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Fogeron ML, Lecoq L, Cole L, Harbers M, Böckmann A. Easy Synthesis of Complex Biomolecular Assemblies: Wheat Germ Cell-Free Protein Expression in Structural Biology. Front Mol Biosci 2021; 8:639587. [PMID: 33842544 PMCID: PMC8027086 DOI: 10.3389/fmolb.2021.639587] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 01/20/2021] [Indexed: 12/18/2022] Open
Abstract
Cell-free protein synthesis (CFPS) systems are gaining more importance as universal tools for basic research, applied sciences, and product development with new technologies emerging for their application. Huge progress was made in the field of synthetic biology using CFPS to develop new proteins for technical applications and therapy. Out of the available CFPS systems, wheat germ cell-free protein synthesis (WG-CFPS) merges the highest yields with the use of a eukaryotic ribosome, making it an excellent approach for the synthesis of complex eukaryotic proteins including, for example, protein complexes and membrane proteins. Separating the translation reaction from other cellular processes, CFPS offers a flexible means to adapt translation reactions to protein needs. There is a large demand for such potent, easy-to-use, rapid protein expression systems, which are optimally serving protein requirements to drive biochemical and structural biology research. We summarize here a general workflow for a wheat germ system providing examples from the literature, as well as applications used for our own studies in structural biology. With this review, we want to highlight the tremendous potential of the rapidly evolving and highly versatile CFPS systems, making them more widely used as common tools to recombinantly prepare particularly challenging recombinant eukaryotic proteins.
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Affiliation(s)
- Marie-Laure Fogeron
- Molecular Microbiology and Structural Biochemistry, Labex Ecofect, UMR 5086 CNRS/Université de Lyon, Lyon, France
| | - Lauriane Lecoq
- Molecular Microbiology and Structural Biochemistry, Labex Ecofect, UMR 5086 CNRS/Université de Lyon, Lyon, France
| | - Laura Cole
- Molecular Microbiology and Structural Biochemistry, Labex Ecofect, UMR 5086 CNRS/Université de Lyon, Lyon, France
| | - Matthias Harbers
- CellFree Sciences, Yokohama, Japan
- RIKEN Center for Integrative Medical Sciences (IMS), Yokohama, Japan
| | - Anja Böckmann
- Molecular Microbiology and Structural Biochemistry, Labex Ecofect, UMR 5086 CNRS/Université de Lyon, Lyon, France
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Pardee K. Perspective: Solidifying the impact of cell-free synthetic biology through lyophilization. Biochem Eng J 2018; 138:91-97. [PMID: 30740032 PMCID: PMC6358126 DOI: 10.1016/j.bej.2018.07.008] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 07/03/2018] [Accepted: 07/09/2018] [Indexed: 12/20/2022]
Abstract
Cell-free synthetic biology is an exciting and new branch in the field of synthetic biology. Based on in vitro transcription and translation systems, this application-focused domain builds on decades of cell-free biochemistry and protein expression to operate synthetic gene networks outside of cellular environments. This has brought new and perhaps even unexpected advantages. Chief among these is the ability to operate genetically encoded tools in a sterile and abiotic format. Recent work has extended this advantage by freeze-drying these cell-free systems into dried pellets or embedded paper-based reactions. Taken together, these new ideas have solved the longstanding challenge of how to deploy poised synthetic gene networks in a biosafe mode outside of the laboratory. There is significant excitement in the potential of this newfound venue and the community has begun to extend proof-of-concept demonstrations in important and creative ways. Here I explore these new efforts and provide my thoughts on the challenges and opportunities ahead for freeze-dried, cell-free synthetic biology.
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3
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Hara KY, Kondo A. ATP regulation in bioproduction. Microb Cell Fact 2015; 14:198. [PMID: 26655598 PMCID: PMC4676173 DOI: 10.1186/s12934-015-0390-6] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Accepted: 11/25/2015] [Indexed: 01/06/2023] Open
Abstract
Adenosine-5'-triphosphate (ATP) is consumed as a biological energy source by many intracellular reactions. Thus, the intracellular ATP supply is required to maintain cellular homeostasis. The dependence on the intracellular ATP supply is a critical factor in bioproduction by cell factories. Recent studies have shown that changing the ATP supply is critical for improving product yields. In this review, we summarize the recent challenges faced by researchers engaged in the development of engineered cell factories, including the maintenance of a large ATP supply and the production of cell factories. The strategies used to enhance ATP supply are categorized as follows: addition of energy substrates, controlling pH, metabolic engineering of ATP-generating or ATP-consuming pathways, and controlling reactions of the respiratory chain. An enhanced ATP supply generated using these strategies improves target production through increases in resource uptake, cell growth, biosynthesis, export of products, and tolerance to toxic compounds.
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Affiliation(s)
- Kiyotaka Y Hara
- Department of Environmental Sciences, Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka, 422-8526, Japan.
| | - Akihiko Kondo
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe, 657-8501, Japan.
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4
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A cell‐free expression and purification process for rapid production of protein biologics. Biotechnol J 2015; 11:238-48. [DOI: 10.1002/biot.201500214] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Revised: 08/14/2015] [Accepted: 09/28/2015] [Indexed: 01/08/2023]
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Samuel PP, Smith LP, Phillips GN, Olson JS. Apoglobin Stability Is the Major Factor Governing both Cell-free and in Vivo Expression of Holomyoglobin. J Biol Chem 2015. [PMID: 26205820 DOI: 10.1074/jbc.m115.672204] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Expression levels in animal muscle tissues and in Escherichia coli vary widely for naturally occurring mammalian myoglobins (Mb). To explore this variation, we developed an in vitro transcription and wheat germ extract-based translation assay to examine quantitatively the factors that govern expression of holoMb. We constructed a library of naturally occurring Mbs from two terrestrial and four deep-diving aquatic mammals and three distal histidine mutants designed to enhance apoglobin stability but decrease hemin affinity. A strong linear correlation is observed between cell-free expression levels of holo-metMb variants and their corresponding apoglobin stabilities, which were measured independently by guanidine HCl-induced unfolding titrations using purified proteins. In contrast, there is little dependence of expression on hemin affinity. Our results confirm quantitatively that deep diving mammals have highly stable Mbs that express to higher levels in animal myocytes, E. coli, and the wheat germ cell-free system than Mbs from terrestrial mammals. Our theoretical analyses show that the rate of aggregation of unfolded apoMb is very large, and as a result, the key factor for high level expression of holoMb, and presumably other heme proteins, is an ultra high fraction of folded, native apoglobin that is capable of rapidly binding hemin. This fraction is determined by the overall equilibrium folding constant and not hemin affinity. These results also demonstrate that the cell-free transcription/translation system can be used as a high throughput platform to screen for apoglobin stability without the need to generate large amounts of protein for in vitro unfolding measurements.
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Affiliation(s)
| | | | - George N Phillips
- From BioSciences at Rice and Department of Chemistry, Rice University, Houston, Texas 77005
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Expression platforms for producing eukaryotic proteins: a comparison of E. coli cell-based and wheat germ cell-free synthesis, affinity and solubility tags, and cloning strategies. ACTA ACUST UNITED AC 2015; 16:67-80. [PMID: 25854603 DOI: 10.1007/s10969-015-9198-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Accepted: 03/25/2015] [Indexed: 10/23/2022]
Abstract
Vectors designed for protein production in Escherichia coli and by wheat germ cell-free translation were tested using 21 well-characterized eukaryotic proteins chosen to serve as controls within the context of a structural genomics pipeline. The controls were carried through cloning, small-scale expression trials, large-scale growth or synthesis, and purification. Successfully purified proteins were also subjected to either crystallization trials or (1)H-(15)N HSQC NMR analyses. Experiments evaluated: (1) the relative efficacy of restriction/ligation and recombinational cloning systems; (2) the value of maltose-binding protein (MBP) as a solubility enhancement tag; (3) the consequences of in vivo proteolysis of the MBP fusion as an alternative to post-purification proteolysis; (4) the effect of the level of LacI repressor on the yields of protein obtained from E. coli using autoinduction; (5) the consequences of removing the His tag from proteins produced by the cell-free system; and (6) the comparative performance of E. coli cells or wheat germ cell-free translation. Optimal promoter/repressor and fusion tag configurations for each expression system are discussed.
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Böckmann A, Ernst M, Meier BH. Spinning proteins, the faster, the better? JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2015; 253:71-9. [PMID: 25797006 DOI: 10.1016/j.jmr.2015.01.012] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Revised: 01/09/2015] [Accepted: 01/18/2015] [Indexed: 05/26/2023]
Abstract
Magic-angle spinning (MAS) is a technique that is a prerequisite for high-resolution solid-state NMR spectroscopy of proteins and other biomolecules. Recently, the 100 kHz limit for the rotation frequency has been broken, arguably making MAS rotors the man-made objects with the highest rotation frequency. This development is expected to have a significant impact on biomolecular NMR as it facilitates proton detection, which allows to partially compensate the loss in overall sensitivity associated with the small sample amounts that fit into MAS rotors with less than 1 mm outer diameter. Under these conditions, the mass-normalized sensitivity of a small rotor becomes much higher than that of larger-volume rotor.
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Affiliation(s)
- Anja Böckmann
- Institut de Biologie et Chimie des Protéines, BMSSI, UMR 5086 CNRS/Université de Lyon 1, 7 passage du Vercors, 69367 Lyon, France.
| | - Matthias Ernst
- Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland.
| | - Beat H Meier
- Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland.
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Terada T, Yokoyama S. Escherichia coli Cell-Free Protein Synthesis and Isotope Labeling of Mammalian Proteins. Methods Enzymol 2015; 565:311-45. [DOI: 10.1016/bs.mie.2015.08.035] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Harbers M. Wheat germ systems for cell-free protein expression. FEBS Lett 2014; 588:2762-73. [PMID: 24931374 DOI: 10.1016/j.febslet.2014.05.061] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 05/25/2014] [Accepted: 05/26/2014] [Indexed: 10/25/2022]
Abstract
Cell-free protein expression plays an important role in biochemical research. However, only recent developments led to new methods to rapidly synthesize preparative amounts of protein that make cell-free protein expression an attractive alternative to cell-based methods. In particular the wheat germ system provides the highest translation efficiency among eukaryotic cell-free protein expression approaches and has a very high success rate for the expression of soluble proteins of good quality. As an open in vitro method, the wheat germ system is a preferable choice for many applications in protein research including options for protein labeling and the expression of difficult-to-express proteins like membrane proteins and multiple protein complexes. Here I describe wheat germ cell-free protein expression systems and give examples how they have been used in genome-wide expression studies, preparation of labeled proteins for structural genomics and protein mass spectroscopy, automated protein synthesis, and screening of enzymatic activities. Future directions for the use of cell-free expression methods are discussed.
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Affiliation(s)
- Matthias Harbers
- RIKEN Center for Life Science Technologies, Suehiro-cho, Tsurumi-ku, Yokohama City, Kanagawa 230-0045, Japan; CellFree Sciences Co., Ltd., 75-1, Ono-cho, Leading Venture Plaza 201, Tsurumi-ku, Yokohama, Kanagawa 230-0046, Japan.
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Makino SI, Beebe ET, Markley JL, Fox BG. Cell-free protein synthesis for functional and structural studies. Methods Mol Biol 2014; 1091:161-78. [PMID: 24203331 DOI: 10.1007/978-1-62703-691-7_11] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
Recent advances in cell-free protein expression systems have made them reliable and practical for functional and structural studies of a wide variety of proteins. In particular, wheat germ cell-free translation can consistently produce target proteins in microgram quantities from relatively inexpensive, small-scale reactions. Here we describe our small-scale protein expression method for rapidly producing proteins for functional assay and techniques for determining if the target is suitable for scale-up to amounts potentially needed for structure determination. The cell-free system is versatile and can be easily customized with the inclusion of additives. We describe simple modifications used for producing membrane proteins.
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Affiliation(s)
- Shin-ichi Makino
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA
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Beebe ET, Makino SI, Markley JL, Fox BG. Automated cell-free protein production methods for structural studies. Methods Mol Biol 2014; 1140:117-135. [PMID: 24590713 DOI: 10.1007/978-1-4939-0354-2_9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In contrast to cell-based protein expression, cell-free production is highly consistent, scalable, and amenable to automation. Robots can handle many samples and perform repetitive procedures that are otherwise prone to human error. Here is described commercially available robotics for a wheat germ cell-free system with emphasis on practical applications for structural and functional studies. In addition, described is a cell-free method for preparing protein complexes.
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Affiliation(s)
- Emily T Beebe
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI, 53706, USA
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12
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Singh S, Chang A, Helmich KE, Bingman CA, Wrobel RL, Beebe ET, Makino SI, Aceti DJ, Dyer K, Hura GL, Sunkara M, Morris AJ, Phillips GN, Thorson JS. Structural and functional characterization of CalS11, a TDP-rhamnose 3'-O-methyltransferase involved in calicheamicin biosynthesis. ACS Chem Biol 2013; 8:1632-9. [PMID: 23662776 PMCID: PMC3875630 DOI: 10.1021/cb400068k] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Sugar methyltransferases (MTs) are an important class of tailoring enzymes that catalyze the transfer of a methyl group from S-adenosyl-l-methionine to sugar-based N-, C- and O-nucleophiles. While sugar N- and C-MTs involved in natural product biosynthesis have been found to act on sugar nucleotide substrates prior to a subsequent glycosyltransferase reaction, corresponding sugar O-methylation reactions studied thus far occur after the glycosyltransfer reaction. Herein we report the first in vitro characterization using (1)H-(13)C-gHSQC with isotopically labeled substrates and the X-ray structure determination at 1.55 Å resolution of the TDP-3'-O-rhamnose-methyltransferase CalS11 from Micromonospora echinospora. This study highlights a unique NMR-based methyltransferase assay, implicates CalS11 to be a metal- and general acid/base-dependent O-methyltransferase, and as a first crystal structure for a TDP-hexose-O-methyltransferase, presents a new template for mechanistic studies and/or engineering.
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Affiliation(s)
- Shanteri Singh
- Center for Pharmaceutical Research and Innovation, University of Kentucky College of Pharmacy, 789 South Limestone Street, Lexington, KY 40536-0596, USA
| | - Aram Chang
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Kate E. Helmich
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Craig A. Bingman
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Russel L. Wrobel
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Emily T. Beebe
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Shin-Ichi Makino
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - David J. Aceti
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Kevin Dyer
- Physical Bioscience Division, Lawrence Berkeley National Laboratory, Berkeley CA 94720, USA
| | - Greg L. Hura
- Physical Bioscience Division, Lawrence Berkeley National Laboratory, Berkeley CA 94720, USA
| | - Manjula Sunkara
- Division of Cardiovascular Medicine, University of Kentucky, Lexington, KY 40536, USA
| | - Andrew J. Morris
- Division of Cardiovascular Medicine, University of Kentucky, Lexington, KY 40536, USA
| | - George N. Phillips
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
- Department of Biochemistry and Cell Biology, Rice University, Houston, Texas 77005, USA
| | - Jon S. Thorson
- Center for Pharmaceutical Research and Innovation, University of Kentucky College of Pharmacy, 789 South Limestone Street, Lexington, KY 40536-0596, USA
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Bernhard F, Tozawa Y. Cell-free expression--making a mark. Curr Opin Struct Biol 2013; 23:374-80. [PMID: 23628286 DOI: 10.1016/j.sbi.2013.03.012] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Revised: 03/26/2013] [Accepted: 03/29/2013] [Indexed: 11/27/2022]
Abstract
Cell-free protein production opens new perspectives for the direct manipulation of expression compartments in combination with reduced complexity of physiological requirements. The technology is therefore in particular suitable for the general synthesis of difficult proteins including toxins and membrane proteins as well as for the analysis of their functional folding in artificial environments. A further key application of cell-free expression is the fast and economic labeling of proteins for structural and functional applications. Two extract sources, wheat embryos and Escherichia coli cells, are currently employed for the preparative scale cell-free production of proteins. Recent achievements in structural characterization include cell-free synthesized membrane proteins and even larger protein assemblies may become feasible.
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Affiliation(s)
- Frank Bernhard
- Institute of Biophysical Chemistry, Centre for Biomolecular Magnetic Resonance, Goethe University, Frankfurt am Main, Germany.
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Mutations in FLS2 Ser-938 dissect signaling activation in FLS2-mediated Arabidopsis immunity. PLoS Pathog 2013; 9:e1003313. [PMID: 23637603 PMCID: PMC3630090 DOI: 10.1371/journal.ppat.1003313] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2012] [Accepted: 03/04/2013] [Indexed: 11/19/2022] Open
Abstract
Flagellin-sensing 2 (FLS2) is a leucine-rich repeat/transmembrane domain/protein kinase (LRR-RLK) that is the plant receptor for bacterial flagellin or the flagellin-derived flg22 peptide. Previous work has shown that after flg22 binding, FLS2 releases BIK1 kinase and homologs and associates with BAK1 kinase, and that FLS2 kinase activity is critical for FLS2 function. However, the detailed mechanisms for activation of FLS2 signaling remain unclear. The present study initially identified multiple FLS2 in vitro phosphorylation sites and found that Serine-938 is important for FLS2 function in vivo. FLS2-mediated immune responses are abolished in transgenic plants expressing FLS2(S938A), while the acidic phosphomimic mutants FLS2(S938D) and FLS2(S938E) conferred responses similar to wild-type FLS2. FLS2-BAK1 association and FLS2-BIK1 disassociation after flg22 exposure still occur with FLS2(S938A), demonstrating that flg22-induced BIK1 release and BAK1 binding are not sufficient for FLS2 activity, and that Ser-938 controls other aspects of FLS2 activity. Purified BIK1 still phosphorylated purified FLS2(S938A) and FLS2(S938D) mutant kinase domains in vitro. Phosphorylation of BIK1 and homologs after flg22 exposure was disrupted in transgenic Arabidopsis thaliana plants expressing FLS2(S938A) or FLS2(D997A) (a kinase catalytic site mutant), but was normally induced in FLS2(S938D) plants. BIK1 association with FLS2 required a kinase-active FLS2, but FLS2-BAK1 association did not. Hence FLS2-BIK1 dissociation and FLS2-BAK1 association are not sufficient for FLS2-mediated defense activation, but the proposed FLS2 phosphorylation site Ser-938 and FLS2 kinase activity are needed both for overall defense activation and for appropriate flg22-stimulated phosphorylation of BIK1 and homologs.
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Emami S, Fan Y, Munro R, Ladizhansky V, Brown LS. Yeast-expressed human membrane protein aquaporin-1 yields excellent resolution of solid-state MAS NMR spectra. JOURNAL OF BIOMOLECULAR NMR 2013; 55:147-155. [PMID: 23344971 DOI: 10.1007/s10858-013-9710-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Accepted: 01/15/2013] [Indexed: 06/01/2023]
Abstract
One of the biggest challenges in solid-state NMR studies of membrane proteins is to obtain a homogeneous natively folded sample giving high spectral resolution sufficient for structural studies. Eukaryotic membrane proteins are especially difficult and expensive targets in this respect. Methylotrophic yeast Pichia pastoris is a reliable producer of eukaryotic membrane proteins for crystallography and a promising economical source of isotopically labeled proteins for NMR. We show that eukaryotic membrane protein human aquaporin 1 can be doubly ((13)C/(15)N) isotopically labeled in this system and functionally reconstituted into phospholipids, giving excellent resolution of solid-state magic angle spinning NMR spectra.
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Affiliation(s)
- Sanaz Emami
- Departments of Physics, and Biophysics Interdepartmental Group, University of Guelph, 50 Stone Road East, Guelph, ON, N1G 2W1, Canada
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Aly KA, Beebe ET, Chan CH, Goren MA, Sepúlveda C, Makino SI, Fox BG, Forest KT. Cell-free production of integral membrane aspartic acid proteases reveals zinc-dependent methyltransferase activity of the Pseudomonas aeruginosa prepilin peptidase PilD. Microbiologyopen 2012; 2:94-104. [PMID: 23255525 PMCID: PMC3584216 DOI: 10.1002/mbo3.51] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Revised: 10/30/2012] [Accepted: 11/05/2012] [Indexed: 12/25/2022] Open
Abstract
Integral membrane aspartic acid proteases are receiving growing recognition for their fundamental roles in cellular physiology of eukaryotes and prokaryotes, and may be medically important pharmaceutical targets. The Gram-negative Pseudomonas aeruginosa PilD and the archaeal Methanococcus voltae FlaK were synthesized in the presence of unilamellar liposomes in a cell-free translation system. Cosynthesis of PilD with its full-length substrate, PilA, or of FlaK with its full-length substrate, FlaB2, led to complete cleavage of the substrate signal peptides. Scaled-up synthesis of PilD, followed by solubilization in dodecyl-β-d-maltoside and chromatography, led to a pure enzyme that retained both of its known biochemical activities: cleavage of the PilA signal peptide and S-adenosyl methionine-dependent methylation of the mature pilin. X-ray fluorescence scans show for the first time that PilD is a zinc-binding protein. Zinc is required for the N-terminal methylation of the mature pilin, but not for signal peptide cleavage. Taken together, our work identifies the P. aeruginosa prepilin peptidase PilD as a zinc-dependent N-methyltransferase and provides a new platform for large-scale synthesis of PilD and other integral membrane proteases important for basic microbial physiology and virulence.
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Affiliation(s)
- Khaled A Aly
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA
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17
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Fan Q, Treder K, Miller WA. Untranslated regions of diverse plant viral RNAs vary greatly in translation enhancement efficiency. BMC Biotechnol 2012; 12:22. [PMID: 22559081 PMCID: PMC3416697 DOI: 10.1186/1472-6750-12-22] [Citation(s) in RCA: 21] [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: 12/23/2011] [Accepted: 05/06/2012] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Whole plants or plant cell cultures can serve as low cost bioreactors to produce massive amounts of a specific protein for pharmacological or industrial use. To maximize protein expression, translation of mRNA must be optimized. Many plant viral RNAs harbor extremely efficient translation enhancers. However, few of these different translation elements have been compared side-by-side. Thus, it is unclear which are the most efficient translation enhancers. Here, we compare the effects of untranslated regions (UTRs) containing translation elements from six plant viruses on translation in wheat germ extract and in monocotyledenous and dicotyledenous plant cells. RESULTS The highest expressing uncapped mRNAs contained viral UTRs harboring Barley yellow dwarf virus (BYDV)-like cap-independent translation elements (BTEs). The BYDV BTE conferred the most efficient translation of a luciferase reporter in wheat germ extract and oat protoplasts, while uncapped mRNA containing the BTE from Tobacco necrosis virus-D translated most efficiently in tobacco cells. Capped mRNA containing the Tobacco mosaic virus omega sequence was the most efficient mRNA in tobacco cells. UTRs from Satellite tobacco necrosis virus, Tomato bushy stunt virus, and Crucifer-infecting tobamovirus (crTMV) did not stimulate translation efficiently. mRNA with the crTMV 5' UTR was unstable in tobacco protoplasts. CONCLUSIONS BTEs confer the highest levels of translation of uncapped mRNAs in vitro and in vivo, while the capped omega sequence is most efficient in tobacco cells. These results provide a basis for understanding mechanisms of translation enhancement, and for maximizing protein synthesis in cell-free systems, transgenic plants, or in viral expression vectors.
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Affiliation(s)
- Qiuling Fan
- Department of Plant Pathology & Microbiology, and Center for Plant Responses to Environmental Stresses, Iowa State University, Ames, IA, 50011, USA
- 1615 E 8th St, #6, Davis, CA, 95616, USA
| | - Krzysztof Treder
- Department of Plant Pathology & Microbiology, and Center for Plant Responses to Environmental Stresses, Iowa State University, Ames, IA, 50011, USA
| | - W Allen Miller
- Department of Plant Pathology & Microbiology, and Center for Plant Responses to Environmental Stresses, Iowa State University, Ames, IA, 50011, USA
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Verardi R, Traaseth NJ, Masterson LR, Vostrikov VV, Veglia G. Isotope labeling for solution and solid-state NMR spectroscopy of membrane proteins. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 992:35-62. [PMID: 23076578 PMCID: PMC3555569 DOI: 10.1007/978-94-007-4954-2_3] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
In this chapter, we summarize the isotopic labeling strategies used to obtain high-quality solution and solid-state NMR spectra of biological samples, with emphasis on integral membrane proteins (IMPs). While solution NMR is used to study IMPs under fast tumbling conditions, such as in the presence of detergent micelles or isotropic bicelles, solid-state NMR is used to study the structure and orientation of IMPs in lipid vesicles and bilayers. In spite of the tremendous progress in biomolecular NMR spectroscopy, the homogeneity and overall quality of the sample is still a substantial obstacle to overcome. Isotopic labeling is a major avenue to simplify overlapped spectra by either diluting the NMR active nuclei or allowing the resonances to be separated in multiple dimensions. In the following we will discuss isotopic labeling approaches that have been successfully used in the study of IMPs by solution and solid-state NMR spectroscopy.
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Affiliation(s)
- Raffaello Verardi
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455
| | | | | | | | - Gianluigi Veglia
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455
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Claridge JK, Schnell JR. Bacterial production and solution NMR studies of a viral membrane ion channel. Methods Mol Biol 2012; 831:165-79. [PMID: 22167674 DOI: 10.1007/978-1-61779-480-3_10] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Advances in solution nuclear magnetic resonance (NMR) methodology that enable studies of very large proteins have also paved the way for studies of membrane proteins that behave like large proteins due to the added weight of surfactants. Solution NMR has been used to determine the high-resolution structures of several small, membrane proteins dissolved in detergent micelles and small bicelles. However, the usual difficulties with membrane proteins in producing, purifying, and stabilizing the proteins away from native membranes remain, requiring intensive screening efforts. Low levels of heterologous expression can be the most detrimental aspect to studying membrane proteins. This is exacerbated for NMR studies because of the costs of isotopically enriched media. Thus, solution NMR studies have tended to focus on relatively small, membrane proteins that can be expressed into inclusion bodies and refolded. Here, we describe the methods used to produce, purify, and refold the proton channel M2 into detergent micelles, and the procedures used to determine chemical shift assignments and the atomic level structure of the closed form of the homotetrameric channel.
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Tonelli M, Singarapu KK, Makino SI, Sahu SC, Matsubara Y, Endo Y, Kainosho M, Markley JL. Hydrogen exchange during cell-free incorporation of deuterated amino acids and an approach to its inhibition. JOURNAL OF BIOMOLECULAR NMR 2011; 51:467-76. [PMID: 21984356 PMCID: PMC3254145 DOI: 10.1007/s10858-011-9575-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Accepted: 09/21/2011] [Indexed: 05/05/2023]
Abstract
Perdeuteration, selective deuteration, and stereo array isotope labeling (SAIL) are valuable strategies for NMR studies of larger proteins and membrane proteins. To minimize scrambling of the label, it is best to use cell-free methods to prepare selectively labeled proteins. However, when proteins are prepared from deuterated amino acids by cell-free translation in H(2)O, exchange reactions can lead to contamination of (2)H sites by (1)H from the solvent. Examination of a sample of SAIL-chlorella ubiquitin prepared by Escherichia coli cell-free synthesis revealed that exchange had occurred at several residues (mainly at Gly, Ala, Asp, Asn, Glu, and Gln). We present results from a study aimed at identifying the exchanging sites and level of exchange and at testing a strategy for minimizing (1)H contamination during wheat germ cell-free translation of proteins produced from deuterated amino acids by adding known inhibitors of transaminases (1 mM aminooxyacetic acid) and glutamate synthetase (0.1 mM L: -methionine sulfoximine). By using a wheat germ cell-free expression system, we produced [U-(2)H, (15)N]-chlorella ubiquitin without and with added inhibitors, and [U-(15)N]-chlorella ubiquitin as a reference to determine the extent of deuterium incorporation. We also prepared a sample of [U-(13)C, (15)N]-chlorella ubiquitin, for use in assigning the sites of exchange. The added inhibitors did not reduce the protein yield and were successful in blocking hydrogen exchange at C(α) sites, with the exception of Gly, and at C(β) sites of Ala. We discovered, in addition, that partial exchange occurred with or without the inhibitors at certain side-chain methyl and methylene groups: Asn-H(β), Asp-H(β), Gln-H(γ), Glu-H(γ), and Lys-H(ε). The side-chain labeling pattern, in particular the mixed chiral labeling resulting from partial exchange at certain sites, should be of interest in studies of large proteins, protein complexes, and membrane proteins.
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Affiliation(s)
- Marco Tonelli
- National Magnetic Resonance Facility at Madison (NMRFAM), Department of Biochemistry, University of Wisconsin-Madison, USA
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22
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High throughput platforms for structural genomics of integral membrane proteins. Curr Opin Struct Biol 2011; 21:517-22. [PMID: 21807498 DOI: 10.1016/j.sbi.2011.07.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2011] [Revised: 06/20/2011] [Accepted: 07/07/2011] [Indexed: 11/20/2022]
Abstract
Structural genomics approaches on integral membrane proteins have been postulated for over a decade, yet specific efforts are lagging years behind their soluble counterparts. Indeed, high throughput methodologies for production and characterization of prokaryotic integral membrane proteins are only now emerging, while large-scale efforts for eukaryotic ones are still in their infancy. Presented here is a review of recent literature on actively ongoing structural genomics of membrane protein initiatives, with a focus on those aimed at implementing interesting techniques aimed at increasing our rate of success for this class of macromolecules.
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Wheat-germ cell-free production of prion proteins for solid-state NMR structural studies. N Biotechnol 2011; 28:232-8. [DOI: 10.1016/j.nbt.2010.06.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2010] [Accepted: 06/28/2010] [Indexed: 12/14/2022]
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Sethe Burgie E, Bingman CA, Makino SI, Wesenberg GE, Pan X, Fox BG, Phillips GN. Structural architecture of Galdieria sulphuraria DCN1L. Proteins 2011; 79:1329-36. [PMID: 21387409 DOI: 10.1002/prot.22937] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2010] [Revised: 10/18/2010] [Accepted: 10/21/2010] [Indexed: 11/05/2022]
Affiliation(s)
- E Sethe Burgie
- Department of Genetics, Center for Eukaryotic Structural Genomics, University of Wisconsin-Madison, Madison Wisconsin 53706-1544, USA
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He M. In vitro protein expression: an emerging alternative to cell-based approaches. N Biotechnol 2010; 28:209-10. [PMID: 20804874 DOI: 10.1016/j.nbt.2010.08.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Accepted: 08/23/2010] [Indexed: 11/17/2022]
Abstract
Protein expression remains a bottleneck in the production of proteins. Owing to several advantages, cell-free translation is emerging as an alternative to cell-based methods for the generation of proteins. Recent advances have led to many novel applications of cell-free systems in biotechnology, proteomics and fundamental biological research. This special issue of New Biotechnology describes recent advances in cell-free protein expression systems and their applications.
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Affiliation(s)
- Mingyue He
- Protein Expression Facility, The Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK.
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Unmet challenges of structural genomics. Curr Opin Struct Biol 2010; 20:587-97. [PMID: 20810277 DOI: 10.1016/j.sbi.2010.08.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2010] [Revised: 07/30/2010] [Accepted: 08/03/2010] [Indexed: 11/22/2022]
Abstract
Structural genomics (SG) programs have developed during the last decade many novel methodologies for faster and more accurate structure determination. These new tools and approaches led to the determination of thousands of protein structures. The generation of enormous amounts of experimental data resulted in significant improvements in the understanding of many biological processes at molecular levels. However, the amount of data collected so far is so large that traditional analysis methods are limiting the rate of extraction of biological and biochemical information from 3D models. This situation has prompted us to review the challenges that remain unmet by SG, as well as the areas in which the potential impact of SG could exceed what has been achieved so far.
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Beebe ET, Makino SI, Nozawa A, Matsubara Y, Frederick RO, Primm JG, Goren MA, Fox BG. Robotic large-scale application of wheat cell-free translation to structural studies including membrane proteins. N Biotechnol 2010; 28:239-49. [PMID: 20637905 DOI: 10.1016/j.nbt.2010.07.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2010] [Accepted: 07/03/2010] [Indexed: 10/19/2022]
Abstract
The use of the Protemist XE, an automated discontinuous-batch protein synthesis robot, in cell-free translation is reported. The soluble Galdieria sulphuraria protein DCN1 was obtained in greater than 2mg total synthesis yield per mL of reaction mixture from the Protemist XE, and the structure was subsequently solved by X-ray crystallography using material from one 10 mL synthesis (PDB ID: 3KEV). The Protemist XE was also capable of membrane protein translation. Thus human sigma-1 receptor was translated in the presence of unilamellar liposomes and bacteriorhodopsin was translated directly into detergent micelles in the presence of all-trans-retinal. The versatility, ease of use, and compact size of the Protemist XE robot demonstrate its suitability for large-scale synthesis of many classes of proteins.
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Affiliation(s)
- Emily T Beebe
- Center for Eukaryotic Structural Genomics, Department of Biochemistry, University of Wisconsin-Madison, 445 Henry Mall, Madison, WI 53706, USA
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