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Protein Fusion Strategies for Membrane Protein Stabilization and Crystal Structure Determination. CRYSTALS 2022. [DOI: 10.3390/cryst12081041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Crystal structures of membrane proteins are highly desired for their use in the mechanistic understanding of their functions and the designing of new drugs. However, obtaining the membrane protein structures is difficult. One way to overcome this challenge is with protein fusion methods, which have been successfully used to determine the structures of many membrane proteins, including receptors, enzymes and adhesion molecules. Existing fusion strategies can be categorized into the N or C terminal fusion, the insertion fusion and the termini restraining. The fusions facilitate protein expression, purification, crystallization and phase determination. Successful applications often require further optimization of protein fusion linkers and interactions, whose design can be facilitated by a shared helix strategy and by AlphaFold prediction in the future.
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Krajewska M, Koprowski P. Solubilization, purification, and functional reconstitution of human ROMK potassium channel in copolymer styrene-maleic acid (SMA) nanodiscs. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2021; 1863:183555. [PMID: 33444624 DOI: 10.1016/j.bbamem.2021.183555] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 12/13/2020] [Accepted: 01/04/2021] [Indexed: 12/18/2022]
Abstract
Expression, purification, and functional reconstitution of mammalian ion channels are often challenging. Heterologous expression of mammalian channels in bacteria can be advantageous due to unrelated protein environment and the lack of risk of copurification of endogenous proteins, e.g., accessory channel subunits that can influence the channel activity. Also, direct recording of channel activity could be challenging due to their intracellular localization like in the case of mitochondrial channels. The activity of purified channels can be characterized at the single-molecule level by electrophysiological techniques, such as planar lipid bilayers (PLB). In this work, we describe a simple approach to accomplish PLB recording of the activity of single renal outer medullary potassium channels ROMK expressed in E. coli. We focused on the ROMK2 isoform that is present at low levels in the mitochondria and can be responsible for mitoKATP activity. We screened for the best construct to express the codon-optimized ROMK proteins with a 6xHis tag for protein purification. The strategy involved the use of optimal styrene-maleic acid (SMA) copolymer, which forms so-called polymer nanodiscs, to solubilize and purify ROMK-containing SMA lipid particles (SMALPs), which were amenable for fusion with PLB. Reconstituted ROMK channels exhibited ion selectivity, rectification, and pharmacological properties, which are in agreement with previous work on ROMK channels.
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Affiliation(s)
- Milena Krajewska
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology PAS, Pasteur str. 3, Warsaw 02-093, Poland
| | - Piotr Koprowski
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology PAS, Pasteur str. 3, Warsaw 02-093, Poland.
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Abarghooi Kahaki F, Monzavi S, Bamehr H, Bandani E, Payandeh Z, Jahangiri A, Khalili S. Expression and Purification of Membrane Proteins in Different Hosts. Int J Pept Res Ther 2020. [DOI: 10.1007/s10989-019-10009-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Alves NS, Astrinidis SA, Eisenhardt N, Sieverding C, Redolfi J, Lorenz M, Weberruss M, Moreno-Andrés D, Antonin W. MISTIC-fusion proteins as antigens for high quality membrane protein antibodies. Sci Rep 2017; 7:41519. [PMID: 28148968 PMCID: PMC5288655 DOI: 10.1038/srep41519] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 12/21/2016] [Indexed: 02/08/2023] Open
Abstract
Lack of high-quality antibodies against transmembrane proteins is a widely recognized hindrance in biomedical and cell biological research. Here we present a robust pipeline for the generation of polyclonal antibodies employing full-length membrane proteins as immunogens to overcome this "antibody bottleneck". We express transmembrane proteins fused to a MISTIC fragment that enhances expression of eukaryotic membrane proteins in E. coli. Purified membrane proteins are used as immunogen for rabbit injection employing standard immunizing protocols. The raised antibodies against membrane proteins of the endoplasmic reticulum and the nuclear envelope, which we use as test cases, function in a wide range of applications and are superior to ones produced against soluble domains as immunogens.
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Affiliation(s)
- Natalia Silva Alves
- Friedrich Miescher Laboratory of the Max Planck Society, Spemannstraße 39, 72076 Tübingen, Germany
| | - Susanne Adina Astrinidis
- Friedrich Miescher Laboratory of the Max Planck Society, Spemannstraße 39, 72076 Tübingen, Germany
| | - Nathalie Eisenhardt
- Friedrich Miescher Laboratory of the Max Planck Society, Spemannstraße 39, 72076 Tübingen, Germany
| | - Cornelia Sieverding
- Friedrich Miescher Laboratory of the Max Planck Society, Spemannstraße 39, 72076 Tübingen, Germany
| | - Josef Redolfi
- Friedrich Miescher Laboratory of the Max Planck Society, Spemannstraße 39, 72076 Tübingen, Germany
| | - Michael Lorenz
- Friedrich Miescher Laboratory of the Max Planck Society, Spemannstraße 39, 72076 Tübingen, Germany
| | - Marion Weberruss
- Friedrich Miescher Laboratory of the Max Planck Society, Spemannstraße 39, 72076 Tübingen, Germany
| | - Daniel Moreno-Andrés
- Friedrich Miescher Laboratory of the Max Planck Society, Spemannstraße 39, 72076 Tübingen, Germany
| | - Wolfram Antonin
- Friedrich Miescher Laboratory of the Max Planck Society, Spemannstraße 39, 72076 Tübingen, Germany
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Yadav DK, Yadav N, Yadav S, Haque S, Tuteja N. An insight into fusion technology aiding efficient recombinant protein production for functional proteomics. Arch Biochem Biophys 2016; 612:57-77. [DOI: 10.1016/j.abb.2016.10.012] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 10/15/2016] [Accepted: 10/18/2016] [Indexed: 11/27/2022]
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Snijder HJA, Hakulinen J. Membrane Protein Production in E. coli for Applications in Drug Discovery. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 896:59-77. [PMID: 27165319 DOI: 10.1007/978-3-319-27216-0_5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Producing high quality purified membrane proteins for structure-based drug design and biophysical assays compatible with typical timelines in drug discovery is a significant challenge. Escherichia coli has been an expression host of the utmost importance for soluble proteins and has applications for membrane proteins as well. However, membrane protein overexpression in E. coli may lead to toxicity and low yields of functional product. Here, we review the challenges encountered with heterologous overproduction of α-helical membrane proteins in E. coli and a range of strategies to overcome them. A detailed protocol is also provided for expression and screening of membrane proteins in E. coli using a His-specific fluorescent probe and fluorescent size-exclusion chromatography.
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Affiliation(s)
| | - Jonna Hakulinen
- Discovery Sciences, AstraZeneca R&D, SE-43183, Mölndal, Sweden
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Zhu LW, Zhang L, Wei LN, Li HM, Yuan ZP, Chen T, Tang YL, Liang XH, Tang YJ. Collaborative regulation of CO2 transport and fixation during succinate production in Escherichia coli. Sci Rep 2015; 5:17321. [PMID: 26626308 PMCID: PMC4667291 DOI: 10.1038/srep17321] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 10/19/2015] [Indexed: 02/05/2023] Open
Abstract
In Escherichia coli, succinic acid is synthesized by CO2 fixation-based carboxylation of C3 metabolites. A two-step process is involved in CO2 integration: CO2 uptake into the cell and CO2 fixation by carboxylation enzymes. The phosphoenolpyruvate (PEP) carboxylase (PPC) and carboxykinase (PCK) are two important carboxylation enzymes within the succinate synthetic pathway, while SbtA and BicA are two important bicarbonate transporters. In this study, we employed a dual expression system, in which genes regulating both CO2 uptake and fixation were co-overexpressed, or overexpressed individually to improve succinate biosynthesis. Active CO2 uptake was observed by the expression of SbtA or/and BicA, but the succinate biosynthesis was decreased. The succinate production was significantly increased only when a CO2 fixation gene (ppc or pck) and a CO2 transport gene (sbtA or bicA) were co-expressed. Co-expression of pck and sbtA provided the best succinate production among all the strains. The highest succinate production of 73.4 g L−1 was 13.3%, 66.4% or 15.0% higher than that obtained with the expression of PCK, SbtA alone, or with empty plasmids, respectively. We believe that combined regulation of CO2 transport and fixation is critical for succinate production. Imbalanced gene expression may disturb the cellular metabolism and succinate production.
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Affiliation(s)
- Li-Wen Zhu
- Key Laboratory of Fermentation Engineering (Ministry of Education) and Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068 China
| | - Lei Zhang
- Key Laboratory of Fermentation Engineering (Ministry of Education) and Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068 China
| | - Li-Na Wei
- Key Laboratory of Fermentation Engineering (Ministry of Education) and Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068 China
| | - Hong-Mei Li
- Key Laboratory of Fermentation Engineering (Ministry of Education) and Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068 China
| | - Zhan-Peng Yuan
- Key Laboratory of Fermentation Engineering (Ministry of Education) and Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068 China
| | - Tao Chen
- Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 China
| | - Ya-Ling Tang
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041 China
| | - Xin-Hua Liang
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041 China
| | - Ya-Jie Tang
- Key Laboratory of Fermentation Engineering (Ministry of Education) and Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068 China
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Marino J, Bordag N, Keller S, Zerbe O. Mistic's membrane association and its assistance in overexpression of a human GPCR are independent processes. Protein Sci 2014; 24:38-48. [PMID: 25297828 DOI: 10.1002/pro.2582] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 09/15/2014] [Accepted: 10/06/2014] [Indexed: 01/19/2023]
Abstract
The interaction of the Bacillus subtilis protein Mistic with the bacterial membrane and its role in promoting the overexpression of other membrane proteins are still matters of debate. In this study, we aimed to determine whether individual helical fragments of Mistic are sufficient for its interaction with membranes in vivo and in vitro. To this end, fragments encompassing each of Mistic's helical segments and combinations of them were produced as GFP-fusions, and their cellular localization was studied in Escherichia coli. Furthermore, peptides corresponding to the four helical fragments were synthesized by solid-phase peptide synthesis, and their ability to acquire secondary structure in a variety of lipids and detergents was studied by circular dichroism spectroscopy. Both types of experiments demonstrate that the third helical fragment of Mistic interacts only with LDAO micelles but does not partition into lipid bilayers. Interestingly, the other three helices interact with membranes in vivo and in vitro. Nevertheless, all of these short sequences can replace full-length Mistic as N-terminal fusions to achieve overexpression of a human G-protein-coupled receptor in E. coli, although with different effects on quantity and quality of the protein produced. A bioinformatic analysis of the Mistic family expanded the number of homologs from 4 to 20, including proteins outside the genus Bacillus. This information allowed us to discover a highly conserved Shine-Dalgarno sequence in the operon mstX-yugO that is important for downstream translation of the potassium ion channel yugO.
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Affiliation(s)
- Jacopo Marino
- Department of Chemistry, University of Zürich, Switzerland
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Broecker J, Fiedler S, Gimpl K, Keller S. Polar Interactions Trump Hydrophobicity in Stabilizing the Self-Inserting Membrane Protein Mistic. J Am Chem Soc 2014; 136:13761-8. [DOI: 10.1021/ja5064795] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jana Broecker
- Molecular Biophysics, University of Kaiserslautern, Erwin-Schrödinger-Straβe 13, 67663 Kaiserslautern, Germany
| | - Sebastian Fiedler
- Molecular Biophysics, University of Kaiserslautern, Erwin-Schrödinger-Straβe 13, 67663 Kaiserslautern, Germany
| | - Katharina Gimpl
- Molecular Biophysics, University of Kaiserslautern, Erwin-Schrödinger-Straβe 13, 67663 Kaiserslautern, Germany
| | - Sandro Keller
- Molecular Biophysics, University of Kaiserslautern, Erwin-Schrödinger-Straβe 13, 67663 Kaiserslautern, Germany
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Kahaki FA, Babaeipour V, Memari HR, Mofid MR. High overexpression and purification of optimized bacterio-opsin from Halobacterium Salinarum R1 in E. coli. Appl Biochem Biotechnol 2014; 174:1558-1571. [PMID: 25123363 DOI: 10.1007/s12010-014-1137-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2014] [Accepted: 08/01/2014] [Indexed: 11/25/2022]
Abstract
The purple membrane of Halobacterium Salinarum carries out a protein, bacteriorhodopsin (bR), which is a model for structure-function studies of membrane proteins. The heterologous expression of integral membrane proteins (IMPS) is difficult. In this study, we reported the heterologous overexpression of bacterio-opsin (bO) in Escherichia coli BL21 (DE3). Bacterio-opsin expression is facilitated by using mistic, a membrane protein from Bacillus subtilis in E. coli BL21 (DE3) membranes. The optimized bO gene was cloned in fusion to the C-terminus of mistic in pET 30a (+) and contains an oct-histidine in C-terminal to facilitate purification. Different medium, temperature, and induction time were used to optimize protein overexpression. The highest expression was obtained from the Terrific Broth (TB) medium at 18 °C with an IPTG concentration of 0.1 mM. The final purified bR was 192 ± 1 mg/L which has an important value for the production of membrane proteins in E. coli.
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Affiliation(s)
- Fatemeh Abarghooi Kahaki
- Department of Life Science Engineering, Faculty of New Technologies, University of Tehran, Tehran, Iran
| | - Valiollah Babaeipour
- Department of Life Science Engineering, Faculty of New Technologies, University of Tehran, Tehran, Iran.
- Department of Biological Science and Biotechnology, Malek Ashtar University of Technology, Tehran, Iran.
| | - Hamid Rajabi Memari
- Center of Biotechnology and Life Sciences and School of Agriculture, Shahid Chamran University of Ahvaz, Ahvaz, Iran
| | - Mohammad Reza Mofid
- Department of Biochemistry and Bioinformatics Research Center, School of Pharmacy and Pharmaceutical Science, Isfahan University of Medical Sciences, Isfahan, Iran
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Jaffee MB, Imperiali B. Optimized protocol for expression and purification of membrane-bound PglB, a bacterial oligosaccharyl transferase. Protein Expr Purif 2013; 89:241-50. [PMID: 23583934 DOI: 10.1016/j.pep.2013.04.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 04/03/2013] [Accepted: 04/04/2013] [Indexed: 11/26/2022]
Abstract
Asparagine-linked glycosylation (NLG) plays a significant role in a diverse range of cellular processes, including protein signaling and trafficking, the immunologic response, and immune system evasion by pathogens. A major impediment to NLG-related research is an incomplete understanding of the central enzyme in the biosynthetic pathway, the oligosaccharyl transferase (OTase). Characterization of the OTase is critical for developing ways to inhibit, engineer, and otherwise manipulate the enzyme for research and therapeutic purposes. The minimal understanding of this enzyme can be attributed to its complex, transmembrane structure, and the resulting instability and resistance to overexpression and purification. The following article describes an optimized procedure for recombinant expression and purification of PglB, a bacterial OTase, in a stably active form. The conditions screened at each step, the order of screening, and the method of comparing conditions are described. Ultimately, the following approach increased expression levels from tens of micrograms to several milligrams of active protein per liter of Escherichia coli culture, and increased stability from several hours to greater than six months post-purification. This represents the first detailed procedure for attaining a pure, active, and stable OTase in milligram quantities. In addition to presenting an optimized protocol for expression and purification of PglB, these results present a general guide for the systematic optimization of the expression, purification, and stability of a large, transmembrane protein.
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Affiliation(s)
- Marcie B Jaffee
- Department of Biology and Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
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Xu Y, Kong J, Kong W. Improved membrane protein expression in Lactococcus lactis by fusion to Mistic. MICROBIOLOGY-SGM 2013; 159:1002-1009. [PMID: 23519161 DOI: 10.1099/mic.0.066621-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Difficulty overexpressing (eukaryotic) membrane proteins is generally considered as the major impediment in their structural and functional research. Lactococcus lactis possesses many properties ideal for membrane protein expression. In order to investigate membrane protein expression in L. lactis, we created a novel expression system by introducing Mistic, a short peptide previously identified in Bacillus subtilis, into L. lactis. The potential of this system was demonstrated in the overexpression of a eukaryotic membrane protein (pkjDes4) and a prokaryotic membrane protein (pkjLi), a newly isolated linoleate isomerase from Lactobacillus acidophilus. The expression levels reached up to 4.4 % and 45.2 % for pkjDes4 and pkjLi, respectively, which represented an exceptionally robust ability to overproduce membrane proteins. Moreover, the expressed pkjLi was functional, with its catalysing nature characterized for the first time in this species. Up to 0.852 mg ml(-1) conjugated linoleic acid was obtained during the linoleic acid conversion catalysed by the recombinant lactococcal strains. In summary, we established a membrane protein expression system in L. lactis and examined its functionality. Our results demonstrate that the Mistic chaperoning strategy can be efficiently applied to L. lactis hosts and show its extraordinary capacity to facilitate the high-yield production of intractable membrane proteins.
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Affiliation(s)
- Yi Xu
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, Shandong Province, China
| | - Jian Kong
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, Shandong Province, China
| | - Wentao Kong
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,State Key Laboratory of Microbial Technology, Shandong University, Jinan, Shandong Province, China
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Panwar P, Deniaud A, Pebay-Peyroula E. Contamination from an affinity column: an encounter with a new villain in the world of membrane-protein crystallization. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 2012; 68:1272-7. [DOI: 10.1107/s090744491202639x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Accepted: 06/11/2012] [Indexed: 11/10/2022]
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Haferkamp I, Linka N. Functional expression and characterisation of membrane transport proteins. PLANT BIOLOGY (STUTTGART, GERMANY) 2012; 14:675-90. [PMID: 22639981 DOI: 10.1111/j.1438-8677.2012.00591.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Membrane transporters set the framework organising the complexity of plant metabolism in cells, tissues and organisms. Their substrate specificity and controlled activity in different cells is a crucial part for plant metabolism to run pathways in concert. Transport proteins catalyse the uptake and exchange of ions, substrates, intermediates, products and cofactors across membranes. Given the large number of metabolites, a wide spectrum of transporters is required. The vast majority of in silico annotated membrane transporters in plant genomes, however, has not yet been functionally characterised. Hence, to understand the metabolic network as a whole, it is important to understand how transporters connect and control the metabolic pathways of plant cells. Heterologous expression and in vitro activity studies of recombinant transport proteins have highly improved their functional analysis in the last two decades. This review provides a comprehensive overview of the recent advances in membrane protein expression and functional characterisation using various host systems and transport assays.
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Affiliation(s)
- I Haferkamp
- Plant Physiology, Technical University of Kaiserslautern, Kaiserslautern, Germany Plant Biochemistry, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - N Linka
- Plant Physiology, Technical University of Kaiserslautern, Kaiserslautern, Germany Plant Biochemistry, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
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Marino J, Geertsma ER, Zerbe O. Topogenesis of heterologously expressed fragments of the human Y4 GPCR. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1818:3055-63. [PMID: 22867850 DOI: 10.1016/j.bbamem.2012.07.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Revised: 06/24/2012] [Accepted: 07/26/2012] [Indexed: 12/12/2022]
Abstract
Fragments of large membrane proteins have the potential to facilitate structural analysis by NMR, but their folding state remains a concern. Here we determined the quality of folding upon heterologous expression for a series of N- or C-terminally truncated fragments of the human Y4 G-protein coupled receptor, amounting to six different complementation pairs. As the individual fragments lack a specific function that could be used to ascertain proper folding, we instead assessed folding on a basic level by studying their membrane topology and by comparing it to well-established structural models of GPCRs. The topology of the fragments was determined using a reporter assay based on C-terminal green fluorescent protein- or alkaline phosphatase-fusions. N-terminal fusions to Lep or Mistic were used if a periplasmic orientation of the N-terminus of the fragments was expected based on predictions. Fragments fused to Mistic expressed at comparably high levels, whereas Lep fusions were produced to a much lower extent. Though none of the fragments exclusively adopted one orientation, often the correct topology predominated. In addition, systematic analysis of the fragment series suggested that the C-terminal half of the Y4 receptor is more important for adopting the correct topology than the N-terminal part. Using the detergent dodecylphosphocholine, selected fragments were solubilized from the membrane and proved sufficiently stable to allow purification. Finally, as a first step toward reconstituting a functional receptor from two fragments, we observed a physical interaction between complementing fragments pairs upon co-expression.
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Affiliation(s)
- Jacopo Marino
- Institute of Organic Chemistry, University of Zurich, Winterthurerstrasse 190, CH 8057, Zurich, Switzerland
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Deniaud A, Panwar P, Frelet-Barrand A, Bernaudat F, Juillan-Binard C, Ebel C, Rolland N, Pebay-Peyroula E. Oligomeric status and nucleotide binding properties of the plastid ATP/ADP transporter 1: toward a molecular understanding of the transport mechanism. PLoS One 2012; 7:e32325. [PMID: 22438876 PMCID: PMC3306366 DOI: 10.1371/journal.pone.0032325] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2011] [Accepted: 01/25/2012] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Chloroplast ATP/ADP transporters are essential to energy homeostasis in plant cells. However, their molecular mechanism remains poorly understood, primarily due to the difficulty of producing and purifying functional recombinant forms of these transporters. METHODOLOGY/PRINCIPAL FINDINGS In this work, we describe an expression and purification protocol providing good yields and efficient solubilization of NTT1 protein from Arabidopsis thaliana. By biochemical and biophysical analyses, we identified the best detergent for solubilization and purification of functional proteins, LAPAO. Purified NTT1 was found to accumulate as two independent pools of well folded, stable monomers and dimers. ATP and ADP binding properties were determined, and Pi, a co-substrate of ADP, was confirmed to be essential for nucleotide steady-state transport. Nucleotide binding studies and analysis of NTT1 mutants lead us to suggest the existence of two distinct and probably inter-dependent binding sites. Finally, fusion and deletion experiments demonstrated that the C-terminus of NTT1 is not essential for multimerization, but probably plays a regulatory role, controlling the nucleotide exchange rate. CONCLUSIONS/SIGNIFICANCE Taken together, these data provide a comprehensive molecular characterization of a chloroplast ATP/ADP transporter.
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Affiliation(s)
- Aurélien Deniaud
- CEA, Institut de Biologie Structurale Jean-Pierre Ebel, Grenoble, France
- CNRS, Institut de Biologie Structurale, Grenoble, France
- Université Joseph Fourier Grenoble 1, Institut de Biologie Structurale, Grenoble, France
| | - Pankaj Panwar
- CEA, Institut de Biologie Structurale Jean-Pierre Ebel, Grenoble, France
- CNRS, Institut de Biologie Structurale, Grenoble, France
- Université Joseph Fourier Grenoble 1, Institut de Biologie Structurale, Grenoble, France
| | - Annie Frelet-Barrand
- CNRS, Laboratoire de Physiologie Cellulaire & Végétale, UMR5168, Grenoble, France
- CEA, LPCV, Institut de Recherches en Technologies et Sciences pour le Vivant, Grenoble, France
- Université Joseph Fourier Grenoble 1, LPCV
- INRA, LPCV, UMR1200, Grenoble, France
| | - Florent Bernaudat
- CEA, Institut de Biologie Structurale Jean-Pierre Ebel, Grenoble, France
- CNRS, Institut de Biologie Structurale, Grenoble, France
- Université Joseph Fourier Grenoble 1, Institut de Biologie Structurale, Grenoble, France
| | - Céline Juillan-Binard
- CEA, Institut de Biologie Structurale Jean-Pierre Ebel, Grenoble, France
- CNRS, Institut de Biologie Structurale, Grenoble, France
- Université Joseph Fourier Grenoble 1, Institut de Biologie Structurale, Grenoble, France
| | - Christine Ebel
- CEA, Institut de Biologie Structurale Jean-Pierre Ebel, Grenoble, France
- CNRS, Institut de Biologie Structurale, Grenoble, France
- Université Joseph Fourier Grenoble 1, Institut de Biologie Structurale, Grenoble, France
| | - Norbert Rolland
- CNRS, Laboratoire de Physiologie Cellulaire & Végétale, UMR5168, Grenoble, France
- CEA, LPCV, Institut de Recherches en Technologies et Sciences pour le Vivant, Grenoble, France
- Université Joseph Fourier Grenoble 1, LPCV
- INRA, LPCV, UMR1200, Grenoble, France
| | - Eva Pebay-Peyroula
- CEA, Institut de Biologie Structurale Jean-Pierre Ebel, Grenoble, France
- CNRS, Institut de Biologie Structurale, Grenoble, France
- Université Joseph Fourier Grenoble 1, Institut de Biologie Structurale, Grenoble, France
- * E-mail:
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Bernaudat F, Frelet-Barrand A, Pochon N, Dementin S, Hivin P, Boutigny S, Rioux JB, Salvi D, Seigneurin-Berny D, Richaud P, Joyard J, Pignol D, Sabaty M, Desnos T, Pebay-Peyroula E, Darrouzet E, Vernet T, Rolland N. Heterologous expression of membrane proteins: choosing the appropriate host. PLoS One 2011; 6:e29191. [PMID: 22216205 PMCID: PMC3244453 DOI: 10.1371/journal.pone.0029191] [Citation(s) in RCA: 97] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Accepted: 11/22/2011] [Indexed: 11/19/2022] Open
Abstract
Background Membrane proteins are the targets of 50% of drugs, although they only represent 1% of total cellular proteins. The first major bottleneck on the route to their functional and structural characterisation is their overexpression; and simply choosing the right system can involve many months of trial and error. This work is intended as a guide to where to start when faced with heterologous expression of a membrane protein. Methodology/Principal Findings The expression of 20 membrane proteins, both peripheral and integral, in three prokaryotic (E. coli, L. lactis, R. sphaeroides) and three eukaryotic (A. thaliana, N. benthamiana, Sf9 insect cells) hosts was tested. The proteins tested were of various origins (bacteria, plants and mammals), functions (transporters, receptors, enzymes) and topologies (between 0 and 13 transmembrane segments). The Gateway system was used to clone all 20 genes into appropriate vectors for the hosts to be tested. Culture conditions were optimised for each host, and specific strategies were tested, such as the use of Mistic fusions in E. coli. 17 of the 20 proteins were produced at adequate yields for functional and, in some cases, structural studies. We have formulated general recommendations to assist with choosing an appropriate system based on our observations of protein behaviour in the different hosts. Conclusions/Significance Most of the methods presented here can be quite easily implemented in other laboratories. The results highlight certain factors that should be considered when selecting an expression host. The decision aide provided should help both newcomers and old-hands to select the best system for their favourite membrane protein.
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Affiliation(s)
- Florent Bernaudat
- Institut de Biologie Structurale Jean-Pierre Ebel, CEA, Grenoble, France.
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