1
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Wang Z, He M, He H, Kilby K, Antueno RD, Castle E, McMullen N, Qian Z, Zeev-Ben-Mordehai T, Duncan R, Pan C. Nonenveloped Avian Reoviruses Released with Small Extracellular Vesicles Are Highly Infectious. Viruses 2023; 15:1610. [PMID: 37515296 PMCID: PMC10384003 DOI: 10.3390/v15071610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 07/20/2023] [Accepted: 07/21/2023] [Indexed: 07/30/2023] Open
Abstract
Vesicle-encapsulated nonenveloped viruses are a recently recognized alternate form of nonenveloped viruses that can avoid immune detection and potentially increase systemic transmission. Avian orthoreoviruses (ARVs) are the leading cause of various disease conditions among birds and poultry. However, whether ARVs use cellular vesicle trafficking routes for egress and cell-to-cell transmission is still poorly understood. We demonstrated that fusogenic ARV-infected quail cells generated small (~100 nm diameter) extracellular vesicles (EVs) that contained electron-dense material when observed by transmission electron microscope. Cryo-EM tomography indicated that these vesicles did not contain ARV virions or core particles, but the EV fractions of OptiPrep gradients did contain a small percent of the ARV virions released from cells. Western blotting of detergent-treated EVs revealed that soluble virus proteins and the fusogenic p10 FAST protein were contained within the EVs. Notably, virus particles mixed with the EVs were up to 50 times more infectious than virions alone. These results suggest that EVs and perhaps fusogenic FAST-EVs could contribute to ARV virulence.
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Affiliation(s)
- Zuopei Wang
- Laboratory of Molecular Virology and Immunology, Technology Innovation Center, Haid Research Institute, Guangdong Haid Group Co., Ltd., Panyu, Guangzhou 511400, China
| | - Menghan He
- Laboratory of Molecular Virology and Immunology, Technology Innovation Center, Haid Research Institute, Guangdong Haid Group Co., Ltd., Panyu, Guangzhou 511400, China
| | - Han He
- Department of Microbiology & Immunology, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Kyle Kilby
- Department of Microbiology & Immunology, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Roberto de Antueno
- Department of Microbiology & Immunology, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Elizabeth Castle
- Department of Microbiology & Immunology, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Nichole McMullen
- Department of Microbiology & Immunology, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Zhuoyu Qian
- Department of Biochemical Engineering, University College London, London WC1E 6BT, UK
| | | | - Roy Duncan
- Department of Microbiology & Immunology, Dalhousie University, Halifax, NS B3H 4R2, Canada
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Chungen Pan
- Laboratory of Molecular Virology and Immunology, Technology Innovation Center, Haid Research Institute, Guangdong Haid Group Co., Ltd., Panyu, Guangzhou 511400, China
- Department of Microbiology & Immunology, Dalhousie University, Halifax, NS B3H 4R2, Canada
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2
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Leung MR, Zeng J, Wang X, Roelofs MC, Huang W, Zenezini Chiozzi R, Hevler JF, Heck AJR, Dutcher SK, Brown A, Zhang R, Zeev-Ben-Mordehai T. Structural specializations of the sperm tail. Cell 2023; 186:2880-2896.e17. [PMID: 37327785 PMCID: PMC10948200 DOI: 10.1016/j.cell.2023.05.026] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 03/16/2023] [Accepted: 05/17/2023] [Indexed: 06/18/2023]
Abstract
Sperm motility is crucial to reproductive success in sexually reproducing organisms. Impaired sperm movement causes male infertility, which is increasing globally. Sperm are powered by a microtubule-based molecular machine-the axoneme-but it is unclear how axonemal microtubules are ornamented to support motility in diverse fertilization environments. Here, we present high-resolution structures of native axonemal doublet microtubules (DMTs) from sea urchin and bovine sperm, representing external and internal fertilizers. We identify >60 proteins decorating sperm DMTs; at least 15 are sperm associated and 16 are linked to infertility. By comparing DMTs across species and cell types, we define core microtubule inner proteins (MIPs) and analyze evolution of the tektin bundle. We identify conserved axonemal microtubule-associated proteins (MAPs) with unique tubulin-binding modes. Additionally, we identify a testis-specific serine/threonine kinase that links DMTs to outer dense fibers in mammalian sperm. Our study provides structural foundations for understanding sperm evolution, motility, and dysfunction at a molecular level.
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Affiliation(s)
- Miguel Ricardo Leung
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, 3584 CG Utrecht, the Netherlands
| | - Jianwei Zeng
- Department of Biochemistry and Molecular Biophysics, Washington University in St. Louis, School of Medicine, St. Louis, MO, USA
| | - Xiangli Wang
- Department of Biochemistry and Molecular Biophysics, Washington University in St. Louis, School of Medicine, St. Louis, MO, USA
| | - Marc C Roelofs
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, 3584 CG Utrecht, the Netherlands
| | - Wei Huang
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH, USA
| | - Riccardo Zenezini Chiozzi
- Biomolecular Mass Spectrometry & Proteomics, Bijvoet Centre for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Johannes F Hevler
- Biomolecular Mass Spectrometry & Proteomics, Bijvoet Centre for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Albert J R Heck
- Biomolecular Mass Spectrometry & Proteomics, Bijvoet Centre for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Susan K Dutcher
- Department of Genetics, Washington University in St. Louis, St Louis, MO, USA
| | - Alan Brown
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Rui Zhang
- Department of Biochemistry and Molecular Biophysics, Washington University in St. Louis, School of Medicine, St. Louis, MO, USA.
| | - Tzviya Zeev-Ben-Mordehai
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, 3584 CG Utrecht, the Netherlands.
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3
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Leung MR, Zenezini-Chiozzi R, Hevler J, Ravi RT, Heck AJ, Zeev-Ben-Mordehai T. The remarkable sperm mitochondrial sheath: insights from cryo-electron tomography. Biophys J 2022. [DOI: 10.1016/j.bpj.2021.11.2684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
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4
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Hurdiss DL, El Kazzi P, Bauer L, Papageorgiou N, Ferron FP, Donselaar T, van Vliet AL, Shamorkina TM, Snijder J, Canard B, Decroly E, Brancale A, Zeev-Ben-Mordehai T, Förster F, van Kuppeveld FJ, Coutard B. Fluoxetine targets an allosteric site in the enterovirus 2C AAA+ ATPase and stabilizes a ring-shaped hexameric complex. Sci Adv 2022; 8:eabj7615. [PMID: 34985963 PMCID: PMC8730599 DOI: 10.1126/sciadv.abj7615] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 11/10/2021] [Indexed: 06/14/2023]
Abstract
Enteroviruses are globally prevalent human pathogens responsible for many diseases. The nonstructural protein 2C is a AAA+ helicase and plays a key role in enterovirus replication. Drug repurposing screens identified 2C-targeting compounds such as fluoxetine and dibucaine, but how they inhibit 2C is unknown. Here, we present a crystal structure of the soluble and monomeric fragment of coxsackievirus B3 2C protein in complex with (S)-fluoxetine (SFX), revealing an allosteric binding site. To study the functional consequences of SFX binding, we engineered an adenosine triphosphatase (ATPase)–competent, hexameric 2C protein. Using this system, we show that SFX, dibucaine, HBB [2-(α-hydroxybenzyl)-benzimidazole], and guanidine hydrochloride inhibit 2C ATPase activity. Moreover, cryo–electron microscopy analysis demonstrated that SFX and dibucaine lock 2C in a defined hexameric state, rationalizing their mode of inhibition. Collectively, these results provide important insights into 2C inhibition and a robust engineering strategy for structural, functional, and drug-screening analysis of 2C proteins.
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Affiliation(s)
- Daniel L. Hurdiss
- Virology Section, Infectious Diseases and Immunology Division, Department of Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, 3584CL Utrecht, Netherlands
- Cryo-Electron Microscopy, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, Netherlands
| | | | - Lisa Bauer
- Virology Section, Infectious Diseases and Immunology Division, Department of Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, 3584CL Utrecht, Netherlands
| | | | | | - Tim Donselaar
- Virology Section, Infectious Diseases and Immunology Division, Department of Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, 3584CL Utrecht, Netherlands
| | - Arno L.W. van Vliet
- Virology Section, Infectious Diseases and Immunology Division, Department of Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, 3584CL Utrecht, Netherlands
| | - Tatiana M. Shamorkina
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, Netherlands
| | - Joost Snijder
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, Netherlands
| | - Bruno Canard
- Aix Marseille Université, CNRS, AFMB UMR 7257, Marseille, France
| | - Etienne Decroly
- Aix Marseille Université, CNRS, AFMB UMR 7257, Marseille, France
| | - Andrea Brancale
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, King Edward VII Avenue, Cardiff CF10 3NB, UK
| | - Tzviya Zeev-Ben-Mordehai
- Cryo-Electron Microscopy, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, Netherlands
| | - Friedrich Förster
- Cryo-Electron Microscopy, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, Netherlands
| | - Frank J.M. van Kuppeveld
- Virology Section, Infectious Diseases and Immunology Division, Department of Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, 3584CL Utrecht, Netherlands
| | - Bruno Coutard
- Unité des Virus Émergents (UVE: Aix-Marseille Univ-IRD 190-Inserm 1207), Marseille, France
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5
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Leung MR, Ravi RT, Gadella BM, Zeev-Ben-Mordehai T. Membrane Remodeling and Matrix Dispersal Intermediates During Mammalian Acrosomal Exocytosis. Front Cell Dev Biol 2021; 9:765673. [PMID: 34957098 PMCID: PMC8708559 DOI: 10.3389/fcell.2021.765673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 10/19/2021] [Indexed: 11/13/2022] Open
Abstract
To become fertilization-competent, mammalian sperm must undergo a complex series of biochemical and morphological changes in the female reproductive tract. These changes, collectively called capacitation, culminate in the exocytosis of the acrosome, a large vesicle overlying the nucleus. Acrosomal exocytosis is not an all-or-nothing event but rather a regulated process in which vesicle cargo disperses gradually. However, the structural mechanisms underlying this controlled release remain undefined. In addition, unlike other exocytotic events, fusing membranes are shed as vesicles; the cell thus loses the entire anterior two-thirds of its plasma membrane and yet remains intact, while the remaining nonvesiculated plasma membrane becomes fusogenic. Precisely how cell integrity is maintained throughout this drastic vesiculation process is unclear, as is how it ultimately leads to the acquisition of fusion competence. Here, we use cryoelectron tomography to visualize these processes in unfixed, unstained, fully hydrated sperm. We show that paracrystalline structures within the acrosome disassemble during capacitation and acrosomal exocytosis, representing a plausible mechanism for gradual dispersal of the acrosomal matrix. We find that the architecture of the sperm head supports an atypical membrane fission-fusion pathway that maintains cell integrity. Finally, we detail how the acrosome reaction transforms both the micron-scale topography and the nanoscale protein landscape of the sperm surface, thus priming the sperm for fertilization.
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Affiliation(s)
- Miguel Ricardo Leung
- Bijvoet Centre for Biomolecular Research, Utrecht University, Utrecht, Netherlands.,The Division of Structural Biology, Wellcome Centre for Human Genetics, The University of Oxford, Oxford, United Kingdom
| | - Ravi Teja Ravi
- Bijvoet Centre for Biomolecular Research, Utrecht University, Utrecht, Netherlands
| | - Bart M Gadella
- Department of Farm and Animal Health and Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
| | - Tzviya Zeev-Ben-Mordehai
- Bijvoet Centre for Biomolecular Research, Utrecht University, Utrecht, Netherlands.,The Division of Structural Biology, Wellcome Centre for Human Genetics, The University of Oxford, Oxford, United Kingdom
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6
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Maitan PP, Bromfield EG, Hoogendijk R, Leung MR, Zeev-Ben-Mordehai T, van de Lest CH, Jansen JWA, Leemans B, Guimarães JD, Stout TAE, Gadella BM, Henning H. Bicarbonate-Stimulated Membrane Reorganization in Stallion Spermatozoa. Front Cell Dev Biol 2021; 9:772254. [PMID: 34869370 PMCID: PMC8635755 DOI: 10.3389/fcell.2021.772254] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 10/25/2021] [Indexed: 11/13/2022] Open
Abstract
Classical in vitro fertilization (IVF) is still poorly successful in horses. This lack of success is thought to be due primarily to inadequate capacitation of stallion spermatozoa under in vitro conditions. In species in which IVF is successful, bicarbonate, calcium, and albumin are considered the key components that enable a gradual reorganization of the sperm plasma membrane that allows the spermatozoa to undergo an acrosome reaction and fertilize the oocyte. The aim of this work was to comprehensively examine contributors to stallion sperm capacitation by investigating bicarbonate-induced membrane remodelling steps, and elucidating the contribution of cAMP signalling to these events. In the presence of capacitating media containing bicarbonate, a significant increase in plasma membrane fluidity was readily detected using merocyanine 540 staining in the majority of viable spermatozoa within 15 min of bicarbonate exposure. Specific inhibition of soluble adenylyl cyclase (sAC) in the presence of bicarbonate by LRE1 significantly reduced the number of viable sperm with high membrane fluidity. This suggests a vital role for sAC-mediated cAMP production in the regulation of membrane fluidity. Cryo-electron tomography of viable cells with high membrane fluidity revealed a range of membrane remodelling intermediates, including destabilized membranes and zones with close apposition of the plasma membrane and the outer acrosomal membrane. However, lipidomic analysis of equivalent viable spermatozoa with high membrane fluidity demonstrated that this phenomenon was neither accompanied by a gross change in the phospholipid composition of stallion sperm membranes nor detectable sterol efflux (p > 0.05). After an early increase in membrane fluidity, a significant and cAMP-dependent increase in viable sperm with phosphatidylserine (PS), but not phosphatidylethanolamine (PE) exposure was noted. While the events observed partly resemble findings from the in vitro capacitation of sperm from other mammalian species, the lack of cholesterol removal appears to be an equine-specific phenomenon. This research will assist in the development of a defined medium for the capacitation of stallion sperm and will facilitate progress toward a functional IVF protocol for horse gametes.
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Affiliation(s)
- Paula Piccolo Maitan
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands.,Department of Veterinary Medicine, Universidade Federal de Viçosa, Viçosa, Brazil
| | - Elizabeth G Bromfield
- Department of Biomolecular Health Science, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands.,Priority Research Centre for Reproductive Science, The University of Newcastle, Callaghan, NSW, Australia
| | - Romy Hoogendijk
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
| | - Miguel Ricardo Leung
- Cryo-Electron Microscopy, Bijvoet Centre for Biomolecular Research, Utrecht University, Utrecht, Netherlands
| | - Tzviya Zeev-Ben-Mordehai
- Cryo-Electron Microscopy, Bijvoet Centre for Biomolecular Research, Utrecht University, Utrecht, Netherlands
| | - Chris H van de Lest
- Department of Biomolecular Health Science, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
| | - Jeroen W A Jansen
- Department of Biomolecular Health Science, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
| | - Bart Leemans
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
| | | | - Tom A E Stout
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
| | - Bart M Gadella
- Department of Biomolecular Health Science, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands.,Department of Population Health Science, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
| | - Heiko Henning
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
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7
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Khanal S, Leung MR, Royfman A, Fishman EL, Saltzman B, Bloomfield-Gadêlha H, Zeev-Ben-Mordehai T, Avidor-Reiss T. A dynamic basal complex modulates mammalian sperm movement. Nat Commun 2021; 12:3808. [PMID: 34155206 PMCID: PMC8217517 DOI: 10.1038/s41467-021-24011-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 05/28/2021] [Indexed: 01/04/2023] Open
Abstract
Reproductive success depends on efficient sperm movement driven by axonemal dynein-mediated microtubule sliding. Models predict sliding at the base of the tail - the centriole - but such sliding has never been observed. Centrioles are ancient organelles with a conserved architecture; their rigidity is thought to restrict microtubule sliding. Here, we show that, in mammalian sperm, the atypical distal centriole (DC) and its surrounding atypical pericentriolar matrix form a dynamic basal complex (DBC) that facilitates a cascade of internal sliding deformations, coupling tail beating with asymmetric head kinking. During asymmetric tail beating, the DC's right side and its surroundings slide ~300 nm rostrally relative to the left side. The deformation throughout the DBC is transmitted to the head-tail junction; thus, the head tilts to the left, generating a kinking motion. These findings suggest that the DBC evolved as a dynamic linker coupling sperm head and tail into a single self-coordinated system.
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Affiliation(s)
- Sushil Khanal
- Department of Biological Sciences, University of Toledo, Toledo, OH, USA
| | - Miguel Ricardo Leung
- The Division of Structural Biology, Wellcome Centre for Human Genetics, The University of Oxford, Oxford, UK
- Cryo-Electron Microscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands
| | - Abigail Royfman
- Department of Biological Sciences, University of Toledo, Toledo, OH, USA
| | - Emily L Fishman
- Department of Biological Sciences, University of Toledo, Toledo, OH, USA
| | - Barbara Saltzman
- School of Population Health, College of Health and Human Services, University of Toledo, Toledo, OH, USA
| | - Hermes Bloomfield-Gadêlha
- Department of Engineering Mathematics and Bristol Robotics Laboratory, University of Bristol, Bristol, UK
| | - Tzviya Zeev-Ben-Mordehai
- The Division of Structural Biology, Wellcome Centre for Human Genetics, The University of Oxford, Oxford, UK.
- Cryo-Electron Microscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands.
| | - Tomer Avidor-Reiss
- Department of Biological Sciences, University of Toledo, Toledo, OH, USA.
- Department of Urology, College of Medicine and Life Sciences, University of Toledo, Toledo, OH, USA.
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8
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Leung MR, Roelofs MC, Ravi RT, Maitan P, Henning H, Zhang M, Bromfield EG, Howes SC, Gadella BM, Bloomfield-Gadêlha H, Zeev-Ben-Mordehai T. The multi-scale architecture of mammalian sperm flagella and implications for ciliary motility. EMBO J 2021; 40:e107410. [PMID: 33694216 PMCID: PMC8013824 DOI: 10.15252/embj.2020107410] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 01/27/2021] [Accepted: 02/12/2021] [Indexed: 12/14/2022] Open
Abstract
Motile cilia are molecular machines used by a myriad of eukaryotic cells to swim through fluid environments. However, available molecular structures represent only a handful of cell types, limiting our understanding of how cilia are modified to support motility in diverse media. Here, we use cryo‐focused ion beam milling‐enabled cryo‐electron tomography to image sperm flagella from three mammalian species. We resolve in‐cell structures of centrioles, axonemal doublets, central pair apparatus, and endpiece singlets, revealing novel protofilament‐bridging microtubule inner proteins throughout the flagellum. We present native structures of the flagellar base, which is crucial for shaping the flagellar beat. We show that outer dense fibers are directly coupled to microtubule doublets in the principal piece but not in the midpiece. Thus, mammalian sperm flagella are ornamented across scales, from protofilament‐bracing structures reinforcing microtubules at the nano‐scale to accessory structures that impose micron‐scale asymmetries on the entire assembly. Our structures provide vital foundations for linking molecular structure to ciliary motility and evolution.
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Affiliation(s)
- Miguel Ricardo Leung
- Cryo-Electron Microscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands.,The Division of Structural Biology, Wellcome Centre for Human Genetics, The University of Oxford, Oxford, UK
| | - Marc C Roelofs
- Cryo-Electron Microscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands
| | - Ravi Teja Ravi
- Cryo-Electron Microscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands
| | - Paula Maitan
- Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.,Veterinary Department, Universidade Federal de Viçosa, Viçosa, Brazil
| | - Heiko Henning
- Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Min Zhang
- Department of Farm & Animal Health and Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Elizabeth G Bromfield
- Department of Farm & Animal Health and Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.,Priority Research Centre for Reproductive Science, Faculty of Science, The University of Newcastle, Callaghan, NSW, Australia
| | - Stuart C Howes
- Cryo-Electron Microscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands
| | - Bart M Gadella
- Department of Farm & Animal Health and Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | | | - Tzviya Zeev-Ben-Mordehai
- Cryo-Electron Microscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands.,The Division of Structural Biology, Wellcome Centre for Human Genetics, The University of Oxford, Oxford, UK
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9
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Leung MR, Zeev-Ben-Mordehai T. Cryo-electron microscopy of cholinesterases, present and future. J Neurochem 2020; 158:1236-1243. [PMID: 33222205 PMCID: PMC8518539 DOI: 10.1111/jnc.15245] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 10/30/2020] [Accepted: 11/11/2020] [Indexed: 02/06/2023]
Abstract
Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) exist in a variety of oligomeric forms, each with defined cellular and subcellular distributions. Although crystal structures of AChE and BChE have been available for many years, structures of the physiologically relevant ChE tetramer were only recently solved by cryo‐electron microscopy (cryo‐EM) single‐particle analysis. Here, we briefly review how these structures contribute to our understanding of cholinesterase oligomerization, highlighting the advantages of using cryo‐EM to resolve structures of protein assemblies that cannot be expressed recombinantly. We argue that the next frontier in cholinesterase structural biology is to image membrane‐anchored ChE oligomers directly in their native environment—the cell.
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Affiliation(s)
- Miguel Ricardo Leung
- Cryo-Electron Microscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands.,The Division of Structural Biology, Wellcome Centre for Human Genetics, The University of Oxford, Oxford, UK
| | - Tzviya Zeev-Ben-Mordehai
- Cryo-Electron Microscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands.,The Division of Structural Biology, Wellcome Centre for Human Genetics, The University of Oxford, Oxford, UK
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10
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Ravi RT, Leung MR, Zeev-Ben-Mordehai T. Looking back and looking forward: contributions of electron microscopy to the structural cell biology of gametes and fertilization. Open Biol 2020; 10:200186. [PMID: 32931719 PMCID: PMC7536082 DOI: 10.1098/rsob.200186] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 08/25/2020] [Indexed: 01/22/2023] Open
Abstract
Mammalian gametes-the sperm and the egg-represent opposite extremes of cellular organization and scale. Studying the ultrastructure of gametes is crucial to understanding their interactions, and how to manipulate them in order to either encourage or prevent their union. Here, we survey the prominent electron microscopy (EM) techniques, with an emphasis on considerations for applying them to study mammalian gametes. We review how conventional EM has provided significant insight into gamete ultrastructure, but also how the harsh sample preparation methods required preclude understanding at a truly molecular level. We present recent advancements in cryo-electron tomography that provide an opportunity to image cells in a near-native state and at unprecedented levels of detail. New and emerging cellular EM techniques are poised to rekindle exploration of fundamental questions in mammalian reproduction, especially phenomena that involve complex membrane remodelling and protein reorganization. These methods will also allow novel lines of enquiry into problems of practical significance, such as investigating unexplained causes of human infertility and improving assisted reproductive technologies for biodiversity conservation.
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Affiliation(s)
- Ravi Teja Ravi
- Cryo-Electron Microscopy, Bijvoet Centre for Biomolecular Research, Utrecht University, 3584CH Utrecht, The Netherlands
| | - Miguel Ricardo Leung
- Cryo-Electron Microscopy, Bijvoet Centre for Biomolecular Research, Utrecht University, 3584CH Utrecht, The Netherlands
- Division of Structural Biology, Wellcome Centre for Human Genetics, The University of Oxford, Oxford OX3 7BN, UK
| | - Tzviya Zeev-Ben-Mordehai
- Cryo-Electron Microscopy, Bijvoet Centre for Biomolecular Research, Utrecht University, 3584CH Utrecht, The Netherlands
- Division of Structural Biology, Wellcome Centre for Human Genetics, The University of Oxford, Oxford OX3 7BN, UK
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11
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Toker L, Silman I, Zeev-Ben-Mordehai T, Sussman JL, Schopfer LM, Lockridge O. Polyproline-rich peptides associated with Torpedo californica acetylcholinesterase tetramers. Chem Biol Interact 2020; 319:109007. [PMID: 32087110 DOI: 10.1016/j.cbi.2020.109007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Revised: 01/31/2020] [Accepted: 02/17/2020] [Indexed: 01/30/2023]
Abstract
Acetylcholinesterase (AChE) terminates cholinergic neurotransmission by hydrolyzing acetylcholine. The collagen-tailed AChE tetramer is a product of 2 genes, ACHE and ColQ. The AChE tetramer consists of 4 identical AChE subunits and one polyproline-rich peptide, whose function is to hold the 4 AChE subunits together. Our goal was to determine the amino acid sequence of the polyproline-rich peptide(s) in Torpedo californica AChE (TcAChE) tetramers to aid in the analysis of images that will be acquired by cryo-EM. Collagen-tailed AChE was solubilized from Torpedo californica electric organ, converted to 300 kDa tetramers by digestion with trypsin, and purified by affinity chromatography. Polyproline-rich peptides were released by denaturing the TcAChE tetramers in a boiling water bath, and reducing disulfide bonds with dithiothreitol. Carbamidomethylated peptides were separated from TcAChE protein on a spin filter before they were analyzed by liquid chromatography tandem mass spectrometry on a high resolution Orbitrap Fusion Lumos mass spectrometer. Of the 64 identified collagen-tail (ColQ) peptides, 60 were from the polyproline-rich region near the N-terminus of ColQ. The most abundant proline-rich peptides were SVNKCCLLTPPPPPMFPPPFFTETNILQE, at 40% of total mass-spectral signal intensity, and SVNKCCLLTPPPPPMFPPPFFTETNILQEVDLNNLPLEIKPTEPSCK, at 27% of total intensity. The high abundance of these 2 peptides makes them candidates for the principal form of the polyproline-rich peptide in the trypsin-treated TcAChE tetramers.
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Affiliation(s)
- Lilly Toker
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, 7610001, Israel.
| | - Israel Silman
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, 7610001, Israel.
| | - Tzviya Zeev-Ben-Mordehai
- Cryo-Electron Microscopy, Bijvoet Center for Biomolecular Research, Utrecht University, 3584, CH, Utrecht, the Netherlands.
| | - Joel L Sussman
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, 7610001, Israel.
| | - Lawrence M Schopfer
- Eppley Institute, University of Nebraska Medical Center, Omaha, NE, 68198, USA.
| | - Oksana Lockridge
- Eppley Institute, University of Nebraska Medical Center, Omaha, NE, 68198, USA.
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12
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Chorev DS, Baker LA, Wu D, Beilsten-Edmands V, Rouse SL, Zeev-Ben-Mordehai T, Jiko C, Samsudin F, Gerle C, Khalid S, Stewart AG, Matthews SJ, Grünewald K, Robinson CV. Protein assemblies ejected directly from native membranes yield complexes for mass spectrometry. Science 2019; 362:829-834. [PMID: 30442809 DOI: 10.1126/science.aau0976] [Citation(s) in RCA: 134] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Accepted: 10/08/2018] [Indexed: 12/25/2022]
Abstract
Membrane proteins reside in lipid bilayers and are typically extracted from this environment for study, which often compromises their integrity. In this work, we ejected intact assemblies from membranes, without chemical disruption, and used mass spectrometry to define their composition. From Escherichia coli outer membranes, we identified a chaperone-porin association and lipid interactions in the β-barrel assembly machinery. We observed efflux pumps bridging inner and outer membranes, and from inner membranes we identified a pentameric pore of TonB, as well as the protein-conducting channel SecYEG in association with F1FO adenosine triphosphate (ATP) synthase. Intact mitochondrial membranes from Bos taurus yielded respiratory complexes and fatty acid-bound dimers of the ADP (adenosine diphosphate)/ATP translocase (ANT-1). These results highlight the importance of native membrane environments for retaining small-molecule binding, subunit interactions, and associated chaperones of the membrane proteome.
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Affiliation(s)
- Dror S Chorev
- Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, UK
| | - Lindsay A Baker
- Division of Structural Biology, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Di Wu
- Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, UK
| | - Victoria Beilsten-Edmands
- Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, UK
| | - Sarah L Rouse
- Department of Life Sciences, Imperial College, London, South Kensington Campus, London SW7 2AZ, UK
| | | | - Chimari Jiko
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Kumatori, Japan
| | - Firdaus Samsudin
- School of Chemistry, University of Southampton, University Road, Southampton SO17 1BJ, UK
| | - Christoph Gerle
- Institute for Protein Research, Osaka University, Suita, Osaka, Japan.,Core Research for Evolutional Science and Technology, Japan and Science and Technology Agency, Kawaguchi, Japan
| | - Syma Khalid
- School of Chemistry, University of Southampton, University Road, Southampton SO17 1BJ, UK
| | - Alastair G Stewart
- Molecular, Structural and Computational Biology Division, Victor Chang Cardiac Research Institute, Darlinghurst, NSW, Australia.,Faculty of Medicine, The University of New South Wales, Sydney, NSW, Australia
| | - Stephen J Matthews
- Department of Life Sciences, Imperial College, London, South Kensington Campus, London SW7 2AZ, UK
| | - Kay Grünewald
- Division of Structural Biology, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK.,Centre of Structural Systems Biology (CSSB), Notkestr. 85, D-22607, Heinrich-Pette Institute/University of Hamburg, Hamburg, Germany
| | - Carol V Robinson
- Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, UK.
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13
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Zeng X, Leung MR, Zeev-Ben-Mordehai T, Xu M. A convolutional autoencoder approach for mining features in cellular electron cryo-tomograms and weakly supervised coarse segmentation. J Struct Biol 2018; 202:150-160. [PMID: 29289599 PMCID: PMC6661905 DOI: 10.1016/j.jsb.2017.12.015] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 12/24/2017] [Accepted: 12/27/2017] [Indexed: 01/08/2023]
Abstract
Cellular electron cryo-tomography enables the 3D visualization of cellular organization in the near-native state and at submolecular resolution. However, the contents of cellular tomograms are often complex, making it difficult to automatically isolate different in situ cellular components. In this paper, we propose a convolutional autoencoder-based unsupervised approach to provide a coarse grouping of 3D small subvolumes extracted from tomograms. We demonstrate that the autoencoder can be used for efficient and coarse characterization of features of macromolecular complexes and surfaces, such as membranes. In addition, the autoencoder can be used to detect non-cellular features related to sample preparation and data collection, such as carbon edges from the grid and tomogram boundaries. The autoencoder is also able to detect patterns that may indicate spatial interactions between cellular components. Furthermore, we demonstrate that our autoencoder can be used for weakly supervised semantic segmentation of cellular components, requiring a very small amount of manual annotation.
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Affiliation(s)
- Xiangrui Zeng
- Computational Biology Department, School of Computer Science, Carnegie Mellon University, Pittsburgh 15213, USA
| | - Miguel Ricardo Leung
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK; Cryo-electron Microscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, Netherlands
| | - Tzviya Zeev-Ben-Mordehai
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK; Cryo-electron Microscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, Netherlands
| | - Min Xu
- Computational Biology Department, School of Computer Science, Carnegie Mellon University, Pittsburgh 15213, USA.
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14
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Xu M, Chai X, Muthakana H, Liang X, Yang G, Zeev-Ben-Mordehai T, Xing EP. Deep learning-based subdivision approach for large scale macromolecules structure recovery from electron cryo tomograms. Bioinformatics 2018; 33:i13-i22. [PMID: 28881965 PMCID: PMC5946875 DOI: 10.1093/bioinformatics/btx230] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Motivation Cellular Electron CryoTomography (CECT) enables 3D visualization of cellular organization at near-native state and in sub-molecular resolution, making it a powerful tool for analyzing structures of macromolecular complexes and their spatial organizations inside single cells. However, high degree of structural complexity together with practical imaging limitations makes the systematic de novo discovery of structures within cells challenging. It would likely require averaging and classifying millions of subtomograms potentially containing hundreds of highly heterogeneous structural classes. Although it is no longer difficult to acquire CECT data containing such amount of subtomograms due to advances in data acquisition automation, existing computational approaches have very limited scalability or discrimination ability, making them incapable of processing such amount of data. Results To complement existing approaches, in this article we propose a new approach for subdividing subtomograms into smaller but relatively homogeneous subsets. The structures in these subsets can then be separately recovered using existing computation intensive methods. Our approach is based on supervised structural feature extraction using deep learning, in combination with unsupervised clustering and reference-free classification. Our experiments show that, compared with existing unsupervised rotation invariant feature and pose-normalization based approaches, our new approach achieves significant improvements in both discrimination ability and scalability. More importantly, our new approach is able to discover new structural classes and recover structures that do not exist in training data. Availability and Implementation Source code freely available at http://www.cs.cmu.edu/∼mxu1/software. Supplementary information Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Min Xu
- Computational Biology Department, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Xiaoqi Chai
- Biomedical Engineering Department, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Hariank Muthakana
- Computer Science Department, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Xiaodan Liang
- Machine Learning Department, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Ge Yang
- Biomedical Engineering Department, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Tzviya Zeev-Ben-Mordehai
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Eric P Xing
- Machine Learning Department, Carnegie Mellon University, Pittsburgh, PA, USA
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15
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Hagen C, Dent KC, Zeev-Ben-Mordehai T, Grange M, Bosse JB, Whittle C, Klupp BG, Siebert CA, Vasishtan D, Bäuerlein FJB, Cheleski J, Werner S, Guttmann P, Rehbein S, Henzler K, Demmerle J, Adler B, Koszinowski U, Schermelleh L, Schneider G, Enquist LW, Plitzko JM, Mettenleiter TC, Grünewald K. Structural Basis of Vesicle Formation at the Inner Nuclear Membrane. Cell 2016; 163:1692-701. [PMID: 26687357 PMCID: PMC4701712 DOI: 10.1016/j.cell.2015.11.029] [Citation(s) in RCA: 147] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 09/11/2015] [Accepted: 11/06/2015] [Indexed: 12/22/2022]
Abstract
Vesicular nucleo-cytoplasmic transport is becoming recognized as a general cellular mechanism for translocation of large cargoes across the nuclear envelope. Cargo is recruited, enveloped at the inner nuclear membrane (INM), and delivered by membrane fusion at the outer nuclear membrane. To understand the structural underpinning for this trafficking, we investigated nuclear egress of progeny herpesvirus capsids where capsid envelopment is mediated by two viral proteins, forming the nuclear egress complex (NEC). Using a multi-modal imaging approach, we visualized the NEC in situ forming coated vesicles of defined size. Cellular electron cryo-tomography revealed a protein layer showing two distinct hexagonal lattices at its membrane-proximal and membrane-distant faces, respectively. NEC coat architecture was determined by combining this information with integrative modeling using small-angle X-ray scattering data. The molecular arrangement of the NEC establishes the basic mechanism for budding and scission of tailored vesicles at the INM. Multimodal imaging reveals mechanism of vesicle formation at inner nuclear membrane Nucleo-cytoplasmic cargo vesicle coat in situ comprises two distinct lattices Lattices are formed by hexameric building blocks made of the nuclear egress complex Induction of membrane curvature based solely on heterodimeric interactions
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Affiliation(s)
- Christoph Hagen
- Oxford Particle Imaging Centre, Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Kyle C Dent
- Oxford Particle Imaging Centre, Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK; Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot OX11 0DE, UK
| | - Tzviya Zeev-Ben-Mordehai
- Oxford Particle Imaging Centre, Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Michael Grange
- Oxford Particle Imaging Centre, Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Jens B Bosse
- Department of Molecular Biology, Princeton Neuroscience Institute, Princeton University, Washington Road, Princeton, NJ 08544, USA
| | - Cathy Whittle
- Oxford Particle Imaging Centre, Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Barbara G Klupp
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, 17493 Greifswald-Insel Riems, Germany
| | - C Alistair Siebert
- Oxford Particle Imaging Centre, Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Daven Vasishtan
- Oxford Particle Imaging Centre, Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Felix J B Bäuerlein
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Juliana Cheleski
- Oxford Particle Imaging Centre, Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Stephan Werner
- Helmholtz Zentrum Berlin für Materialien und Energie GmbH, Wilhelm-Conrad-Röntgen Campus, 12489 Berlin, Germany
| | - Peter Guttmann
- Helmholtz Zentrum Berlin für Materialien und Energie GmbH, Wilhelm-Conrad-Röntgen Campus, 12489 Berlin, Germany
| | - Stefan Rehbein
- Helmholtz Zentrum Berlin für Materialien und Energie GmbH, Wilhelm-Conrad-Röntgen Campus, 12489 Berlin, Germany
| | - Katja Henzler
- Helmholtz Zentrum Berlin für Materialien und Energie GmbH, Wilhelm-Conrad-Röntgen Campus, 12489 Berlin, Germany
| | - Justin Demmerle
- Micron Oxford, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Barbara Adler
- Max von Pettenkofer-Institut, Ludwig-Maximilians-Universität München, Pettenkoferstr. 9a, 80336 Munich, Germany
| | - Ulrich Koszinowski
- Max von Pettenkofer-Institut, Ludwig-Maximilians-Universität München, Pettenkoferstr. 9a, 80336 Munich, Germany
| | - Lothar Schermelleh
- Micron Oxford, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Gerd Schneider
- Helmholtz Zentrum Berlin für Materialien und Energie GmbH, Wilhelm-Conrad-Röntgen Campus, 12489 Berlin, Germany
| | - Lynn W Enquist
- Department of Molecular Biology, Princeton Neuroscience Institute, Princeton University, Washington Road, Princeton, NJ 08544, USA
| | - Jürgen M Plitzko
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Thomas C Mettenleiter
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, 17493 Greifswald-Insel Riems, Germany.
| | - Kay Grünewald
- Oxford Particle Imaging Centre, Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK.
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16
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Zeev-Ben-Mordehai T, Weberruß M, Lorenz M, Cheleski J, Hellberg T, Whittle C, El Omari K, Vasishtan D, Dent KC, Harlos K, Franzke K, Hagen C, Klupp BG, Antonin W, Mettenleiter TC, Grünewald K. Crystal Structure of the Herpesvirus Nuclear Egress Complex Provides Insights into Inner Nuclear Membrane Remodeling. Cell Rep 2015; 13:2645-52. [PMID: 26711332 PMCID: PMC4700048 DOI: 10.1016/j.celrep.2015.11.008] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 10/16/2015] [Accepted: 10/31/2015] [Indexed: 11/18/2022] Open
Abstract
Although nucleo-cytoplasmic transport is typically mediated through nuclear pore complexes, herpesvirus capsids exit the nucleus via a unique vesicular pathway. Together, the conserved herpesvirus proteins pUL31 and pUL34 form the heterodimeric nuclear egress complex (NEC), which, in turn, mediates the formation of tight-fitting membrane vesicles around capsids at the inner nuclear membrane. Here, we present the crystal structure of the pseudorabies virus NEC. The structure revealed that a zinc finger motif in pUL31 and an extensive interaction network between the two proteins stabilize the complex. Comprehensive mutational analyses, characterized both in situ and in vitro, indicated that the interaction network is not redundant but rather complementary. Fitting of the NEC crystal structure into the recently determined cryoEM-derived hexagonal lattice, formed in situ by pUL31 and pUL34, provided details on the molecular basis of NEC coat formation and inner nuclear membrane remodeling.
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Affiliation(s)
- Tzviya Zeev-Ben-Mordehai
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Marion Weberruß
- Friedrich Miescher Laboratory of the Max Planck Society, 72076 Tübingen, Germany
| | - Michael Lorenz
- Friedrich Miescher Laboratory of the Max Planck Society, 72076 Tübingen, Germany
| | - Juliana Cheleski
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Teresa Hellberg
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, 17493 Greifswald - Insel Riems, Germany
| | - Cathy Whittle
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Kamel El Omari
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Daven Vasishtan
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Kyle C Dent
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Karl Harlos
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Kati Franzke
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, 17493 Greifswald - Insel Riems, Germany
| | - Christoph Hagen
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Barbara G Klupp
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, 17493 Greifswald - Insel Riems, Germany
| | - Wolfram Antonin
- Friedrich Miescher Laboratory of the Max Planck Society, 72076 Tübingen, Germany.
| | - Thomas C Mettenleiter
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, 17493 Greifswald - Insel Riems, Germany
| | - Kay Grünewald
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK.
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17
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Zeev-Ben-Mordehai T, Vasishtan D, Siebert CA, Whittle C, Grünewald K. Extracellular vesicles: a platform for the structure determination of membrane proteins by Cryo-EM. Structure 2014; 22:1687-92. [PMID: 25438672 PMCID: PMC4229021 DOI: 10.1016/j.str.2014.09.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Revised: 09/09/2014] [Accepted: 09/12/2014] [Indexed: 01/13/2023]
Abstract
Membrane protein-enriched extracellular vesicles (MPEEVs) provide a platform for studying intact membrane proteins natively anchored with the correct topology in genuine biological membranes. This approach circumvents the need to conduct tedious detergent screens for solubilization, purification, and reconstitution required in classical membrane protein studies. We have applied this method to three integral type I membrane proteins, namely the Caenorhabditis elegans cell-cell fusion proteins AFF-1 and EFF-1 and the glycoprotein B (gB) from Herpes simplex virus type 1 (HSV1). Electron cryotomography followed by subvolume averaging allowed the 3D reconstruction of EFF-1 and HSV1 gB in the membrane as well as an analysis of the spatial distribution and interprotein interactions on the membrane. MPEEVs have many applications beyond structural/functional investigations, such as facilitating the raising of antibodies, for protein-protein interaction assays or for diagnostics use, as biomarkers, and possibly therapeutics. Intact membrane proteins with correct topology in genuine biological membranes Display system circumvents need for detergent solubilization and reconstitution 3D reconstruction of proteins in the membrane by subvolume averaging Mapping spatial distribution and relationships between proteins on the membrane
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Affiliation(s)
- Tzviya Zeev-Ben-Mordehai
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Daven Vasishtan
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - C Alistair Siebert
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Cathy Whittle
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Kay Grünewald
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK.
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18
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Zeev-Ben-Mordehai T, Vasishtan D, Siebert CA, Grünewald K. The full-length cell-cell fusogen EFF-1 is monomeric and upright on the membrane. Nat Commun 2014; 5:3912. [PMID: 24867324 PMCID: PMC4050280 DOI: 10.1038/ncomms4912] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Accepted: 04/17/2014] [Indexed: 01/04/2023] Open
Abstract
Fusogens are membrane proteins that remodel lipid bilayers to facilitate membrane merging. Although several fusogen ectodomain structures have been solved, structural information on full-length, natively membrane-anchored fusogens is scarce. Here we present the electron cryo microscopy three-dimensional reconstruction of the Caenorhabditis elegans epithelial fusion failure 1 (EFF-1) protein natively anchored in cell-derived membrane vesicles. This reveals a membrane protruding, asymmetric, elongated monomer. Flexible fitting of a protomer of the EFF-1 crystal structure, which is homologous to viral class-II fusion proteins, shows that EFF-1 has a hairpin monomeric conformation before fusion. These structural insights, when combined with our observations of membrane-merging intermediates between vesicles, enable us to propose a model for EFF-1 mediated fusion. This process, involving identical proteins on both membranes to be fused, follows a mechanism that shares features of SNARE-mediated fusion while using the structural building blocks of the unilaterally acting class-II viral fusion proteins. Cell–cell fusion in Caenorhabditis elegans is mediated by EFF-1 and AFF-1 proteins. Here, the authors present an electron cryomicroscopy 3D reconstruction of EFF-1 in the membrane, and combine snapshots of membrane fusion in vitro with a recently reported crystal structure to propose a mechanism for the fusion process.
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Affiliation(s)
- Tzviya Zeev-Ben-Mordehai
- Oxford Particle Imaging Centre, Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Daven Vasishtan
- Oxford Particle Imaging Centre, Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - C Alistair Siebert
- Oxford Particle Imaging Centre, Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Kay Grünewald
- Oxford Particle Imaging Centre, Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
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19
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Maurer UE, Zeev-Ben-Mordehai T, Pandurangan AP, Cairns TM, Hannah BP, Whitbeck JC, Eisenberg RJ, Cohen GH, Topf M, Huiskonen JT, Grünewald K. The structure of herpesvirus fusion glycoprotein B-bilayer complex reveals the protein-membrane and lateral protein-protein interaction. Structure 2013; 21:1396-405. [PMID: 23850455 PMCID: PMC3737472 DOI: 10.1016/j.str.2013.05.018] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Revised: 05/17/2013] [Accepted: 05/20/2013] [Indexed: 12/19/2022]
Abstract
Glycoprotein B (gB) is a key component of the complex herpesvirus fusion machinery. We studied membrane interaction of two gB ectodomain forms and present an electron cryotomography structure of the gB-bilayer complex. The two forms differed in presence or absence of the membrane proximal region (MPR) but showed an overall similar trimeric shape. The presence of the MPR impeded interaction with liposomes. In contrast, the MPR-lacking form interacted efficiently with liposomes. Lateral interaction resulted in coat formation on the membranes. The structure revealed that interaction of gB with membranes was mediated by the fusion loops and limited to the outer membrane leaflet. The observed intrinsic propensity of gB to cluster on membranes indicates an additional role of gB in driving the fusion process forward beyond the transient fusion pore opening and subsequently leading to fusion pore expansion. Full-length gB ectodomain has a structure similar to the ectodomain lacking the MPR The gB-bilayer structure reveals that the interaction is limited to the outer leaflet gB trimers have an intrinsic propensity to interact laterally and form protein arrays Arrays of gB trimers on membranes render the fusion pore open state irreversible
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Affiliation(s)
- Ulrike E Maurer
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Martinsried 82152, Germany
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Zeev-Ben-Mordehai T, Maurer UE, Huiskonen JT, Avinoam O, Eisenberg RJ, Cohen GH, Podbilewicz B, Grünewald K. Studying membrane fusion at molecular resolution. Acta Crystallogr A 2011. [DOI: 10.1107/s0108767311095316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Avinoam O, Fridman K, Valansi C, Abutbul I, Zeev-Ben-Mordehai T, Maurer UE, Sapir A, Danino D, Grünewald K, White JM, Podbilewicz B. Conserved eukaryotic fusogens can fuse viral envelopes to cells. Science 2011; 332:589-92. [PMID: 21436398 DOI: 10.1126/science.1202333] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Caenorhabditis elegans proteins AFF-1 and EFF-1 [C. elegans fusion family (CeFF) proteins] are essential for developmental cell-to-cell fusion and can merge insect cells. To study the structure and function of AFF-1, we constructed vesicular stomatitis virus (VSV) displaying AFF-1 on the viral envelope, substituting the native fusogen VSV glycoprotein. Electron microscopy and tomography revealed that AFF-1 formed distinct supercomplexes resembling pentameric and hexameric "flowers" on pseudoviruses. Viruses carrying AFF-1 infected mammalian cells only when CeFFs were on the target cell surface. Furthermore, we identified fusion family (FF) proteins within and beyond nematodes, and divergent members from the human parasitic nematode Trichinella spiralis and the chordate Branchiostoma floridae could also fuse mammalian cells. Thus, FF proteins are part of an ancient family of cellular fusogens that can promote fusion when expressed on a viral particle.
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Affiliation(s)
- Ori Avinoam
- Department of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel
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22
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Zeev-Ben-Mordehai T, Mylonas E, Paz A, Peleg Y, Toker L, Silman I, Svergun DI, Sussman JL. The quaternary structure of amalgam, a Drosophila neuronal adhesion protein, explains its dual adhesion properties. Biophys J 2010; 97:2316-26. [PMID: 19843464 DOI: 10.1016/j.bpj.2009.07.045] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2009] [Revised: 07/30/2009] [Accepted: 07/31/2009] [Indexed: 10/20/2022] Open
Abstract
Amalgam (Ama) is a secreted neuronal adhesion protein that contains three tandem immunoglobulin domains. It has both homophilic and heterophilic cell adhesion properties, and is required for axon guidance and fasciculation during early stages of Drosophila development. Here, we report its biophysical characterization and use small-angle x-ray scattering to determine its low-resolution structure in solution. The biophysical studies revealed that Ama forms dimers in solution, and that its secondary and tertiary structures are typical for the immunoglobulin superfamily. Ab initio and rigid-body modeling by small-angle x-ray scattering revealed a distinct V-shaped dimer in which the two monomer chains are aligned parallel to each other, with the dimerization interface being formed by domain 1. These data provide a structural basis for the dual adhesion characteristics of Ama. Thus, the dimeric structure explains its homophilic adhesion properties. Its V shape suggests a mechanism for its interaction with its receptor, the single-pass transmembrane adhesion protein neurotactin, in which each "arm" of Ama binds to the extracellular domain of neurotactin, thus promoting its clustering on the outer face of the plasma membrane.
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Zeev-Ben-Mordehai T, Paz A, Peleg Y, Toker L, Wolf SG, Rydberg EH, Sussman JL, Silman I. Amalgam, an axon guidance Drosophila adhesion protein belonging to the immunoglobulin superfamily: Over-expression, purification and biophysical characterization. Protein Expr Purif 2009; 63:147-57. [DOI: 10.1016/j.pep.2008.09.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2008] [Revised: 09/17/2008] [Accepted: 09/22/2008] [Indexed: 11/24/2022]
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Aricescu AR, Assenberg R, Bill RM, Busso D, Chang VT, Davis SJ, Dubrovsky A, Gustafsson L, Hedfalk K, Heinemann U, Jones IM, Ksiazek D, Lang C, Maskos K, Messerschmidt A, Macieira S, Peleg Y, Perrakis A, Poterszman A, Schneider G, Sixma TK, Sussman JL, Sutton G, Tarboureich N, Zeev-Ben-Mordehai T, Jones EY. Eukaryotic expression: developments for structural proteomics. Acta Crystallogr D Biol Crystallogr 2006; 62:1114-24. [PMID: 17001089 PMCID: PMC7161643 DOI: 10.1107/s0907444906029805] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/24/2006] [Accepted: 07/31/2006] [Indexed: 12/02/2022]
Abstract
The production of sufficient quantities of protein is an essential prelude to a structure determination, but for many viral and human proteins this cannot be achieved using prokaryotic expression systems. Groups in the Structural Proteomics In Europe (SPINE) consortium have developed and implemented high‐throughput (HTP) methodologies for cloning, expression screening and protein production in eukaryotic systems. Studies focused on three systems: yeast (Pichia pastoris and Saccharomyces cerevisiae), baculovirus‐infected insect cells and transient expression in mammalian cells. Suitable vectors for HTP cloning are described and results from their use in expression screening and protein‐production pipelines are reported. Strategies for co‐expression, selenomethionine labelling (in all three eukaryotic systems) and control of glycosylation (for secreted proteins in mammalian cells) are assessed.
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Affiliation(s)
- A R Aricescu
- Division of Structural Biology and Oxford Protein Production Facility, Wellcome Trust Centre for Human Genetics, Oxford, England
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Prilusky J, Felder CE, Zeev-Ben-Mordehai T, Rydberg EH, Man O, Beckmann JS, Silman I, Sussman JL. FoldIndex(C): a simple tool to predict whether a given protein sequence is intrinsically unfolded. Bioinformatics 2005; 21:3435-8. [PMID: 15955783 DOI: 10.1093/bioinformatics/bti537] [Citation(s) in RCA: 731] [Impact Index Per Article: 38.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
An easy-to-use, versatile and freely available graphic web server, FoldIndex is described: it predicts if a given protein sequence is intrinsically unfolded implementing the algorithm of Uversky and co-workers, which is based on the average residue hydrophobicity and net charge of the sequence. FoldIndex has an error rate comparable to that of more sophisticated fold prediction methods. Sliding windows permit identification of large regions within a protein that possess folding propensities different from those of the whole protein.
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Affiliation(s)
- Jaime Prilusky
- Biological Services, Weizmann Institute of Science, Rehovot 76100, Israel
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Venema DR, Zeev-Ben-Mordehai T, Auld VJ. Transient apical polarization of Gliotactin and Coracle is required for parallel alignment of wing hairs in Drosophila. Dev Biol 2005; 275:301-14. [PMID: 15501220 DOI: 10.1016/j.ydbio.2004.07.040] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2003] [Revised: 07/12/2004] [Accepted: 07/16/2004] [Indexed: 11/22/2022]
Abstract
In Drosophila, wing hairs are aligned in a distally oriented, parallel array. The frizzled pathway determines proximal-distal cell polarity in the wing; however, in frizzled pathway mutants, wing hairs remain parallel. How wing hairs align has not been determined. We have demonstrated a novel role for the septate junction proteins Gliotactin (Gli) and Coracle (Cora) in this process. Prior to prehair extension, Gli and Cora were restricted to basolateral membranes. During pupal prehair development, Gli and Cora transiently formed apical ribbons oriented from the distal wing tip to the proximal hinge. These ribbons were aligned beneath prehair bases and persisted for several hours. During this time, Gli was lost entirely from the basolateral domain. A Gliotactin mutation altered the apical polarization Gli and Cora and induced defects in hair alignment in pupal and adult stages. Genetic and cell biological assays demonstrated that Gli and Cora function to align hairs independently of frizzled. Taken together, our results indicate that Gli and Cora function as the first-identified members of a long-predicted, frizzled-independent parallel alignment mechanism. We propose a model whereby the apical polarization of Gli and Cora functions to stabilize and align prehairs relative to anterior-posterior cell boundaries during pupal wing development.
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Affiliation(s)
- Dennis R Venema
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada V6T 1Z4
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Zeev-Ben-Mordehai T, Rydberg EH, Solomon A, Toker L, Auld VJ, Silman I, Botti S, Sussman JL. The intracellular domain of theDrosophila cholinesterase-like neural adhesion protein, gliotactin, is natively unfolded. Proteins 2003; 53:758-67. [PMID: 14579366 DOI: 10.1002/prot.10471] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Drosophila gliotactin (Gli) is a 109-kDa transmembrane, cholinesterase-like adhesion molecule (CLAM), expressed in peripheral glia, that is crucial for formation of the blood-nerve barrier. The intracellular portion (Gli-cyt) was cloned and expressed in the cytosolic fraction of Escherichia coli BLR(DE3) at 45 mg/L and purified by Ni-NTA (nitrilotriacetic acid) chromatography. Although migration on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), under denaturing conditions, was unusually slow, molecular weight determination by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) confirmed that the product was consistent with its theoretical size. Gel filtration chromatography yielded an anomalously large Stokes radius, suggesting a fully unfolded conformation. Circular dichroism (CD) spectroscopy demonstrated that Gli-cyt was >50% unfolded, further suggesting a nonglobular conformation. Finally, 1D-(1)H NMR conclusively demonstrated that Gli-cyt possesses an extended unfolded structure. In addition, Gli-cyt was shown to possess charge and hydrophobic properties characteristic of natively unfolded proteins (i.e., proteins that, when purified, are intrinsically disordered under physiologic conditions in vitro).
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Zeev-Ben-Mordehai T, Silman I, Sussman JL. Acetylcholinesterase in motion: visualizing conformational changes in crystal structures by a morphing procedure. Biopolymers 2003; 68:395-406. [PMID: 12601798 DOI: 10.1002/bip.10287] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In order to visualize and appreciate conformational changes between homologous three-dimensional (3D) protein structures or protein/inhibitor complexes, we have developed a user-friendly morphing procedure. It enabled us to detect coordinated conformational changes not easily discernible by analytic methods or by comparison of static images. This procedure was applied to comparison of native Torpedo californica acetylcholinesterase and of complexes with reversible inhibitors and conjugates with covalent inhibitors. It was likewise shown to be valuable for the visualization of conformational differences between acetylcholinesterases from different species. The procedure involves generation, in Cartesian space, of 25 interpolated intermediate structures between the initial and final 3D structures, which then serve as the individual frames in a QuickTime movie.
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Affiliation(s)
- T Zeev-Ben-Mordehai
- Department of Structural Biology, Weizmann Institute of Science, Rehovot 76100, Israel
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