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Pak JS, DeLoughery ZJ, Wang J, Acharya N, Park Y, Jaworski A, Özkan E. NELL2-Robo3 complex structure reveals mechanisms of receptor activation for axon guidance. Nat Commun 2020; 11:1489. [PMID: 32198364 PMCID: PMC7083938 DOI: 10.1038/s41467-020-15211-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Accepted: 02/24/2020] [Indexed: 11/24/2022] Open
Abstract
Axon pathfinding is critical for nervous system development, and it is orchestrated by molecular cues that activate receptors on the axonal growth cone. Robo family receptors bind Slit guidance cues to mediate axon repulsion. In mammals, the divergent family member Robo3 does not bind Slits, but instead signals axon repulsion from its own ligand, NELL2. Conversely, canonical Robos do not mediate NELL2 signaling. Here, we present the structures of NELL-Robo3 complexes, identifying a mode of ligand engagement for Robos that is orthogonal to Slit binding. We elucidate the structural basis for differential binding between NELL and Robo family members and show that NELL2 repulsive activity is a function of its Robo3 affinity and is enhanced by ligand trimerization. Our results reveal a mechanism of oligomerization-induced Robo activation for axon guidance and shed light on Robo family member ligand binding specificity, conformational variability, divergent modes of signaling, and evolution.
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Affiliation(s)
- Joseph S Pak
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, 60637, USA
- Grossman Institute for Neuroscience, Quantitative Biology and Human Behavior, University of Chicago, Chicago, IL, 60637, USA
| | - Zachary J DeLoughery
- Department of Neuroscience, Division of Biology and Medicine, Brown University, Providence, RI, 02912, USA
- Robert J. and Nancy D. Carney Institute for Brain Science, Providence, RI, 02912, USA
| | - Jing Wang
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, 60637, USA
- Grossman Institute for Neuroscience, Quantitative Biology and Human Behavior, University of Chicago, Chicago, IL, 60637, USA
| | - Nischal Acharya
- Department of Neuroscience, Division of Biology and Medicine, Brown University, Providence, RI, 02912, USA
- Robert J. and Nancy D. Carney Institute for Brain Science, Providence, RI, 02912, USA
| | - Yeonwoo Park
- Department of Human Genetics, University of Chicago, Chicago, IL, 60637, USA
| | - Alexander Jaworski
- Department of Neuroscience, Division of Biology and Medicine, Brown University, Providence, RI, 02912, USA.
- Robert J. and Nancy D. Carney Institute for Brain Science, Providence, RI, 02912, USA.
| | - Engin Özkan
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, 60637, USA.
- Grossman Institute for Neuroscience, Quantitative Biology and Human Behavior, University of Chicago, Chicago, IL, 60637, USA.
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2
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Crystal structure of human PLD1 provides insight into activation by PI(4,5)P 2 and RhoA. Nat Chem Biol 2020; 16:400-407. [PMID: 32198492 PMCID: PMC7117805 DOI: 10.1038/s41589-020-0499-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Accepted: 02/10/2020] [Indexed: 11/08/2022]
Abstract
The signal transduction enzyme phospholipase D1 (PLD1) hydrolyzes phosphatidylcholine to generate the lipid second-messenger phosphatidic acid, which plays roles in disease processes such as thrombosis and cancer. PLD1 is directly and synergistically regulated by protein kinase C, Arf and Rho GTPases, and the membrane lipid phosphatidylinositol-4,5-bisphosphate (PIP2). Here, we present a 1.8 Å-resolution crystal structure of the human PLD1 catalytic domain, which is characterized by a globular fold with a funnel-shaped hydrophobic cavity leading to the active site. Adjacent is a PIP2-binding polybasic pocket at the membrane interface that is essential for activity. The C terminus folds into and contributes part of the catalytic pocket, which harbors a phosphohistidine that mimics an intermediate stage of the catalytic cycle. Mapping of PLD1 mutations that disrupt RhoA activation identifies the RhoA-PLD1 binding interface. This structure sheds light on PLD1 regulation by lipid and protein effectors, enabling rationale inhibitor design for this well-studied therapeutic target.
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3
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Wenzel S, Imasaki T, Takagi Y. A practical method for efficient and optimal production of Seleno-methionine-labeled recombinant protein complexes in the insect cells. Protein Sci 2019; 28:808-822. [PMID: 30663186 DOI: 10.1002/pro.3575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 01/04/2019] [Accepted: 01/07/2019] [Indexed: 11/07/2022]
Abstract
The use of Seleno-methionine (SeMet) incorporated protein crystals for single or multi-wavelength anomalous diffraction (SAD or MAD) to facilitate phasing has become almost synonymous with modern X-ray crystallography. The anomalous signals from SeMets can be used for phasing as well as sequence markers for subsequent model building. The production of large quantities of SeMet incorporated recombinant proteins is relatively straightforward when expressed in Escherichia coli. In contrast, production of SeMet substituted recombinant proteins expressed in the insect cells is not as robust due to the toxicity of SeMet in eukaryotic systems. Previous protocols for SeMet-incorporation in the insect cells are laborious, and more suited for secreted proteins. In addition, these protocols have generally not addressed the SeMet toxicity issue, and typically result in low recovery of the labeled proteins. Here we report that SeMet toxicity can be circumvented by fully infecting insect cells with baculovirus. Quantitatively controlling infection levels using our Titer Estimation of Quality Control (TEQC) method allow for the incorporation of substantial amounts of SeMet, resulting in an efficient and optimal production of labeled recombinant protein complexes. With the method described here, we were able to consistently reach incorporation levels of about 75% and protein yield of 60-90% compared with native protein expression.
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Affiliation(s)
- Sabine Wenzel
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, Indiana, 46202
| | - Tsuyoshi Imasaki
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, Indiana, 46202
| | - Yuichiro Takagi
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, Indiana, 46202
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4
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Xu H, Li T, Rohou A, Arthur CP, Tzakoniati F, Wong E, Estevez A, Kugel C, Franke Y, Chen J, Ciferri C, Hackos DH, Koth CM, Payandeh J. Structural Basis of Nav1.7 Inhibition by a Gating-Modifier Spider Toxin. Cell 2019; 176:702-715.e14. [PMID: 30661758 DOI: 10.1016/j.cell.2018.12.018] [Citation(s) in RCA: 112] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 09/11/2018] [Accepted: 12/11/2018] [Indexed: 12/19/2022]
Abstract
Voltage-gated sodium (Nav) channels are targets of disease mutations, toxins, and therapeutic drugs. Despite recent advances, the structural basis of voltage sensing, electromechanical coupling, and toxin modulation remains ill-defined. Protoxin-II (ProTx2) from the Peruvian green velvet tarantula is an inhibitor cystine-knot peptide and selective antagonist of the human Nav1.7 channel. Here, we visualize ProTx2 in complex with voltage-sensor domain II (VSD2) from Nav1.7 using X-ray crystallography and cryoelectron microscopy. Membrane partitioning orients ProTx2 for unfettered access to VSD2, where ProTx2 interrogates distinct features of the Nav1.7 receptor site. ProTx2 positions two basic residues into the extracellular vestibule to antagonize S4 gating-charge movement through an electrostatic mechanism. ProTx2 has trapped activated and deactivated states of VSD2, revealing a remarkable ∼10 Å translation of the S4 helix, providing a structural framework for activation gating in voltage-gated ion channels. Finally, our results deliver key templates to design selective Nav channel antagonists.
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Affiliation(s)
- Hui Xu
- Department of Structural Biology, Genentech, South San Francisco, CA 94080, USA
| | - Tianbo Li
- Department of Biochemical and Cellular Pharmacology, Genentech, South San Francisco, CA 94080, USA.
| | - Alexis Rohou
- Department of Structural Biology, Genentech, South San Francisco, CA 94080, USA.
| | | | - Foteini Tzakoniati
- Department of Structural Biology, Genentech, South San Francisco, CA 94080, USA
| | - Evera Wong
- Department of Neuroscience, Genentech, South San Francisco, CA 94080, USA
| | - Alberto Estevez
- Department of Structural Biology, Genentech, South San Francisco, CA 94080, USA
| | - Christine Kugel
- Department of Biomolecular Resources, Genentech, South San Francisco, CA 94080, USA
| | - Yvonne Franke
- Department of Biomolecular Resources, Genentech, South San Francisco, CA 94080, USA
| | - Jun Chen
- Department of Biochemical and Cellular Pharmacology, Genentech, South San Francisco, CA 94080, USA
| | - Claudio Ciferri
- Department of Structural Biology, Genentech, South San Francisco, CA 94080, USA
| | - David H Hackos
- Department of Neuroscience, Genentech, South San Francisco, CA 94080, USA.
| | - Christopher M Koth
- Department of Structural Biology, Genentech, South San Francisco, CA 94080, USA.
| | - Jian Payandeh
- Department of Structural Biology, Genentech, South San Francisco, CA 94080, USA.
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Abstract
Exciting new technological developments have pushed the boundaries of structural biology, and have enabled studies of biological macromolecules and assemblies that would have been unthinkable not long ago. Yet, the enhanced capabilities of structural biologists to pry into the complex molecular world have also placed new demands on the abilities of protein engineers to reproduce this complexity into the test tube. With this challenge in mind, we review the contents of the modern molecular engineering toolbox that allow the manipulation of proteins in a site-specific and chemically well-defined fashion. Thus, we cover concepts related to the modification of cysteines and other natural amino acids, native chemical ligation, intein and sortase-based approaches, amber suppression, as well as chemical and enzymatic bio-conjugation strategies. We also describe how these tools can be used to aid methodology development in X-ray crystallography, nuclear magnetic resonance, cryo-electron microscopy and in the studies of dynamic interactions. It is our hope that this monograph will inspire structural biologists and protein engineers alike to apply these tools to novel systems, and to enhance and broaden their scope to meet the outstanding challenges in understanding the molecular basis of cellular processes and disease.
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6
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Mattarocci S, Reinert JK, Bunker RD, Fontana GA, Shi T, Klein D, Cavadini S, Faty M, Shyian M, Hafner L, Shore D, Thomä NH, Rass U. Rif1 maintains telomeres and mediates DNA repair by encasing DNA ends. Nat Struct Mol Biol 2017; 24:588-595. [PMID: 28604726 DOI: 10.1038/nsmb.3420] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 05/09/2017] [Indexed: 12/29/2022]
Abstract
In yeast, Rif1 is part of the telosome, where it inhibits telomerase and checkpoint signaling at chromosome ends. In mammalian cells, Rif1 is not telomeric, but it suppresses DNA end resection at chromosomal breaks, promoting repair by nonhomologous end joining (NHEJ). Here, we describe crystal structures for the uncharacterized and conserved ∼125-kDa N-terminal domain of Rif1 from Saccharomyces cerevisiae (Rif1-NTD), revealing an α-helical fold shaped like a shepherd's crook. We identify a high-affinity DNA-binding site in the Rif1-NTD that fully encases DNA as a head-to-tail dimer. Engagement of the Rif1-NTD with telomeres proved essential for checkpoint control and telomere length regulation. Unexpectedly, Rif1-NTD also promoted NHEJ at DNA breaks in yeast, revealing a conserved role of Rif1 in DNA repair. We propose that tight associations between the Rif1-NTD and DNA gate access of processing factors to DNA ends, enabling Rif1 to mediate diverse telomere maintenance and DNA repair functions.
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Affiliation(s)
- Stefano Mattarocci
- Department of Molecular Biology and Institute of Genetics and Genomics in Geneva (iGE3), University of Geneva, Geneva, Switzerland
| | - Julia K Reinert
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland.,Faculty of Natural Sciences, University of Basel, Basel, Switzerland
| | - Richard D Bunker
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Gabriele A Fontana
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Tianlai Shi
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland.,Faculty of Natural Sciences, University of Basel, Basel, Switzerland
| | - Dominique Klein
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Simone Cavadini
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Mahamadou Faty
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Maksym Shyian
- Department of Molecular Biology and Institute of Genetics and Genomics in Geneva (iGE3), University of Geneva, Geneva, Switzerland
| | - Lukas Hafner
- Department of Molecular Biology and Institute of Genetics and Genomics in Geneva (iGE3), University of Geneva, Geneva, Switzerland
| | - David Shore
- Department of Molecular Biology and Institute of Genetics and Genomics in Geneva (iGE3), University of Geneva, Geneva, Switzerland
| | - Nicolas H Thomä
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Ulrich Rass
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
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7
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Pike ACW, Garman EF, Krojer T, von Delft F, Carpenter EP. An overview of heavy-atom derivatization of protein crystals. Acta Crystallogr D Struct Biol 2016; 72:303-18. [PMID: 26960118 PMCID: PMC4784662 DOI: 10.1107/s2059798316000401] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 01/08/2016] [Indexed: 11/11/2022] Open
Abstract
Heavy-atom derivatization is one of the oldest techniques for obtaining phase information for protein crystals and, although it is no longer the first choice, it remains a useful technique for obtaining phases for unknown structures and for low-resolution data sets. It is also valuable for confirming the chain trace in low-resolution electron-density maps. This overview provides a summary of the technique and is aimed at first-time users of the method. It includes guidelines on when to use it, which heavy atoms are most likely to work, how to prepare heavy-atom solutions, how to derivatize crystals and how to determine whether a crystal is in fact a derivative.
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Affiliation(s)
- Ashley C. W. Pike
- Structural Genomics Consortium, University of Oxford, Roosevelt Drive, Oxford OX11 9HP, England
| | - Elspeth F. Garman
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, England
| | - Tobias Krojer
- Structural Genomics Consortium, University of Oxford, Roosevelt Drive, Oxford OX11 9HP, England
| | - Frank von Delft
- Structural Genomics Consortium, University of Oxford, Roosevelt Drive, Oxford OX11 9HP, England
- Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot OX11 0QX, England
- Department of Biochemistry, University of Johannesburg, Aukland Park 2006, South Africa
| | - Elisabeth P. Carpenter
- Structural Genomics Consortium, University of Oxford, Roosevelt Drive, Oxford OX11 9HP, England
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8
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Cronin NB, Yang J, Zhang Z, Kulkarni K, Chang L, Yamano H, Barford D. Atomic-Resolution Structures of the APC/C Subunits Apc4 and the Apc5 N-Terminal Domain. J Mol Biol 2015; 427:3300-3315. [PMID: 26343760 PMCID: PMC4590430 DOI: 10.1016/j.jmb.2015.08.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 08/19/2015] [Accepted: 08/26/2015] [Indexed: 10/25/2022]
Abstract
Many essential biological processes are mediated by complex molecular machines comprising multiple subunits. Knowledge on the architecture of individual subunits and their positions within the overall multimeric complex is key to understanding the molecular mechanisms of macromolecular assemblies. The anaphase-promoting complex/cyclosome (APC/C) is a large multisubunit complex that regulates cell cycle progression by ubiquitinating cell cycle proteins for proteolysis by the proteasome. The holo-complex is composed of 15 different proteins that assemble to generate a complex of 20 subunits. Here, we describe the crystal structures of Apc4 and the N-terminal domain of Apc5 (Apc5(N)). Apc4 comprises a WD40 domain split by a long α-helical domain, whereas Apc5(N) has an α-helical fold. In a separate study, we had fitted these atomic models to a 3.6-Å-resolution cryo-electron microscopy map of the APC/C. We describe how, in the context of the APC/C, regions of Apc4 disordered in the crystal assume order through contacts to Apc5, whereas Apc5(N) shows small conformational changes relative to its crystal structure. We discuss the complementary approaches of high-resolution electron microscopy and protein crystallography to the structure determination of subunits of multimeric complexes.
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Affiliation(s)
- Nora B Cronin
- Division of Structural Biology, Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, United Kingdom
| | - Jing Yang
- Division of Structural Biology, Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, United Kingdom; MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - Ziguo Zhang
- Division of Structural Biology, Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, United Kingdom; MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - Kiran Kulkarni
- Division of Structural Biology, Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, United Kingdom; Division of Biochemical Sciences, Council of Scientific and Industrial Research National Chemical Laboratory, Pune 411008, India
| | - Leifu Chang
- Division of Structural Biology, Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, United Kingdom; MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - Hiroyuki Yamano
- Cancer Institute, University College London, Paul O'Gorman Building, 72 Huntley Street, London WC1E 6BT, United Kingdom
| | - David Barford
- Division of Structural Biology, Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, United Kingdom; MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom.
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9
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Yamaguchi M, Yu S, Qiao R, Weissmann F, Miller DJ, VanderLinden R, Brown NG, Frye JJ, Peters JM, Schulman BA. Structure of an APC3-APC16 complex: insights into assembly of the anaphase-promoting complex/cyclosome. J Mol Biol 2014; 427:1748-64. [PMID: 25490258 DOI: 10.1016/j.jmb.2014.11.020] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2014] [Revised: 11/14/2014] [Accepted: 11/15/2014] [Indexed: 01/05/2023]
Abstract
The anaphase-promoting complex/cyclosome (APC/C) is a massive E3 ligase that controls mitosis by catalyzing ubiquitination of key cell cycle regulatory proteins. The APC/C assembly contains two subcomplexes: the "Platform" centers around a cullin-RING-like E3 ligase catalytic core; the "Arc Lamp" is a hub that mediates transient association with regulators and ubiquitination substrates. The Arc Lamp contains the small subunits APC16, CDC26, and APC13, and tetratricopeptide repeat (TPR) proteins (APC7, APC3, APC6, and APC8) that homodimerize and stack with quasi-2-fold symmetry. Within the APC/C complex, APC3 serves as center for regulation. APC3's TPR motifs recruit substrate-binding coactivators, CDC20 and CDH1, via their C-terminal conserved Ile-Arg (IR) tail sequences. Human APC3 also binds APC16 and APC7 and contains a >200-residue loop that is heavily phosphorylated during mitosis, although the basis for APC3 interactions and whether loop phosphorylation is required for ubiquitination are unclear. Here, we map the basis for human APC3 assembly with APC16 and APC7, report crystal structures of APC3Δloop alone and in complex with the C-terminal domain of APC16, and test roles of APC3's loop and IR tail binding surfaces in APC/C-catalyzed ubiquitination. The structures show how one APC16 binds asymmetrically to the symmetric APC3 dimer and, together with biochemistry and prior data, explain how APC16 recruits APC7 to APC3, show how APC3's C-terminal domain is rearranged in the full APC/C assembly, and visualize residues in the IR tail binding cleft important for coactivator-dependent ubiquitination. Overall, the results provide insights into assembly, regulation, and interactions of TPR proteins and the APC/C.
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Affiliation(s)
- Masaya Yamaguchi
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Shanshan Yu
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Renping Qiao
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), 1030 Vienna, Austria
| | - Florian Weissmann
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), 1030 Vienna, Austria
| | - Darcie J Miller
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Ryan VanderLinden
- Howard Hughes Medical Institute, St. Jude Children's Research Hospital, Memphis, TN 38105 USA
| | - Nicholas G Brown
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Jeremiah J Frye
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Jan-Michael Peters
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), 1030 Vienna, Austria
| | - Brenda A Schulman
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA; Howard Hughes Medical Institute, St. Jude Children's Research Hospital, Memphis, TN 38105 USA.
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10
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Crystal structure of the human COP9 signalosome. Nature 2014; 512:161-5. [PMID: 25043011 DOI: 10.1038/nature13566] [Citation(s) in RCA: 170] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 06/06/2014] [Indexed: 12/26/2022]
Abstract
Ubiquitination is a crucial cellular signalling process, and is controlled on multiple levels. Cullin-RING E3 ubiquitin ligases (CRLs) are regulated by the eight-subunit COP9 signalosome (CSN). CSN inactivates CRLs by removing their covalently attached activator, NEDD8. NEDD8 cleavage by CSN is catalysed by CSN5, a Zn(2+)-dependent isopeptidase that is inactive in isolation. Here we present the crystal structure of the entire ∼350-kDa human CSN holoenzyme at 3.8 Å resolution, detailing the molecular architecture of the complex. CSN has two organizational centres: a horseshoe-shaped ring created by its six proteasome lid-CSN-initiation factor 3 (PCI) domain proteins, and a large bundle formed by the carboxy-terminal α-helices of every subunit. CSN5 and its dimerization partner, CSN6, are intricately embedded at the core of the helical bundle. In the substrate-free holoenzyme, CSN5 is autoinhibited, which precludes access to the active site. We find that neddylated CRL binding to CSN is sensed by CSN4, and communicated to CSN5 with the assistance of CSN6, resulting in activation of the deneddylase.
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11
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The pseudokinase MLKL mediates necroptosis via a molecular switch mechanism. Immunity 2013; 39:443-53. [PMID: 24012422 DOI: 10.1016/j.immuni.2013.06.018] [Citation(s) in RCA: 961] [Impact Index Per Article: 87.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Accepted: 06/20/2013] [Indexed: 11/21/2022]
Abstract
Mixed lineage kinase domain-like (MLKL) is a component of the "necrosome," the multiprotein complex that triggers tumor necrosis factor (TNF)-induced cell death by necroptosis. To define the specific role and molecular mechanism of MLKL action, we generated MLKL-deficient mice and solved the crystal structure of MLKL. Although MLKL-deficient mice were viable and displayed no hematopoietic anomalies or other obvious pathology, cells derived from these animals were resistant to TNF-induced necroptosis unless MLKL expression was restored. Structurally, MLKL comprises a four-helical bundle tethered to the pseudokinase domain, which contains an unusual pseudoactive site. Although the pseudokinase domain binds ATP, it is catalytically inactive and its essential nonenzymatic role in necroptotic signaling is induced by receptor-interacting serine-threonine kinase 3 (RIPK3)-mediated phosphorylation. Structure-guided mutation of the MLKL pseudoactive site resulted in constitutive, RIPK3-independent necroptosis, demonstrating that modification of MLKL is essential for propagation of the necroptosis pathway downstream of RIPK3.
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12
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Assenberg R, Wan PT, Geisse S, Mayr LM. Advances in recombinant protein expression for use in pharmaceutical research. Curr Opin Struct Biol 2013; 23:393-402. [DOI: 10.1016/j.sbi.2013.03.008] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Revised: 03/24/2013] [Accepted: 03/25/2013] [Indexed: 10/26/2022]
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13
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Fast Single-Use VLP Vaccine Productions Based on Insect Cells and the Baculovirus Expression Vector System: Influenza as Case Study. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2013; 138:99-125. [DOI: 10.1007/10_2013_186] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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14
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Fischer ES, Scrima A, Böhm K, Matsumoto S, Lingaraju GM, Faty M, Yasuda T, Cavadini S, Wakasugi M, Hanaoka F, Iwai S, Gut H, Sugasawa K, Thomä NH. The molecular basis of CRL4DDB2/CSA ubiquitin ligase architecture, targeting, and activation. Cell 2012; 147:1024-39. [PMID: 22118460 DOI: 10.1016/j.cell.2011.10.035] [Citation(s) in RCA: 347] [Impact Index Per Article: 28.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Revised: 08/12/2011] [Accepted: 10/16/2011] [Indexed: 01/23/2023]
Abstract
The DDB1-CUL4-RBX1 (CRL4) ubiquitin ligase family regulates a diverse set of cellular pathways through dedicated substrate receptors (DCAFs). The DCAF DDB2 detects UV-induced pyrimidine dimers in the genome and facilitates nucleotide excision repair. We provide the molecular basis for DDB2 receptor-mediated cyclobutane pyrimidine dimer recognition in chromatin. The structures of the fully assembled DDB1-DDB2-CUL4A/B-RBX1 (CRL4(DDB2)) ligases reveal that the mobility of the ligase arm creates a defined ubiquitination zone around the damage, which precludes direct ligase activation by DNA lesions. Instead, the COP9 signalosome (CSN) mediates the CRL4(DDB2) inhibition in a CSN5 independent, nonenzymatic, fashion. In turn, CSN inhibition is relieved upon DNA damage binding to the DDB2 module within CSN-CRL4(DDB2). The Cockayne syndrome A DCAF complex crystal structure shows that CRL4(DCAF(WD40)) ligases share common architectural features. Our data support a general mechanism of ligase activation, which is induced by CSN displacement from CRL4(DCAF) on substrate binding to the DCAF.
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Affiliation(s)
- Eric S Fischer
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058 Basel, Switzerland
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15
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Borer AS, Wassmann P, Schmidt M, Hoffman DR, Zhou JJ, Wright C, Schirmer T, Marković-Housley Z. Crystal structure of Sol I 2: a major allergen from fire ant venom. J Mol Biol 2011; 415:635-48. [PMID: 22100449 DOI: 10.1016/j.jmb.2011.10.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Revised: 10/05/2011] [Accepted: 10/07/2011] [Indexed: 11/28/2022]
Abstract
Sol i 2 is a potent allergen from the venom of red imported fire ant, which contains allergens Sol i 1, Sol i 2, Sol i 3, and Sol i 4 that are known to be powerful triggers of anaphylaxis. Sol i 2 causes IgE antibody production in about one-third of individuals stung by fire ants. Baculovirus recombinant dimeric Sol i 2 was crystallized as a native and selenomethionyl-derivatized protein, and its structure has been determined by single-wavelength anomalous dispersion at 2.6 Å resolution. The overall fold of each subunit consists of five helices that enclose a central hydrophobic cavity. The structure is stabilized by three intramolecular disulfide bridges and one intermolecular disulfide bridge. The nearest structural homologue is the sequence-unrelated odorant binding protein and pheromone binding protein LUSH of the fruit fly Drosophila, which may suggest a similar biological function. To test this hypothesis, we measured the reversible binding of various pheromones, plant odorants, and other ligands to Sol i 2 by the changes in N-phenyl-1-naphthylamine fluorescence emission upon binding of ligands that compete with N-phenyl-1-naphthylamine. The highest binding affinity was observed for hydrophobic ligands such as aphid alarm pheromone (E)-β-farnesene, analogs of ant alarm pheromones, and plant volatiles decane, undecane, and β-caryophyllene. Conceivably, Sol i 2 may play a role in capturing and/or transporting small hydrophobic ligands such as pheromones, odors, fatty acids, or short-living hydrophobic primers. Molecular surface analysis, in combination with sequence alignment, can explain the serological cross-reactivity observed between some ant species.
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Affiliation(s)
- Aline S Borer
- Department of Structural Biology, Biozentrum, University of Basel, Basel, Switzerland
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Yuk IH, Baskar D, Duffy PH, Hsiung J, Leung S, Lin AA. Overcoming challenges in WAVE bioreactors without feedback controls for pH and dissolved oxygen. Biotechnol Prog 2011; 27:1397-406. [DOI: 10.1002/btpr.659] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Revised: 05/26/2011] [Indexed: 11/12/2022]
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17
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Payandeh J, Scheuer T, Zheng N, Catterall WA. The crystal structure of a voltage-gated sodium channel. Nature 2011; 475:353-8. [PMID: 21743477 PMCID: PMC3266868 DOI: 10.1038/nature10238] [Citation(s) in RCA: 1065] [Impact Index Per Article: 81.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2011] [Accepted: 05/27/2011] [Indexed: 01/07/2023]
Abstract
Voltage-gated sodium (Na(V)) channels initiate electrical signalling in excitable cells and are the molecular targets for drugs and disease mutations, but the structural basis for their voltage-dependent activation, ion selectivity and drug block is unknown. Here we report the crystal structure of a voltage-gated Na(+) channel from Arcobacter butzleri (NavAb) captured in a closed-pore conformation with four activated voltage sensors at 2.7 Å resolution. The arginine gating charges make multiple hydrophilic interactions within the voltage sensor, including unanticipated hydrogen bonds to the protein backbone. Comparisons to previous open-pore potassium channel structures indicate that the voltage-sensor domains and the S4-S5 linkers dilate the central pore by pivoting together around a hinge at the base of the pore module. The NavAb selectivity filter is short, ∼4.6 Å wide, and water filled, with four acidic side chains surrounding the narrowest part of the ion conduction pathway. This unique structure presents a high-field-strength anionic coordination site, which confers Na(+) selectivity through partial dehydration via direct interaction with glutamate side chains. Fenestrations in the sides of the pore module are unexpectedly penetrated by fatty acyl chains that extend into the central cavity, and these portals are large enough for the entry of small, hydrophobic pore-blocking drugs. This structure provides the template for understanding electrical signalling in excitable cells and the actions of drugs used for pain, epilepsy and cardiac arrhythmia at the atomic level.
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Affiliation(s)
- Jian Payandeh
- Department of Pharmacology, University of Washington, Seattle, WA
| | - Todd Scheuer
- Department of Pharmacology, University of Washington, Seattle, WA
| | - Ning Zheng
- Department of Pharmacology, University of Washington, Seattle, WA
,Howard Hughes Medical Institute, University of Washington, Seattle WA
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A Raf-induced allosteric transition of KSR stimulates phosphorylation of MEK. Nature 2011; 472:366-9. [PMID: 21441910 DOI: 10.1038/nature09860] [Citation(s) in RCA: 193] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Accepted: 01/20/2011] [Indexed: 11/08/2022]
Abstract
In metazoans, the Ras-Raf-MEK (mitogen-activated protein-kinase kinase)-ERK (extracellular signal-regulated kinase) signalling pathway relays extracellular stimuli to elicit changes in cellular function and gene expression. Aberrant activation of this pathway through oncogenic mutations is responsible for a large proportion of human cancer. Kinase suppressor of Ras (KSR) functions as an essential scaffolding protein to coordinate the assembly of Raf-MEK-ERK complexes. Here we integrate structural and biochemical studies to understand how KSR promotes stimulatory Raf phosphorylation of MEK (refs 6, 7). We show, from the crystal structure of the kinase domain of human KSR2 (KSR2(KD)) in complex with rabbit MEK1, that interactions between KSR2(KD) and MEK1 are mediated by their respective activation segments and C-lobe αG helices. Analogous to BRAF (refs 8, 9), KSR2 self-associates through a side-to-side interface involving Arg 718, a residue identified in a genetic screen as a suppressor of Ras signalling. ATP is bound to the KSR2(KD) catalytic site, and we demonstrate KSR2 kinase activity towards MEK1 by in vitro assays and chemical genetics. In the KSR2(KD)-MEK1 complex, the activation segments of both kinases are mutually constrained, and KSR2 adopts an inactive conformation. BRAF allosterically stimulates the kinase activity of KSR2, which is dependent on formation of a side-to-side KSR2-BRAF heterodimer. Furthermore, KSR2-BRAF heterodimerization results in an increase of BRAF-induced MEK phosphorylation via the KSR2-mediated relay of a signal from BRAF to release the activation segment of MEK for phosphorylation. We propose that KSR interacts with a regulatory Raf molecule in cis to induce a conformational switch of MEK, facilitating MEK's phosphorylation by a separate catalytic Raf molecule in trans.
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Mutation of high-affinity methionine permease contributes to selenomethionyl protein production in Saccharomyces cerevisiae. Appl Environ Microbiol 2010; 76:6351-9. [PMID: 20693451 DOI: 10.1128/aem.01026-10] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The production of selenomethionine (SeMet) derivatives of recombinant proteins allows phase determination by single-wavelength or multiwavelength anomalous dispersion phasing in X-ray crystallography, and this popular approach has permitted the crystal structures of numerous proteins to be determined. Although yeast is an ideal host for the production of large amounts of eukaryotic proteins that require posttranslational modification, the toxic effects of SeMet often interfere with the preparation of protein derivatives containing this compound. We previously isolated a mutant strain (SMR-94) of the methylotrophic yeast Pichia pastoris that is resistant to both SeMet and selenate and demonstrated its applicability for the production of proteins suitable for X-ray crystallographic analysis. However, the molecular basis for resistance to SeMet by the SMR-94 strain remains unclear. Here, we report the characterization of SeMet-resistant mutants of Saccharomyces cerevisiae and the identification of a mutant allele of the MUP1 gene encoding high-affinity methionine permease, which confers SeMet resistance. Although the total methionine uptake by the mup1 mutant (the SRY5-7 strain) decreased to 47% of the wild-type level, it was able to incorporate SeMet into the overexpressed epidermal growth factor peptide with 73% occupancy, indicating the importance of the moderate uptake of SeMet by amino acid permeases other than Mup1p for the alleviation of SeMet toxicity. In addition, under standard culture conditions, the mup1 mutant showed higher productivity of the SeMet derivative relative to other SeMet-resistant mutants. Based on these results, we conclude that the mup1 mutant would be useful for the preparation of selenomethionyl proteins for X-ray crystallography.
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Wu Y, Yang Y, Ye S, Jiang Y. Structure of the gating ring from the human large-conductance Ca(2+)-gated K(+) channel. Nature 2010; 466:393-7. [PMID: 20574420 PMCID: PMC2910425 DOI: 10.1038/nature09252] [Citation(s) in RCA: 164] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2010] [Accepted: 06/07/2010] [Indexed: 12/11/2022]
Abstract
Large-conductance Ca(2+)-gated K(+) (BK) channels are essential for many biological processes such as smooth muscle contraction and neurotransmitter release. This group of channels can be activated synergistically by both voltage and intracellular Ca(2+), with the large carboxy-terminal intracellular portion being responsible for Ca(2+) sensing. Here we present the crystal structure of the entire cytoplasmic region of the human BK channel in a Ca(2+)-free state. The structure reveals four intracellular subunits, each comprising two tandem RCK domains, assembled into a gating ring similar to that seen in the MthK channel and probably representing its physiological assembly. Three Ca(2+) binding sites including the Ca(2+) bowl are mapped onto the structure based on mutagenesis data. The Ca(2+) bowl, located within the second RCK domain, forms an EF-hand-like motif and is strategically positioned close to the assembly interface between two subunits. The other two Ca(2+) (or Mg(2+)) binding sites, Asp 367 and Glu 374/Glu 399, are located on the first RCK domain. The Asp 367 site has high Ca(2+) sensitivity and is positioned in the groove between the amino- and carboxy-terminal subdomains of RCK1, whereas the low-affinity Mg(2+)-binding Glu 374/Glu 399 site is positioned on the upper plateau of the gating ring and close to the membrane. Our structure also contains the linker connecting the transmembrane and intracellular domains, allowing us to dock a voltage-gated K(+) channel pore of known structure onto the gating ring with reasonable accuracy and generate a structural model for the full BK channel.
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Affiliation(s)
- Yunkun Wu
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040
| | - Yi Yang
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040
| | - Sheng Ye
- Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, P.R. China
| | - Youxing Jiang
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040
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Walden H. Selenium incorporation using recombinant techniques. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 2010; 66:352-7. [PMID: 20382987 PMCID: PMC2852298 DOI: 10.1107/s0907444909038207] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2009] [Accepted: 09/21/2009] [Indexed: 11/29/2022]
Abstract
An overview of techniques for recombinant incorporation of selenium and subsequent purification and crystallization of the resulting labelled protein. Using selenomethionine to phase macromolecular structures is common practice in structure determination, along with the use of selenocysteine. Selenium is consequently the most commonly used heavy atom for MAD. In addition to the well established recombinant techniques for the incorporation of selenium in prokaryal expression systems, there have been recent advances in selenium labelling in eukaryal expression, which will be discussed. Tips and things to consider for the purification and crystallization of seleno-labelled proteins are also included.
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Affiliation(s)
- Helen Walden
- Protein Structure and Function Laboratory, Cancer Research UK London Research Institute, Lincoln's Inn Fields, London WC2A 3PX, England.
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22
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Recent advances in the production of proteins in insect and mammalian cells for structural biology. J Struct Biol 2010; 172:55-65. [PMID: 20153433 DOI: 10.1016/j.jsb.2010.02.006] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2009] [Revised: 02/04/2010] [Accepted: 02/07/2010] [Indexed: 11/22/2022]
Abstract
The production of proteins in sufficient quantity and of appropriate quality is an essential pre-requisite for structural studies. Escherichia coli remains the dominant expression system in structural biology with nearly 90% of the structures in the Protein Data Bank (PDB) derived from proteins produced in this bacterial host. However, many mammalian and eukaryotic viral proteins require post-translation modification for proper folding and/or are part of large multimeric complexes. Therefore expression in higher eukaryotic cell lines from both invertebrate and vertebrate is required to produce these proteins. Although these systems are generally more time-consuming and expensive to use than bacteria, there have been improvements in technology that have streamlined the processes involved. For example, the use of multi-host vectors, i.e., containing promoters for not only E. coli but also mammalian and baculovirus expression in insect cells, enables target genes to be evaluated in both bacterial and higher eukaryotic hosts from a single vector. Culturing cells in micro-plate format allows screening of large numbers of vectors in parallel and is amenable to automation. The development of large-scale transient expression in mammalian cells offers a way of rapidly producing proteins with relatively high throughput. Strategies for selenomethionine-labelling (important for obtaining phase information in crystallography) and controlling glycosylation (important for reducing the chemical heterogeneity of glycoproteins) have also been reported for higher eukaryotic cell expression systems.
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Kitajima T, Yagi E, Kubota T, Chiba Y, Nishikawa S, Jigami Y. Use of novel selenomethionine-resistant yeast to produce selenomethionyl protein suitable for structural analysis. FEMS Yeast Res 2009; 9:439-45. [DOI: 10.1111/j.1567-1364.2009.00484.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Eibl R, Werner S, Eibl D. Bag bioreactor based on wave-induced motion: characteristics and applications. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2009; 115:55-87. [PMID: 19373453 DOI: 10.1007/10_2008_15] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Today wave-mixed bag bioreactors are common devices in modern biotechnological processes where simple, safe and flexible production has top priority. Numerous studies that have been published on ex vivo generation of cells, viruses and therapeutic agents during the last 10 years have confirmed their suitability and even superiority to stirred bioreactors made from glass or stainless steel for animal as well as plant cell cultivations. In these studies the wave-mixed bag bioreactors enabled middle to high cell density and adequate productivity in laboratory and pilot scale. This mainly results from low-shear conditions and highly efficient oxygen transfer for cell cultures, as demonstrated for the widely used BioWave((R)).Starting with an overview of wave-mixed bag bioreactors and their common operation strategies, this chapter delineates engineering aspects of BioWave((R)), which like Wave Reactor and BIOSTAT((R))CultiBag RM originates from the prototype of a wave-mixed bag bioreactor introduced in 1998. Subsequently, the second part of the chapter focuses on reported BioWave((R)) applications. Conditions and results from cultivations with animal cells, plant cells, microbial cells and nematodes are presented and discussed.
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Affiliation(s)
- Regine Eibl
- Institute of Biotechnology, Zurich University of Applied Sciences, School of Life Sciences and Facility Management, Campus Grüntal, CH-8820, Wädenswil, Switzerland,
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Xu Y, Chen Y, Zhang P, Jeffrey PD, Shi Y. Structure of a protein phosphatase 2A holoenzyme: insights into B55-mediated Tau dephosphorylation. Mol Cell 2008; 31:873-85. [PMID: 18922469 DOI: 10.1016/j.molcel.2008.08.006] [Citation(s) in RCA: 220] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2008] [Revised: 07/14/2008] [Accepted: 08/05/2008] [Indexed: 10/21/2022]
Abstract
Protein phosphatase 2A (PP2A) regulates many essential aspects of cellular physiology. Members of the regulatory B/B55/PR55 family are thought to play a key role in the dephosphorylation of Tau, whose hyperphosphorylation contributes to Alzheimer's disease. The underlying mechanisms of the PP2A-Tau connection remain largely enigmatic. Here, we report the complete reconstitution of a Tau dephosphorylation assay and the crystal structure of a heterotrimeric PP2A holoenzyme involving the regulatory subunit Balpha. We show that Balpha specifically and markedly facilitates dephosphorylation of the phosphorylated Tau in our reconstituted assay. The Balpha subunit comprises a seven-bladed beta propeller, with an acidic, substrate-binding groove located in the center of the propeller. The beta propeller latches onto the ridge of the PP2A scaffold subunit with the help of a protruding beta hairpin arm. Structure-guided mutagenesis studies revealed the underpinnings of PP2A-mediated dephosphorylation of Tau.
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Affiliation(s)
- Yanhui Xu
- Department of Molecular Biology, Lewis Thomas Laboratory, Princeton University, Princeton, NJ 08544, USA
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Negrete A, Kotin RM. Strategies for manufacturing recombinant adeno-associated virus vectors for gene therapy applications exploiting baculovirus technology. BRIEFINGS IN FUNCTIONAL GENOMICS AND PROTEOMICS 2008; 7:303-11. [PMID: 18632744 DOI: 10.1093/bfgp/eln034] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The development of recombinant adeno-associated virus (rAAV) gene therapy applications is hampered by the inability to produce rAAV in sufficient quantities to support pre-clinical and clinical trials. Contrasting with adherent cell cultures, suspension cultures provide a straightforward means for expansion, however, transiently expressing the necessary, but cytotoxic virus proteins remains the challenge for rAAV production. Both the expansion and expression issues are resolved by using the baculovirus expression vector (bev) and insect cell culture system. This review addresses strategies for the production of rAAV exploiting baculovirus technology at different scales using different configurations of bioreactors as well as processing and product characterization issues. The yields obtained with these optimized processes exceed approximately 1 x 10(14) vector particles per liter of cell culture suitable for pre-clinical and clinical trials and possible commercialization.
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Eibl R, Eibl D. Application of Disposable Bag Bioreactors in Tissue Engineering and for the Production of Therapeutic Agents. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2008. [DOI: 10.1007/10_2008_3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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