1
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Schade R, Butler DSC, McKenna JA, Di Luccia B, Shokoohi V, Hamblin M, Pham THM, Monack DM. Transcriptional profiling links unique human macrophage phenotypes to the growth of intracellular Salmonella enterica serovar Typhi. Sci Rep 2024; 14:12811. [PMID: 38834738 PMCID: PMC11150401 DOI: 10.1038/s41598-024-63588-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Accepted: 05/30/2024] [Indexed: 06/06/2024] Open
Abstract
Macrophages provide a crucial environment for Salmonella enterica serovar Typhi (S. Typhi) to multiply during typhoid fever, yet our understanding of how human macrophages and S. Typhi interact remains limited. In this study, we delve into the dynamics of S. Typhi replication within human macrophages and the resulting heterogeneous transcriptomic responses of macrophages during infection. Our study reveals key factors that influence macrophage diversity, uncovering distinct immune and metabolic pathways associated with different stages of S. Typhi intracellular replication in macrophages. Of note, we found that macrophages harboring replicating S. Typhi are skewed towards an M1 pro-inflammatory state, whereas macrophages containing non-replicating S. Typhi exhibit neither a distinct M1 pro-inflammatory nor M2 anti-inflammatory state. Additionally, macrophages with replicating S. Typhi were characterized by the increased expression of genes associated with STAT3 phosphorylation and the activation of the STAT3 transcription factor. Our results shed light on transcriptomic pathways involved in the susceptibility of human macrophages to intracellular S. Typhi replication, thereby providing crucial insight into host phenotypes that restrict and support S. Typhi infection.
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Affiliation(s)
- Ruth Schade
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Daniel S C Butler
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Joy A McKenna
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Blanda Di Luccia
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Vida Shokoohi
- Stanford Functional Genomics Facility, Stanford University, Stanford, CA, USA
| | - Meagan Hamblin
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Trung H M Pham
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA
| | - Denise M Monack
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, 94305, USA.
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2
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Lim SL, Liu J, Dupouy G, Singh G, Baudrey S, Yang L, Zhong JY, Chabouté ME, Lim BL. In planta imaging of pyridine nucleotides using second-generation fluorescent protein biosensors. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2024. [PMID: 38761168 DOI: 10.1111/tpj.16796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 04/11/2024] [Accepted: 04/24/2024] [Indexed: 05/20/2024]
Abstract
Redox changes of pyridine nucleotides in cellular compartments are highly dynamic and their equilibria are under the influence of various reducing and oxidizing reactions. To obtain spatiotemporal data on pyridine nucleotides in living plant cells, typical biochemical approaches require cell destruction. To date, genetically encoded fluorescent biosensors are considered to be the best option to bridge the existing technology gap, as they provide a fast, accurate, and real-time readout. However, the existing pyridine nucleotides genetically encoded fluorescent biosensors are either sensitive to pH change or slow in dissociation rate. Herein, we employed the biosensors which generate readouts that are pH stable for in planta measurement of NADH/NAD+ ratio and NADPH level. We generated transgenic Arabidopsis lines that express these biosensors in plastid stroma and cytosol of whole plants and pollen tubes under the control of CaMV 35S and LAT52 promoters, respectively. These transgenic biosensor lines allow us to monitor real-time dynamic changes in NADH/NAD+ ratio and NADPH level in the plastids and cytosol of various plant tissues, including pollen tubes, root hairs, and mesophyll cells, using a variety of fluorescent instruments. We anticipate that these valuable transgenic lines may allow improvements in plant redox biology studies.
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Affiliation(s)
- Shey-Li Lim
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - Jinhong Liu
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - Gilles Dupouy
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, Strasbourg, 67084, France
| | - Gaurav Singh
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, Strasbourg, 67084, France
| | - Stéphanie Baudrey
- Architecture et Réactivité de l'ARN, Université de Strasbourg, CNRS, UPR 9002, Strasbourg, 67000, France
| | - Lang Yang
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - Jia Yi Zhong
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - Marie-Edith Chabouté
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, Strasbourg, 67084, France
| | - Boon Leong Lim
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
- HKU Shenzhen Institute of Research and Innovation, Shenzhen, China
- State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong, China
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3
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Fristot E, Cambray G, Bonnet J. LactoSpanks: A Collection of IPTG Inducible Promoters for the Commensal Lactic Acid Bacteria Lactobacillus gasseri. ACS Synth Biol 2024; 13:951-957. [PMID: 38335132 DOI: 10.1021/acssynbio.3c00438] [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] [Indexed: 02/12/2024]
Abstract
Lactic acid bacteria (LAB) are important for many biotechnological applications such as bioproduction and engineered probiotics for therapy. Inducible promoters are key gene expression control elements, yet those available in LAB are mainly based on bacteriocin systems and have many drawbacks, including large gene clusters, costly inducer peptides, and little portability to in vivo settings. Using Lactobacillus gasseri, a model commensal bacteria from the human gut, we report the engineering of synthetic LactoSpanks promoters (Pls), a collection of variable strength inducible promoters controlled by the LacI repressor from E. coli and induced by isopropyl β-d-1-thiogalactopyranoside (IPTG). We first show that the Phyper-spank promoter from Bacillus subtilis is functional in L. gasseri, albeit with substantial leakage. We then construct and screen a semirational library of Phyper-spank variants to select a set of four IPTG-inducible promoters that span a range of expression levels and exhibit reduced leakages and operational dynamic ranges (from ca. 9 to 28 fold-change). With their low genetic footprint and simplicity of use, LactoSpanks will support many applications in L. gasseri, and potentially other lactic acid and Gram-positive bacteria.
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Affiliation(s)
- Elsa Fristot
- Centre de Biologie Structurale (CBS), University of Montpellier, INSERM U1054, CNRS UMR 5048, 34090 Montpellier, France
| | - Guillaume Cambray
- Centre de Biologie Structurale (CBS), University of Montpellier, INSERM U1054, CNRS UMR 5048, 34090 Montpellier, France
- Diversité des Génomes et Interactions Microorganismes Insectes (DGIMI), University of Montpellier, INRAE UMR1333, 34090 Montpellier, France
| | - Jerome Bonnet
- Centre de Biologie Structurale (CBS), University of Montpellier, INSERM U1054, CNRS UMR 5048, 34090 Montpellier, France
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4
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Augenstreich J, Shuster M, Fan Y, Lyu Z, Ling J, Briken V. BBQ methods: streamlined workflows for bacterial burden quantification in infected cells by confocal microscopy. Biol Open 2024; 13:bio060189. [PMID: 38156988 PMCID: PMC10836645 DOI: 10.1242/bio.060189] [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: 10/31/2023] [Accepted: 12/18/2023] [Indexed: 01/03/2024] Open
Abstract
Accurate quantification of bacterial burden within macrophages, termed bacterial burden quantification (BBQ), is crucial for understanding host-pathogen interactions. Various methods have been employed, each with strengths and weaknesses. This article addresses limitations in existing techniques and introduces two novel, automated methods for BBQ within macrophages based on confocal microscopy data analysis. The first method refines total fluorescence quantification by incorporating filtering steps to exclude uninfected cells, while the second method calculates total bacterial volume per cell to mitigate potential biases in fluorescence-based readouts. These workflows utilize PyImageJ and Cellpose software, providing reliable, unbiased, and rapid quantification of bacterial load. The proposed workflows were validated using Salmonella enterica serovar Typhimurium and Mycobacterium tuberculosis models, demonstrating their effectiveness in accurately assessing bacterial burden. These automated workflows offer valuable tools for studying bacterial interactions within host cells and provide insights for various research applications.
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Affiliation(s)
- Jacques Augenstreich
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | - Michael Shuster
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | - Yongqiang Fan
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | - Zhihui Lyu
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | - Jiqiang Ling
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | - Volker Briken
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
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5
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Augenstreich J, Shuster M, Fan Y, Lyu Z, Ling J, Briken V. BBQ methods: Streamlined workflows for Bacterial Burden Quantification in infected cells by confocal microscopy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.01.560379. [PMID: 37873092 PMCID: PMC10592879 DOI: 10.1101/2023.10.01.560379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Accurate quantification of bacterial burden within macrophages, termed Bacterial Burden Quantification (BBQ), is crucial for understanding host-pathogen interactions. Various methods have been employed, each with strengths and weaknesses. This article addresses limitations in existing techniques and introduces two novel automated methods for BBQ within macrophages based on confocal microscopy data analysis. The first method refines total fluorescence quantification by incorporating filtering steps to exclude uninfected cells, while the second method calculates total bacterial volume per cell to mitigate potential biases in fluorescence-based readouts. These workflows utilize PyImageJ and Cellpose software, providing reliable, unbiased, and rapid quantification of bacterial load. The proposed workflows were validated using Salmonella enterica serovar Typhimurium and Mycobacterium tuberculosis models, demonstrating their effectiveness in accurately assessing bacterial burden. These automated workflows offer valuable tools for studying bacterial interactions within host cells and provide insights for various research applications.
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Affiliation(s)
- Jacques Augenstreich
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742 USA
| | - Michael Shuster
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742 USA
| | - Yongqiang Fan
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742 USA
- Current affiliation: College of Life and Health Sciences, Northeastern University, Shenyang 110819, People’s Republic of China
| | - Zhihui Lyu
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742 USA
| | - Jiqiang Ling
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742 USA
| | - Volker Briken
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742 USA
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6
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Van Zyl WF, Van Staden AD, Dicks LMT, Trindade M. Use of the mCherry fluorescent protein to optimize the expression of class I lanthipeptides in Escherichia coli. Microb Cell Fact 2023; 22:149. [PMID: 37559122 PMCID: PMC10413542 DOI: 10.1186/s12934-023-02162-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 07/29/2023] [Indexed: 08/11/2023] Open
Abstract
BACKGROUND Lanthipeptides are a rapidly expanding family of ribosomally synthesized and post-translationally modified natural compounds with diverse biological functions. Lanthipeptide structural and biosynthetic genes can readily be identified in genomic datasets, which provides a substantial repository for unique peptides with a wide range of potentially novel bioactivities. To realize this potential efficiently optimized heterologous production systems are required. However, only a few class I lanthipeptides have been successfully expressed using Escherichia coli as heterologous producer. This may be attributed to difficulties experienced in the co-expression of structural genes and multiple processing genes as well as complex optimization experiments. RESULTS Here, an optimized modular plasmid system is presented for the complete biosynthesis for each of the class I lanthipeptides nisin and clausin, in E. coli. Genes encoding precursor lanthipeptides were fused to the gene encoding the mCherry red fluorescent protein and co-expressed along with the required synthetases from the respective operons. Antimicrobially active nisin and clausin were proteolytically liberated from the expressed mCherry fusions. The mCherry-NisA expression system combined with in vivo fluorescence monitoring was used to elucidate the effect of culture media composition, promoter arrangement, and culture conditions including choice of growth media and inducer agents on the heterologous expression of the class I lanthipeptides. To evaluate the promiscuity of the clausin biosynthetic enzymes, the optimized clausin expression system was used for the heterologous expression of epidermin. CONCLUSION We succeeded in developing novel mCherry-fusion based plug and play heterologous expression systems to produce two different subgroups of class I lanthipeptides. Fully modified Pre-NisA, Pre-ClausA and Pre-EpiA fused to the mCherry fluorescence gene was purified from the Gram-negative host E. coli BL21 (DE3). Our study demonstrates the potential of using in vivo fluorescence as a platform to evaluate the expression of mCherry-fused lanthipeptides in E. coli. This allowed a substantial reduction in optimization time, since expression could be monitored in real-time, without the need for extensive and laborious purification steps or the use of in vitro activity assays. The optimized heterologous expression systems developed in this study may be employed in future studies for the scalable expression of novel NisA derivatives, or novel genome mined derivatives of ClausA and other class I lanthipeptides in E. coli.
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Affiliation(s)
- Winschau F Van Zyl
- Department of Microbiology, Stellenbosch University, Cape Town, South Africa.
- Department of Microbiology and Biochemistry, University of the Free State, Bloemfontein, South Africa.
| | - Anton D Van Staden
- Department of Microbiology, Stellenbosch University, Cape Town, South Africa
- Division of Clinical Pharmacology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Leon M T Dicks
- Department of Microbiology, Stellenbosch University, Cape Town, South Africa
| | - Marla Trindade
- Institute for Microbial Biotechnology and Metagenomics, University of the Western Cape, Cape Town, South Africa
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7
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Matera A, Dulak K, Sordon S, Waśniewski K, Huszcza E, Popłoński J. Evaluation of double expression system for co-expression and co-immobilization of flavonoid glucosylation cascade. Appl Microbiol Biotechnol 2022; 106:7763-7778. [PMID: 36334126 PMCID: PMC9668961 DOI: 10.1007/s00253-022-12259-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 10/18/2022] [Accepted: 10/23/2022] [Indexed: 11/07/2022]
Abstract
Abstract
Glucosylation cascade consisting of Leloir glycosyltransferase and sucrose synthase with in situ regeneration system of expensive and low available nucleotide sugars is a game-changing strategy for enzyme-based production of glycoconjugates of relevant natural products. We designed a stepwise approach including co-expression and one-step purification and co-immobilization on glass-based EziG resins of sucrose synthase from Glycine max (GmSuSy) with promiscuous glucosyltransferase YjiC from Bacillus licheniformis to produce efficient, robust, and versatile biocatalyst suited for preparative scale flavonoid glucosylation. The undertaken investigations identified optimal reaction conditions (30 °C, pH 7.5, and 10 mM Mg2+) and the best-suited carrier (EziG Opal). The prepared catalyst exhibited excellent reusability, retaining up to 96% of initial activity after 12 cycles of reactions. The semi-preparative glucosylation of poorly soluble isoflavone Biochanin A resulted in the production of 73 mg Sissotrin (Biochanin A 7-O-glucoside). Additionally, the evaluation of the designed double-controlled, monocistronic expression system with two independently induced promoters (rhaBAD and trc) brought beneficial information for dual-expression plasmid design. Key points • Simultaneous and titratable expression from two independent promoters is possible, although full control over the expression is limited. • Designed catalyst managed to glucosylate poorly soluble isoflavone. • The STY of Sissotrin using the designed catalyst reached 0.26 g/L∙h∙g of the resin. Graphical Abstract ![]()
Supplementary information The online version contains supplementary material available at 10.1007/s00253-022-12259-5.
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Affiliation(s)
- Agata Matera
- Department of Food Chemistry and Biocatalysis, Wrocław University of Environmental and Life Sciences, C.K. Norwida 25, 50-375, Wrocław, Poland
| | - Kinga Dulak
- Department of Food Chemistry and Biocatalysis, Wrocław University of Environmental and Life Sciences, C.K. Norwida 25, 50-375, Wrocław, Poland
| | - Sandra Sordon
- Department of Food Chemistry and Biocatalysis, Wrocław University of Environmental and Life Sciences, C.K. Norwida 25, 50-375, Wrocław, Poland
| | - Kacper Waśniewski
- Department of Food Chemistry and Biocatalysis, Wrocław University of Environmental and Life Sciences, C.K. Norwida 25, 50-375, Wrocław, Poland
| | - Ewa Huszcza
- Department of Food Chemistry and Biocatalysis, Wrocław University of Environmental and Life Sciences, C.K. Norwida 25, 50-375, Wrocław, Poland
| | - Jarosław Popłoński
- Department of Food Chemistry and Biocatalysis, Wrocław University of Environmental and Life Sciences, C.K. Norwida 25, 50-375, Wrocław, Poland.
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8
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Lu T, Shinozaki M, Nagoshi N, Nakamura M, Okano H. Long Preservation of AAV-Transduced Fluorescence by a Modified Organic Solvent-Based Clearing Method. Int J Mol Sci 2022; 23:ijms23179637. [PMID: 36077034 PMCID: PMC9455935 DOI: 10.3390/ijms23179637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 08/17/2022] [Accepted: 08/23/2022] [Indexed: 11/26/2022] Open
Abstract
The development of tissue clearing technologies allows 3D imaging of whole tissues and organs, especially in studies of the central nervous system innervated throughout the body. Although the three-dimensional imaging of solvent-cleared organs (3DISCO) method provides a powerful clearing capacity and high transparency, the rapid quenching of endogenous fluorescence and peroxide removal process decreases its practicability. This study provides a modified method named tDISCO to solve these limitations. The tDISCO protocol can preserve AAV-transduced endogenous EGFP fluorescence for months and achieve high transparency in a fast and simple clearing process. In addition to the brain, tDISCO was applied to other organs and even hard bone tissue. tDISCO also enabled us to visualize the long projection neurons and axons with high resolution. This method provides a fast and simple clearing protocol for 3D visualization of the AAV- transduced long projection neurons throughout the brain and spinal cord.
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Affiliation(s)
- Tao Lu
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Munehisa Shinozaki
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Narihito Nagoshi
- Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Masaya Nakamura
- Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
- Correspondence: (M.N.); (H.O.)
| | - Hideyuki Okano
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
- Correspondence: (M.N.); (H.O.)
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9
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Wen J, Vischer NOE, de Vos AL, Manders EMM, Setlow P, Brul S. Organization and dynamics of the SpoVAEa protein and its surrounding inner membrane lipids, upon germination of Bacillus subtilis spores. Sci Rep 2022; 12:4944. [PMID: 35322191 PMCID: PMC8943000 DOI: 10.1038/s41598-022-09147-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 03/17/2022] [Indexed: 11/09/2022] Open
Abstract
The SpoVA proteins make up a channel in the inner membrane (IM) of Bacillus subtilis spores. This channel responds to signals from activated germinant receptors (GRs), and allows release of Ca2+-DPA from the spore core during germination. In the current work, we studied the location and dynamics of SpoVAEa in dormant spores. Notably, the SpoVAEa-SGFP2 proteins were present in a single spot in spores, similar to the IM complex formed by all GRs termed the germinosome. However, while the GRs' spot remains in one location, the SpoVAEa-SGFP2 spot in the IM moved randomly with high frequency. It seems possible that this movement may be a means of communicating germination signals from the germinosome to the IM SpoVA channel, thus stimulating CaDPA release in germination. The dynamics of the SpoVAEa-SGFP2 and its surrounding IM region as stained by fluorescent dyes were also tracked during spore germination, as the dormant spore IM appeared to have an immobile germination related functional microdomain. This microdomain disappeared around the time of appearance of a germinated spore, and the loss of fluorescence of the IM with fluorescent dyes, as well as the appearance of peak SpoVAEa-SGFP2 fluorescent intensity occurred in parallel. These observed events were highly related to spores' rapid phase darkening, which is considered as due to rapid Ca2+DPA release. We also tested the response of SpoVAEa and the IM to thermal treatments at 40-80 °C. Heat treatment triggered an increase of green autofluorescence, which is speculated to be due to coat protein denaturation, and 80 °C treatments induce the appearance of phase-grey-like spores. These spores presumably have a similar intracellular physical state as the phase grey spores detected in the germination but lack the functional proteins for further germination events.
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Affiliation(s)
- Juan Wen
- Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Norbert O E Vischer
- Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Arend L de Vos
- Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Erik M M Manders
- Confocal.Nl B.V., Science Park 106, 1098 XG, Amsterdam, The Netherlands
| | - Peter Setlow
- Department of Molecular Biology and Biophysics, UConn Health, 263 Farmington Avenue, Farmington, CT, 06030-3305, USA
| | - Stanley Brul
- Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands.
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10
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Guerra P, Vuillemenot LA, Rae B, Ladyhina V, Milias-Argeitis A. Systematic In Vivo Characterization of Fluorescent Protein Maturation in Budding Yeast. ACS Synth Biol 2022; 11:1129-1141. [PMID: 35180343 PMCID: PMC8938947 DOI: 10.1021/acssynbio.1c00387] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
Fluorescent protein
(FP) maturation can limit the accuracy with
which dynamic intracellular processes are captured and reduce the in vivo brightness of a given FP in fast-dividing cells.
The knowledge of maturation timescales can therefore help users determine
the appropriate FP for each application. However, in vivo maturation rates can greatly deviate from in vitro estimates that are mostly available. In this work, we present the
first systematic study of in vivo maturation for
12 FPs in budding yeast. To overcome the technical limitations of
translation inhibitors commonly used to study FP maturation, we implemented
a new approach based on the optogenetic stimulations of FP expression
in cells grown under constant nutrient conditions. Combining the rapid
and orthogonal induction of FP transcription with a mathematical model
of expression and maturation allowed us to accurately estimate maturation
rates from microscopy data in a minimally invasive manner. Besides
providing a useful resource for the budding yeast community, we present
a new joint experimental and computational approach for characterizing
FP maturation, which is applicable to a wide range of organisms.
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Affiliation(s)
- Paolo Guerra
- Molecular Systems Biology, Groningen Biomolecular Sciences & Biotechnology Institute, University of Groningen, 9747 AG Groningen, Netherlands
| | - Luc-Alban Vuillemenot
- Molecular Systems Biology, Groningen Biomolecular Sciences & Biotechnology Institute, University of Groningen, 9747 AG Groningen, Netherlands
| | - Brady Rae
- Molecular Systems Biology, Groningen Biomolecular Sciences & Biotechnology Institute, University of Groningen, 9747 AG Groningen, Netherlands
| | - Valeriia Ladyhina
- Molecular Systems Biology, Groningen Biomolecular Sciences & Biotechnology Institute, University of Groningen, 9747 AG Groningen, Netherlands
| | - Andreas Milias-Argeitis
- Molecular Systems Biology, Groningen Biomolecular Sciences & Biotechnology Institute, University of Groningen, 9747 AG Groningen, Netherlands
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11
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Li T, Yu D, Oak HC, Zhu B, Wang L, Jiang X, Molday RS, Kriegstein A, Piao X. Phospholipid-flippase chaperone CDC50A is required for synapse maintenance by regulating phosphatidylserine exposure. EMBO J 2021; 40:e107915. [PMID: 34585770 PMCID: PMC8561630 DOI: 10.15252/embj.2021107915] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 08/25/2021] [Accepted: 09/01/2021] [Indexed: 12/13/2022] Open
Abstract
Synaptic refinement is a critical physiological process that removes excess synapses to establish and maintain functional neuronal circuits. Recent studies have shown that focal exposure of phosphatidylserine (PS) on synapses acts as an "eat me" signal to mediate synaptic pruning. However, the molecular mechanism underlying PS externalization at synapses remains elusive. Here, we find that murine CDC50A, a chaperone of phospholipid flippases, localizes to synapses, and that its expression depends on neuronal activity. Cdc50a knockdown leads to phosphatidylserine exposure at synapses and subsequent erroneous synapse removal by microglia partly via the GPR56 pathway. Taken together, our data support that CDC50A safeguards synapse maintenance by regulating focal phosphatidylserine exposure at synapses.
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Affiliation(s)
- Tao Li
- Weill Institute for NeuroscienceUniversity of California, San Francisco (UCSF)San FranciscoCAUSA
- Newborn Brain Research InstituteUniversity of California, San Francisco (UCSF)San FranciscoCAUSA
| | - Diankun Yu
- Weill Institute for NeuroscienceUniversity of California, San Francisco (UCSF)San FranciscoCAUSA
- Newborn Brain Research InstituteUniversity of California, San Francisco (UCSF)San FranciscoCAUSA
| | - Hayeon C Oak
- Weill Institute for NeuroscienceUniversity of California, San Francisco (UCSF)San FranciscoCAUSA
- Newborn Brain Research InstituteUniversity of California, San Francisco (UCSF)San FranciscoCAUSA
| | - Beika Zhu
- Weill Institute for NeuroscienceUniversity of California, San Francisco (UCSF)San FranciscoCAUSA
- Newborn Brain Research InstituteUniversity of California, San Francisco (UCSF)San FranciscoCAUSA
| | - Li Wang
- Weill Institute for NeuroscienceUniversity of California, San Francisco (UCSF)San FranciscoCAUSA
- Department of NeurologyUniversity of California, San FranciscoSan FranciscoCAUSA
| | - Xueqiao Jiang
- Weill Institute for NeuroscienceUniversity of California, San Francisco (UCSF)San FranciscoCAUSA
- Newborn Brain Research InstituteUniversity of California, San Francisco (UCSF)San FranciscoCAUSA
| | - Robert S Molday
- Department of Biochemistry and Molecular BiologyUniversity of British ColumbiaVancouverBCCanada
| | - Arnold Kriegstein
- Weill Institute for NeuroscienceUniversity of California, San Francisco (UCSF)San FranciscoCAUSA
- Department of NeurologyUniversity of California, San FranciscoSan FranciscoCAUSA
| | - Xianhua Piao
- Weill Institute for NeuroscienceUniversity of California, San Francisco (UCSF)San FranciscoCAUSA
- Newborn Brain Research InstituteUniversity of California, San Francisco (UCSF)San FranciscoCAUSA
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell ResearchUniversity of California, San Francisco (UCSF)San FranciscoCAUSA
- Division of NeonatologyDepartment of PediatricsUniversity of California, San Francisco (UCSF)San FranciscoCAUSA
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12
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Lakatos Z, Benkő P, Juhász G, Lőrincz P. Drosophila Rab39 Attenuates Lysosomal Degradation. Int J Mol Sci 2021; 22:ijms221910635. [PMID: 34638976 PMCID: PMC8508792 DOI: 10.3390/ijms221910635] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 09/27/2021] [Accepted: 09/28/2021] [Indexed: 11/16/2022] Open
Abstract
Lysosomal degradation, the common destination of autophagy and endocytosis, is one of the most important elements of eukaryotic metabolism. The small GTPases Rab39A and B are potential new effectors of this pathway, as their malfunction is implicated in severe human diseases like cancer and neurodegeneration. In this study, the lysosomal regulatory role of the single Drosophila Rab39 ortholog was characterized, providing valuable insight into the potential cell biological mechanisms mediated by these proteins. Using a de novo CRISPR-generated rab39 mutant, we found no failure in the early steps of endocytosis and autophagy. On the contrary, we found that Rab39 mutant nephrocytes internalize and degrade endocytic cargo at a higher rate compared to control cells. In addition, Rab39 mutant fat body cells contain small yet functional autolysosomes without lysosomal fusion defect. Our data identify Drosophila Rab39 as a negative regulator of lysosomal clearance during both endocytosis and autophagy.
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Affiliation(s)
- Zsolt Lakatos
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, H-1117 Budapest, Hungary; (Z.L.); (P.B.)
| | - Péter Benkő
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, H-1117 Budapest, Hungary; (Z.L.); (P.B.)
- Department of Physiology, Semmelweis University, H-1094 Budapest, Hungary
| | - Gábor Juhász
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, H-1117 Budapest, Hungary; (Z.L.); (P.B.)
- Biological Research Centre, Institute of Genetics, Hungarian Academy of Sciences, H-6726 Szeged, Hungary
- Correspondence: (G.J.); (P.L.)
| | - Péter Lőrincz
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, H-1117 Budapest, Hungary; (Z.L.); (P.B.)
- Premium Postdoctoral Research Program, Hungarian Academy of Sciences, H-1052 Budapest, Hungary
- Correspondence: (G.J.); (P.L.)
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13
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Munir MT, Maneewan N, Pichon J, Gharbia M, Oumarou-Mahamane I, Baude J, Thorin C, Lepelletier D, Le Pape P, Eveillard M, Irle M, Pailhoriès H, Aviat F, Belloncle C, Federighi M, Dubreil L. Confocal spectral microscopy, a non-destructive approach to follow contamination and biofilm formation of mCherry Staphylococcus aureus on solid surfaces. Sci Rep 2021; 11:15574. [PMID: 34341378 PMCID: PMC8329050 DOI: 10.1038/s41598-021-94939-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 07/01/2021] [Indexed: 01/23/2023] Open
Abstract
Methods to test the safety of wood material for hygienically sensitive places are indirect, destructive and limited to incomplete microbial recovery via swabbing, brushing and elution-based techniques. Therefore, we chose mCherry Staphylococcus aureus as a model bacterium for solid and porous surface contamination. Confocal spectral laser microscope (CSLM) was employed to characterize and use the autofluorescence of Sessile oak (Quercus petraea), Douglas fir (Pseudotsuga menziesii) and poplar (Populus euramericana alba L.) wood discs cut into transversal (RT) and tangential (LT) planes. The red fluorescent area occupied by bacteria was differentiated from that of wood, which represented the bacterial quantification, survival and bio-distribution on surfaces from one hour to one week after inoculation. More bacteria were present near the surface on LT face wood as compared to RT and they persisted throughout the study period. Furthermore, this innovative methodology identified that S. aureus formed a dense biofilm on melamine but not on oak wood in similar inoculation and growth conditions. Conclusively, the endogenous fluorescence of materials and the model bacterium permitted direct quantification of surface contamination by using CSLM and it is a promising tool for hygienic safety evaluation.
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Affiliation(s)
| | | | - Julien Pichon
- UMR703 PAnTher APEX, INRAE/ONIRIS - La Chantrerie, 101 Route de Gachet, 44307, Nantes, France
| | | | | | - Jessica Baude
- CIRI, Inserm U1111, Lyon 1 University, ENS Lyon, CNRS UMR 5308, Lyon, France
| | | | | | - Patrice Le Pape
- EA 1155 IICiMed, IRS 2, University of Nantes, 44200, Nantes, France
| | - Matthieu Eveillard
- CRCINA, Inserm, University of Nantes, University of Angers, 44200, Angers, France.,Laboratory of Bacteriology-Hygiene, University Hospital of Angers, 49933, Angers, France
| | - Mark Irle
- LIMBHA, Ecole Supérieure du Bois, 44000, Nantes, France
| | - Hélène Pailhoriès
- Laboratory of Bacteriology-Hygiene, University Hospital of Angers, 49933, Angers, France.,HIFIH, UPRES EA3859, SFR 4208, University of Angers, Angers, France
| | - Florence Aviat
- Your ResearcH-Bio-Scientific, 44430, Le Landreau, France
| | | | | | - Laurence Dubreil
- UMR703 PAnTher APEX, INRAE/ONIRIS - La Chantrerie, 101 Route de Gachet, 44307, Nantes, France.
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14
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Zhou K, Amiri M, Salari A, Yu Y, Xu H, Seidler U, Nikolovska K. Functional characterization of the sodium/hydrogen exchanger 8 and its role in proliferation of colonic epithelial cells. Am J Physiol Cell Physiol 2021; 321:C471-C488. [PMID: 34288721 DOI: 10.1152/ajpcell.00582.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Intestinal NaCl, HCO3-, and fluid absorption are strongly dependent on apical Na+/H+ exchange. The intestine expresses three presumably apical sodium-hydrogen exchanger (NHE) isoforms: NHE2, NHE3, and NHE8. We addressed the role of NHE8 [solute carrier 9A8 (SLC9A8)] and its interplay with NHE2 (SLC9A2) in luminal proton extrusion during acute and chronic enterocyte acidosis and studied the differential effects of NHE8 and NHE2 on enterocyte proliferation. In contrast to NHE3, which was upregulated in differentiated versus undifferentiated colonoids, the expression of NHE2 and NHE8 remained constant during differentiation of colonoids and Caco2Bbe cells. Heterogeneously expressed Flag-tagged rat (r)Nhe8 and human (h)NHE8 translocated to the apical membrane of Caco2Bbe cells. rNhe8 and hNHE8, when expressed in NHE-deficient PS120 fibroblasts showed higher sensitivity to HOE642 compared to NHE2. Lentiviral shRNA knockdown of endogenous NHE2 in Caco2Bbe cells (C2Bbe/shNHE2) resulted in a decreased steady-state intracellular pH (pHi), an increased NHE8 mRNA expression, and augmented NHE8-mediated apical NHE activity. Lentiviral shRNA knockdown of endogenous NHE8 in Caco2Bbe cells (C2Bbe/shNHE8) resulted in a decreased steady-state pHi as well, accompanied by decreased NHE2 mRNA expression and activity, which together contributed to reduced apical NHE activity in the NHE8-knockdown cells. Chronic acidosis increased NHE8 but not NHE2 mRNA expression. Alterations in NHE2 and NHE8 expression/activity affected proliferation, with C2Bbe/shNHE2 cells having lower and C2Bbe/shNHE8 having higher proliferative capacity, accompanied by amplified ERK1/2 signaling pathway and increased EGFR expression in the latter cell line. Thus, both Na+/H+ exchangers have distinct functions during cellular homeostasis by triggering different signaling pathways to regulate cellular proliferation and pHi control.
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Affiliation(s)
- Kunyan Zhou
- Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hannover, Germany
| | - Mahdi Amiri
- Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hannover, Germany
| | - Azam Salari
- Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hannover, Germany
| | - Yan Yu
- Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hannover, Germany
| | - Hua Xu
- Department of Pediatrics, University of Arizona Health Science Center, Tucson, Arizona
| | - Ursula Seidler
- Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hannover, Germany
| | - Katerina Nikolovska
- Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hannover, Germany
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15
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Morita A, Satouh Y, Kosako H, Kobayashi H, Iwase A, Sato K. Clathrin-mediated endocytosis is essential for the selective degradation of maternal membrane proteins and preimplantation development. Development 2021; 148:270925. [PMID: 34269385 DOI: 10.1242/dev.199461] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 06/23/2021] [Indexed: 11/20/2022]
Abstract
Fertilization triggers significant cellular remodeling through the oocyte-to-embryo transition. In this transition, the ubiquitin-proteasome system and autophagy are essential for the degradation of maternal components; however, the significance of degradation of cell surface components remains unknown. In this study, we show that multiple maternal plasma membrane proteins, such as the glycine transporter GlyT1a, are selectively internalized from the plasma membrane to endosomes in mouse embryos by the late two-cell stage and then transported to lysosomes for degradation at the later stages. During this process, large amounts of ubiquitylated proteins accumulated on endosomes. Furthermore, the degradation of GlyT1a with mutations in potential ubiquitylation sites was delayed, suggesting that ubiquitylation may be involved in GlyT1a degradation. The clathrin inhibitor blocked GlyT1a internalization. Strikingly, the protein kinase C (PKC) activator triggered the heterochronic internalization of GlyT1a; the PKC inhibitor markedly blocked GlyT1a endocytosis. Lastly, clathrin inhibition completely blocked embryogenesis at the two-cell stage and inhibited cell division after the four-cell stage. These findings demonstrate that PKC-dependent clathrin-mediated endocytosis is essential for the selective degradation of maternal membrane proteins during oocyte-to-embryo transition and early embryogenesis.
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Affiliation(s)
- Akihito Morita
- Laboratory of Molecular Traffic, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, 371-8512, Japan.,Department of Obstetrics and Gynecology, Gunma University Graduate School of Medicine, Maebashi, 371-8511, Japan
| | - Yuhkoh Satouh
- Laboratory of Molecular Traffic, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, 371-8512, Japan
| | - Hidetaka Kosako
- Division of Cell Signaling, Fujii Memorial Institute of Medical Sciences, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, 770-8503, Japan
| | - Hisae Kobayashi
- Laboratory of Molecular Traffic, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, 371-8512, Japan
| | - Akira Iwase
- Department of Obstetrics and Gynecology, Gunma University Graduate School of Medicine, Maebashi, 371-8511, Japan
| | - Ken Sato
- Laboratory of Molecular Traffic, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, 371-8512, Japan
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16
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Wimmi S, Balinovic A, Jeckel H, Selinger L, Lampaki D, Eisemann E, Meuskens I, Linke D, Drescher K, Endesfelder U, Diepold A. Dynamic relocalization of cytosolic type III secretion system components prevents premature protein secretion at low external pH. Nat Commun 2021; 12:1625. [PMID: 33712575 PMCID: PMC7954860 DOI: 10.1038/s41467-021-21863-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 02/12/2021] [Indexed: 01/31/2023] Open
Abstract
Many bacterial pathogens use a type III secretion system (T3SS) to manipulate host cells. Protein secretion by the T3SS injectisome is activated upon contact to any host cell, and it has been unclear how premature secretion is prevented during infection. Here we report that in the gastrointestinal pathogens Yersinia enterocolitica and Shigella flexneri, cytosolic injectisome components are temporarily released from the proximal interface of the injectisome at low external pH, preventing protein secretion in acidic environments, such as the stomach. We show that in Yersinia enterocolitica, low external pH is detected in the periplasm and leads to a partial dissociation of the inner membrane injectisome component SctD, which in turn causes the dissociation of the cytosolic T3SS components. This effect is reversed upon restoration of neutral pH, allowing a fast activation of the T3SS at the native target regions within the host. These findings indicate that the cytosolic components form an adaptive regulatory interface, which regulates T3SS activity in response to environmental conditions.
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Affiliation(s)
- Stephan Wimmi
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Alexander Balinovic
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
- Department of Physics, Mellon College of Science, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Hannah Jeckel
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
- Department of Physics, Philipps-Universität Marburg, Marburg, Germany
| | - Lisa Selinger
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Dimitrios Lampaki
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
- Max-Planck-Institut für Immunbiologie und Epigenetik, Freiburg, Germany
| | - Emma Eisemann
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
- James Madison University, Harrisonburg, VA, USA
| | - Ina Meuskens
- Department of Biosciences, University of Oslo, Oslo, Norway
| | - Dirk Linke
- Department of Biosciences, University of Oslo, Oslo, Norway
| | - Knut Drescher
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
- Department of Physics, Philipps-Universität Marburg, Marburg, Germany
| | - Ulrike Endesfelder
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
- Department of Physics, Mellon College of Science, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Andreas Diepold
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany.
- SYNMIKRO, LOEWE Center for Synthetic Microbiology, Marburg, Germany.
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17
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Arias CAD, Matsudo MC, Ferreira-Camargo LS, Molino JVD, Mayfield SP, de Carvalho JCM. Semicontinuous system for the production of recombinant mCherry protein in Chlamydomonas reinhardtii. Biotechnol Prog 2021; 37:e3101. [PMID: 33169497 DOI: 10.1002/btpr.3101] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 10/23/2020] [Accepted: 10/28/2020] [Indexed: 12/15/2022]
Abstract
Biotechnology advances have allowed bacteria, yeasts, plants, mammalian and insect cells to function as heterologous protein expression systems. Recently, microalgae have gained attention as an innovative platform for recombinant protein production, due to low culture media cost, compared to traditional systems, as well as the fact that microalgae such as Chlamydomonas reinhardtii are considered safe (GRAS) by the Food and Drug Administration (FDA). Previous studies showed that recombinant protein production in traditional platforms by semicontinuous process increased biomass and bio product productivity, when compared to batch process. As there is a lack of studies on semicontinuous process for recombinant protein production in microalgae, the production of recombinant mCherry fluorescent protein was evaluated by semicontinuous cultivation of Chlamydomonas reinhardtii in bubble column photobioreactor. This semicontinuous cultivation process was evaluated in the following conditions: 20%, 40%, and 60% culture portion withdrawal. The highest culture withdrawal percentage (60%) provided the best results, as an up to 161% increase in mCherry productivity (454.5 RFU h-1 - Relative Fluorescence Unit h-1 ), in comparison to batch cultivation (174.0 RFU h-1 ) of the same strain. All cultivations were carried out for 13 days, at pH 7, temperature 25°C and, by semicontinuous process, two culture withdrawals were taken during the cultivations. Throughout the production cycles, it was possible to obtain biomass concentration up to 1.36 g L-1 .
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Affiliation(s)
- Cesar Andres Diaz Arias
- Department of Biochemical and Pharmaceutical Technology, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | | | | | - João Vitor Dutra Molino
- Department of Biochemical and Pharmaceutical Technology, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Stephen Patrick Mayfield
- Department of Molecular Biology, and The California Center for Algae Biotechnology, University of California, San Diego, California, USA
| | - João Carlos Monteiro de Carvalho
- Department of Biochemical and Pharmaceutical Technology, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, SP, Brazil
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18
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Lee JH, Kim JY, Noh S, Lee H, Lee SY, Mun JY, Park H, Chung WS. Astrocytes phagocytose adult hippocampal synapses for circuit homeostasis. Nature 2020; 590:612-617. [PMID: 33361813 DOI: 10.1038/s41586-020-03060-3] [Citation(s) in RCA: 148] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Accepted: 11/05/2020] [Indexed: 02/07/2023]
Abstract
In the adult hippocampus, synapses are constantly formed and eliminated1,2. However, the exact function of synapse elimination in the adult brain, and how it is regulated, are largely unknown. Here we show that astrocytic phagocytosis3 is important for maintaining proper hippocampal synaptic connectivity and plasticity. By using fluorescent phagocytosis reporters, we find that excitatory and inhibitory synapses are eliminated by glial phagocytosis in the CA1 region of the adult mouse hippocampus. Unexpectedly, we found that astrocytes have a major role in the neuronal activity-dependent elimination of excitatory synapses. Furthermore, mice in which astrocytes lack the phagocytic receptor MEGF10 show a reduction in the elimination of excitatory synapses; as a result, excessive but functionally impaired synapses accumulate. Finally, Megf10-knockout mice show defective long-term synaptic plasticity and impaired formation of hippocampal memories. Together, our data provide strong evidence that astrocytes eliminate unnecessary excitatory synaptic connections in the adult hippocampus through MEGF10, and that this astrocytic function is crucial for maintaining circuit connectivity and thereby supporting cognitive function.
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Affiliation(s)
- Joon-Hyuk Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Ji-Young Kim
- Research Group for Neurovascular Unit, Korea Brain Research Institute (KBRI), Daegu, Republic of Korea.,Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea
| | - Seulgi Noh
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea.,Research Group for Neural Circuit, Korea Brain Research Institute (KBRI), Daegu, Republic of Korea
| | - Hyoeun Lee
- Research Group for Neurovascular Unit, Korea Brain Research Institute (KBRI), Daegu, Republic of Korea
| | - Se Young Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Ji Young Mun
- Research Group for Neural Circuit, Korea Brain Research Institute (KBRI), Daegu, Republic of Korea
| | - Hyungju Park
- Research Group for Neurovascular Unit, Korea Brain Research Institute (KBRI), Daegu, Republic of Korea. .,Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea.
| | - Won-Suk Chung
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea.
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19
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Kostyuk AI, Kokova AD, Podgorny OV, Kelmanson IV, Fetisova ES, Belousov VV, Bilan DS. Genetically Encoded Tools for Research of Cell Signaling and Metabolism under Brain Hypoxia. Antioxidants (Basel) 2020; 9:E516. [PMID: 32545356 PMCID: PMC7346190 DOI: 10.3390/antiox9060516] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 06/04/2020] [Accepted: 06/06/2020] [Indexed: 02/08/2023] Open
Abstract
Hypoxia is characterized by low oxygen content in the tissues. The central nervous system (CNS) is highly vulnerable to a lack of oxygen. Prolonged hypoxia leads to the death of brain cells, which underlies the development of many pathological conditions. Despite the relevance of the topic, different approaches used to study the molecular mechanisms of hypoxia have many limitations. One promising lead is the use of various genetically encoded tools that allow for the observation of intracellular parameters in living systems. In the first part of this review, we provide the classification of oxygen/hypoxia reporters as well as describe other genetically encoded reporters for various metabolic and redox parameters that could be implemented in hypoxia studies. In the second part, we discuss the advantages and disadvantages of the primary hypoxia model systems and highlight inspiring examples of research in which these experimental settings were combined with genetically encoded reporters.
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Affiliation(s)
- Alexander I. Kostyuk
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.D.K.); (O.V.P.); (I.V.K.); (E.S.F.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
| | - Aleksandra D. Kokova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.D.K.); (O.V.P.); (I.V.K.); (E.S.F.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
| | - Oleg V. Podgorny
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.D.K.); (O.V.P.); (I.V.K.); (E.S.F.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
- Koltzov Institute of Developmental Biology, 119334 Moscow, Russia
| | - Ilya V. Kelmanson
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.D.K.); (O.V.P.); (I.V.K.); (E.S.F.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
| | - Elena S. Fetisova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.D.K.); (O.V.P.); (I.V.K.); (E.S.F.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
- Faculty of Biology, Lomonosov Moscow State University, 119992 Moscow, Russia
| | - Vsevolod V. Belousov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.D.K.); (O.V.P.); (I.V.K.); (E.S.F.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
- Institute for Cardiovascular Physiology, Georg August University Göttingen, D-37073 Göttingen, Germany
- Federal Center for Cerebrovascular Pathology and Stroke, 117997 Moscow, Russia
| | - Dmitry S. Bilan
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.D.K.); (O.V.P.); (I.V.K.); (E.S.F.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
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20
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Gao J, Qian H, Guo X, Mi Y, Guo J, Zhao J, Xu C, Zheng T, Duan M, Tang Z, Lin C, Shen Z, Jiang Y, Wang X. The signal peptide of Cry1Ia can improve the expression of eGFP or mCherry in Escherichia coli and Bacillus thuringiensis and enhance the host's fluorescent intensity. Microb Cell Fact 2020; 19:112. [PMID: 32448275 PMCID: PMC7247199 DOI: 10.1186/s12934-020-01371-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 05/16/2020] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND The signal peptides (SPs) of secretory proteins are frequently used or modified to guide recombinant proteins outside the cytoplasm of prokaryotic cells. In the periplasmic space and extracellular environment, recombinant proteins are kept away from the intracellular proteases and often they can fold correctly and efficiently. Consequently, expression levels of the recombinant protein can be enhanced by the presence of a SP. However, little attention has been paid to the use of SPs with low translocation efficiency for recombinant protein production. In this paper, the function of the signal peptide of Bacillus thuringiensis (Bt) Cry1Ia toxin (Iasp), which is speculated to be a weak translocation signal, on regulation of protein expression was investigated using fluorescent proteins as reporters. RESULTS When fused to the N-terminal of eGFP or mCherry, the Iasp can improve the expression of the fluorescent proteins and as a consequence enhance the fluorescent intensity of both Escherichia coli and Bt host cells. Real-time quantitative PCR analysis revealed the higher transcript levels of Iegfp over those of egfp gene in E. coli TG1 cells. By immunoblot analysis and confocal microscope observation, lower translocation efficiency of IeGFP was demonstrated. The novel fluorescent fusion protein IeGFP was then used to compare the relative strengths of cry1Ia (Pi) and cry1Ac (Pac) gene promoters in Bt strain, the latter promoter proving the stronger. The eGFP reporter, by contrast, cannot indicate unambiguously the regulation pattern of Pi at the same level of sensitivity. The fluorescent signals of E. coli and Bt cells expressing the Iasp fused mCherry (ImCherry) were also enhanced. Importantly, the Iasp can also enhanced the expression of two difficult-to-express proteins, matrix metalloprotease-13 (MMP13) and myostatin (growth differentiating factor-8, GDF8) in E. coli BL21-star (DE3) strain. CONCLUSIONS We identified the positive effects of a weak signal peptide, Iasp, on the expression of fluorescent proteins and other recombinant proteins in bacteria. The produced IeGFP and ImCherry can be used as novel fluorescent protein variants in prokaryotic cells. The results suggested the potential application of Iasp as a novel fusion tag for improving the recombinant protein expression.
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Affiliation(s)
- Jianhua Gao
- College of Life Sciences, Shanxi Agricultural University, Taigu, 030801, China.
| | - Hongmei Qian
- College of Life Sciences, Shanxi Agricultural University, Taigu, 030801, China
| | - Xiaoqin Guo
- College of Life Sciences, Shanxi Agricultural University, Taigu, 030801, China
| | - Yi Mi
- College of Life Sciences, Shanxi Agricultural University, Taigu, 030801, China
| | - Junpei Guo
- College of Life Sciences, Shanxi Agricultural University, Taigu, 030801, China
| | - Juanli Zhao
- College of Life Sciences, Shanxi Agricultural University, Taigu, 030801, China
| | - Chao Xu
- State Key Laboratory of Rice Biology, Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Ting Zheng
- State Key Laboratory of Rice Biology, Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Ming Duan
- Experimental Teaching Center, Shanxi Agricultural University, Taigu, 030801, China
| | - Zhongwei Tang
- College of Life Sciences, Shanxi Agricultural University, Taigu, 030801, China
| | - Chaoyang Lin
- State Key Laboratory of Rice Biology, Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Zhicheng Shen
- State Key Laboratory of Rice Biology, Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Yiwei Jiang
- Department of Agronomy, Purdue University, West Lafayette, IN, 47907, USA
| | - Xingchun Wang
- College of Life Sciences, Shanxi Agricultural University, Taigu, 030801, China.
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21
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Wang X, Kong Y, Zhao H, Yan X. Dependence of the
Bacillus subtilis
biofilm expansion rate on phenotypes and the morphology under different growing conditions. Dev Growth Differ 2019; 61:431-443. [DOI: 10.1111/dgd.12627] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Revised: 08/16/2019] [Accepted: 08/20/2019] [Indexed: 11/29/2022]
Affiliation(s)
- Xiaoling Wang
- School of Mechanical Engineering University of Science and Technology Beijing Beijing China
- School of Engineering and Applied Sciences Harvard University Cambridge MA USA
| | - Yuhao Kong
- School of Mechanical Engineering University of Science and Technology Beijing Beijing China
| | - Hui Zhao
- State Key Laboratory of Computer Science Institute of Software Chinese Academy of Sciences Beijing China
- University of Chinese Academy of Sciences Huairou China
| | - Xiaoqiang Yan
- School of Mechanical Engineering University of Science and Technology Beijing Beijing China
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22
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Garay-Novillo JN, García-Morena D, Ruiz-Masó JÁ, Barra JL, Del Solar G. Combining Modules for Versatile and Optimal Labeling of Lactic Acid Bacteria: Two pMV158-Family Promiscuous Replicons, a Pneumococcal System for Constitutive or Inducible Gene Expression, and Two Fluorescent Proteins. Front Microbiol 2019; 10:1431. [PMID: 31297101 PMCID: PMC6607859 DOI: 10.3389/fmicb.2019.01431] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 06/06/2019] [Indexed: 11/24/2022] Open
Abstract
Labeling of bacterial cells with fluorescent proteins allows tracking the bacteria in competition and interactomic in vivo and in vitro studies. During the last years, a few plasmid vectors have been developed aimed at the fluorescent labeling of specific members of the lactic acid bacteria (LAB), a heterogeneous group that includes microorganisms used in the food industry, as probiotics, or as live vectors for mucosal vaccines. Successful and versatile labeling of a broad range of LAB not only requires a vector containing a promiscuous replicon and a widely recognized expression system for the constitutive or regulated expression of the fluorescence determinant, but also the knowledge of the main features of the entire plasmid/host/fluorescent protein ensemble. By using the LAB model species Lactococcus lactis, we have compared the utility properties of a set of labeling vectors constructed by combining a promiscuous replicon (pMV158 or pSH71) of the pMV158 plasmid family with the gene encoding either the EGFP or the mCherry fluorescent protein placed under control of promoter PX or PM from the pneumococcal mal gene cluster for maltosaccharide uptake and utilization, respectively. Some vectors carrying PM also harbor the malR gene, whose product represses transcription from this promoter, thus enabling maltose-inducible synthesis of the fluorescent proteins. We have determined the plasmid copy number (PCN) and segregational stability of the different constructs, as well as the effect of these features on the fitness and fluorescence intensity of the lactococcal host. Constructs based on the pSH71 replicon had a high copy number (∼115) and were segregationally stable. The copy number of vectors based on the pMV158 replicon was lower (∼8–45) and varied substantially depending on the genetic context of the plasmid and on the bacterial growth conditions; as a consequence, inheritance of these vectors was less stable. Synthesis of the fluorescent proteins encoded by these plasmids did not significantly decrease the host fitness. By employing inducible expression vectors, the fluorescent proteins were shown to be very stable in this bacterium. Importantly, conditions for accurate quantification of the emitted fluorescence were established based on the maturation times of the fluorescent proteins.
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Affiliation(s)
- Javier Nicolás Garay-Novillo
- Departamento de Biotecnología Microbiana y de Plantas, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Madrid, Spain.,Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC-CONICET), Córdoba, Argentina
| | - Diego García-Morena
- Departamento de Biotecnología Microbiana y de Plantas, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - José Ángel Ruiz-Masó
- Departamento de Biotecnología Microbiana y de Plantas, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - José Luis Barra
- Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC-CONICET), Córdoba, Argentina
| | - Gloria Del Solar
- Departamento de Biotecnología Microbiana y de Plantas, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Madrid, Spain
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23
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Zhou B, Zhang X, Wang G, Barbour KW, Berger FG, Wang Q. Drug screening assay based on the interaction of intact Keap1 and Nrf2 proteins in cancer cells. Bioorg Med Chem 2019; 27:92-99. [PMID: 30473361 DOI: 10.1016/j.bmc.2018.11.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 10/29/2018] [Accepted: 11/13/2018] [Indexed: 12/15/2022]
Abstract
BACKGROUND The Nrf2-Keap1 interaction is the major regulatory pathway for cytoprotective responses against oxidative and electrophilic stresses. Keap1, a substrate protein of a Cul3-dependent E3 ubiquitin ligase complex, is a negative regulator of Nrf2. The use of chemicals to regulate the interaction between Keap1 and Nrf2 has been proposed as a strategy for the chemoprevention of degenerative diseases and cancers. RESULTS The interactions between Keap1 and Nrf2 in vitro and in vivo were investigated using fluorescence resonance energy transfer (FRET) and bimolecular fluorescence complementation (BiFC) strategies in our study. Nrf2 with its N-terminal fused to eGFP and Keap1 with its C-terminal fused to mCherry were expressed and purified in vitro. When purified eGFP-Nrf2 and Keap1-mChrry proteins were mixed together, a strong FRET signal could be detected, indicating an efficient energy transfer from eGFP to mCherry. Moreover, the FRET was detected in vivo using confocal microscopy in colon cancer HCT-116 cells that were co-transfected with eGFP-Nrf2 and Keap1-mCherry. Finally, using an eGFP BiFC approach, the Keap1-Nrf2 interaction was also detected in MCF7 cells by transfecting eGFP N-terminal fused to Nrf2 (eN158-Nrf2) and eGFP C-terminal fused to Keap1 (eC159-Keap1). Using the BiFC and FRET systems, we demonstrated that the prototypical Nrf2-activiting compound tBHQ and the antitumor drug F-dUrd might interfere with the intracellular interaction between Keap1 and Nrf2 whereas the 5-Fu have little role in activating the protective response of Nrf2 pathway in cancer cells. CONCLUSIONS By analyzing the perturbation of the energy transfer between the donor and acceptor fluorophores and the bimolecular fluorescence complementation of eGFP, we can screen potential inhibitors for the interaction between Keap1 and Nrf2.
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Affiliation(s)
- Bo Zhou
- College of Life Science, Northeast Forestry University, Harbin, China; Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, USA
| | - Xiaolei Zhang
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, USA
| | - Guiren Wang
- Biomedical Engineering Program and Mechanical Engineering Department, University of South Carolina, Columbia, SC, USA.
| | - Karen W Barbour
- Center for Colon Cancer Research, University of South Carolina, Columbia, SC, USA.
| | - Franklin G Berger
- Center for Colon Cancer Research, University of South Carolina, Columbia, SC, USA.
| | - Qian Wang
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, USA.
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24
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Hartmann SK, Stockdreher Y, Wandrey G, Hosseinpour Tehrani H, Zambanini T, Meyer AJ, Büchs J, Blank LM, Schwarzländer M, Wierckx N. Online in vivo monitoring of cytosolic NAD redox dynamics in Ustilago maydis. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1859:1015-1024. [DOI: 10.1016/j.bbabio.2018.05.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 04/06/2018] [Accepted: 05/20/2018] [Indexed: 12/20/2022]
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25
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Cabanillas DG, Jiang J, Movahed N, Germain H, Yamaji Y, Zheng H, Laliberté JF. Turnip Mosaic Virus Uses the SNARE Protein VTI11 in an Unconventional Route for Replication Vesicle Trafficking. THE PLANT CELL 2018; 30:2594-2615. [PMID: 30150314 PMCID: PMC6241277 DOI: 10.1105/tpc.18.00281] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 07/17/2018] [Accepted: 08/25/2018] [Indexed: 05/11/2023]
Abstract
Infection of plant cells by RNA viruses leads to the generation of organelle-like subcellular structures that contain the viral replication complex. During Turnip mosaic virus (TuMV) infection of Nicotiana benthamiana, the viral membrane protein 6K2 plays a key role in the release of motile replication vesicles from the host endoplasmic reticulum (ER). Here, we demonstrate that 6K2 contains a GxxxG motif within its predicted transmembrane domain that is vital for TuMV infection. Replacement of the Gly with Val within this motif inhibited virus production, and this was due to a relocation of the viral protein to the Golgi apparatus and the plasma membrane. This indicated that passage of 6K2 through the Golgi apparatus is a dead-end avenue for virus infection. Impairing the fusion of transport vesicles between the ER and the Golgi apparatus by overexpression of the SNARE Sec22 protein resulted in enhanced intercellular virus movement. Likewise, expression of nonfunctional, Golgi-located synaptotagmin during infection enhanced TuMV intercellular movement. 6K2 copurified with VTI11, a prevacuolar compartment SNARE protein. An Arabidopsis thaliana vti11 mutant was completely resistant to TuMV infection. We conclude that TuMV replication vesicles bypass the Golgi apparatus and take an unconventional pathway that may involve prevacuolar compartments/multivesicular bodies for virus infection.
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Affiliation(s)
- Daniel Garcia Cabanillas
- Institut National de la Recherche Scientifique, Institut Armand-Frappier, Laval, Québec H7V 1B7, Canada
| | - Jun Jiang
- Institut National de la Recherche Scientifique, Institut Armand-Frappier, Laval, Québec H7V 1B7, Canada
| | - Nooshin Movahed
- Department of Biology, McGill University, Montréal, Québec H3A 1B1, Canada
| | - Hugo Germain
- Department of Chemistry, Biochemistry, and Physics, Université du Québec à Trois-Rivières, Trois-Rivières, Québec G9A 5H7, Canada
| | - Yasuyuki Yamaji
- Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo 1138657, Japan
| | - Huanquan Zheng
- Department of Biology, McGill University, Montréal, Québec H3A 1B1, Canada
| | - Jean-François Laliberté
- Institut National de la Recherche Scientifique, Institut Armand-Frappier, Laval, Québec H7V 1B7, Canada
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26
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Anjum M, Madsen JS, Espinosa-Gongora C, Jana B, Wiese M, Nielsen DS, Sørensen SJ, Moodley A, Bortolaia V, Guardabassi L. A culture-independent method for studying transfer of IncI1 plasmids from wild-type Escherichia coli in complex microbial communities. J Microbiol Methods 2018; 152:18-26. [PMID: 30030013 DOI: 10.1016/j.mimet.2018.07.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 07/16/2018] [Accepted: 07/16/2018] [Indexed: 11/25/2022]
Abstract
IncI1 plasmids play a central role in the transfer of antimicrobial resistance genes among Enterobacteriaceae in animals and humans. Knowledge on the dynamics of IncI1 plasmid transfer is limited, mainly due to lack of culture-independent methods that can quantify donor strain survival and plasmid transfer in complex microbial communities. The aim of this study was to develop a culture-independent method to study the dynamics of IncI1 plasmids transfer by fluorescence-activated cell sorting. We genetically modified three wild-type Escherichia coli of animal (n = 2) and human (n = 1) origin carrying blaCMY-2 or blaCTX-M-1 on two epidemic IncI1 plasmids (pST12 and pST7). Non-coding regions on the chromosome and on the IncI1 plasmid of each strain were tagged with mCherry (red) and GFPmut3 (green) fluorescent proteins, respectively, using lambda recombineering. A gene cassette expressing mCherry and lacIq was inserted into the chromosome, whereas the plasmid was marked with a GFPmut3 cassette with LacIq repressible promoter. Therefore, gfpmut3 was repressed in donor strains but expressed in recipient strains acquiring the plasmids. We demonstrated that genetic engineering of the strains did not affect the growth rate and plasmid transfer-ability in filter and broth matings. A proof-of-concept experiment using the CoMiniGut, an in vitro model of the colon, proved the validity of our method for studying the survival of wild-type E. coli and horizontal transfer of IncI1 plasmids under different pH and oxygen conditions. The dual-labeling method by fluorescent proteins is useful to determine persistence of exogenous E. coli and transfer dynamics of IncI1 plasmids in microbial communities.
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Affiliation(s)
- Mehreen Anjum
- Department of Veterinary and Animal Sciences, University of Copenhagen, Stigbøjlen 4, 1-20, 1870 Frederiksberg C, Denmark
| | - Jonas Stenløkke Madsen
- Department of Biology, University of Copenhagen 1, Building: 1-1-215, 2100 København Ø, Denmark
| | - Carmen Espinosa-Gongora
- Department of Veterinary and Animal Sciences, University of Copenhagen, Stigbøjlen 4, 1-20, 1870 Frederiksberg C, Denmark
| | - Bimal Jana
- Department of Veterinary and Animal Sciences, University of Copenhagen, Stigbøjlen 4, 1-20, 1870 Frederiksberg C, Denmark
| | - Maria Wiese
- Department of Food Science, University of Copenhagen, Rolighedsvej 26, 1958 Frederiksberg C, Denmark
| | - Dennis Sandris Nielsen
- Department of Food Science, University of Copenhagen, Rolighedsvej 26, 1958 Frederiksberg C, Denmark
| | - Søren Johannes Sørensen
- Department of Biology, University of Copenhagen 1, Building: 1-1-215, 2100 København Ø, Denmark
| | - Arshnee Moodley
- Department of Veterinary and Animal Sciences, University of Copenhagen, Stigbøjlen 4, 1-20, 1870 Frederiksberg C, Denmark
| | - Valeria Bortolaia
- National Food Institute, Technical University of Denmark, Kemitorvet, Building 204, 2800 Kgs. Lyngby, Denmark
| | - Luca Guardabassi
- Department of Veterinary and Animal Sciences, University of Copenhagen, Stigbøjlen 4, 1-20, 1870 Frederiksberg C, Denmark.
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27
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Pinilla-Redondo R, Riber L, Sørensen SJ. Fluorescence Recovery Allows the Implementation of a Fluorescence Reporter Gene Platform Applicable for the Detection and Quantification of Horizontal Gene Transfer in Anoxic Environments. Appl Environ Microbiol 2018; 84:e02507-17. [PMID: 29330182 PMCID: PMC5835726 DOI: 10.1128/aem.02507-17] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2017] [Accepted: 12/20/2017] [Indexed: 02/02/2023] Open
Abstract
The study of horizontal gene transfer (HGT) in microbial communities has been revolutionized by significant advances in cultivation-independent methods based on fluorescence reporter gene technologies. Recently, the combination of these novel approaches with flow cytometry has presented itself as one of the most powerful tools to study the spread of mobile genetic elements (MGEs) in the environment. However, the use of fluorescent markers, like green fluorescent protein (GFP) and mCherry, is limited by environmental constraints, such as oxygen availability and pH levels, that affect the correct maturation of their fluorophores. Few studies have characterized the effects of such environmental conditions in a systematic way, and the sheer amount of distinct protein variants requires each system to be examined in an individual fashion. The lack of efficient and reliable markers to monitor HGT in anaerobic environments, coupled to the abundance of ecologically and clinically relevant oxygen-deprived niches in which bacteria thrive, calls for the urgent development of suitable tools that permit its study. In an attempt to devise a process that allows the implementation of the mentioned dual-labeling system to anoxic milieus, the aerobic fluorescence recovery of mCherry and GFPmut3, as well as the effect of pH on their fluorescence intensities, was studied. The findings present a solution to an intrinsic problem that has long hampered the utilization of this system, highlight its pH limitations, and provide experimental tools that will help broaden its horizon of application to other fields.IMPORTANCE Many anaerobic environments, like the gastrointestinal tract, anaerobic digesters, and the interiors of dense biofilms, have been shown to be hotspots for horizontal gene transfer (HGT). Despite the increasing wealth of reports warning about the alarming spread of antibiotic resistance determinants, to date, HGT studies mainly rely on cultivation-based methods. Unfortunately, the relevance of these studies is often questionable, as only a minor fraction of bacteria can be cultivated. A recently developed approach to monitoring the fate of plasmids in microbial communities is based on a fluorescence dual-labeling system and allows the bypassing of cultivation. However, the fluorescent proteins on which it is founded are constrained by pH levels and by their strict dependence on oxygen for the maturation of their fluorophores. This study focused on the development and validation of an appropriate aerobic fluorescence recovery (AFR) method for this platform, as this embodies the missing technical link impeding its implementation in anoxic environments.
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Affiliation(s)
| | - Leise Riber
- Section of Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Søren J Sørensen
- Section of Microbiology, University of Copenhagen, Copenhagen, Denmark
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28
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Preparing thin cross sections of Arabidopsis roots without embedding. Biotechniques 2017; 63:281-283. [DOI: 10.2144/000114621] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 11/01/2017] [Indexed: 11/23/2022] Open
Abstract
Here, we describe a method for obtaining thin cross sections of Arabidopsis thaliana roots without fixation and embedding. Roots were grown in pinholes made in a solidified growth medium, and cross sections were prepared without pretreatment. Using this method, we detected unique distributions of two polar-localized proteins—green fluorescent protein (GFP)-tagged BOR1 and NIP5;1—with less sample preparation time than conventional methods. This method is simple, rapid, and yields high-quality cross-section images that are free from artifacts commonly associated with embedding or the sample preparation procedures used in many conventional methods.
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29
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Morita M, Sawaki K, Kinoshita D, Sakurai C, Hori N, Hatsuzawa K. Quantitative analysis of phagosome formation and maturation using an Escherichia coli probe expressing a tandem fluorescent protein. J Biochem 2017; 162:309-316. [PMID: 28575453 DOI: 10.1093/jb/mvx034] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 05/11/2017] [Indexed: 11/14/2022] Open
Abstract
Phagosome formation and maturation are essential innate immune mechanisms to engulf and digest foreign particles. To analyze these processes quantitatively, we established a specific Escherichia coli probe expressing a tandem fluorescent protein, comprising glutathione S-transferase fused with monomeric Cherry (mCherry) and monomeric Venus (mVenus). We demonstrated that mVenus was more susceptible to bleaching in an acidic environment than mCherry, and that the mVenus:mCherry fluorescence intensity ratio can be used to monitor phagosomal pH changes during maturation. Using this probe, we revealed that synaptosomal-associated protein of 23 kDa, a plasma membrane soluble N-ethylmaleimide-sensitive factor attachment protein receptor protein, actively regulated phagocytosis of E. coli and subsequent phagosome maturation in macrophages. Our results indicated that this probe has the potential to be a powerful tool in understanding the molecular mechanisms of phagosome formation and maturation.
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Affiliation(s)
- Maya Morita
- Division of Molecular Biology, School of Life Sciences, Faculty of Medicine, Tottori University, Yonago, Tottori 683-8503, Japan
| | - Kazumasa Sawaki
- Division of Molecular Biology, School of Life Sciences, Faculty of Medicine, Tottori University, Yonago, Tottori 683-8503, Japan
| | - Daiki Kinoshita
- Division of Molecular Biology, School of Life Sciences, Faculty of Medicine, Tottori University, Yonago, Tottori 683-8503, Japan
| | - Chiye Sakurai
- Division of Molecular Biology, School of Life Sciences, Faculty of Medicine, Tottori University, Yonago, Tottori 683-8503, Japan
| | - Naohiro Hori
- Division of Molecular Biology, School of Life Sciences, Faculty of Medicine, Tottori University, Yonago, Tottori 683-8503, Japan
| | - Kiyotaka Hatsuzawa
- Division of Molecular Biology, School of Life Sciences, Faculty of Medicine, Tottori University, Yonago, Tottori 683-8503, Japan
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30
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Kong M, Shin JH, Heu S, Park JK, Ryu S. Lateral flow assay-based bacterial detection using engineered cell wall binding domains of a phage endolysin. Biosens Bioelectron 2017; 96:173-177. [PMID: 28494369 DOI: 10.1016/j.bios.2017.05.010] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 04/28/2017] [Accepted: 05/04/2017] [Indexed: 10/19/2022]
Abstract
The development of a cost-effective and efficient bacterial detection assay is essential for diagnostic fields, particularly in resource-poor settings. Although antibodies have been widely used for bacterial capture, the production of soluble antibodies is still expensive and time-consuming. Here, we developed a nitrocellulose-based lateral flow assay using cell wall binding domains (CBDs) from phage as a recognition element and colloidal gold nanoparticles as a colorimetric signal for the detection of a model pathogenic bacterium, Bacillus cereus (B. cereus). To improve conjugation efficiency and detection sensitivity, cysteine-glutathione-S-transferase-tagged CBDs and maltose-binding protein-tagged CBDs were produced in Escherichia coli (E. coli) and incorporated in our assays. The sensitivity of the strip to detect B. cereus was 1×104 CFU/mL and the overall assay time was 20min. The assay showed superior results compared to the antibody-based approach, and did not show any significant cross-reactivity. This proof of concept study indicates that the lateral flow assay using engineered CBDs hold considerable promise as simple, rapid, and cost-effective biosensors for whole cell detection.
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Affiliation(s)
- Minsuk Kong
- Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, Center for Food and Bioconvergence, Research Institute of Agriculture and Life Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Joong Ho Shin
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Sunggi Heu
- Crop Cultivation and Environment Research Division, National Institute of Crop Science, RDA, Suwon 16429, Republic of Korea
| | - Je-Kyun Park
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea.
| | - Sangryeol Ryu
- Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, Center for Food and Bioconvergence, Research Institute of Agriculture and Life Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea.
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31
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Fougère A, Jackson AP, Paraskevi Bechtsi D, Braks JAM, Annoura T, Fonager J, Spaccapelo R, Ramesar J, Chevalley-Maurel S, Klop O, van der Laan AMA, Tanke HJ, Kocken CHM, Pasini EM, Khan SM, Böhme U, van Ooij C, Otto TD, Janse CJ, Franke-Fayard B. Variant Exported Blood-Stage Proteins Encoded by Plasmodium Multigene Families Are Expressed in Liver Stages Where They Are Exported into the Parasitophorous Vacuole. PLoS Pathog 2016; 12:e1005917. [PMID: 27851824 PMCID: PMC5113031 DOI: 10.1371/journal.ppat.1005917] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 09/06/2016] [Indexed: 01/05/2023] Open
Abstract
Many variant proteins encoded by Plasmodium-specific multigene families are exported into red blood cells (RBC). P. falciparum-specific variant proteins encoded by the var, stevor and rifin multigene families are exported onto the surface of infected red blood cells (iRBC) and mediate interactions between iRBC and host cells resulting in tissue sequestration and rosetting. However, the precise function of most other Plasmodium multigene families encoding exported proteins is unknown. To understand the role of RBC-exported proteins of rodent malaria parasites (RMP) we analysed the expression and cellular location by fluorescent-tagging of members of the pir, fam-a and fam-b multigene families. Furthermore, we performed phylogenetic analyses of the fam-a and fam-b multigene families, which indicate that both families have a history of functional differentiation unique to RMP. We demonstrate for all three families that expression of family members in iRBC is not mutually exclusive. Most tagged proteins were transported into the iRBC cytoplasm but not onto the iRBC plasma membrane, indicating that they are unlikely to play a direct role in iRBC-host cell interactions. Unexpectedly, most family members are also expressed during the liver stage, where they are transported into the parasitophorous vacuole. This suggests that these protein families promote parasite development in both the liver and blood, either by supporting parasite development within hepatocytes and erythrocytes and/or by manipulating the host immune response. Indeed, in the case of Fam-A, which have a steroidogenic acute regulatory-related lipid transfer (START) domain, we found that several family members can transfer phosphatidylcholine in vitro. These observations indicate that these proteins may transport (host) phosphatidylcholine for membrane synthesis. This is the first demonstration of a biological function of any exported variant protein family of rodent malaria parasites. Malaria-parasites invade and multiply in hepatocytes and erythrocytes. The human parasite P. falciparum transports proteins encoded by multigene families onto the surface of erythrocytes, mediating interactions between infected red blood cells (iRBCs) and other host-cells and are thought to play a key role in parasite survival during blood-stage development. The function of other exported Plasmodium protein families remains largely unknown. We provide novel insights into expression and cellular location of proteins encoded by three large multigene families of rodent malaria parasites (Fam-a, Fam-b and PIR). Multiple members of the same family are expressed in a single iRBC, unlike P. falciparum PfEMP1 proteins where individual iRBCs express only a single member. Most proteins we examined are located in the RBC cytoplasm and are not transported onto the iRBC surface membrane, indicating that these proteins are unlikely to mediate interactions between iRBCs and host-cells. Unexpectedly, liver stages also express many of these proteins, where they locate to the vacuole surrounding the parasite inside the hepatocyte. In support of a role of these proteins for parasite growth within their host cells we provide evidence that Fam-A proteins have a role in uptake and transport of (host) phosphatidylcholine for parasite-membrane synthesis.
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Affiliation(s)
- Aurélie Fougère
- Leiden Malaria Research Group, Parasitology, Center of infectious Diseases, Leiden University Medical Center (LUMC), Leiden, The Netherlands
- Department of Experimental Medicine, University of Perugia, Italy
| | - Andrew P. Jackson
- Department of Infection Biology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UnitedKingdom
| | | | - Joanna A. M. Braks
- Leiden Malaria Research Group, Parasitology, Center of infectious Diseases, Leiden University Medical Center (LUMC), Leiden, The Netherlands
| | - Takeshi Annoura
- Leiden Malaria Research Group, Parasitology, Center of infectious Diseases, Leiden University Medical Center (LUMC), Leiden, The Netherlands
- Department of Department of Parasitology, National Institute of Infectious Diseases (NIID), Tokyo, Japan
| | - Jannik Fonager
- Leiden Malaria Research Group, Parasitology, Center of infectious Diseases, Leiden University Medical Center (LUMC), Leiden, The Netherlands
- Department of Microbiological Diagnostics and Virology, Statens Serum Institute, Copenhagen, Denmark
| | | | - Jai Ramesar
- Leiden Malaria Research Group, Parasitology, Center of infectious Diseases, Leiden University Medical Center (LUMC), Leiden, The Netherlands
| | - Séverine Chevalley-Maurel
- Leiden Malaria Research Group, Parasitology, Center of infectious Diseases, Leiden University Medical Center (LUMC), Leiden, The Netherlands
| | - Onny Klop
- Leiden Malaria Research Group, Parasitology, Center of infectious Diseases, Leiden University Medical Center (LUMC), Leiden, The Netherlands
- Biomedical Primate Research Centre (BPRC), Rijswijk, The Netherlands
| | | | - Hans J. Tanke
- Department of Molecular Cell Biology, Leiden University Medical Center (LUMC), Leiden, The Netherlands
| | | | - Erica M. Pasini
- Biomedical Primate Research Centre (BPRC), Rijswijk, The Netherlands
| | - Shahid M. Khan
- Leiden Malaria Research Group, Parasitology, Center of infectious Diseases, Leiden University Medical Center (LUMC), Leiden, The Netherlands
| | - Ulrike Böhme
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, UnitedKingdom
| | - Christiaan van Ooij
- The Francis Crick Institute, Mill Hill Laboratory, Mill Hill, London, UnitedKingdom
| | - Thomas D. Otto
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, UnitedKingdom
| | - Chris J. Janse
- Leiden Malaria Research Group, Parasitology, Center of infectious Diseases, Leiden University Medical Center (LUMC), Leiden, The Netherlands
| | - Blandine Franke-Fayard
- Leiden Malaria Research Group, Parasitology, Center of infectious Diseases, Leiden University Medical Center (LUMC), Leiden, The Netherlands
- * E-mail:
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32
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Al-Sady B, Greenstein RA, El-Samad HJ, Braun S, Madhani HD. Sensitive and Quantitative Three-Color Protein Imaging in Fission Yeast Using Spectrally Diverse, Recoded Fluorescent Proteins with Experimentally-Characterized In Vivo Maturation Kinetics. PLoS One 2016; 11:e0159292. [PMID: 27479698 PMCID: PMC4968791 DOI: 10.1371/journal.pone.0159292] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2016] [Accepted: 06/30/2016] [Indexed: 11/29/2022] Open
Abstract
Schizosaccharomyces pombe is an outstanding model organism for cell biological investigations, yet the range of useful and well-characterized fluorescent proteins (XFPs) is limited. We generated and characterized three recoded fluorescent proteins for 3-color analysis in S.pombe, Super-folder GFP, monomeric Kusabira Orange 2 and E2Crimson. Upon optimization and expression in S. pombe, the three proteins enabled sensitive simultaneous 3-color detection capability. Furthermore, we describe a strategy that combines a pulse-chase approach and mathematical modeling to quantify the maturation kinetics of these proteins in vivo. We observed maturation kinetics in S. pombe that are expected from those described for these proteins in vitro and/or in other cell types, but also unpredicted behaviors. Our studies provide a kinetically-characterized, integrated three-color XFP toolbox for S. pombe.
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Affiliation(s)
- Bassem Al-Sady
- Department of Microbiology and Immunology, the GW Hooper Foundation, University of California San Francisco, San Francisco, California 94143, United States of America
- * E-mail: (BA-S); (HDM)
| | - Rachel A. Greenstein
- Department of Microbiology and Immunology, the GW Hooper Foundation, University of California San Francisco, San Francisco, California 94143, United States of America
- TETRAD graduate program, University of California San Francisco, San Francisco, California 94143, United States of America
| | - Hana J. El-Samad
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, California 94143, United States of America
| | - Sigurd Braun
- Department of Physiological Chemistry, Biomedical Center, Ludwigs-Maximilians-University of Munich, 82152 Martinsried, Germany
| | - Hiten D. Madhani
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, California 94143, United States of America
- * E-mail: (BA-S); (HDM)
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33
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Wang X, Koehler SA, Wilking JN, Sinha NN, Cabeen MT, Srinivasan S, Seminara A, Rubinstein S, Sun Q, Brenner MP, Weitz DA. Probing phenotypic growth in expanding Bacillus subtilis biofilms. Appl Microbiol Biotechnol 2016; 100:4607-15. [PMID: 27003268 DOI: 10.1007/s00253-016-7461-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2016] [Revised: 02/26/2016] [Accepted: 03/10/2016] [Indexed: 12/19/2022]
Abstract
We develop an optical imaging technique for spatially and temporally tracking biofilm growth and the distribution of the main phenotypes of a Bacillus subtilis strain with a triple-fluorescent reporter for motility, matrix production, and sporulation. We develop a calibration procedure for determining the biofilm thickness from the transmission images, which is based on Beer-Lambert's law and involves cross-sectioning of biofilms. To obtain the phenotype distribution, we assume a linear relationship between the number of cells and their fluorescence and determine the best combination of calibration coefficients that matches the total number of cells for all three phenotypes and with the total number of cells from the transmission images. Based on this analysis, we resolve the composition of the biofilm in terms of motile, matrix-producing, sporulating cells and low-fluorescent materials which includes matrix and cells that are dead or have low fluorescent gene expression. We take advantage of the circular growth to make kymograph plots of all three phenotypes and the dominant phenotype in terms of radial distance and time. To visualize the nonlocal character of biofilm growth, we also make kymographs using the local colonization time. Our technique is suitable for real-time, noninvasive, quantitative studies of the growth and phenotype distribution of biofilms which are either exposed to different conditions such as biocides, nutrient depletion, dehydration, or waste accumulation.
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Affiliation(s)
- Xiaoling Wang
- School of Mechanical Engineering, University of Science and Technology Beijing, Beijing, 100083, China. .,School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, 02138, USA.
| | - Stephan A Koehler
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, 02138, USA
| | - James N Wilking
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, 02138, USA.,Department of Chemical and Biological Engineering, Montana State University, Bozeman, MT, 59717-3920, USA
| | - Naveen N Sinha
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, 02138, USA
| | - Matthew T Cabeen
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Siddarth Srinivasan
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, 02138, USA
| | - Agnese Seminara
- CNRS, LPMC UMR 7336, Université Nice Sophia Antipolis, Parc Valrose, 06108, Nice, France
| | - Shmuel Rubinstein
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, 02138, USA
| | - Qingping Sun
- Department of Mechanical Engineering, The Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Michael P Brenner
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, 02138, USA
| | - David A Weitz
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, 02138, USA. .,Department of Physics, Harvard University, Cambridge, MA, 02138, USA.
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34
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Karimi S, Ahl D, Vågesjö E, Holm L, Phillipson M, Jonsson H, Roos S. In Vivo and In Vitro Detection of Luminescent and Fluorescent Lactobacillus reuteri and Application of Red Fluorescent mCherry for Assessing Plasmid Persistence. PLoS One 2016; 11:e0151969. [PMID: 27002525 PMCID: PMC4803345 DOI: 10.1371/journal.pone.0151969] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 03/07/2016] [Indexed: 01/08/2023] Open
Abstract
Lactobacillus reuteri is a symbiont that inhabits the gastrointestinal (GI) tract of mammals, and several strains are used as probiotics. After introduction of probiotic strains in a complex ecosystem like the GI tract, keeping track of them is a challenge. The main objectives of this study were to introduce reporter proteins that would enable in vivo and in vitro detection of L. reuteri and increase knowledge about its interactions with the host. We describe for the first time cloning of codon-optimized reporter genes encoding click beetle red luciferase (CBRluc) and red fluorescent protein mCherry in L. reuteri strains ATCC PTA 6475 and R2LC. The plasmid persistence of mCherry-expressing lactobacilli was evaluated by both flow cytometry (FCM) and conventional plate count (PC), and the plasmid loss rates measured by FCM were lower overall than those determined by PC. Neutralization of pH and longer induction duration significantly improved the mCherry signal. The persistency, dose-dependent signal intensity and localization of the recombinant bacteria in the GI tract of mice were studied with an in vivo imaging system (IVIS), which allowed us to detect fluorescence from 6475-CBRluc-mCherry given at a dose of 1×1010 CFU and luminescence signals at doses ranging from 1×105 to 1×1010 CFU. Both 6475-CBRluc-mCherry and R2LC-CBRluc were localized in the colon 1 and 2 h after ingestion, but the majority of the latter were still found in the stomach, possibly reflecting niche specificity for R2LC. Finally, an in vitro experiment showed that mCherry-producing R2LC adhered efficiently to the intra cellular junctions of cultured IPEC-J2 cells. In conclusion, the two reporter genes CBRluc and mCherry were shown to be suitable markers for biophotonic imaging (BPI) of L. reuteri and may provide useful tools for future studies of in vivo and in vitro interactions between the bacteria and the host.
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Affiliation(s)
- Shokoufeh Karimi
- Department of Microbiology, Uppsala BioCenter, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - David Ahl
- Department of Medical Cell Biology, Biomedical Center, Uppsala University, Uppsala, Sweden
| | - Evelina Vågesjö
- Department of Medical Cell Biology, Biomedical Center, Uppsala University, Uppsala, Sweden
| | - Lena Holm
- Department of Medical Cell Biology, Biomedical Center, Uppsala University, Uppsala, Sweden
| | - Mia Phillipson
- Department of Medical Cell Biology, Biomedical Center, Uppsala University, Uppsala, Sweden
| | - Hans Jonsson
- Department of Microbiology, Uppsala BioCenter, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Stefan Roos
- Department of Microbiology, Uppsala BioCenter, Swedish University of Agricultural Sciences, Uppsala, Sweden
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35
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Rajkovic A, Hummels KR, Witzky A, Erickson S, Gafken PR, Whitelegge JP, Faull KF, Kearns DB, Ibba M. Translation Control of Swarming Proficiency in Bacillus subtilis by 5-Amino-pentanolylated Elongation Factor P. J Biol Chem 2016; 291:10976-85. [PMID: 27002156 DOI: 10.1074/jbc.m115.712091] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Indexed: 01/02/2023] Open
Abstract
Elongation factor P (EF-P) accelerates diprolyl synthesis and requires a posttranslational modification to maintain proteostasis. Two phylogenetically distinct EF-P modification pathways have been described and are encoded in the majority of Gram-negative bacteria, but neither is present in Gram-positive bacteria. Prior work suggested that the EF-P-encoding gene (efp) primarily supports Bacillus subtilis swarming differentiation, whereas EF-P in Gram-negative bacteria has a more global housekeeping role, prompting our investigation to determine whether EF-P is modified and how it impacts gene expression in motile cells. We identified a 5-aminopentanol moiety attached to Lys(32) of B. subtilis EF-P that is required for swarming motility. A fluorescent in vivo B. subtilis reporter system identified peptide motifs whose efficient synthesis was most dependent on 5-aminopentanol EF-P. Examination of the B. subtilis genome sequence showed that these EF-P-dependent peptide motifs were represented in flagellar genes. Taken together, these data show that, in B. subtilis, a previously uncharacterized posttranslational modification of EF-P can modulate the synthesis of specific diprolyl motifs present in proteins required for swarming motility.
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Affiliation(s)
- Andrei Rajkovic
- From the Molecular, Cellular, and Developmental Biology Program and Center for RNA Biology and
| | | | | | | | - Philip R Gafken
- the Proteomics Facility, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, and
| | - Julian P Whitelegge
- the Pasarow Mass Spectrometry Laboratory, Semel Institute for Neuroscience and Human Behavior, and Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, UCLA, Los Angeles, California 90095
| | - Kym F Faull
- the Pasarow Mass Spectrometry Laboratory, Semel Institute for Neuroscience and Human Behavior, and Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, UCLA, Los Angeles, California 90095
| | - Daniel B Kearns
- the Department of Biology, Indiana University, Bloomington, Indiana 47305
| | - Michael Ibba
- From the Molecular, Cellular, and Developmental Biology Program and Center for RNA Biology and Microbiology, Ohio State University, Columbus, Ohio 43210,
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36
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Barns KJ, Weisshaar JC. Single-cell, time-resolved study of the effects of the antimicrobial peptide alamethicin on Bacillus subtilis. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:725-32. [PMID: 26777771 DOI: 10.1016/j.bbamem.2016.01.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 01/05/2016] [Accepted: 01/07/2016] [Indexed: 12/14/2022]
Abstract
Alamethicin is a well-studied antimicrobial peptide (AMP) that kills Gram-positive bacteria. It forms narrow, barrel-stave pores in planar lipid bilayers. We present a detailed, time-resolved microscopy study of the sequence of events during the attack of alamethicin on individual, live Bacillus subtilis cells expressing GFP in the cytoplasm. At the minimum inhibitory concentration (MIC), the first observed symptom is the halting of growth, as judged by the plateau in measured cell length vs time. The data strongly suggest that this growth-halting event occurs prior to membrane permeabilization. Gradual degradation of the proton-motive force, inferred from a decrease in pH-dependent GFP fluorescence intensity, evidently begins minutes later and continues over about 5 min. There follows an abrupt permeabilization of the cytoplasmic membrane to the DNA stain Sytox Orange and concomitant loss of small osmolytes, causing observable cell shrinkage, presumably due to decreased turgor pressure. This permeabilization of the cytoplasmic membrane occurs uniformly across the entire membrane, not locally, on a timescale of 5s or less. GFP gradually leaks out of the cell envelope, evidently impeded by the shrunken peptidoglycan layer. Disruption of the cell envelope by alamethicin occurs in stages, with larger and larger species permeating the envelope as time evolves over tens of minutes. Some of the observed symptoms are consistent with the formation of barrel-stave pores, but the data do not rule out "chaotic pore" or "carpet" mechanisms. We contrast the effects of alamethicin and the human cathelicidin LL-37 on B. subtilis.
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Affiliation(s)
- Kenneth J Barns
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA
| | - James C Weisshaar
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA; Molecular Biophysics Program, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA.
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37
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van Zyl WF, Deane SM, Dicks LMT. Reporter systems for in vivo tracking of lactic acid bacteria in animal model studies. Gut Microbes 2015; 6:291-9. [PMID: 26516656 PMCID: PMC4826117 DOI: 10.1080/19490976.2015.1086058] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Bioluminescence (BLI) and fluorescence imaging (FI) allow for non-invasive detection of viable microorganisms from within living tissue and are thus ideally suited for in vivo probiotic studies. Highly sensitive optical imaging techniques detect signals from the excitation of fluorescent proteins, or luciferase-catalyzed oxidation reactions. The excellent relation between microbial numbers and photon emission allow for quantification of tagged bacteria in vivo with extreme accuracy. More information is gained over a shorter period compared to traditional pre-clinical animal studies. The review summarizes the latest advances in in vivo bioluminescence and fluorescence imaging and points out the advantages and limitations of different techniques. The practical application of BLI and FI in the tracking of lactic acid bacteria in animal models is addressed.
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Affiliation(s)
- Winschau F van Zyl
- Department of Microbiology; Stellenbosch University; Matieland, Stellenbosch, South Africa
| | - Shelly M Deane
- Department of Microbiology; Stellenbosch University; Matieland, Stellenbosch, South Africa
| | - Leon M T Dicks
- Department of Microbiology; Stellenbosch University; Matieland, Stellenbosch, South Africa,Correspondence to: Leon M T Dicks;
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38
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van Zyl WF, Deane SM, Dicks LMT. Use of the mCherry Fluorescent Protein To Study Intestinal Colonization by Enterococcus mundtii ST4SA and Lactobacillus plantarum 423 in Mice. Appl Environ Microbiol 2015; 81:5993-6002. [PMID: 26116681 PMCID: PMC4551250 DOI: 10.1128/aem.01247-15] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 05/22/2015] [Indexed: 12/19/2022] Open
Abstract
Lactic acid bacteria (LAB) are natural inhabitants of the gastrointestinal tract (GIT) of humans and animals, and some LAB species receive considerable attention due to their health benefits. Although many papers have been published on probiotic LAB, only a few reports have been published on the migration and colonization of the cells in the GIT. This is due mostly to the lack of efficient reporter systems. In this study, we report on the application of the fluorescent mCherry protein in the in vivo tagging of the probiotic strains Enterococcus mundtii ST4SA and Lactobacillus plantarum 423. The mCherry gene, encoding a red fluorescent protein (RFP), was integrated into a nonfunctional region on the genome of L. plantarum 423 by homologous recombination. In the case of E. mundtii ST4SA, the mCherry gene was cloned into the pGKV223D LAB/Escherichia coli expression vector. Expression of the mCherry gene did not alter the growth rate of the two strains and had no effect on bacteriocin production. Both strains colonized the cecum and colon of mice.
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Affiliation(s)
- Winschau F van Zyl
- Department of Microbiology, University of Stellenbosch, Stellenbosch, South Africa
| | - Shelly M Deane
- Department of Microbiology, University of Stellenbosch, Stellenbosch, South Africa
| | - Leon M T Dicks
- Department of Microbiology, University of Stellenbosch, Stellenbosch, South Africa
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39
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Abstract
Elongation factor P (EF-P) is a ubiquitous bacterial protein that is required for the synthesis of poly-proline motifs during translation. In Escherichia coli and Salmonella enterica, the posttranslational β-lysylation of Lys34 by the PoxA protein is critical for EF-P activity. PoxA is absent from many bacterial species such as Pseudomonas aeruginosa, prompting a search for alternative EF-P posttranslation modification pathways. Structural analyses of P. aeruginosa EF-P revealed the attachment of a single cyclic rhamnose moiety to an Arg residue at a position equivalent to that at which β-Lys is attached to E. coli EF-P. Analysis of the genomes of organisms that both lack poxA and encode an Arg32-containing EF-P revealed a highly conserved glycosyltransferase (EarP) encoded at a position adjacent to efp. EF-P proteins isolated from P. aeruginosa ΔearP, or from a ΔrmlC::acc1 strain deficient in dTDP-l-rhamnose biosynthesis, were unmodified. In vitro assays confirmed the ability of EarP to use dTDP-l-rhamnose as a substrate for the posttranslational glycosylation of EF-P. The role of rhamnosylated EF-P in translational control was investigated in P. aeruginosa using a Pro4-green fluorescent protein (Pro4GFP) in vivo reporter assay, and the fluorescence was significantly reduced in Δefp, ΔearP, and ΔrmlC::acc1 strains. ΔrmlC::acc1, ΔearP, and Δefp strains also displayed significant increases in their sensitivities to a range of antibiotics, including ertapenem, polymyxin B, cefotaxim, and piperacillin. Taken together, our findings indicate that posttranslational rhamnosylation of EF-P plays a key role in P. aeruginosa gene expression and survival. Infections with pathogenic Salmonella, E. coli, and Pseudomonas isolates can all lead to infectious disease with potentially fatal sequelae. EF-P proteins contribute to the pathogenicity of the causative agents of these and other diseases by controlling the translation of proteins critical for modulating antibiotic resistance, motility, and other traits that play key roles in establishing virulence. In Salmonella spp. and E. coli, the attachment of β-Lys is required for EF-P activity, but the proteins required for this posttranslational modification pathway are absent from many organisms. Instead, bacteria such as P. aeruginosa activate EF-P by posttranslational modification with rhamnose, revealing a new role for protein glycosylation that may also prove useful as a target for the development of novel antibiotics.
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40
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Schuster M, Kilaru S, Guo M, Sommerauer M, Lin C, Steinberg G. Red fluorescent proteins for imaging Zymoseptoria tritici during invasion of wheat. Fungal Genet Biol 2015; 79:132-40. [PMID: 26092800 PMCID: PMC4502450 DOI: 10.1016/j.fgb.2015.03.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 03/12/2015] [Accepted: 03/25/2015] [Indexed: 10/28/2022]
Abstract
The use of fluorescent proteins (FPs) in plant pathogenic fungi provides valuable insight into their intracellular dynamics, cell organization and invasion mechanisms. Compared with green-fluorescent proteins, their red-fluorescent "cousins" show generally lower fluorescent signal intensity and increased photo-bleaching. However, the combined usage of red and green fluorescent proteins allows powerful insight in co-localization studies. Efficient signal detection requires a bright red-fluorescent protein (RFP), combined with a suitable corresponding filter set. We provide a set of four vectors, suitable for yeast recombination-based cloning that carries mRFP, TagRFP, mCherry and tdTomato. These vectors confer carboxin resistance after targeted single-copy integration into the sdi1 locus of Zymoseptoria tritici. Expression of the RFPs does not affect virulence of this wheat pathogen. We tested all four RFPs in combination with four epi-fluorescence filter sets and in confocal laser scanning microscopy, both in and ex planta. Our data reveal that mCherry is the RFP of choice for investigation in Z. tritici, showing highest signal intensity in epi-fluorescence, when used with a Cy3 filter set, and laser scanning confocal microscopy. However, mCherry bleached significantly faster than mRFP, which favors this red tag in long-term observation experiments. Finally, we used dual-color imaging of eGFP and mCherry expressing wild-type strains in planta and show that pycnidia are formed by single strains. This demonstrates the strength of this method in tracking the course of Z. tritici infection in wheat.
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Affiliation(s)
- M Schuster
- Biosciences, University of Exeter, Exeter EX4 4QD, UK
| | - S Kilaru
- Biosciences, University of Exeter, Exeter EX4 4QD, UK
| | - M Guo
- Biosciences, University of Exeter, Exeter EX4 4QD, UK
| | - M Sommerauer
- AHF Analysentechnik AG, Kohlplattenweg 18, DE-72074 Tübingen, Germany
| | - C Lin
- Mathematics, University of Exeter, Exeter EX4 3QF, UK
| | - G Steinberg
- Biosciences, University of Exeter, Exeter EX4 4QD, UK.
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41
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Bukowska-Faniband E, Hederstedt L. The PASTA domain of penicillin-binding protein SpoVD is dispensable for endospore cortex peptidoglycan assembly in Bacillus subtilis. Microbiology (Reading) 2015; 161:330-340. [DOI: 10.1099/mic.0.000011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Ewa Bukowska-Faniband
- Microbiology Group, Department of Biology, Lund University, Biology Building A, Sölvegatan 35, SE-223 62 Lund, Sweden
| | - Lars Hederstedt
- Microbiology Group, Department of Biology, Lund University, Biology Building A, Sölvegatan 35, SE-223 62 Lund, Sweden
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42
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Ivanov S, Harrison MJ. A set of fluorescent protein-based markers expressed from constitutive and arbuscular mycorrhiza-inducible promoters to label organelles, membranes and cytoskeletal elements in Medicago truncatula. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2014; 80:1151-63. [PMID: 25329881 DOI: 10.1111/tpj.12706] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 10/01/2014] [Accepted: 10/15/2014] [Indexed: 05/24/2023]
Abstract
Medicago truncatula is widely used for analyses of arbuscular mycorrhizal (AM) symbiosis and nodulation. To complement the genetic and genomic resources that exist for this species, we generated fluorescent protein fusions that label the nucleus, endoplasmic reticulum, Golgi apparatus, trans-Golgi network, plasma membrane, apoplast, late endosome/multivesicular bodies (MVB), transitory late endosome/ tonoplast, tonoplast, plastids, mitochondria, peroxisomes, autophagosomes, plasmodesmata, actin, microtubules, periarbuscular membrane (PAM) and periarbuscular apoplastic space (PAS) and expressed them from the constitutive AtUBQ10 promoter and the AM symbiosis-specific MtBCP1 promoter. All marker constructs showed the expected expression patterns and sub-cellular locations in M. truncatula root cells. As a demonstration of their utility, we used several markers to investigate AM symbiosis where root cells undergo major cellular alterations to accommodate their fungal endosymbiont. We demonstrate that changes in the position and size of the nuclei occur prior to hyphal entry into the cortical cells and do not require DELLA signaling. Changes in the cytoskeleton, tonoplast and plastids also occur in the colonized cells and in contrast to previous studies, we show that stromulated plastids are abundant in cells with developing and mature arbuscules, while lens-shaped plastids occur in cells with degenerating arbuscules. Arbuscule development and secretion of the PAM creates a periarbuscular apoplastic compartment which has been assumed to be continuous with apoplast of the cell. However, fluorescent markers secreted to the periarbuscular apoplast challenge this assumption. This marker resource will facilitate cell biology studies of AM symbiosis, as well as other aspects of legume biology.
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Affiliation(s)
- Sergey Ivanov
- Boyce Thompson Institute for Plant Research, Tower Road, Ithaca, NY, 14853, USA
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43
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Couturier L, Trylinski M, Mazouni K, Darnet L, Schweisguth F. A fluorescent tagging approach in Drosophila reveals late endosomal trafficking of Notch and Sanpodo. ACTA ACUST UNITED AC 2014; 207:351-63. [PMID: 25365996 PMCID: PMC4226730 DOI: 10.1083/jcb.201407071] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Signaling and endocytosis are highly integrated processes that regulate cell fate. In the Drosophila melanogaster sensory bristle lineages, Numb inhibits the recycling of Notch and its trafficking partner Sanpodo (Spdo) to regulate cell fate after asymmetric cell division. In this paper, we have used a dual GFP/Cherry tagging approach to study the distribution and endosomal sorting of Notch and Spdo in living pupae. The specific properties of GFP, i.e., quenching at low pH, and Cherry, i.e., slow maturation time, revealed distinct pools of Notch and Spdo: cargoes exhibiting high GFP/low Cherry fluorescence intensities localized mostly at the plasma membrane and early/sorting endosomes, whereas low GFP/high Cherry cargoes accumulated in late acidic endosomes. These properties were used to show that Spdo is sorted toward late endosomes in a Numb-dependent manner. This dual-tagging approach should be generally applicable to study the trafficking dynamics of membrane proteins in living cells and tissues.
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Affiliation(s)
- Lydie Couturier
- Developmental and Stem Cell Biology Department, Institut Pasteur, 75015 Paris, France Centre National de la Recherche Scientifique, URA2578, 75015 Paris, France
| | - Mateusz Trylinski
- Developmental and Stem Cell Biology Department, Institut Pasteur, 75015 Paris, France Centre National de la Recherche Scientifique, URA2578, 75015 Paris, France Master Biosciences, École Normale Supérieure de Lyon, 75015 Paris, France
| | - Khallil Mazouni
- Developmental and Stem Cell Biology Department, Institut Pasteur, 75015 Paris, France Centre National de la Recherche Scientifique, URA2578, 75015 Paris, France
| | - Léa Darnet
- Developmental and Stem Cell Biology Department, Institut Pasteur, 75015 Paris, France Centre National de la Recherche Scientifique, URA2578, 75015 Paris, France
| | - François Schweisguth
- Developmental and Stem Cell Biology Department, Institut Pasteur, 75015 Paris, France Centre National de la Recherche Scientifique, URA2578, 75015 Paris, France
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Withers R, Doherty GP, Jordan M, Yang X, Dixon NE, Lewis PJ. AtfA, a new factor in global regulation of transcription in Acinetobacter spp. Mol Microbiol 2014; 93:1130-43. [PMID: 25047957 DOI: 10.1111/mmi.12723] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/18/2014] [Indexed: 11/29/2022]
Abstract
Acinetobacter species are widely distributed bacteria in the environment, and have recently gained notoriety as opportunistic nosocomial pathogens. Here we characterize a novel RNA polymerase-interacting protein named acidic transcription factor A, AtfA. It is small and highly acidic, and is widely distributed throughout the γ proteobacteria, including other significant pathogens in the genera Moraxella, Pseudomonas, Legionella and Vibrio. In the model species A. baylyi ADP1, deletion of atfA significantly affects expression of over 500 genes, resulting in a large cell phenotype, reduced cell fitness, impaired biofilm formation and twitching motility, and increased sensitivity to antibiotics. Deletion of atfA also causes dramatically enhanced sensitivity to ethanol, which is an important growth promoter and virulence factor in Acinetobacter spp. The results suggest that auxiliary factors of RNA polymerase with important biological roles remain to be discovered.
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Affiliation(s)
- Ryan Withers
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW, Australia
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Hebisch E, Knebel J, Landsberg J, Frey E, Leisner M. High variation of fluorescence protein maturation times in closely related Escherichia coli strains. PLoS One 2013; 8:e75991. [PMID: 24155882 PMCID: PMC3796512 DOI: 10.1371/journal.pone.0075991] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Accepted: 08/22/2013] [Indexed: 02/06/2023] Open
Abstract
Fluorescent proteins (FPs) are widely used in biochemistry, biology and biophysics. For quantitative analysis of gene expression FPs are often used as marking molecules. Therefore, sufficient knowledge of maturation times and their affecting factors is of high interest. Here, we investigate the maturation process of the FPs GFP and mCherry expressed by the three closely related Escherichia coli strains of the Colicin E2 system, a model system for colicinogenic interaction. One strain, the C strain produces Colicin, a toxin to which the S strain is sensitive, and against which the R strain is resistant. Under the growth conditions used in this study, the S and R strain have similar growth rates, as opposed to the C strain whose growth rate is significantly reduced due to the toxin production. In combination with theoretical modelling we studied the maturation kinetics of the two FPs in these strains and could confirm an exponential and sigmoidal maturation kinetic for GFP and mCherry, respectively. Our subsequent quantitative experimental analysis revealed a high variance in maturation times independent of the strain studied. In addition, we determined strain dependent maturation times and maturation behaviour. Firstly, FPs expressed by the S and R strain mature on similar average time-scales as opposed to FPs expressed by the C strain. Secondly, dependencies of maturation time with growth conditions are most pronounced in the GFP expressing C strain: Doubling the growth rate of this C strain results in an increased maturation time by a factor of 1.4. As maturation times can vary even between closely related strains, our data emphasize the importance of profound knowledge of individual strains' maturation times for accurate interpretation of gene expression data.
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Affiliation(s)
- Elke Hebisch
- Department of NanoBiophotonics, Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany
| | - Johannes Knebel
- Arnold-Sommerfeld-Center for Theoretical Physics and Center for NanoScience, Department of Physics, Ludwig-Maximilians Universität München, München, Germany
| | - Janek Landsberg
- Laboratoire Interdisciplinaire de Physique, Universite Joseph Fourier de Grenoble, Saint Martin d'Heres, France
| | - Erwin Frey
- Arnold-Sommerfeld-Center for Theoretical Physics and Center for NanoScience, Department of Physics, Ludwig-Maximilians Universität München, München, Germany
| | - Madeleine Leisner
- Arnold-Sommerfeld-Center for Theoretical Physics and Center for NanoScience, Department of Physics, Ludwig-Maximilians Universität München, München, Germany
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Live-cell imaging tool optimization to study gene expression levels and dynamics in single cells of Bacillus cereus. Appl Environ Microbiol 2013; 79:5643-51. [PMID: 23851094 DOI: 10.1128/aem.01347-13] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Single-cell methods are a powerful application in microbial research to study the molecular mechanism underlying phenotypic heterogeneity and cell-to-cell variability. Here, we describe the optimization and application of single-cell time-lapse fluorescence microscopy for the food spoilage bacterium Bacillus cereus specifically. This technique is useful to study cellular development and adaptation, gene expression, protein localization, protein mobility, and cell-to-cell communication over time at the single-cell level. By adjusting existing protocols, we have enabled the visualization of growth and development of single B. cereus cells within a microcolony over time. Additionally, several different fluorescent reporter proteins were tested in order to select the most suitable green fluorescent protein (GFP) and red fluorescent protein (RFP) candidates for visualization of growth stage- and cell compartment-specific gene expression in B. cereus. With a case study concerning cotD expression during sporulation, we demonstrate the applicability of time-lapse fluorescence microscopy. It enables the assessment of gene expression levels, dynamics, and heterogeneity at the single-cell level. We show that cotD is not heterogeneously expressed among cells of a subpopulation. Furthermore, we discourage using plasmid-based reporter fusions for such studies, due to an introduced heterogeneity through copy number differences. This stresses the importance of using single-copy integrated reporter fusions for single-cell studies.
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