Ecological Control of Crop Pests and College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Meilian Chen
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China.,Fujian-Taiwan Joint Center for Ecological Control of Crop Pests and College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Xiaolian Lin
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China.,Fujian-Taiwan Joint Center for Ecological Control of Crop Pests and College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Honghong Zhang
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Wilfred M Anjago
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Lianyu Lin
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China.,Fujian-Taiwan Joint Center for Ecological Control of Crop Pests and College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Waheed Abdul
- Fujian-Taiwan Joint Center for Ecological Control of Crop Pests and College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Zonghua Wang
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China.,Fujian-Taiwan Joint Center for Ecological Control of Crop Pests and College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China.,College of Ocean Science Minjiang University, Fuzhou 350108, China
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32
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Leidenheimer NJ. Cognate Ligand Chaperoning: a Novel Mechanism for the Post-translational Regulation of Neurotransmitter Receptor Biogenesis. Front Cell Neurosci 2017; 11:245. [PMID: 28860972 PMCID: PMC5559506 DOI: 10.3389/fncel.2017.00245] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 08/02/2017] [Indexed: 11/13/2022] Open
Abstract
The functional unit for inter-neuronal communication in the central nervous system is the neuronal synapse. The number of postsynaptic neurotransmitter receptors at the cell surface is an important determinant of synaptic efficacy and plasticity. A diverse array of post-translational processes regulate postsynaptic receptor number, including receptor exocytosis, lateral diffusion, surface stabilization, endocytosis, and recycling, thus highlighting the importance of mechanisms that control postsynaptic receptor levels. Another putative post-translational mechanism for regulating receptor surface expression is cognate ligand chaperoning. It has been proposed that neurotransmitters function as cognate ligand chaperones by binding, within the endoplasmic reticulum (ER) lumen, to their nascent neurotransmitter receptors and facilitating receptor biogenesis. Here we discuss proof-of-concept evidence that small molecules can selectively facilitate the biogenesis of their targets and examine the specific evidence in support of cognate ligand chaperoning of neurotransmitter receptor biogenesis.
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Affiliation(s)
- Nancy J Leidenheimer
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences CenterShreveport, LA, United States
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33
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A mitochondrial proteomics view of complex I deficiency in Candida albicans. Mitochondrion 2017; 38:48-57. [PMID: 28801230 DOI: 10.1016/j.mito.2017.08.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 08/01/2017] [Accepted: 08/07/2017] [Indexed: 12/28/2022]
Abstract
Proteomic analyses were carried out on isolated mitochondrial samples of C. albicans from gene-deleted mutants (nuo1Δ, nuo2Δ and goa1Δ) as well as the parental strain in order to better understand the contribution of these three fungal-specific mitochondrial ETC complex I (CI) subunits to cellular activities. Herein, we identify 2333 putative proteins from four strains, in which a total of 663 proteins (28.5%) are putatively located in mitochondria. Comparison of protein abundances between mutants and the parental strain reveal 146 differentially-expressed proteins, of which 78 are decreased and 68 are increased in at least one mutant. The common changes across the three mutants include the down-regulation of nuclear-encoded CI subunit proteins as well as phospholipid, ergosterol and cell wall mannan synthesis, and up-regulated proteins in CIV and the alternative oxidase (AOX2). As for gene-specific functions, we find that NUO1 participates in nucleotide synthesis and ribosomal biogenesis; NUO2 is involved in vesicle trafficking; and GOA1 appears to regulate membrane transporter proteins, ROS removal, and substrates trafficking between peroxisomes and mitochondria. The proteomic view of general as well as mutant-specific proteins further extends our understanding of the functional roles of non-mammalian CI-specific subunit proteins in cell processes. Particularly intriguing is the confirmation of a regulatory role for GOA1 on ETC function, a protein found almost exclusively in Candida species. SIGNIFICANCE Fungal mitochondria are critical for fungal pathogenesis. The absence of any of the three fungal specific CI subunits in mitochondria causes an avirulence phenotype of C. albicans in a murine model of invasive disease. As model yeast (Saccharomyces cerevisiae) lacks a CI and is rarely a pathogen of humans, C. albicans is a better choice for establishing a link between mitochondrial CI and pathogenesis. Apart from the general effects of CI mutants on respiration, previous phenotyping of these mutants were quite similar to each other or to CI conservative subunit. By comparison to transcriptional data, the proteomic data obtained in this study indicate that biosynthetic events in each mutant such as cell wall and cell membrane phospholipids and ergosterol are generally decreased in both transcriptomal and translational levels. However, in the case of mitochondrial function, glycolysis/gluconeogenesis, and ROS scavengers, often gene changes are opposite that of proteomic data in mutants. We hypothesize that the loss of energy production in mutants is compensated by increases in protein levels of glycolysis, gluconeogenesis, and anti-ROS scavengers that at least extend mutant survival.
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The role of flavin-containing enzymes in mitochondrial membrane hyperpolarization and ROS production in respiring Saccharomyces cerevisiae cells under heat-shock conditions. Sci Rep 2017; 7:2586. [PMID: 28566714 PMCID: PMC5451409 DOI: 10.1038/s41598-017-02736-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 04/19/2017] [Indexed: 01/01/2023] Open
Abstract
Heat shock is known to accelerate mitochondrial ROS production in Saccharomyces cerevisiae cells. But how yeast mitochondria produce ROS under heat-shock condition is not completely clear. Previously, it was shown that ROS production in heat-stressed fermenting yeast cells was accompanied by mitochondrial membrane potential (MMP) increase. In the current investigation the relationship between ROS production and MMP was studied in respiring yeast cells in stationary phase, using diphenyleneiodonium chloride (DPI), an inhibitor of flavin-containing proteins, as well as the mutants deleted for NDE1, NDE2 and NDI1 genes, encoding flavin-containing external and internal NADH dehydrogenases. It was shown that heat shock induced a transient burst in mitochondrial ROS production, which was paralleled by MMP rise. ROS production and MMP was significantly suppressed by DPI addition and deletion of NDE1. The effect of DPI on ROS production and MMP rise was specific for respiring cells. The results obtained suggest that the functioning of mitochondrial flavin-binding enzymes, Nde1p for instance, is required for the hyperpolarization of inner mitochondrial membrane and ROS production in respiring S. cerevisiae cells under heat-shock conditions.
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35
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Mejía-Barajas JA, Martínez-Mora JA, Salgado-Garciglia R, Noriega-Cisneros R, Ortiz-Avila O, Cortés-Rojo C, Saavedra-Molina A. Electron transport chain in a thermotolerant yeast. J Bioenerg Biomembr 2017; 49:195-203. [PMID: 28181110 DOI: 10.1007/s10863-017-9696-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 01/25/2017] [Indexed: 10/20/2022]
Abstract
Yeasts capable of growing and surviving at high temperatures are regarded as thermotolerant. For appropriate functioning of cellular processes and cell survival, the maintenance of an optimal redox state is critical of reducing and oxidizing species. We studied mitochondrial functions of the thermotolerant Kluyveromyces marxianus SLP1 and the mesophilic OFF1 yeasts, through the evaluation of its mitochondrial membrane potential (ΔΨm), ATPase activity, electron transport chain (ETC) activities, alternative oxidase activity, lipid peroxidation. Mitochondrial membrane potential and the cytoplasmic free Ca2+ ions (Ca2+ cyt) increased in the SLP1 yeast when exposed to high temperature, compared with the mesophilic yeast OFF1. ATPase activity in the mesophilic yeast diminished 80% when exposed to 40° while the thermotolerant SLP1 showed no change, despite an increase in the mitochondrial lipid peroxidation. The SLP1 thermotolerant yeast exposed to high temperature showed a diminution of 33% of the oxygen consumption in state 4. The uncoupled state 3 of oxygen consumption did not change in the mesophilic yeast when it had an increase of temperature, whereas in the thermotolerant SLP1 yeast resulted in an increase of 2.5 times when yeast were grown at 30o, while a decrease of 51% was observed when it was exposed to high temperature. The activities of the ETC complexes were diminished in the SLP1 when exposed to high temperature, but also it was distinguished an alternative oxidase activity. Our results suggest that the mitochondria state, particularly ETC state, is an important characteristic of the thermotolerance of the SLP1 yeast strain.
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Affiliation(s)
- Jorge A Mejía-Barajas
- Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, 58030, Morelia, Michoacán, Mexico
| | - José A Martínez-Mora
- Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, 58030, Morelia, Michoacán, Mexico
| | - Rafael Salgado-Garciglia
- Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, 58030, Morelia, Michoacán, Mexico
| | - Ruth Noriega-Cisneros
- Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, 58030, Morelia, Michoacán, Mexico
| | - Omar Ortiz-Avila
- Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, 58030, Morelia, Michoacán, Mexico
| | - Christian Cortés-Rojo
- Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, 58030, Morelia, Michoacán, Mexico
| | - Alfredo Saavedra-Molina
- Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, 58030, Morelia, Michoacán, Mexico.
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Nižnanský Ľ, Varečka Ľ, Kryštofová S. Disruption of GABA shunt affects Trichoderma atroviride response to nutritional and environmental stimuli. ACTA CHIMICA SLOVACA 2016. [DOI: 10.1515/acs-2016-0019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
The fungus Trichoderma atroviride is a member of the genus Trichoderma to which belong many species known for high cellulase production, formation of various antibiotics, plant biocontrol and antagonistic activities against other fungi. Deletion of T. atroviride glutamate decarboxylase gene gad caused minor defects in germination, hyphal branching, slower growth and disruption of conidiation pattern. GABA can be used by fungi as a secondary carbon source and as a primary nitrogen source. We analyzed the effect of different nutrient compositions and environmental conditions (light and temperature) on growth and development of T. atroviride in strains defective in the functional GAD. The gad mutants grown on NH4NO3 as a sole carbon source grew slower and formed conidiation bands closer to each other which was clearly demonstrated during their cultivation in race tubes. The gad mutants exhibited slightly lower apical extension growth rate at the room temperature but their apical extension rate dropped significantly at 30 °C. Higher temperature had also inhibitory effect on gad mutant conidiation, whereas 30 °C seems optimal temperature for the parental strain. The optimal temperature for gad mutant conidiation was lower than in F534, about 25 °C.
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Affiliation(s)
- Ľuboš Nižnanský
- Institute of Forensic Medicine, Faculty of Medicine, Comenius University in Bratislava
- Institute of Biochemistry and Microbiology, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava
| | - Ľudovít Varečka
- Institute of Biochemistry and Microbiology, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava
| | - Svetlana Kryštofová
- Institute of Biochemistry and Microbiology, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava
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Mekonnen DW, Ludewig F. Phenotypic and chemotypic studies using Arabidopsis and yeast reveal that GHB converts to SSA and induce toxicity. PLANT MOLECULAR BIOLOGY 2016; 91:429-40. [PMID: 27037708 DOI: 10.1007/s11103-016-0475-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 03/29/2016] [Indexed: 05/04/2023]
Abstract
γ-Hydroxybutyric acid (GHB) is a naturally occurring compound. It is detected in organisms such as yeasts, plants and mammals. GHB is produced from the reduction of succinic semialdehyde (SSA) by the activity of GHB dehydrogenase. Arabidopsis genome contains two GHB dehydrogenase encoding genes. The accumulation of GHB in ssadh mutants led to the speculation that GHB is the cause of aberrant phenotypes. Conversely, the accumulation of GHB in Arabidopsis plants subjected to abiotic stresses was described as a way of avoiding SSA induced damage. To resolve these contrasting views on GHB, we examined the effect of exogenous GHB and SSA on the growth of yeast and Arabidopsis plants. GHB concentrations up to 1.5 mM didn't affect shoots of Arabidopsis plants; however, root growth was inhibited. In contrast, 0.3 mM SSA has severely affected the growth of plants. Treatment of yeast wild-type strain with 10 mM SSA and 10 mM GHB didn't affect the growth. However, the growth of yeast uga2 mutant was greatly inhibited by the same concentration of SSA, but not GHB. Metabolic analysis and enzyme activity assay on native gel showed that Arabidopsis, but not yeast, possesses a GHB dehydrogenase activity that converts GHB back to SSA. The enzymatic assay has also indicated the existence of an additional GHB dehydrogenase encoding gene(s) in Arabidopsis genome. Taken together, we conclude that GHB is less toxic than SSA. Its accumulation in ssadh mutants and during abiotic stresses is a response to avoid the SSA induced damage.
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Affiliation(s)
- Dereje Worku Mekonnen
- Cologne Biocenter, Botanical Institute II, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany.
| | - Frank Ludewig
- Cologne Biocenter, Botanical Institute II, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany
- Division of Biochemistry, Department Biology, University Erlangen-Nuremberg, Staudtstr. 5, 91058, Erlangen, Germany
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Han S, Liu Y, Xie L, Zhu B, Hu Y. Comparative expression profiling of genes involved in primary metabolism in high-yield and wild-type strains of Acremonium chrysogenum. Antonie van Leeuwenhoek 2015; 109:357-69. [PMID: 26708072 DOI: 10.1007/s10482-015-0638-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 12/17/2015] [Indexed: 11/26/2022]
Abstract
Cephalosporin C (CPC) productivity of Acremonium chrysogenum has been improved significantly through classical strain improvement programs. Here, we used transcription and metabolite profiling to address mechanisms underlying CPC production in a high yield (HY) strain. Transcription and metabolite profiling indicated that enzymes involved in amino acid production are higher in abundance in the HY strain. Moreover, results indicate a higher flow of precursors from the glycolysis and gluconeogenesis pathways to serine synthesis at the late stage of fermentation in the HY strain. In addition, less pyruvate would enter the TCA cycle thus favoring valine synthesis. Amino acid production would also benefit from a more active pentose phosphate pathway and γ-amino butyric acid shunt both generating NADPH. Moreover the glyoxylate pathway seems to be more active in the HY strain. These results may provide new leads for CPC strain improvement in industry.
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Affiliation(s)
- Shu Han
- Shanghai Institute of Pharmaceutical Industry, 1320 Beijing Road (W), Shanghai, 200040, China
- China State Institute of Pharmaceutical Industry, Zhangjiang Institute, 285 Gebaini Road, Shanghai, 201203, China
| | - Yan Liu
- China State Institute of Pharmaceutical Industry, Zhangjiang Institute, 285 Gebaini Road, Shanghai, 201203, China
| | - Liping Xie
- China State Institute of Pharmaceutical Industry, Zhangjiang Institute, 285 Gebaini Road, Shanghai, 201203, China
| | - Baoquan Zhu
- Shanghai Institute of Pharmaceutical Industry, 1320 Beijing Road (W), Shanghai, 200040, China
| | - Youjia Hu
- China State Institute of Pharmaceutical Industry, Zhangjiang Institute, 285 Gebaini Road, Shanghai, 201203, China.
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39
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Parente AF, Naves PE, Pigosso LL, Casaletti L, McEwen JG, Parente-Rocha JA, Soares CM. The response of Paracoccidioides spp. to nitrosative stress. Microbes Infect 2015; 17:575-85. [DOI: 10.1016/j.micinf.2015.03.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Revised: 03/05/2015] [Accepted: 03/23/2015] [Indexed: 01/14/2023]
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40
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Pyatrikas DV, Fedoseeva IV, Varakina NN, Rusaleva TM, Stepanov AV, Fedyaeva AV, Borovskii GB, Rikhvanov EG. Relation between cell death progression, reactive oxygen species production and mitochondrial membrane potential in fermenting Saccharomyces cerevisiae cells under heat-shock conditions. FEMS Microbiol Lett 2015; 362:fnv082. [DOI: 10.1093/femsle/fnv082] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/13/2015] [Indexed: 12/21/2022] Open
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41
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Wang P, Eshaq RS, Meshul CK, Moore C, Hood RL, Leidenheimer NJ. Neuronal gamma-aminobutyric acid (GABA) type A receptors undergo cognate ligand chaperoning in the endoplasmic reticulum by endogenous GABA. Front Cell Neurosci 2015; 9:188. [PMID: 26041994 PMCID: PMC4435044 DOI: 10.3389/fncel.2015.00188] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 04/28/2015] [Indexed: 01/01/2023] Open
Abstract
GABAA receptors mediate fast inhibitory neurotransmission in the brain. Dysfunction of these receptors is associated with various psychiatric/neurological disorders and drugs targeting this receptor are widely used therapeutic agents. Both the efficacy and plasticity of GABAA receptor-mediated neurotransmission depends on the number of surface GABAA receptors. An understudied aspect of receptor cell surface expression is the post-translational regulation of receptor biogenesis within the endoplasmic reticulum (ER). We have previously shown that exogenous GABA can act as a ligand chaperone of recombinant GABAA receptors in the early secretory pathway leading us to now investigate whether endogenous GABA facilitates the biogenesis of GABAA receptors in primary cerebral cortical cultures. In immunofluorescence labeling experiments, we have determined that neurons expressing surface GABAA receptors contain both GABA and its degradative enzyme GABA transaminase (GABA-T). Treatment of neurons with GABA-T inhibitors, a treatment known to increase intracellular GABA levels, decreases the interaction of the receptor with the ER quality control protein calnexin, concomittantly increasing receptor forward-trafficking and plasma membrane insertion. The effect of GABA-T inhibition on the receptor/calnexin interaction is not due to the activation of surface GABAA or GABAB receptors. Consistent with our hypothesis that GABA acts as a cognate ligand chaperone in the ER, immunogold-labeling of rodent brain slices reveals the presence of GABA within the rough ER. The density of this labeling is similar to that present in mitochondria, the organelle in which GABA is degraded. Lastly, the effect of GABA-T inhibition on the receptor/calnexin interaction was prevented by pretreatment with a GABA transporter inhibitor. Together, these data indicate that endogenous GABA acts in the rough ER as a cognate ligand chaperone to facilitate the biogenesis of neuronal GABAA receptors.
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Affiliation(s)
- Ping Wang
- Department of Biochemistry and Molecular Biology, Louisiana State University, Health Sciences Center-Shreveport Shreveport, LA, USA
| | - Randa S Eshaq
- Department of Biochemistry and Molecular Biology, Louisiana State University, Health Sciences Center-Shreveport Shreveport, LA, USA
| | - Charles K Meshul
- Veterans Hospital Portland/Research Services/Neurocytology Laboratory and Department of Behavioral Neuroscience, Oregon Health & Science University Portland, OR, USA
| | - Cynthia Moore
- Veterans Hospital Portland/Research Services/Neurocytology Laboratory and Department of Behavioral Neuroscience, Oregon Health & Science University Portland, OR, USA
| | - Rebecca L Hood
- Veterans Hospital Portland/Research Services/Neurocytology Laboratory and Department of Behavioral Neuroscience, Oregon Health & Science University Portland, OR, USA
| | - Nancy J Leidenheimer
- Department of Biochemistry and Molecular Biology, Louisiana State University, Health Sciences Center-Shreveport Shreveport, LA, USA
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42
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Liu L, Pan A, Spofford C, Zhou N, Alper HS. An evolutionary metabolic engineering approach for enhancing lipogenesis in Yarrowia lipolytica. Metab Eng 2015; 29:36-45. [DOI: 10.1016/j.ymben.2015.02.003] [Citation(s) in RCA: 97] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2014] [Revised: 01/27/2015] [Accepted: 02/16/2015] [Indexed: 12/29/2022]
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43
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Galvez Rojas RL, Ahn IY, Suárez Mantilla B, Sant'Anna C, Pral EMF, Silber AM. The Uptake of GABA in Trypanosoma cruzi. J Eukaryot Microbiol 2015; 62:629-36. [PMID: 25851259 DOI: 10.1111/jeu.12219] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Revised: 01/12/2015] [Accepted: 02/02/2015] [Indexed: 12/27/2022]
Abstract
Gamma aminobutyric acid (GABA) is widely known as a neurotransmitter and signal transduction molecule found in vertebrates, plants, and some protozoan organisms. However, the presence of GABA and its role in trypanosomatids is unknown. Here, we report the presence of intracellular GABA and the biochemical characterization of its uptake in Trypanosoma cruzi, the etiological agent of Chagas' disease. Kinetic parameters indicated that GABA is taken up by a single transport system in pathogenic and nonpathogenic forms. Temperature dependence assays showed a profile similar to glutamate transport, but the effect of extracellular cations Na(+) , K(+) , and H(+) on GABA uptake differed, suggesting a different uptake mechanism. In contrast to reports for other amino acid transporters in T. cruzi, GABA uptake was Na(+) dependent and increased with pH, with a maximum activity at pH 8.5. The sensitivity to oligomycin showed that GABA uptake is dependent on ATP synthesis. These data point to a secondary active Na(+) /GABA symporter energized by Na(+) -exporting ATPase. Finally, we show that GABA occurs in the parasite's cytoplasm under normal culture conditions, indicating that it is regularly taken up from the culture medium or synthesized through an still undescribed metabolic pathway.
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Affiliation(s)
- Robert L Galvez Rojas
- Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Il-Young Ahn
- Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Brian Suárez Mantilla
- Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Celso Sant'Anna
- Instituto Nacional de Metrologia (INMetro), Rio de Janeiro, Brazil
| | | | - Ariel Mariano Silber
- Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
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Wan C, Zhang M, Fang Q, Xiong L, Zhao X, Hasunuma T, Bai F, Kondo A. The impact of zinc sulfate addition on the dynamic metabolic profiling of Saccharomyces cerevisiae subjected to long term acetic acid stress treatment and identification of key metabolites involved in the antioxidant effect of zinc. Metallomics 2015; 7:322-32. [DOI: 10.1039/c4mt00275j] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Zinc modulates cellular amino acid metabolism and redox balance to exert its antioxidant effect.
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Affiliation(s)
- Chun Wan
- School of Life Science and Biotechnology
- Dalian University of Technology
- Dalian 116024, China
| | - Mingming Zhang
- School of Life Science and Biotechnology
- Dalian University of Technology
- Dalian 116024, China
| | - Qing Fang
- School of Life Science and Biotechnology
- Dalian University of Technology
- Dalian 116024, China
| | - Liang Xiong
- School of Life Science and Biotechnology
- Dalian University of Technology
- Dalian 116024, China
| | - Xinqing Zhao
- School of Life Science and Biotechnology
- Dalian University of Technology
- Dalian 116024, China
- School of Life Science and Biotechnology
- Shanghai Jiaotong University
| | - Tomohisa Hasunuma
- Organization of Advanced Science and Technology
- Kobe University
- Kobe 657-8501, Japan
| | - Fengwu Bai
- School of Life Science and Biotechnology
- Dalian University of Technology
- Dalian 116024, China
- School of Life Science and Biotechnology
- Shanghai Jiaotong University
| | - Akihiko Kondo
- Department of Chemical Science and Engineering
- Graduate School of Engineering
- Kobe University
- Kobe 657-8501, Japan
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Lertwattanasakul N, Kosaka T, Hosoyama A, Suzuki Y, Rodrussamee N, Matsutani M, Murata M, Fujimoto N, Tsuchikane K, Limtong S, Fujita N, Yamada M. Genetic basis of the highly efficient yeast Kluyveromyces marxianus: complete genome sequence and transcriptome analyses. BIOTECHNOLOGY FOR BIOFUELS 2015; 8:47. [PMID: 25834639 PMCID: PMC4381506 DOI: 10.1186/s13068-015-0227-x] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 02/19/2015] [Indexed: 05/07/2023]
Abstract
BACKGROUND High-temperature fermentation technology with thermotolerant microbes has been expected to reduce the cost of bioconversion of cellulosic biomass to fuels or chemicals. Thermotolerant Kluyveromyces marxianus possesses intrinsic abilities to ferment and assimilate a wide variety of substrates including xylose and to efficiently produce proteins. These capabilities have been found to exceed those of the traditional ethanol producer Saccharomyces cerevisiae or lignocellulose-bioconvertible ethanologenic Scheffersomyces stipitis. RESULTS The complete genome sequence of K. marxianus DMKU 3-1042 as one of the most thermotolerant strains in the same species has been determined. A comparison of its genomic information with those of other yeasts and transcriptome analysis revealed that the yeast bears beneficial properties of temperature resistance, wide-range bioconversion ability, and production of recombinant proteins. The transcriptome analysis clarified distinctive metabolic pathways under three different growth conditions, static culture, high temperature, and xylose medium, in comparison to the control condition of glucose medium under a shaking condition at 30°C. Interestingly, the yeast appears to overcome the issue of reactive oxygen species, which tend to accumulate under all three conditions. CONCLUSIONS This study reveals many gene resources for the ability to assimilate various sugars in addition to species-specific genes in K. marxianus, and the molecular basis of its attractive traits for industrial applications including high-temperature fermentation. Especially, the thermotolerance trait may be achieved by an integrated mechanism consisting of various strategies. Gene resources and transcriptome data of the yeast are particularly useful for fundamental and applied researches for innovative applications.
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Affiliation(s)
- Noppon Lertwattanasakul
- />Applied Molecular Bioscience, Graduate School of Medicine, Yamaguchi University, Ube, 755-8505 Japan
- />Department of Microbiology, Faculty of Science, Kasetsart University, Bangkok, 10900 Thailand
| | - Tomoyuki Kosaka
- />Department of Biological Chemistry, Faculty of Agriculture, Yamaguchi University, Yamaguchi, 753-8515 Japan
| | - Akira Hosoyama
- />National Institute of Technology and Evaluation, Shibuya-ku, Tokyo 151-0066 Japan
| | - Yutaka Suzuki
- />Department of Medical Genome Sciences, The University of Tokyo, Chiba, 277-8562 Japan
| | - Nadchanok Rodrussamee
- />Applied Molecular Bioscience, Graduate School of Medicine, Yamaguchi University, Ube, 755-8505 Japan
- />Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai, 50200 Thailand
| | - Minenosuke Matsutani
- />Department of Biological Chemistry, Faculty of Agriculture, Yamaguchi University, Yamaguchi, 753-8515 Japan
| | - Masayuki Murata
- />Applied Molecular Bioscience, Graduate School of Medicine, Yamaguchi University, Ube, 755-8505 Japan
| | - Naoko Fujimoto
- />Applied Molecular Bioscience, Graduate School of Medicine, Yamaguchi University, Ube, 755-8505 Japan
| | - Keiko Tsuchikane
- />National Institute of Technology and Evaluation, Shibuya-ku, Tokyo 151-0066 Japan
| | - Savitree Limtong
- />Department of Microbiology, Faculty of Science, Kasetsart University, Bangkok, 10900 Thailand
| | - Nobuyuki Fujita
- />National Institute of Technology and Evaluation, Shibuya-ku, Tokyo 151-0066 Japan
| | - Mamoru Yamada
- />Applied Molecular Bioscience, Graduate School of Medicine, Yamaguchi University, Ube, 755-8505 Japan
- />Department of Biological Chemistry, Faculty of Agriculture, Yamaguchi University, Yamaguchi, 753-8515 Japan
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Cao J, Singh NK, Locy RD. Characterization of the recombinant succinic semi-aldehyde dehydrogenase from Saccharomyces cerevisiae. Yeast 2014; 31:411-20. [PMID: 25092794 DOI: 10.1002/yea.3035] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Revised: 07/22/2014] [Accepted: 07/27/2014] [Indexed: 11/12/2022] Open
Abstract
The yeast succinic semi-aldehyde dehydrogenase gene (SSADH; EC 1.2.1.16) was cloned and overexpressed in Escherichia coli. Based on SDS-PAGE, the molecular mass of the subunit was around 54 kDa, and the purified recombinant enzyme had a tetrameric molecular mass of ca. 200 kDa. The specific activity of the recombinant enzyme was 1.90 µM NADH formed/min/mg, and showed maximal activity at pH 8.4. The recombinant protein was highly specific for succinate semi-aldehyde (Km = 15.48 ± 0.14 µM) and could use both NAD(+) and NADP(+) as co-factors, with Km values of 579.06 ± 30.1 µM and 1.017 ± 0.46 mM, respectively. Initial velocity studies showed that NADH was a competitive inhibitor with respect to NAD(+) (Ki = 129.5 µM) but a non-competitive inhibitor with respect to succinate semi-aldehyde. Adenine nucleotides of AMP, ADP and ATP inhibited yeast SSADH activity with Ki = 1.13-10.2 mM, and showed competitive inhibition with respect to NAD(+) and mixed-competitive, non-competitive and non-competitive inhibition, respectively, with respect to succinate semi-aldehyde. The kinetic data suggest a 'ping-pong' mechanism.
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Affiliation(s)
- Juxiang Cao
- Department of Biological Sciences, Auburn University, AL, USA; Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
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47
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Tomita H, Yokooji Y, Ishibashi T, Imanaka T, Atomi H. An archaeal glutamate decarboxylase homolog functions as an aspartate decarboxylase and is involved in β-alanine and coenzyme A biosynthesis. J Bacteriol 2014. [PMID: 24415726 DOI: 10.1128/jb.01327-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2023] Open
Abstract
β-Alanine is a precursor for coenzyme A (CoA) biosynthesis and is a substrate for the bacterial/eukaryotic pantothenate synthetase and archaeal phosphopantothenate synthetase. β-Alanine is synthesized through various enzymes/pathways in bacteria and eukaryotes, including the direct decarboxylation of Asp by aspartate 1-decarboxylase (ADC), the degradation of pyrimidine, or the oxidation of polyamines. However, in most archaea, homologs of these enzymes are not present; thus, the mechanisms of β-alanine biosynthesis remain unclear. Here, we performed a biochemical and genetic study on a glutamate decarboxylase (GAD) homolog encoded by TK1814 from the hyperthermophilic archaeon Thermococcus kodakarensis. GADs are distributed in all three domains of life, generally catalyzing the decarboxylation of Glu to γ-aminobutyrate (GABA). The recombinant TK1814 protein displayed not only GAD activity but also ADC activity using pyridoxal 5'-phosphate as a cofactor. Kinetic studies revealed that the TK1814 protein prefers Asp as its substrate rather than Glu, with nearly a 20-fold difference in catalytic efficiency. Gene disruption of TK1814 resulted in a strain that could not grow in standard medium. Addition of β-alanine, 4'-phosphopantothenate, or CoA complemented the growth defect, whereas GABA could not. Our results provide genetic evidence that TK1814 functions as an ADC in T. kodakarensis, providing the β-alanine necessary for CoA biosynthesis. The results also suggest that the GAD activity of TK1814 is not necessary for growth, at least under the conditions applied in this study. TK1814 homologs are distributed in a wide range of archaea and may be responsible for β-alanine biosynthesis in these organisms.
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Affiliation(s)
- Hiroya Tomita
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, Japan
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48
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An archaeal glutamate decarboxylase homolog functions as an aspartate decarboxylase and is involved in β-alanine and coenzyme A biosynthesis. J Bacteriol 2014; 196:1222-30. [PMID: 24415726 DOI: 10.1128/jb.01327-13] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
β-Alanine is a precursor for coenzyme A (CoA) biosynthesis and is a substrate for the bacterial/eukaryotic pantothenate synthetase and archaeal phosphopantothenate synthetase. β-Alanine is synthesized through various enzymes/pathways in bacteria and eukaryotes, including the direct decarboxylation of Asp by aspartate 1-decarboxylase (ADC), the degradation of pyrimidine, or the oxidation of polyamines. However, in most archaea, homologs of these enzymes are not present; thus, the mechanisms of β-alanine biosynthesis remain unclear. Here, we performed a biochemical and genetic study on a glutamate decarboxylase (GAD) homolog encoded by TK1814 from the hyperthermophilic archaeon Thermococcus kodakarensis. GADs are distributed in all three domains of life, generally catalyzing the decarboxylation of Glu to γ-aminobutyrate (GABA). The recombinant TK1814 protein displayed not only GAD activity but also ADC activity using pyridoxal 5'-phosphate as a cofactor. Kinetic studies revealed that the TK1814 protein prefers Asp as its substrate rather than Glu, with nearly a 20-fold difference in catalytic efficiency. Gene disruption of TK1814 resulted in a strain that could not grow in standard medium. Addition of β-alanine, 4'-phosphopantothenate, or CoA complemented the growth defect, whereas GABA could not. Our results provide genetic evidence that TK1814 functions as an ADC in T. kodakarensis, providing the β-alanine necessary for CoA biosynthesis. The results also suggest that the GAD activity of TK1814 is not necessary for growth, at least under the conditions applied in this study. TK1814 homologs are distributed in a wide range of archaea and may be responsible for β-alanine biosynthesis in these organisms.
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Ramond E, Gesbert G, Rigard M, Dairou J, Dupuis M, Dubail I, Meibom K, Henry T, Barel M, Charbit A. Glutamate utilization couples oxidative stress defense and the tricarboxylic acid cycle in Francisella phagosomal escape. PLoS Pathog 2014; 10:e1003893. [PMID: 24453979 PMCID: PMC3894225 DOI: 10.1371/journal.ppat.1003893] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Accepted: 12/05/2013] [Indexed: 11/18/2022] Open
Abstract
Intracellular bacterial pathogens have developed a variety of strategies to avoid degradation by the host innate immune defense mechanisms triggered upon phagocytocis. Upon infection of mammalian host cells, the intracellular pathogen Francisella replicates exclusively in the cytosolic compartment. Hence, its ability to escape rapidly from the phagosomal compartment is critical for its pathogenicity. Here, we show for the first time that a glutamate transporter of Francisella (here designated GadC) is critical for oxidative stress defense in the phagosome, thus impairing intra-macrophage multiplication and virulence in the mouse model. The gadC mutant failed to efficiently neutralize the production of reactive oxygen species. Remarkably, virulence of the gadC mutant was partially restored in mice defective in NADPH oxidase activity. The data presented highlight links between glutamate uptake, oxidative stress defense, the tricarboxylic acid cycle and phagosomal escape. This is the first report establishing the role of an amino acid transporter in the early stage of the Francisella intracellular lifecycle.
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Affiliation(s)
- Elodie Ramond
- Université Paris Descartes, Sorbonne Paris Cité, Bâtiment Leriche, Paris, France
- INSERM, U1002, Unité de Pathogénie des Infections Systémiques, Paris, France
| | - Gael Gesbert
- Université Paris Descartes, Sorbonne Paris Cité, Bâtiment Leriche, Paris, France
- INSERM, U1002, Unité de Pathogénie des Infections Systémiques, Paris, France
| | - Mélanie Rigard
- Centre international de recherche en infectiologie, Université de Lyon, Lyon, France
- Bacterial Pathogenesis and Innate Immunity Laboratory, INSERM U851 “Immunity, Infection and Vaccination”, Lyon, France
| | - Julien Dairou
- Platform “Bioprofiler” Université Paris Diderot, Paris, France
| | - Marion Dupuis
- Université Paris Descartes, Sorbonne Paris Cité, Bâtiment Leriche, Paris, France
- INSERM, U1002, Unité de Pathogénie des Infections Systémiques, Paris, France
| | - Iharilalao Dubail
- Université Paris Descartes, Sorbonne Paris Cité, Bâtiment Leriche, Paris, France
- INSERM, U1002, Unité de Pathogénie des Infections Systémiques, Paris, France
| | - Karin Meibom
- Université Paris Descartes, Sorbonne Paris Cité, Bâtiment Leriche, Paris, France
- INSERM, U1002, Unité de Pathogénie des Infections Systémiques, Paris, France
| | - Thomas Henry
- Centre international de recherche en infectiologie, Université de Lyon, Lyon, France
- Bacterial Pathogenesis and Innate Immunity Laboratory, INSERM U851 “Immunity, Infection and Vaccination”, Lyon, France
| | - Monique Barel
- Université Paris Descartes, Sorbonne Paris Cité, Bâtiment Leriche, Paris, France
- INSERM, U1002, Unité de Pathogénie des Infections Systémiques, Paris, France
| | - Alain Charbit
- Université Paris Descartes, Sorbonne Paris Cité, Bâtiment Leriche, Paris, France
- INSERM, U1002, Unité de Pathogénie des Infections Systémiques, Paris, France
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50
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Cao J, Barbosa JM, Singh N, Locy RD. GABA transaminases from Saccharomyces cerevisiae and Arabidopsis thaliana complement function in cytosol and mitochondria. Yeast 2013; 30:279-89. [PMID: 23740823 DOI: 10.1002/yea.2962] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 05/23/2013] [Accepted: 05/29/2013] [Indexed: 11/09/2022] Open
Abstract
GABA transaminase (GABA-T) catalyses the conversion of GABA to succinate semialdehyde (SSA) in the GABA shunt pathway. The GABA-T from Saccharomyces cerevisiae (ScGABA-TKG) is an α-ketoglutarate-dependent enzyme encoded by the UGA1 gene, while higher plant GABA-T is a pyruvate/glyoxylate-dependent enzyme encoded by POP2 in Arabidopsis thaliana (AtGABA-T). The GABA-T from A. thaliana is localized in mitochondria and mediated by an 18-amino acid N-terminal mitochondrial targeting peptide predicated by both web-based utilities TargetP 1.1 and PSORT. Yeast UGA1 appears to lack a mitochondrial targeting peptide and is localized in the cytosol. To verify this bioinformatic analysis and examine the significance of ScGABA-TKG and AtGABA-T compartmentation and substrate specificity on physiological function, expression vectors were constructed to modify both ScGABA-TKG and AtGABA-T, so that they express in yeast mitochondria and cytosol. Physiological function was evaluated by complementing yeast ScGABA-TKG deletion mutant Δuga1 with AtGABA-T or ScGABA-TKG targeted to the cytosol or mitochondria for the phenotypes of GABA growth defect, thermosensitivity and heat-induced production of reactive oxygen species (ROS). This study demonstrates that AtGABA-T is functionally interchangeable with ScGABA-TKG for GABA growth, thermotolerance and limiting production of ROS, regardless of location in mitochondria or cytosol of yeast cells, but AtGABA-T is about half as efficient in doing so as ScGABA-TKG. These results are consistent with the hypothesis that pyruvate/glyoxylate-limited production of NADPH mediates the effect of the GABA shunt in moderating heat stress in Saccharomyces.
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Affiliation(s)
- Juxiang Cao
- Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA
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