1
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Jin W, Zhou Y, Bartesaghi A. Accurate size-based protein localization from cryo-ET tomograms. J Struct Biol X 2024; 10:100104. [PMID: 39044770 PMCID: PMC11263962 DOI: 10.1016/j.yjsbx.2024.100104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/25/2024] Open
Abstract
Cryo-electron tomography (cryo-ET) combined with sub-tomogram averaging (STA) allows the determination of protein structures imaged within the native context of the cell at near-atomic resolution. Particle picking is an essential step in the cryo-ET/STA image analysis pipeline that consists in locating the position of proteins within crowded cellular tomograms so that they can be aligned and averaged in 3D to improve resolution. While extensive work in 2D particle picking has been done in the context of single-particle cryo-EM, comparatively fewer strategies have been proposed to pick particles from 3D tomograms, in part due to the challenges associated with working with noisy 3D volumes affected by the missing wedge. While strategies based on 3D template-matching and deep learning are commonly used, these methods are computationally expensive and require either an external template or manual labelling which can bias the results and limit their applicability. Here, we propose a size-based method to pick particles from tomograms that is fast, accurate, and does not require external templates or user provided labels. We compare the performance of our approach against a commonly used algorithm based on deep learning, crYOLO, and show that our method: i) has higher detection accuracy, ii) does not require user input for labeling or time-consuming training, and iii) runs efficiently on non-specialized CPU hardware. We demonstrate the effectiveness of our approach by automatically detecting particles from tomograms representing different types of samples and using these particles to determine the high-resolution structures of ribosomes imaged in vitro and in situ.
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Affiliation(s)
- Weisheng Jin
- Department of Computer Science, Duke University, Durham, USA
| | - Ye Zhou
- Department of Computer Science, Duke University, Durham, USA
| | - Alberto Bartesaghi
- Department of Computer Science, Duke University, Durham, USA
- Department of Biochemistry, Duke University School of Medicine, Durham, USA
- Department of Electrical and Computer Engineering, Pratt School of Engineering, Duke University, Durham, USA
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2
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Zheng T, Cai S. Recent technical advances in cellular cryo-electron tomography. Int J Biochem Cell Biol 2024; 175:106648. [PMID: 39181502 DOI: 10.1016/j.biocel.2024.106648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Revised: 08/20/2024] [Accepted: 08/20/2024] [Indexed: 08/27/2024]
Abstract
Understanding the in situ structure, organization, and interactions of macromolecules is essential for elucidating their functions and mechanisms of action. Cellular cryo-electron tomography (cryo-ET) is a cutting-edge technique that reveals in situ molecular-resolution architectures of macromolecules in their lifelike states. It also provides insights into the three-dimensional distribution of macromolecules and their spatial relationships with various subcellular structures. Thus, cellular cryo-ET bridges the gap between structural biology and cell biology. With rapid advancements, this technique achieved substantial improvements in throughput, automation, and resolution. This review presents the fundamental principles and methodologies of cellular cryo-ET, highlighting recent developments in sample preparation, data collection, and image processing. We also discuss emerging trends and potential future directions. As cellular cryo-ET continues to develop, it is set to play an increasingly vital role in structural cell biology.
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Affiliation(s)
- Tianyu Zheng
- Department of Chemical Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China; Institute for Biological Electron Microscopy, Southern University of Science and Technology, Shenzhen 518055, China
| | - Shujun Cai
- Department of Chemical Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China; Institute for Biological Electron Microscopy, Southern University of Science and Technology, Shenzhen 518055, China.
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3
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Wagner J, Carvajal AI, Bracher A, Beck F, Wan W, Bohn S, Körner R, Baumeister W, Fernandez-Busnadiego R, Hartl FU. Visualizing chaperonin function in situ by cryo-electron tomography. Nature 2024:10.1038/s41586-024-07843-w. [PMID: 39169181 DOI: 10.1038/s41586-024-07843-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Accepted: 07/18/2024] [Indexed: 08/23/2024]
Abstract
Chaperonins are large barrel-shaped complexes that mediate ATP-dependent protein folding1-3. The bacterial chaperonin GroEL forms juxtaposed rings that bind unfolded protein and the lid-shaped cofactor GroES at their apertures. In vitro analyses of the chaperonin reaction have shown that substrate protein folds, unimpaired by aggregation, while transiently encapsulated in the GroEL central cavity by GroES4-6. To determine the functional stoichiometry of GroEL, GroES and client protein in situ, here we visualized chaperonin complexes in their natural cellular environment using cryo-electron tomography. We find that, under various growth conditions, around 55-70% of GroEL binds GroES asymmetrically on one ring, with the remainder populating symmetrical complexes. Bound substrate protein is detected on the free ring of the asymmetrical complex, defining the substrate acceptor state. In situ analysis of GroEL-GroES chambers, validated by high-resolution structures obtained in vitro, showed the presence of encapsulated substrate protein in a folded state before release into the cytosol. Based on a comprehensive quantification and conformational analysis of chaperonin complexes, we propose a GroEL-GroES reaction cycle that consists of linked asymmetrical and symmetrical subreactions mediating protein folding. Our findings illuminate the native conformational and functional chaperonin cycle directly within cells.
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Affiliation(s)
- Jonathan Wagner
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
- Research Group Molecular Structural Biology, Max Planck Institute of Biochemistry, Martinsried, Germany
- Institute of Neuropathology, University Medical Center Göttingen, Göttingen, Germany
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen, Germany
| | - Alonso I Carvajal
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Andreas Bracher
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Florian Beck
- Research Group CryoEM Technology, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - William Wan
- Vanderbilt University Center for Structural Biology, Nashville, TN, USA
| | - Stefan Bohn
- Research Group CryoEM Technology, Max Planck Institute of Biochemistry, Martinsried, Germany
- Institute of Structural Biology, Helmholtz Center Munich, Oberschleissheim, Germany
| | - Roman Körner
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Wolfgang Baumeister
- Research Group Molecular Structural Biology, Max Planck Institute of Biochemistry, Martinsried, Germany.
| | - Ruben Fernandez-Busnadiego
- Institute of Neuropathology, University Medical Center Göttingen, Göttingen, Germany.
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen, Germany.
- Faculty of Physics, University of Göttingen, Göttingen, Germany.
| | - F Ulrich Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany.
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4
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Eisenstein F, Fukuda Y, Danev R. Smart parallel automated cryo-electron tomography. Nat Methods 2024:10.1038/s41592-024-02373-9. [PMID: 39117874 DOI: 10.1038/s41592-024-02373-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Accepted: 06/20/2024] [Indexed: 08/10/2024]
Abstract
In situ cryo-electron tomography enables investigation of macromolecules in their native cellular environment. Samples have become more readily available owing to recent software and hardware advancements. Data collection, however, still requires an experienced operator and appreciable microscope time to carefully select targets for high-throughput tilt series acquisition. Here, we developed smart parallel automated cryo-electron tomography (SPACEtomo), a workflow using machine learning approaches to fully automate the entire cryo-electron tomography process, including lamella detection, biological feature segmentation, target selection and parallel tilt series acquisition, all without the need for human intervention. This degree of automation will be essential for obtaining statistically relevant datasets and high-resolution structures of macromolecules in their native context.
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Affiliation(s)
- Fabian Eisenstein
- Graduate School of Medicine, University of Tokyo, Tokyo, Japan
- Institute of Molecular Biology and Biophysics, ETH Zürich, Zürich, Switzerland
| | - Yoshiyuki Fukuda
- Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan
| | - Radostin Danev
- Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
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5
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Watson AJI, Bartesaghi A. Advances in cryo-ET data processing: meeting the demands of visual proteomics. Curr Opin Struct Biol 2024; 87:102861. [PMID: 38889501 PMCID: PMC11283971 DOI: 10.1016/j.sbi.2024.102861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 05/20/2024] [Accepted: 05/21/2024] [Indexed: 06/20/2024]
Abstract
Cryogenic electron tomography (cryo-ET), a method that enables the viewing of biomolecules in near-native environments at high resolution, is rising in accessibility and applicability. Over the past several years, once slow sample preparation and data collection procedures have seen innovations which enable rapid collection of the large datasets required for attaining high resolution structures. Increased data availability has provided a driving force for exciting improvements in cryo-ET data processing methodologies throughout the entire processing pipeline and the development of accessible graphical user interfaces (GUIs) that enable individuals inexperienced in computational fields to convert raw tilt series into 3D structures. These advances in data processing are enabling cryo-ET to attain higher resolution and extending its applicability to more complex samples.
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Affiliation(s)
- Abigail J I Watson
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Alberto Bartesaghi
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, 27710, USA; Department of Computer Science, Duke University, Durham, NC, 27708, USA; Department of Electrical and Computer Engineering, Duke University, Durham, NC, 27708, USA.
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6
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Noble AJ, de Marco A. Cryo-focused ion beam for in situ structural biology: State of the art, challenges, and perspectives. Curr Opin Struct Biol 2024; 87:102864. [PMID: 38901373 DOI: 10.1016/j.sbi.2024.102864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 05/24/2024] [Accepted: 05/26/2024] [Indexed: 06/22/2024]
Abstract
Cryogenic-focused ion beam (cryo-FIB) instruments became essential for high-resolution imaging in cryo-preserved cells and tissues. Cryo-FIBs use accelerated ions to thin samples that would otherwise be too thick for cryo-electron microscopy (cryo-EM). This allows visualizing cellular ultrastructures in near-native frozen hydrated states. This review describes the current state-of-the-art capabilities of cryo-FIB technology and its applications in structural cell and tissue biology. We discuss recent advances in instrumentation, imaging modalities, automation, sample preparation protocols, and targeting techniques. We outline remaining challenges and future directions to make cryo-FIB more precise, enable higher throughput, and be widely accessible. Further improvements in targeting, efficiency, robust sample preparation, emerging ion sources, automation, and downstream electron tomography have the potential to reveal intricate molecular architectures across length scales inside cells and tissues. Cryo-FIB is poised to become an indispensable tool for preparing native biological systems in situ for high-resolution 3D structural analysis.
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Affiliation(s)
- Alex J Noble
- Simons Electron Microscopy Center, New York Structural Biology Center, 89 Convent Avenue New York, NY, 10027, USA. https://twitter.com/alexjamesnoble
| | - Alex de Marco
- Simons Electron Microscopy Center, New York Structural Biology Center, 89 Convent Avenue New York, NY, 10027, USA.
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7
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Xie Y, Shu T, Liu T, Spindler MC, Mahamid J, Hocky GM, Gresham D, Holt LJ. Polysome collapse and RNA condensation fluidize the cytoplasm. Mol Cell 2024; 84:2698-2716.e9. [PMID: 39059370 DOI: 10.1016/j.molcel.2024.06.024] [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: 07/14/2023] [Revised: 03/25/2024] [Accepted: 06/24/2024] [Indexed: 07/28/2024]
Abstract
The cell interior is packed with macromolecules of mesoscale size, and this crowded milieu significantly influences cellular physiology. Cellular stress responses almost universally lead to inhibition of translation, resulting in polysome collapse and release of mRNA. The released mRNA molecules condense with RNA-binding proteins to form ribonucleoprotein (RNP) condensates known as processing bodies and stress granules. Here, we show that polysome collapse and condensation of RNA transiently fluidize the cytoplasm, and coarse-grained molecular dynamic simulations support this as a minimal mechanism for the observed biophysical changes. Increased mesoscale diffusivity correlates with the efficient formation of quality control bodies (Q-bodies), membraneless organelles that compartmentalize misfolded peptides during stress. Synthetic, light-induced RNA condensation also fluidizes the cytoplasm. Together, our study reveals a functional role for stress-induced translation inhibition and formation of RNP condensates in modulating the physical properties of the cytoplasm to enable efficient response of cells to stress conditions.
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Affiliation(s)
- Ying Xie
- Institute for Systems Genetics, New York University Langone Medical Center, New York, NY, USA; Department of Biology, New York University, New York, NY, USA
| | - Tong Shu
- Institute for Systems Genetics, New York University Langone Medical Center, New York, NY, USA
| | - Tiewei Liu
- Institute for Systems Genetics, New York University Langone Medical Center, New York, NY, USA; Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - Marie-Christin Spindler
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Julia Mahamid
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany; Cell Biology and Biophysics Unit, EMBL, Heidelberg, Germany
| | - Glen M Hocky
- Department of Chemistry and Simons Center for Computational Physical Chemistry, New York University, New York, NY, USA
| | - David Gresham
- Department of Biology, New York University, New York, NY, USA.
| | - Liam J Holt
- Institute for Systems Genetics, New York University Langone Medical Center, New York, NY, USA.
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8
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Hutchings J, Villa E. Expanding insights from in situ cryo-EM. Curr Opin Struct Biol 2024; 88:102885. [PMID: 38996624 DOI: 10.1016/j.sbi.2024.102885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 05/28/2024] [Accepted: 06/21/2024] [Indexed: 07/14/2024]
Abstract
The combination of cryo-electron tomography and subtomogram analysis affords 3D high-resolution views of biological macromolecules in their native cellular environment, or in situ. Streamlined methods for acquiring and processing these data are advancing attainable resolutions into the realm of drug discovery. Yet regardless of resolution, structure prediction driven by artificial intelligence (AI) combined with subtomogram analysis is becoming powerful in understanding macromolecular assemblies. Automated and AI-assisted data mining is increasingly necessary to cope with the growing wealth of tomography data and to maximize the information obtained from them. Leveraging developments from AI and single-particle analysis could be essential in fulfilling the potential of in situ cryo-EM. Here, we highlight new developments for in situ cryo-EM and the emerging potential for AI in this process.
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Affiliation(s)
- Joshua Hutchings
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA; Howard Hughes Medical Institute, University of California San Diego, La Jolla, CA 92093, USA
| | - Elizabeth Villa
- School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA; Howard Hughes Medical Institute, University of California San Diego, La Jolla, CA 92093, USA.
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9
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Keller J, Fernández-Busnadiego R. In situ studies of membrane biology by cryo-electron tomography. Curr Opin Cell Biol 2024; 88:102363. [PMID: 38677049 DOI: 10.1016/j.ceb.2024.102363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 03/26/2024] [Accepted: 04/08/2024] [Indexed: 04/29/2024]
Abstract
Cryo-electron tomography (cryo-ET) allows high resolution 3D imaging of biological samples in near-native environments. Thus, cryo-ET has become the method of choice to analyze the unperturbed organization of cellular membranes. Here, we briefly discuss current cryo-ET workflows and their application to study membrane biology in situ, under basal and pathological conditions.
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Affiliation(s)
- Jenny Keller
- University Medical Center Göttingen, Institute for Neuropathology, Göttingen, 37077, Germany; Collaborative Research Center 1190 "Compartmental Gates and Contact Sites in Cells", University of Göttingen, Göttingen, Germany.
| | - Rubén Fernández-Busnadiego
- University Medical Center Göttingen, Institute for Neuropathology, Göttingen, 37077, Germany; Collaborative Research Center 1190 "Compartmental Gates and Contact Sites in Cells", University of Göttingen, Göttingen, Germany; Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen, 37077, Germany; Faculty of Physics, University of Göttingen, Göttingen, 37077, Germany.
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10
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Hale VL, Hooker J, Russo CJ, Löwe J. Honeycomb gold specimen supports enabling orthogonal focussed ion beam-milling of elongated cells for cryo-ET. J Struct Biol 2024; 216:108097. [PMID: 38772448 PMCID: PMC7616276 DOI: 10.1016/j.jsb.2024.108097] [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: 12/29/2023] [Revised: 05/11/2024] [Accepted: 05/18/2024] [Indexed: 05/23/2024]
Abstract
Cryo-focussed ion beam (FIB)-milling is a powerful technique that opens up thick, cellular specimens to high-resolution structural analysis by electron cryotomography (cryo-ET). FIB-milled lamellae can be produced from cells on grids, or cut from thicker, high-pressure frozen specimens. However, these approaches can put geometrical constraints on the specimen that may be unhelpful, particularly when imaging structures within the cell that have a very defined orientation. For example, plunge frozen rod-shaped bacteria orient parallel to the plane of the grid, yet the Z-ring, a filamentous structure of the tubulin-like protein FtsZ and the key organiser of bacterial division, runs around the circumference of the cell such that it is perpendicular to the imaging plane. It is therefore difficult or impractical to image many complete rings with current technologies. To circumvent this problem, we have fabricated monolithic gold specimen supports with a regular array of cylindrical wells in a honeycomb geometry, which trap bacteria in a vertical orientation. These supports, which we call "honeycomb gold discs", replace standard EM grids and when combined with FIB-milling enable the production of lamellae containing cross-sections through cells. The resulting lamellae are more stable and resistant to breakage and charging than conventional lamellae. The design of the honeycomb discs can be modified according to need and so will also enable cryo-ET and cryo-EM imaging of other specimens in otherwise difficult to obtain orientations.
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Affiliation(s)
| | - James Hooker
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | | | - Jan Löwe
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK.
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11
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Galaz-Montoya JG. The advent of preventive high-resolution structural histopathology by artificial-intelligence-powered cryogenic electron tomography. Front Mol Biosci 2024; 11:1390858. [PMID: 38868297 PMCID: PMC11167099 DOI: 10.3389/fmolb.2024.1390858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2024] [Accepted: 05/08/2024] [Indexed: 06/14/2024] Open
Abstract
Advances in cryogenic electron microscopy (cryoEM) single particle analysis have revolutionized structural biology by facilitating the in vitro determination of atomic- and near-atomic-resolution structures for fully hydrated macromolecular complexes exhibiting compositional and conformational heterogeneity across a wide range of sizes. Cryogenic electron tomography (cryoET) and subtomogram averaging are rapidly progressing toward delivering similar insights for macromolecular complexes in situ, without requiring tags or harsh biochemical purification. Furthermore, cryoET enables the visualization of cellular and tissue phenotypes directly at molecular, nanometric resolution without chemical fixation or staining artifacts. This forward-looking review covers recent developments in cryoEM/ET and related technologies such as cryogenic focused ion beam milling scanning electron microscopy and correlative light microscopy, increasingly enhanced and supported by artificial intelligence algorithms. Their potential application to emerging concepts is discussed, primarily the prospect of complementing medical histopathology analysis. Machine learning solutions are poised to address current challenges posed by "big data" in cryoET of tissues, cells, and macromolecules, offering the promise of enabling novel, quantitative insights into disease processes, which may translate into the clinic and lead to improved diagnostics and targeted therapeutics.
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Affiliation(s)
- Jesús G. Galaz-Montoya
- Department of Bioengineering, James H. Clark Center, Stanford University, Stanford, CA, United States
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12
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Dudka W, Salo VT, Mahamid J. Zooming into lipid droplet biology through the lens of electron microscopy. FEBS Lett 2024; 598:1127-1142. [PMID: 38726814 DOI: 10.1002/1873-3468.14899] [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: 01/26/2024] [Revised: 04/08/2024] [Accepted: 04/24/2024] [Indexed: 05/25/2024]
Abstract
Electron microscopy (EM), in its various flavors, has significantly contributed to our understanding of lipid droplets (LD) as central organelles in cellular metabolism. For example, EM has illuminated that LDs, in contrast to all other cellular organelles, are uniquely enclosed by a single phospholipid monolayer, revealed the architecture of LD contact sites with different organelles, and provided near-atomic resolution maps of key enzymes that regulate neutral lipid biosynthesis and LD biogenesis. In this review, we first provide a brief history of pivotal findings in LD biology unveiled through the lens of an electron microscope. We describe the main EM techniques used in the context of LD research and discuss their current capabilities and limitations, thereby providing a foundation for utilizing suitable EM methodology to address LD-related questions with sufficient level of structural preservation, detail, and resolution. Finally, we highlight examples where EM has recently been and is expected to be instrumental in expanding the frontiers of LD biology.
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Affiliation(s)
- Wioleta Dudka
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Veijo T Salo
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Julia Mahamid
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
- Cell Biology and Biophysics Unit, EMBL, Heidelberg, Germany
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13
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Tuijtel MW, Cruz-León S, Kreysing JP, Welsch S, Hummer G, Beck M, Turoňová B. Thinner is not always better: Optimizing cryo-lamellae for subtomogram averaging. SCIENCE ADVANCES 2024; 10:eadk6285. [PMID: 38669330 PMCID: PMC11051657 DOI: 10.1126/sciadv.adk6285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 03/26/2024] [Indexed: 04/28/2024]
Abstract
Cryo-electron tomography (cryo-ET) is a powerful method to elucidate subcellular architecture and to structurally analyze biomolecules in situ by subtomogram averaging, yet data quality critically depends on specimen thickness. Cells that are too thick for transmission imaging can be thinned into lamellae by cryo-focused ion beam (cryo-FIB) milling. Despite being a crucial parameter directly affecting attainable resolution, optimal lamella thickness has not been systematically investigated nor the extent of structural damage caused by gallium ions used for FIB milling. We thus systematically determined how resolution is affected by these parameters. We find that ion-induced damage does not affect regions more than 30 nanometers from either lamella surface and that up to ~180-nanometer lamella thickness does not negatively affect resolution. This shows that there is no need to generate very thin lamellae and lamella thickness can be chosen such that it captures cellular features of interest, thereby opening cryo-ET also for studies of large complexes.
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Affiliation(s)
- Maarten W. Tuijtel
- Department of Molecular Sociology, Max Planck Institute of Biophysics, Max-von-Laue-Straße 3, 60438 Frankfurt am Main, Germany
| | - Sergio Cruz-León
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Max-von-Laue-Straße 3, 60438 Frankfurt am Main, Germany
| | - Jan Philipp Kreysing
- Department of Molecular Sociology, Max Planck Institute of Biophysics, Max-von-Laue-Straße 3, 60438 Frankfurt am Main, Germany
- IMPRS on Cellular Biophysics, Max-von-Laue-Straße 3, 60438 Frankfurt am Main, Germany
| | - Sonja Welsch
- Central Electron Microscopy Facility, Max Planck Institute of Biophysics, Max-von-Laue-Straße 3, 60438 Frankfurt am Main, Germany
| | - Gerhard Hummer
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Max-von-Laue-Straße 3, 60438 Frankfurt am Main, Germany
- Institute of Biophysics, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany
| | - Martin Beck
- Department of Molecular Sociology, Max Planck Institute of Biophysics, Max-von-Laue-Straße 3, 60438 Frankfurt am Main, Germany
- Institute of Biochemistry, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany
| | - Beata Turoňová
- Department of Molecular Sociology, Max Planck Institute of Biophysics, Max-von-Laue-Straße 3, 60438 Frankfurt am Main, Germany
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14
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Tollervey F, Rios MU, Zagoriy E, Woodruff JB, Mahamid J. Native molecular architectures of centrosomes in C. elegans embryos. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.03.587742. [PMID: 38617234 PMCID: PMC11014625 DOI: 10.1101/2024.04.03.587742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
Centrosomes organize microtubules that are essential for mitotic divisions in animal cells. They consist of centrioles surrounded by Pericentriolar Material (PCM). Questions related to mechanisms of centriole assembly, PCM organization, and microtubule formation remain unanswered, in part due to limited availability of molecular-resolution structural analyses in situ. Here, we use cryo-electron tomography to visualize centrosomes across the cell cycle in cells isolated from C. elegans embryos. We describe a pseudo-timeline of centriole assembly and identify distinct structural features including a cartwheel in daughter centrioles, and incomplete microtubule doublets surrounded by a star-shaped density in mother centrioles. We find that centriole and PCM microtubules differ in protofilament number (13 versus 11) indicating distinct nucleation mechanisms. This difference could be explained by atypical γ-tubulin ring complexes with 11-fold symmetry identified at the minus ends of short PCM microtubules. We further characterize a porous and disordered network that forms the interconnected PCM. Thus, our work builds a three-dimensional structural atlas that helps explain how centrosomes assemble, grow, and achieve function.
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Affiliation(s)
- Fergus Tollervey
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
- Collaboration for Joint PhD Degree between EMBL and Heidelberg University, Faculty of Biosciences, Heidelberg, Germany
| | - Manolo U. Rios
- Department of Cell Biology and Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Evgenia Zagoriy
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
| | - Jeffrey B. Woodruff
- Department of Cell Biology and Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Julia Mahamid
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
- Cell Biology and Biophysics Unit, EMBL, 69117 Heidelberg, Germany
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15
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Nogales E, Mahamid J. Bridging structural and cell biology with cryo-electron microscopy. Nature 2024; 628:47-56. [PMID: 38570716 PMCID: PMC11211576 DOI: 10.1038/s41586-024-07198-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 02/13/2024] [Indexed: 04/05/2024]
Abstract
Most life scientists would agree that understanding how cellular processes work requires structural knowledge about the macromolecules involved. For example, deciphering the double-helical nature of DNA revealed essential aspects of how genetic information is stored, copied and repaired. Yet, being reductionist in nature, structural biology requires the purification of large amounts of macromolecules, often trimmed off larger functional units. The advent of cryogenic electron microscopy (cryo-EM) greatly facilitated the study of large, functional complexes and generally of samples that are hard to express, purify and/or crystallize. Nevertheless, cryo-EM still requires purification and thus visualization outside of the natural context in which macromolecules operate and coexist. Conversely, cell biologists have been imaging cells using a number of fast-evolving techniques that keep expanding their spatial and temporal reach, but always far from the resolution at which chemistry can be understood. Thus, structural and cell biology provide complementary, yet unconnected visions of the inner workings of cells. Here we discuss how the interplay between cryo-EM and cryo-electron tomography, as a connecting bridge to visualize macromolecules in situ, holds great promise to create comprehensive structural depictions of macromolecules as they interact in complex mixtures or, ultimately, inside the cell itself.
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Affiliation(s)
- Eva Nogales
- Molecular and Cell Biology Department, Institute for Quantitative Biomedicine, University of California, Berkeley, CA, USA.
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
- Howard Hughes Medical Institute, Berkeley, CA, USA.
| | - Julia Mahamid
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany.
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany.
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16
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Keck C, Enninga J, Swistak L. Caught in the act: In situ visualization of bacterial secretion systems by cryo-electron tomography. Mol Microbiol 2024; 121:636-645. [PMID: 37975530 DOI: 10.1111/mmi.15186] [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: 07/31/2023] [Revised: 10/09/2023] [Accepted: 10/15/2023] [Indexed: 11/19/2023]
Abstract
Bacterial secretion systems, such as the type 3, 4, and 6 are multiprotein nanomachines expressed at the surface of pathogens with Gram-negative like envelopes. They are known to be crucial for virulence and to translocate bacteria-encoded effector proteins into host cells to manipulate cellular functions. This facilitates either pathogen attachment or invasion of the targeted cell. Effector proteins also promote evasion of host immune recognition. Imaging by cryo-electron microscopy in combination with structure determination has become a powerful approach to understand how these nanomachines work. Still, questions on their assembly, the precise secretion mechanisms, and their direct involvement in pathogenicity remain unsolved. Here, we present an overview of the recent developments in in situ cryo-electron microscopy. We discuss its potential for the investigation of the role of bacterial secretion systems during the host-bacterial crosstalk at the molecular level. These in situ studies open new perspectives for our understanding of secretion system structure and function.
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Affiliation(s)
- Camille Keck
- Dynamics of Host-Pathogen Interactions, Institut Pasteur, Université de Paris Cité, CNRS UMR3691, Paris, France
| | - Jost Enninga
- Dynamics of Host-Pathogen Interactions, Institut Pasteur, Université de Paris Cité, CNRS UMR3691, Paris, France
| | - Léa Swistak
- Dynamics of Host-Pathogen Interactions, Institut Pasteur, Université de Paris Cité, CNRS UMR3691, Paris, France
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17
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Zhao J, Yu X, Shentu X, Li D. The application and development of electron microscopy for three-dimensional reconstruction in life science: a review. Cell Tissue Res 2024; 396:1-18. [PMID: 38416172 DOI: 10.1007/s00441-024-03878-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 02/13/2024] [Indexed: 02/29/2024]
Abstract
Imaging technologies have played a pivotal role in advancing biological research by enabling visualization of biological structures and processes. While traditional electron microscopy (EM) produces two-dimensional images, emerging techniques now allow high-resolution three-dimensional (3D) characterization of specimens in situ, meeting growing needs in molecular and cellular biology. Combining transmission electron microscopy (TEM) with serial sectioning inaugurated 3D imaging, attracting biologists seeking to explore cell ultrastructure and driving advancement of 3D EM reconstruction. By comprehensively and precisely rendering internal structure and distribution, 3D TEM reconstruction provides unparalleled ultrastructural insights into cells and molecules, holding tremendous value for elucidating structure-function relationships and broadly propelling structural biology. Here, we first introduce the principle of 3D reconstruction of cells and tissues by classical approaches in TEM and then discuss modern technologies utilizing TEM and on new SEM-based as well as cryo-electron microscope (cryo-EM) techniques. 3D reconstruction techniques from serial sections, electron tomography (ET), and the recent single-particle analysis (SPA) are examined; the focused ion beam scanning electron microscopy (FIB-SEM), the serial block-face scanning electron microscopy (SBF-SEM), and automatic tape-collecting lathe ultramicrotome (ATUM-SEM) for 3D reconstruction of large volumes are discussed. Finally, we review the challenges and development prospects of these technologies in life science. It aims to provide an informative reference for biological researchers.
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Affiliation(s)
- Jingjing Zhao
- Zhejiang Provincial Key Laboratory of Biometrology and Inspection and Quarantine, College of Life Science, China , Jiliang University, Hangzhou, 310018, China
| | - Xiaoping Yu
- Zhejiang Provincial Key Laboratory of Biometrology and Inspection and Quarantine, College of Life Science, China , Jiliang University, Hangzhou, 310018, China
| | - Xuping Shentu
- Zhejiang Provincial Key Laboratory of Biometrology and Inspection and Quarantine, College of Life Science, China , Jiliang University, Hangzhou, 310018, China
| | - Danting Li
- Zhejiang Provincial Key Laboratory of Biometrology and Inspection and Quarantine, College of Life Science, China , Jiliang University, Hangzhou, 310018, China.
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18
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Kraus F, He Y, Swarup S, Overmyer KA, Jiang Y, Brenner J, Capitanio C, Bieber A, Jen A, Nightingale NM, Anderson BJ, Lee C, Paulo JA, Smith IR, Plitzko JM, Schulman BA, Wilfling F, Coon JJ, Wade Harper J. Lysosomal storage disease proteo/lipidomic profiling using nMOST links ferritinophagy with mitochondrial iron deficiencies in cells lacking NPC2. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.26.586828. [PMID: 38585873 PMCID: PMC10996675 DOI: 10.1101/2024.03.26.586828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Lysosomal storage diseases (LSDs) comprised ~50 monogenic diseases characterized by the accumulation of cellular material in lysosomes and associated defects in lysosomal function, but systematic molecular phenotyping is lacking. Here, we develop a nanoflow-based multi-omic single-shot technology (nMOST) workflow allowing simultaneously quantify HeLa cell proteomes and lipidomes from more than two dozen LSD mutants, revealing diverse molecular phenotypes. Defects in delivery of ferritin and its autophagic receptor NCOA4 to lysosomes (ferritinophagy) were pronounced in NPC2-/- cells, which correlated with increased lyso-phosphatidylcholine species and multi-lamellar membrane structures visualized by cryo-electron-tomography. Ferritinophagy defects correlated with loss of mitochondrial cristae, MICOS-complex components, and electron transport chain complexes rich in iron-sulfur cluster proteins. Strikingly, mitochondrial defects were alleviated when iron was provided through the transferrin system. This resource reveals how defects in lysosomal function can impact mitochondrial homeostasis in trans and highlights nMOST as a discovery tool for illuminating molecular phenotypes across LSDs.
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Affiliation(s)
- Felix Kraus
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
- equal contribution
| | - Yuchen He
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
- equal contribution
| | - Sharan Swarup
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
- equal contribution
| | - Katherine A Overmyer
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
- Morgridge Institute for Research, Madison, WI 53715, USA
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Yizhi Jiang
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
| | - Johann Brenner
- Mechanisms of Cellular Quality Control, Max Planck Institute of Biophysics, Frankfurt, Germany
- CryoEM Technology, Max Planck Institute of Biochemistry, Munich, Germany
| | - Cristina Capitanio
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Anna Bieber
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Annie Jen
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Nicole M Nightingale
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Benton J Anderson
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Chan Lee
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
| | - Joao A Paulo
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Ian R Smith
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Jürgen M Plitzko
- CryoEM Technology, Max Planck Institute of Biochemistry, Munich, Germany
| | - Brenda A Schulman
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Florian Wilfling
- Mechanisms of Cellular Quality Control, Max Planck Institute of Biophysics, Frankfurt, Germany
| | - Joshua J Coon
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
- Morgridge Institute for Research, Madison, WI 53715, USA
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - J Wade Harper
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
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19
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Powell BM, Brant TS, Davis JH, Mosalaganti S. Rapid structural analysis of bacterial ribosomes in situ. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.22.586148. [PMID: 38585831 PMCID: PMC10996489 DOI: 10.1101/2024.03.22.586148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Rapid structural analysis of purified proteins and their complexes has become increasingly common thanks to key methodological advances in cryo-electron microscopy (cryo-EM) and associated data processing software packages. In contrast, analogous structural analysis in cells via cryo-electron tomography (cryo-ET) remains challenging due to critical technical bottlenecks, including low-throughput sample preparation and imaging, and laborious data processing methods. Here, we describe the development of a rapid in situ cryo-ET sample preparation and data analysis workflow that results in the routine determination of sub-nm resolution ribosomal structures. We apply this workflow to E. coli, producing a 5.8 Å structure of the 70S ribosome from cells in less than 10 days, and we expect this workflow will be widely applicable to related bacterial samples.
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Affiliation(s)
- Barrett M. Powell
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Tyler S. Brant
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, 48109
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan, 48109
| | - Joseph H. Davis
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139
- Program in Computational and Systems Biology, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Shyamal Mosalaganti
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, 48109
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, Michigan, 48109
- Department of Biophysics, University of Michigan, Ann Arbor, Michigan, 48109
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20
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McCafferty CL, Klumpe S, Amaro RE, Kukulski W, Collinson L, Engel BD. Integrating cellular electron microscopy with multimodal data to explore biology across space and time. Cell 2024; 187:563-584. [PMID: 38306982 DOI: 10.1016/j.cell.2024.01.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 01/03/2024] [Accepted: 01/03/2024] [Indexed: 02/04/2024]
Abstract
Biology spans a continuum of length and time scales. Individual experimental methods only glimpse discrete pieces of this spectrum but can be combined to construct a more holistic view. In this Review, we detail the latest advancements in volume electron microscopy (vEM) and cryo-electron tomography (cryo-ET), which together can visualize biological complexity across scales from the organization of cells in large tissues to the molecular details inside native cellular environments. In addition, we discuss emerging methodologies for integrating three-dimensional electron microscopy (3DEM) imaging with multimodal data, including fluorescence microscopy, mass spectrometry, single-particle analysis, and AI-based structure prediction. This multifaceted approach fills gaps in the biological continuum, providing functional context, spatial organization, molecular identity, and native interactions. We conclude with a perspective on incorporating diverse data into computational simulations that further bridge and extend length scales while integrating the dimension of time.
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Affiliation(s)
| | - Sven Klumpe
- Research Group CryoEM Technology, Max-Planck-Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany.
| | - Rommie E Amaro
- Department of Molecular Biology, University of California, San Diego, La Jolla, CA 92093, USA.
| | - Wanda Kukulski
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bühlstrasse 28, 3012 Bern, Switzerland.
| | - Lucy Collinson
- Electron Microscopy Science Technology Platform, Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK.
| | - Benjamin D Engel
- Biozentrum, University of Basel, Spitalstrasse 41, 4056 Basel, Switzerland.
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21
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Konturek-Ciesla A, Olofzon R, Kharazi S, Bryder D. Implications of stress-induced gene expression for hematopoietic stem cell aging studies. NATURE AGING 2024; 4:177-184. [PMID: 38228925 PMCID: PMC10878961 DOI: 10.1038/s43587-023-00558-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 12/15/2023] [Indexed: 01/18/2024]
Abstract
A decline in hematopoietic stem cell (HSC) function is believed to underlie hematological shortcomings with age; however, a comprehensive molecular understanding of these changes is currently lacking. Here we provide evidence that a transcriptional signature reported in several previous studies on HSC aging is linked to stress-induced changes in gene expression rather than aging. Our findings have strong implications for the design and interpretation of HSC aging studies.
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Affiliation(s)
- Anna Konturek-Ciesla
- Division of Molecular Hematology, Lund Stem Cell Center, Institution for Laboratory Medicine, Lund University, Lund, Sweden
| | - Rasmus Olofzon
- Division of Molecular Hematology, Lund Stem Cell Center, Institution for Laboratory Medicine, Lund University, Lund, Sweden
| | - Shabnam Kharazi
- Division of Molecular Hematology, Lund Stem Cell Center, Institution for Laboratory Medicine, Lund University, Lund, Sweden
| | - David Bryder
- Division of Molecular Hematology, Lund Stem Cell Center, Institution for Laboratory Medicine, Lund University, Lund, Sweden.
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22
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Eskelinen EL. Novel insights into autophagosome biogenesis revealed by cryo-electron tomography. FEBS Lett 2024; 598:9-16. [PMID: 37625816 DOI: 10.1002/1873-3468.14726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 08/11/2023] [Accepted: 08/14/2023] [Indexed: 08/27/2023]
Abstract
Autophagosome biogenesis, from the appearance of the phagophore to elongation and closure into an autophagosome, is one of the long-lasting open questions in the autophagy field. Recent studies utilising cryo-electron tomography and detailed analysis of the image data have revealed new information on the membrane dynamics of these events, including the shape and dimensions of omegasomes, phagophores and autophagosomes, and their relationships with the organelles around them. One of the important predictions from the new results is that 60-80% of the autophagosome membrane area is delivered by direct lipid transfer or lipid synthesis. Cryo-electron tomography can be expected to provide new directions for autophagy research in the near future.
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23
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Schiøtz OH, Kaiser CJO, Klumpe S, Morado DR, Poege M, Schneider J, Beck F, Klebl DP, Thompson C, Plitzko JM. Serial Lift-Out: sampling the molecular anatomy of whole organisms. Nat Methods 2023:10.1038/s41592-023-02113-5. [PMID: 38110637 DOI: 10.1038/s41592-023-02113-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 10/25/2023] [Indexed: 12/20/2023]
Abstract
Cryo-focused ion beam milling of frozen-hydrated cells and subsequent cryo-electron tomography (cryo-ET) has enabled the structural elucidation of macromolecular complexes directly inside cells. Application of the technique to multicellular organisms and tissues, however, is still limited by sample preparation. While high-pressure freezing enables the vitrification of thicker samples, it prolongs subsequent preparation due to increased thinning times and the need for extraction procedures. Additionally, thinning removes large portions of the specimen, restricting the imageable volume to the thickness of the final lamella, typically <300 nm. Here we introduce Serial Lift-Out, an enhanced lift-out technique that increases throughput and obtainable contextual information by preparing multiple sections from single transfers. We apply Serial Lift-Out to Caenorhabditis elegans L1 larvae, yielding a cryo-ET dataset sampling the worm's anterior-posterior axis, and resolve its ribosome structure to 7 Å and a subregion of the 11-protofilament microtubule to 13 Å, illustrating how Serial Lift-Out enables the study of multicellular molecular anatomy.
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Affiliation(s)
- Oda Helene Schiøtz
- Research Group CryoEM Technology, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Christoph J O Kaiser
- Research Group CryoEM Technology, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Sven Klumpe
- Research Group CryoEM Technology, Max Planck Institute of Biochemistry, Martinsried, Germany.
| | - Dustin R Morado
- Department of Cell and Virus Structure, Max Planck Institute of Biochemistry, Martinsried, Germany
- Department for Biochemistry and Biophysics, Science for Life Laboratory, Stockholm University, Stockholm, Sweden
| | - Matthias Poege
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Jonathan Schneider
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Florian Beck
- Research Group CryoEM Technology, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - David P Klebl
- Department of Cell and Virus Structure, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Christopher Thompson
- Materials and Structural Analysis, Thermo Fisher Scientific, Eindhoven, the Netherlands
| | - Jürgen M Plitzko
- Research Group CryoEM Technology, Max Planck Institute of Biochemistry, Martinsried, Germany.
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24
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Weber N, Hinks B, Jensen J, Lidahl T, Mendonça L. Sample Preparation for In Situ Cryotomography of Mammalian Cells. J Vis Exp 2023:10.3791/65697. [PMID: 38163272 PMCID: PMC10921979 DOI: 10.3791/65697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2024] Open
Abstract
In situ cellular cryotomography is a powerful technique for studying complex objects in their native frozen-hydrated cellular context, making it highly relevant to cellular biology and virology. The potential of combining cryotomography with other microscopy modalities makes it a perfect technique for integrative and correlative imaging. However, sample preparation for in situ cellular tomography is not straightforward, as cells do not readily attach and stretch over the electron microscopy grid. Additionally, the grids themselves are fragile and can break if handled too forcefully, resulting in the loss of imageable areas. The geometry of tissue culture dishes can also pose a challenge when manipulating the grids with tweezers. Here, we describe the tips and tricks to overcome these (and other) challenges and prepare good-quality samples for in situ cellular cryotomography and correlative imaging of adherent mammalian cells. With continued advances in cryomicroscopy technology, this technique holds enormous promise for advancing our understanding of complex biological systems.
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Affiliation(s)
- Noah Weber
- College of Liberal Arts, University of Minnesota; Department of Biochemistry, Molecular Biology and Biophysics, Medical School, University of Minnesota
| | - Brennan Hinks
- Department of Biochemistry, Molecular Biology and Biophysics, Medical School, University of Minnesota; College of Biological Sciences, University of Minnesota
| | - Jacob Jensen
- Department of Biochemistry, Molecular Biology and Biophysics, Medical School, University of Minnesota
| | - Thomas Lidahl
- Department of Biochemistry, Molecular Biology and Biophysics, Medical School, University of Minnesota; College of Biological Sciences, University of Minnesota
| | - Luiza Mendonça
- Department of Biochemistry, Molecular Biology and Biophysics, Medical School, University of Minnesota;
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25
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Fung HKH, Hayashi Y, Salo VT, Babenko A, Zagoriy I, Brunner A, Ellenberg J, Müller CW, Cuylen-Haering S, Mahamid J. Genetically encoded multimeric tags for subcellular protein localization in cryo-EM. Nat Methods 2023; 20:1900-1908. [PMID: 37932397 PMCID: PMC10703698 DOI: 10.1038/s41592-023-02053-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Accepted: 09/19/2023] [Indexed: 11/08/2023]
Abstract
Cryo-electron tomography (cryo-ET) allows for label-free high-resolution imaging of macromolecular assemblies in their native cellular context. However, the localization of macromolecules of interest in tomographic volumes can be challenging. Here we present a ligand-inducible labeling strategy for intracellular proteins based on fluorescent, 25-nm-sized, genetically encoded multimeric particles (GEMs). The particles exhibit recognizable structural signatures, enabling their automated detection in cryo-ET data by convolutional neural networks. The coupling of GEMs to green fluorescent protein-tagged macromolecules of interest is triggered by addition of a small-molecule ligand, allowing for time-controlled labeling to minimize disturbance to native protein function. We demonstrate the applicability of GEMs for subcellular-level localization of endogenous and overexpressed proteins across different organelles in human cells using cryo-correlative fluorescence and cryo-ET imaging. We describe means for quantifying labeling specificity and efficiency, and for systematic optimization for rare and abundant protein targets, with emphasis on assessing the potential effects of labeling on protein function.
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Affiliation(s)
- Herman K H Fung
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Yuki Hayashi
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Veijo T Salo
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Anastasiia Babenko
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
- University of Heidelberg, Heidelberg, Germany
| | - Ievgeniia Zagoriy
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Andreas Brunner
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
- Faculty of Biosciences, Collaboration for Joint PhD Degree between EMBL and Heidelberg University, Heidelberg, Germany
| | - Jan Ellenberg
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Christoph W Müller
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Sara Cuylen-Haering
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany.
| | - Julia Mahamid
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany.
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany.
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26
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Adamoski D, Dias MM, Quesñay JEN, Yang Z, Zagoriy I, Steyer AM, Rodrigues CT, da Silva Bastos AC, da Silva BN, Costa RKE, de Abreu FMO, Islam Z, Cassago A, van Heel MG, Consonni SR, Mattei S, Mahamid J, Portugal RV, Ambrosio ALB, Dias SMG. Molecular mechanism of glutaminase activation through filamentation and the role of filaments in mitophagy protection. Nat Struct Mol Biol 2023; 30:1902-1912. [PMID: 37857822 DOI: 10.1038/s41594-023-01118-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 09/06/2023] [Indexed: 10/21/2023]
Abstract
Glutaminase (GLS), which deaminates glutamine to form glutamate, is a mitochondrial tetrameric protein complex. Although inorganic phosphate (Pi) is known to promote GLS filamentation and activation, the molecular basis of this mechanism is unknown. Here we aimed to determine the molecular mechanism of Pi-induced mouse GLS filamentation and its impact on mitochondrial physiology. Single-particle cryogenic electron microscopy revealed an allosteric mechanism in which Pi binding at the tetramer interface and the activation loop is coupled to direct nucleophile activation at the active site. The active conformation is prone to enzyme filamentation. Notably, human GLS filaments form inside tubulated mitochondria following glutamine withdrawal, as shown by in situ cryo-electron tomography of cells thinned by cryo-focused ion beam milling. Mitochondria with GLS filaments exhibit increased protection from mitophagy. We reveal roles of filamentous GLS in mitochondrial morphology and recycling.
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Affiliation(s)
- Douglas Adamoski
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, Brazil
| | - Marilia Meira Dias
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, Brazil
- Cancer Research UK Beatson Institute, Glasgow, UK
| | - Jose Edwin Neciosup Quesñay
- Sao Carlos Institute of Physics, University of Sao Paulo, Sao Carlos, Brazil
- Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| | - Zhengyi Yang
- EMBL Imaging Centre, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Ievgeniia Zagoriy
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Anna M Steyer
- EMBL Imaging Centre, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Camila Tanimoto Rodrigues
- Sao Carlos Institute of Physics, University of Sao Paulo, Sao Carlos, Brazil
- Biological Sciences Department, School of Science, Purdue University, Lafayette, IN, USA
| | - Alliny Cristiny da Silva Bastos
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, Brazil
- Division of Medical Oncology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Bianca Novaes da Silva
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, Brazil
- Graduate Program in Genetics and Molecular Biology, Institute of Biology, University of Campinas, Campinas, Brazil
| | - Renna Karoline Eloi Costa
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, Brazil
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | | | - Zeyaul Islam
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, Brazil
- Diabetes Research Center, Qatar Biomedical Research Institute, Hamad Bin Khalifa University, Qatar Foundation, Doha, Qatar
| | - Alexandre Cassago
- Brazilian Nanotechnology National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, Brazil
- SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA, USA
| | - Marin Gerard van Heel
- Brazilian Nanotechnology National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, Brazil
| | - Sílvio Roberto Consonni
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas, Campinas, Brazil
| | - Simone Mattei
- EMBL Imaging Centre, European Molecular Biology Laboratory, Heidelberg, Germany
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Julia Mahamid
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Rodrigo Villares Portugal
- Brazilian Nanotechnology National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, Brazil
| | | | - Sandra Martha Gomes Dias
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, Brazil.
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27
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Liu HF, Zhou Y, Huang Q, Piland J, Jin W, Mandel J, Du X, Martin J, Bartesaghi A. nextPYP: a comprehensive and scalable platform for characterizing protein variability in situ using single-particle cryo-electron tomography. Nat Methods 2023; 20:1909-1919. [PMID: 37884796 PMCID: PMC10703682 DOI: 10.1038/s41592-023-02045-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 09/12/2023] [Indexed: 10/28/2023]
Abstract
Single-particle cryo-electron tomography is an emerging technique capable of determining the structure of proteins imaged within the native context of cells at molecular resolution. While high-throughput techniques for sample preparation and tilt-series acquisition are beginning to provide sufficient data to allow structural studies of proteins at physiological concentrations, the complex data analysis pipeline and the demanding storage and computational requirements pose major barriers for the development and broader adoption of this technology. Here, we present a scalable, end-to-end framework for single-particle cryo-electron tomography data analysis from on-the-fly pre-processing of tilt series to high-resolution refinement and classification, which allows efficient analysis and visualization of datasets with hundreds of tilt series and hundreds of thousands of particles. We validate our approach using in vitro and cellular datasets, demonstrating its effectiveness at achieving high-resolution and revealing conformational heterogeneity in situ. The framework is made available through an intuitive and easy-to-use computer application, nextPYP ( http://nextpyp.app ).
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Affiliation(s)
- Hsuan-Fu Liu
- Department of Biochemistry, Duke University, Durham, NC, USA
| | - Ye Zhou
- Department of Computer Science, Duke University, Durham, NC, USA
| | - Qinwen Huang
- Department of Computer Science, Duke University, Durham, NC, USA
| | - Jonathan Piland
- Department of Electrical and Computer Engineering, Duke University, Durham, NC, USA
| | - Weisheng Jin
- Department of Computer Science, Duke University, Durham, NC, USA
| | - Justin Mandel
- Department of Computer Science, Duke University, Durham, NC, USA
| | - Xiaochen Du
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Jeffrey Martin
- Department of Computer Science, Duke University, Durham, NC, USA
| | - Alberto Bartesaghi
- Department of Biochemistry, Duke University, Durham, NC, USA.
- Department of Computer Science, Duke University, Durham, NC, USA.
- Department of Electrical and Computer Engineering, Duke University, Durham, NC, USA.
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28
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Huang Y, Zhang Y, Ni T. Towards in situ high-resolution imaging of viruses and macromolecular complexes using cryo-electron tomography. J Struct Biol 2023; 215:108000. [PMID: 37467823 DOI: 10.1016/j.jsb.2023.108000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 07/15/2023] [Accepted: 07/16/2023] [Indexed: 07/21/2023]
Abstract
Cryo-electron tomography and subtomogram averaging are rising and fast-evolving imaging techniques to study biological events, providing structural information at an unprecedented resolution while preserving spatial correlation in their native contexts. The latest technology and methodology development ranging from sample preparation to data collection and data processing, has enabled significant advancement in its applications to various biological systems. This review provides an overview of the current technology development enabling high-resolution structural study in situ, highlighting the use of a priori information of biological samples to assess the quality of subtomogram averaging pipeline. We exemplify the applications of this technique to understanding viruses and principles of macromolecule assembly using different biological systems, ranging from in vitro to in situ samples, which provide structural information at different resolutions and contexts.
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Affiliation(s)
- Yixin Huang
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region
| | - Yu Zhang
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region
| | - Tao Ni
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region.
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29
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Wu Y, Qin C, Du W, Guo Z, Chen L, Guo Q. A practical multicellular sample preparation pipeline broadens the application of in situ cryo-electron tomography. J Struct Biol 2023; 215:107971. [PMID: 37201639 DOI: 10.1016/j.jsb.2023.107971] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 04/28/2023] [Accepted: 05/11/2023] [Indexed: 05/20/2023]
Abstract
The structural studies of macromolecules in their physiological context, particularly in tissue, is constrained by the bottleneck of sample preparation. In this study, we present a practical pipeline for preparing multicellular samples for cryo-electron tomography. The pipeline comprises sample isolation, vitrification, and lift-out-based lamella preparation using commercially available instruments. We demonstrate the efficacy of our pipeline by visualizing pancreatic β cells from mouse islets at the molecular level. This pipeline enables the determination of the properties of insulin crystals in situ for the first time, using unperturbed samples.
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Affiliation(s)
- Yichun Wu
- State Key Laboratory of Protein and Plant Gene Research, Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, School of Life Sciences, Peking University, Beijing 100871, China
| | - Changdong Qin
- School of Life Sciences, Peking University, Beijing 100871, China
| | - Wenjing Du
- State Key Laboratory of Protein and Plant Gene Research, Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, School of Life Sciences, Peking University, Beijing 100871, China; Changping Laboratory, Beijing 102206, China
| | - Zhenxi Guo
- School of Life Sciences, Peking University, Beijing 100871, China; Changping Laboratory, Beijing 102206, China
| | - Liangyi Chen
- State Key Laboratory of Membrane Biology, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, Center for Life Sciences, College of Future Technology, Peking University, Beijing 100871, China
| | - Qiang Guo
- State Key Laboratory of Protein and Plant Gene Research, Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, School of Life Sciences, Peking University, Beijing 100871, China; Changping Laboratory, Beijing 102206, China.
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30
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Klumpe S, Schioetz OH, Kaiser C, Luchner M, Brenner J, Plitzko JM. Developments in cryo-FIB Sample Preparation: Targeting in Cryo-Lift-Out Preparation of Tissues and Machine Learning Models for Fully Automated On-Grid Lamella Preparation. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2023; 29:511-513. [PMID: 37613116 DOI: 10.1093/micmic/ozad067.243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Affiliation(s)
- Sven Klumpe
- Max-Planck-Institute of Biochemistry, Martinsried, Germany
| | - Oda H Schioetz
- Max-Planck-Institute of Biochemistry, Martinsried, Germany
| | | | - Marina Luchner
- Max-Planck-Institute of Biochemistry, Martinsried, Germany
| | - Johann Brenner
- Max-Planck-Institute of Biochemistry, Martinsried, Germany
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31
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Darwish AA, Dougherty TE, Heck BJ, Beggs K, Kassab AJ, Dohnalkova A, Giannuzzi LA. Cryo-Tomography of Cryo-EXLO Manipulated Yarrowia lipolytica Yeast. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2023; 29:1050. [PMID: 37613119 DOI: 10.1093/micmic/ozad067.537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Affiliation(s)
| | | | | | - Kyle Beggs
- Centecorp LLC, Longwood, FL, United States
| | | | - Alice Dohnalkova
- Pacific Northwest National Laboratory, Richland, WA, United States
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32
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Xing H, Taniguchi R, Khusainov I, Kreysing JP, Welsch S, Turoňová B, Beck M. Translation dynamics in human cells visualized at high resolution reveal cancer drug action. Science 2023; 381:70-75. [PMID: 37410833 DOI: 10.1126/science.adh1411] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 06/05/2023] [Indexed: 07/08/2023]
Abstract
Ribosomes catalyze protein synthesis by cycling through various functional states. These states have been extensively characterized in vitro, but their distribution in actively translating human cells remains elusive. We used a cryo-electron tomography-based approach and resolved ribosome structures inside human cells with high resolution. These structures revealed the distribution of functional states of the elongation cycle, a Z transfer RNA binding site, and the dynamics of ribosome expansion segments. Ribosome structures from cells treated with Homoharringtonine, a drug used against chronic myeloid leukemia, revealed how translation dynamics were altered in situ and resolve the small molecules within the active site of the ribosome. Thus, structural dynamics and drug effects can be assessed at high resolution within human cells.
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Affiliation(s)
- Huaipeng Xing
- Department of Molecular Sociology, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
- Faculty of Biochemistry, Chemistry and Pharmacy, Goethe University Frankfurt am Main, 60438 Frankfurt am Main, Germany
| | - Reiya Taniguchi
- Department of Molecular Sociology, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
| | - Iskander Khusainov
- Department of Molecular Sociology, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
| | - Jan Philipp Kreysing
- Department of Molecular Sociology, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
- IMPRS on Cellular Biophysics, 60438 Frankfurt am Main, Germany
| | - Sonja Welsch
- Central Electron Microscopy Facility, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
| | - Beata Turoňová
- Department of Molecular Sociology, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
| | - Martin Beck
- Department of Molecular Sociology, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
- Institute of Biochemistry, Goethe University Frankfurt, Frankfurt am Main, Germany
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33
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Zimmermann L, Chlanda P. Cryo-electron tomography of viral infection - from applications to biosafety. Curr Opin Virol 2023; 61:101338. [PMID: 37348443 DOI: 10.1016/j.coviro.2023.101338] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 04/25/2023] [Accepted: 05/28/2023] [Indexed: 06/24/2023]
Abstract
Cellular cryo-electron tomography (cryo-ET) offers 3D snapshots at molecular resolution capturing pivotal steps during viral infection. However, tomogram quality depends on the vitrification level of the sample and its thickness. In addition, mandatory inactivation protocols to assure biosafety when handling highly pathogenic viruses during cryo-ET can compromise sample preservation. Here, we focus on different strategies applied in cryo-ET and discuss their advantages and limitations with reference to severe acute respiratory syndrome coronavirus 2 studies. We highlight the importance of virus-like particle (VLP) and replicon systems to study virus assembly and replication in a cellular context without inactivation protocols. We discuss the application of chemical fixation and different irradiation methods in cryo-ET sample preparation and acquisition workflows.
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Affiliation(s)
- Liv Zimmermann
- Schaller Research Groups, Department of Infectious Diseases, Virology, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Petr Chlanda
- Schaller Research Groups, Department of Infectious Diseases, Virology, Heidelberg University Hospital, 69120 Heidelberg, Germany.
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34
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Leistner C, Wilkinson M, Burgess A, Lovatt M, Goodbody S, Xu Y, Deuchars S, Radford SE, Ranson NA, Frank RAW. The in-tissue molecular architecture of β-amyloid pathology in the mammalian brain. Nat Commun 2023; 14:2833. [PMID: 37198197 PMCID: PMC10192217 DOI: 10.1038/s41467-023-38495-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Accepted: 05/04/2023] [Indexed: 05/19/2023] Open
Abstract
Amyloid plaques composed of Aβ fibrils are a hallmark of Alzheimer's disease (AD). However, the molecular architecture of amyloid plaques in the context of fresh mammalian brain tissue is unknown. Here, using cryogenic correlated light and electron tomography we report the in situ molecular architecture of Aβ fibrils in the AppNL-G-F familial AD mouse model containing the Arctic mutation and an atomic model of ex vivo purified Arctic Aβ fibrils. We show that in-tissue Aβ fibrils are arranged in a lattice or parallel bundles, and are interdigitated by subcellular compartments, extracellular vesicles, extracellular droplets and extracellular multilamellar bodies. The Arctic Aβ fibril differs significantly from an earlier AppNL-F fibril structure, indicating a striking effect of the Arctic mutation. These structural data also revealed an ensemble of additional fibrillar species, including thin protofilament-like rods and branched fibrils. Together, these results provide a structural model for the dense network architecture that characterises β-amyloid plaque pathology.
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Affiliation(s)
- Conny Leistner
- Astbury Centre for Structural Molecular Biology, School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Martin Wilkinson
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Ailidh Burgess
- Astbury Centre for Structural Molecular Biology, School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
- Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Megan Lovatt
- Astbury Centre for Structural Molecular Biology, School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Stanley Goodbody
- Astbury Centre for Structural Molecular Biology, School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Yong Xu
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
- AstraZeneca, 1 Francis Crick Avenue, Cambridge, CB2 0AA, UK
| | - Susan Deuchars
- Astbury Centre for Structural Molecular Biology, School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Sheena E Radford
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK.
| | - Neil A Ranson
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK.
| | - René A W Frank
- Astbury Centre for Structural Molecular Biology, School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK.
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35
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de Beer M, Daviran D, Roverts R, Rutten L, Macías-Sánchez E, Metz JR, Sommerdijk N, Akiva A. Precise targeting for 3D cryo-correlative light and electron microscopy volume imaging of tissues using a FinderTOP. Commun Biol 2023; 6:510. [PMID: 37169904 PMCID: PMC10175257 DOI: 10.1038/s42003-023-04887-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Accepted: 04/28/2023] [Indexed: 05/13/2023] Open
Abstract
Cryo-correlative light and electron microscopy (cryoCLEM) is a powerful strategy to high resolution imaging in the unperturbed hydrated state. In this approach fluorescence microscopy aids localizing the area of interest, and cryogenic focused ion beam/scanning electron microscopy (cryoFIB/SEM) allows preparation of thin cryo-lamellae for cryoET. However, the current method cannot be accurately applied on bulky (3D) samples such as tissues and organoids. 3D cryo-correlative imaging of large volumes is needed to close the resolution gap between cryo-light microscopy and cryoET, placing sub-nanometer observations in a larger biological context. Currently technological hurdles render 3D cryoCLEM an unexplored approach. Here we demonstrate a cryoCLEM workflow for tissues, correlating cryo-Airyscan confocal microscopy with 3D cryoFIB/SEM volume imaging. Accurate correlation is achieved by imprinting a FinderTOP pattern in the sample surface during high pressure freezing, and allows precise targeting for cryoFIB/SEM volume imaging.
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Affiliation(s)
- Marit de Beer
- Electron Microscopy Center, Radboud Technology Center Microscopy, Radboud University Medical Center, Nijmegen, The Netherlands
- Department of Medical Biosciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Deniz Daviran
- Electron Microscopy Center, Radboud Technology Center Microscopy, Radboud University Medical Center, Nijmegen, The Netherlands
- Department of Medical Biosciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Rona Roverts
- Electron Microscopy Center, Radboud Technology Center Microscopy, Radboud University Medical Center, Nijmegen, The Netherlands
- Department of Medical Biosciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Luco Rutten
- Electron Microscopy Center, Radboud Technology Center Microscopy, Radboud University Medical Center, Nijmegen, The Netherlands
- Department of Medical Biosciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Elena Macías-Sánchez
- Department of Medical Biosciences, Radboud University Medical Center, Nijmegen, The Netherlands
- Department of Stratigraphy and Paleontology, University of Granada, Granada, Spain
| | - Juriaan R Metz
- Department of Animal Ecology and Physiology, Radboud Institute for Biological and Environmental Sciences, Faculty of Science, Radboud University, Nijmegen, The Netherlands
| | - Nico Sommerdijk
- Electron Microscopy Center, Radboud Technology Center Microscopy, Radboud University Medical Center, Nijmegen, The Netherlands.
- Department of Medical Biosciences, Radboud University Medical Center, Nijmegen, The Netherlands.
| | - Anat Akiva
- Electron Microscopy Center, Radboud Technology Center Microscopy, Radboud University Medical Center, Nijmegen, The Netherlands.
- Department of Medical Biosciences, Radboud University Medical Center, Nijmegen, The Netherlands.
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36
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Abstract
Recent advances in cryo-electron microscopy have marked only the beginning of the potential of this technique. To bring structure into cell biology, the modality of cryo-electron tomography has fast developed into a bona fide in situ structural biology technique where structures are determined in their native environment, the cell. Nearly every step of the cryo-focused ion beam-assisted electron tomography (cryo-FIB-ET) workflow has been improved upon in the past decade, since the first windows were carved into cells, unveiling macromolecular networks in near-native conditions. By bridging structural and cell biology, cryo-FIB-ET is advancing our understanding of structure-function relationships in their native environment and becoming a tool for discovering new biology.
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Affiliation(s)
- Lindsey N Young
- Department of Molecular Biology, University of California, San Diego, La Jolla, California, USA;
| | - Elizabeth Villa
- Department of Molecular Biology, University of California, San Diego, La Jolla, California, USA;
- Howard Hughes Medical Institute, University of California, San Diego, La Jolla, California, USA
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37
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Berger C, Premaraj N, Ravelli RBG, Knoops K, López-Iglesias C, Peters PJ. Cryo-electron tomography on focused ion beam lamellae transforms structural cell biology. Nat Methods 2023; 20:499-511. [PMID: 36914814 DOI: 10.1038/s41592-023-01783-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Accepted: 01/20/2023] [Indexed: 03/16/2023]
Abstract
Cryogenic electron microscopy and data processing enable the determination of structures of isolated macromolecules to near-atomic resolution. However, these data do not provide structural information in the cellular environment where macromolecules perform their native functions, and vital molecular interactions can be lost during the isolation process. Cryogenic focused ion beam (FIB) fabrication generates thin lamellae of cellular samples and tissues, enabling structural studies on the near-native cellular interior and its surroundings by cryogenic electron tomography (cryo-ET). Cellular cryo-ET benefits from the technological developments in electron microscopes, detectors and data processing, and more in situ structures are being obtained and at increasingly higher resolution. In this Review, we discuss recent studies employing cryo-ET on FIB-generated lamellae and the technological developments in ultrarapid sample freezing, FIB fabrication of lamellae, tomography, data processing and correlative light and electron microscopy that have enabled these studies. Finally, we explore the future of cryo-ET in terms of both methods development and biological application.
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Affiliation(s)
- Casper Berger
- Division of Nanoscopy, Maastricht MultiModal Molecular Imaging Institute, Maastricht University, Maastricht, the Netherlands
- Structural Biology, The Rosalind Franklin Institute, Didcot, UK
| | - Navya Premaraj
- Division of Nanoscopy, Maastricht MultiModal Molecular Imaging Institute, Maastricht University, Maastricht, the Netherlands
| | - Raimond B G Ravelli
- Division of Nanoscopy, Maastricht MultiModal Molecular Imaging Institute, Maastricht University, Maastricht, the Netherlands
| | - Kèvin Knoops
- Division of Nanoscopy, Maastricht MultiModal Molecular Imaging Institute, Maastricht University, Maastricht, the Netherlands
| | - Carmen López-Iglesias
- Division of Nanoscopy, Maastricht MultiModal Molecular Imaging Institute, Maastricht University, Maastricht, the Netherlands
| | - Peter J Peters
- Division of Nanoscopy, Maastricht MultiModal Molecular Imaging Institute, Maastricht University, Maastricht, the Netherlands.
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38
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Deciphering the molecular mechanisms of actin cytoskeleton regulation in cell migration using cryo-EM. Biochem Soc Trans 2023; 51:87-99. [PMID: 36695514 PMCID: PMC9987995 DOI: 10.1042/bst20220221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 01/12/2023] [Accepted: 01/12/2023] [Indexed: 01/26/2023]
Abstract
The actin cytoskeleton plays a key role in cell migration and cellular morphodynamics in most eukaryotes. The ability of the actin cytoskeleton to assemble and disassemble in a spatiotemporally controlled manner allows it to form higher-order structures, which can generate forces required for a cell to explore and navigate through its environment. It is regulated not only via a complex synergistic and competitive interplay between actin-binding proteins (ABP), but also by filament biochemistry and filament geometry. The lack of structural insights into how geometry and ABPs regulate the actin cytoskeleton limits our understanding of the molecular mechanisms that define actin cytoskeleton remodeling and, in turn, impact emerging cell migration characteristics. With the advent of cryo-electron microscopy (cryo-EM) and advanced computational methods, it is now possible to define these molecular mechanisms involving actin and its interactors at both atomic and ultra-structural levels in vitro and in cellulo. In this review, we will provide an overview of the available cryo-EM methods, applicable to further our understanding of the actin cytoskeleton, specifically in the context of cell migration. We will discuss how these methods have been employed to elucidate ABP- and geometry-defined regulatory mechanisms in initiating, maintaining, and disassembling cellular actin networks in migratory protrusions.
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39
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Martynowycz MW, Shiriaeva A, Clabbers MTB, Nicolas WJ, Weaver SJ, Hattne J, Gonen T. A robust approach for MicroED sample preparation of lipidic cubic phase embedded membrane protein crystals. Nat Commun 2023; 14:1086. [PMID: 36841804 PMCID: PMC9968316 DOI: 10.1038/s41467-023-36733-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 02/15/2023] [Indexed: 02/26/2023] Open
Abstract
Crystallizing G protein-coupled receptors (GPCRs) in lipidic cubic phase (LCP) often yields crystals suited for the cryogenic electron microscopy (cryoEM) method microcrystal electron diffraction (MicroED). However, sample preparation is challenging. Embedded crystals cannot be targeted topologically. Here, we use an integrated fluorescence light microscope (iFLM) inside of a focused ion beam and scanning electron microscope (FIB-SEM) to identify fluorescently labeled GPCR crystals. Crystals are targeted using the iFLM and LCP is milled using a plasma focused ion beam (pFIB). The optimal ion source for preparing biological lamellae is identified using standard crystals of proteinase K. Lamellae prepared using either argon or xenon produced the highest quality data and structures. MicroED data are collected from the milled lamellae and the structures are determined. This study outlines a robust approach to identify and mill membrane protein crystals for MicroED and demonstrates plasma ion-beam milling is a powerful tool for preparing biological lamellae.
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Affiliation(s)
- Michael W Martynowycz
- Howard Hughes Medical Institute, University of California, Los Angeles, CA, 90095, USA.,Department of Biological Chemistry, University of California, Los Angeles, CA, 90095, USA
| | - Anna Shiriaeva
- Howard Hughes Medical Institute, University of California, Los Angeles, CA, 90095, USA.,Department of Biological Chemistry, University of California, Los Angeles, CA, 90095, USA
| | - Max T B Clabbers
- Howard Hughes Medical Institute, University of California, Los Angeles, CA, 90095, USA.,Department of Biological Chemistry, University of California, Los Angeles, CA, 90095, USA
| | - William J Nicolas
- Howard Hughes Medical Institute, University of California, Los Angeles, CA, 90095, USA.,Department of Biological Chemistry, University of California, Los Angeles, CA, 90095, USA
| | - Sara J Weaver
- Howard Hughes Medical Institute, University of California, Los Angeles, CA, 90095, USA.,Department of Biological Chemistry, University of California, Los Angeles, CA, 90095, USA
| | - Johan Hattne
- Howard Hughes Medical Institute, University of California, Los Angeles, CA, 90095, USA.,Department of Biological Chemistry, University of California, Los Angeles, CA, 90095, USA
| | - Tamir Gonen
- Howard Hughes Medical Institute, University of California, Los Angeles, CA, 90095, USA. .,Department of Biological Chemistry, University of California, Los Angeles, CA, 90095, USA. .,Department of Physiology, University of California, Los Angeles, CA, 90095, USA.
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40
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Dumoux M, Glen T, Smith JLR, Ho EML, Perdigão LMA, Pennington A, Klumpe S, Yee NBY, Farmer DA, Lai PYA, Bowles W, Kelley R, Plitzko JM, Wu L, Basham M, Clare DK, Siebert CA, Darrow MC, Naismith JH, Grange M. Cryo-plasma FIB/SEM volume imaging of biological specimens. eLife 2023; 12:83623. [PMID: 36805107 PMCID: PMC9995114 DOI: 10.7554/elife.83623] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 02/20/2023] [Indexed: 02/23/2023] Open
Abstract
Serial focussed ion beam scanning electron microscopy (FIB/SEM) enables imaging and assessment of subcellular structures on the mesoscale (10 nm to 10 µm). When applied to vitrified samples, serial FIB/SEM is also a means to target specific structures in cells and tissues while maintaining constituents' hydration shells for in situ structural biology downstream. However, the application of serial FIB/SEM imaging of non-stained cryogenic biological samples is limited due to low contrast, curtaining, and charging artefacts. We address these challenges using a cryogenic plasma FIB/SEM. We evaluated the choice of plasma ion source and imaging regimes to produce high-quality SEM images of a range of different biological samples. Using an automated workflow we produced three-dimensional volumes of bacteria, human cells, and tissue, and calculated estimates for their resolution, typically achieving 20-50 nm. Additionally, a tag-free localisation tool for regions of interest is needed to drive the application of in situ structural biology towards tissue. The combination of serial FIB/SEM with plasma-based ion sources promises a framework for targeting specific features in bulk-frozen samples (>100 µm) to produce lamellae for cryogenic electron tomography.
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Affiliation(s)
- Maud Dumoux
- Structural Biology, Rosalind Franklin InstituteDidcotUnited Kingdom
| | - Thomas Glen
- Structural Biology, Rosalind Franklin InstituteDidcotUnited Kingdom
| | - Jake LR Smith
- Structural Biology, Rosalind Franklin InstituteDidcotUnited Kingdom
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of OxfordOxfordUnited Kingdom
| | - Elaine ML Ho
- Artificial Intelligence and Informatics, Rosalind Franklin InstituteDidcotUnited Kingdom
| | - Luis MA Perdigão
- Artificial Intelligence and Informatics, Rosalind Franklin InstituteDidcotUnited Kingdom
| | - Avery Pennington
- Diamond Light Source, Harwell Science & Innovation CampusDidcotUnited Kingdom
| | - Sven Klumpe
- Research Group Cryo-EM Technology, Max Planck Institute of BiochemistryMartinsriedGermany
| | - Neville BY Yee
- Artificial Intelligence and Informatics, Rosalind Franklin InstituteDidcotUnited Kingdom
| | - David Andrew Farmer
- Diamond Light Source, Harwell Science & Innovation CampusDidcotUnited Kingdom
| | - Pui YA Lai
- Diamond Light Source, Harwell Science & Innovation CampusDidcotUnited Kingdom
| | - William Bowles
- Structural Biology, Rosalind Franklin InstituteDidcotUnited Kingdom
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of OxfordOxfordUnited Kingdom
- Diamond Light Source, Harwell Science & Innovation CampusDidcotUnited Kingdom
| | - Ron Kelley
- Materials and Structural Analysis Division, Thermo Fisher ScientificEindhovenNetherlands
| | - Jürgen M Plitzko
- Research Group Cryo-EM Technology, Max Planck Institute of BiochemistryMartinsriedGermany
| | - Liang Wu
- Structural Biology, Rosalind Franklin InstituteDidcotUnited Kingdom
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of OxfordOxfordUnited Kingdom
| | - Mark Basham
- Diamond Light Source, Harwell Science & Innovation CampusDidcotUnited Kingdom
| | - Daniel K Clare
- Diamond Light Source, Harwell Science & Innovation CampusDidcotUnited Kingdom
| | - C Alistair Siebert
- Diamond Light Source, Harwell Science & Innovation CampusDidcotUnited Kingdom
| | - Michele C Darrow
- Artificial Intelligence and Informatics, Rosalind Franklin InstituteDidcotUnited Kingdom
| | - James H Naismith
- Structural Biology, Rosalind Franklin InstituteDidcotUnited Kingdom
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of OxfordOxfordUnited Kingdom
| | - Michael Grange
- Structural Biology, Rosalind Franklin InstituteDidcotUnited Kingdom
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of OxfordOxfordUnited Kingdom
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41
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Berger C, Dumoux M, Glen T, Yee NBY, Mitchels JM, Patáková Z, Darrow MC, Naismith JH, Grange M. Plasma FIB milling for the determination of structures in situ. Nat Commun 2023; 14:629. [PMID: 36746945 PMCID: PMC9902539 DOI: 10.1038/s41467-023-36372-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 01/26/2023] [Indexed: 02/08/2023] Open
Abstract
Structural biology studies inside cells and tissues require methods to thin vitrified specimens to electron transparency. Until now, focused ion beams based on gallium have been used. However, ion implantation, changes to surface chemistry and an inability to access high currents limit gallium application. Here, we show that plasma-coupled ion sources can produce cryogenic lamellae of vitrified human cells in a robust and automated manner, with quality sufficient for pseudo-atomic structure determination. Lamellae were produced in a prototype microscope equipped for long cryogenic run times (> 1 week) and with multi-specimen support fully compatible with modern-day transmission electron microscopes. We demonstrate that plasma ion sources can be used for structural biology within cells, determining a structure in situ to 4.9 Å, and characterise the resolution dependence on particle distance from the lamella edge. We describe a workflow upon which different plasmas can be examined to further streamline lamella fabrication.
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Affiliation(s)
- Casper Berger
- Structural Biology, The Rosalind Franklin Institute, Harwell Science & Innovation Campus, Didcot, OX11 0QS, United Kingdom.,Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, OX3 7BN, Oxford, United Kingdom
| | - Maud Dumoux
- Structural Biology, The Rosalind Franklin Institute, Harwell Science & Innovation Campus, Didcot, OX11 0QS, United Kingdom
| | - Thomas Glen
- Structural Biology, The Rosalind Franklin Institute, Harwell Science & Innovation Campus, Didcot, OX11 0QS, United Kingdom
| | - Neville B-Y Yee
- Artificial Intelligence & Informatics, The Rosalind Franklin Institute, Harwell Science & Innovation Campus, Didcot, OX11 0QS, United Kingdom
| | - John M Mitchels
- Thermo Fisher Scientific Brno s.r.o, Brno, 627 00, Czech Republic
| | - Zuzana Patáková
- Thermo Fisher Scientific Brno s.r.o, Brno, 627 00, Czech Republic
| | - Michele C Darrow
- Artificial Intelligence & Informatics, The Rosalind Franklin Institute, Harwell Science & Innovation Campus, Didcot, OX11 0QS, United Kingdom
| | - James H Naismith
- Structural Biology, The Rosalind Franklin Institute, Harwell Science & Innovation Campus, Didcot, OX11 0QS, United Kingdom.,Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, OX3 7BN, Oxford, United Kingdom
| | - Michael Grange
- Structural Biology, The Rosalind Franklin Institute, Harwell Science & Innovation Campus, Didcot, OX11 0QS, United Kingdom. .,Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, OX3 7BN, Oxford, United Kingdom.
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42
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Capitanio C, Bieber A, Wilfling F. How Membrane Contact Sites Shape the Phagophore. CONTACT (THOUSAND OAKS (VENTURA COUNTY, CALIF.)) 2023; 6:25152564231162495. [PMID: 37366413 PMCID: PMC10243513 DOI: 10.1177/25152564231162495] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 02/15/2023] [Accepted: 02/18/2023] [Indexed: 06/28/2023]
Abstract
During macroautophagy, phagophores establish multiple membrane contact sites (MCSs) with other organelles that are pivotal for proper phagophore assembly and growth. In S. cerevisiae, phagophore contacts have been observed with the vacuole, the ER, and lipid droplets. In situ imaging studies have greatly advanced our understanding of the structure and function of these sites. Here, we discuss how in situ structural methods like cryo-CLEM can give unprecedented insights into MCSs, and how they help to elucidate the structural arrangements of MCSs within cells. We further summarize the current knowledge of the contact sites in autophagy, focusing on autophagosome biogenesis in the model organism S. cerevisiae.
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Affiliation(s)
- Cristina Capitanio
- Department of Molecular Machines and
Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
- Aligning Science Across Parkinson's (ASAP)
Collaborative Research Network, Chevy Chase, MD, USA
| | - Anna Bieber
- Department of Molecular Machines and
Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
- Aligning Science Across Parkinson's (ASAP)
Collaborative Research Network, Chevy Chase, MD, USA
| | - Florian Wilfling
- Mechanisms of Cellular Quality Control, Max Planck Institute of Biophysics, Frankfurt a. M., Germany
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43
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Eisenstein F, Yanagisawa H, Kashihara H, Kikkawa M, Tsukita S, Danev R. Parallel cryo electron tomography on in situ lamellae. Nat Methods 2023; 20:131-138. [PMID: 36456783 DOI: 10.1038/s41592-022-01690-1] [Citation(s) in RCA: 48] [Impact Index Per Article: 48.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 09/28/2022] [Indexed: 12/05/2022]
Abstract
In situ cryo electron tomography of cryo focused ion beam milled samples has emerged in recent years as a powerful technique for structural studies of macromolecular complexes in their native cellular environment. However, the possibilities for recording tomographic tilt series in a high-throughput manner are limited, in part by the lamella-shaped samples. Here we utilize a geometrical sample model and optical image shift to record tens of tilt series in parallel, thereby saving time and gaining access to sample areas conventionally used for tracking specimen movement. The parallel cryo electron tomography (PACE-tomo) method achieves a throughput faster than 5 min per tilt series and allows for the collection of sample areas that were previously unreachable, thus maximizing the amount of data from each lamella. Performance testing with ribosomes in vitro and in situ on state-of-the-art and general-purpose microscopes demonstrated the high throughput and quality of PACE-tomo.
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Affiliation(s)
| | | | - Hiroka Kashihara
- Advanced Comprehensive Research Organization, Teikyo University, Tokyo, Japan
| | | | - Sachiko Tsukita
- Advanced Comprehensive Research Organization, Teikyo University, Tokyo, Japan
| | - Radostin Danev
- Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
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44
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de Teresa-Trueba I, Goetz SK, Mattausch A, Stojanovska F, Zimmerli CE, Toro-Nahuelpan M, Cheng DWC, Tollervey F, Pape C, Beck M, Diz-Muñoz A, Kreshuk A, Mahamid J, Zaugg JB. Convolutional networks for supervised mining of molecular patterns within cellular context. Nat Methods 2023; 20:284-294. [PMID: 36690741 PMCID: PMC9911354 DOI: 10.1038/s41592-022-01746-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 12/02/2022] [Indexed: 01/24/2023]
Abstract
Cryo-electron tomograms capture a wealth of structural information on the molecular constituents of cells and tissues. We present DeePiCt (deep picker in context), an open-source deep-learning framework for supervised segmentation and macromolecular complex localization in cryo-electron tomography. To train and benchmark DeePiCt on experimental data, we comprehensively annotated 20 tomograms of Schizosaccharomyces pombe for ribosomes, fatty acid synthases, membranes, nuclear pore complexes, organelles, and cytosol. By comparing DeePiCt to state-of-the-art approaches on this dataset, we show its unique ability to identify low-abundance and low-density complexes. We use DeePiCt to study compositionally distinct subpopulations of cellular ribosomes, with emphasis on their contextual association with mitochondria and the endoplasmic reticulum. Finally, applying pre-trained networks to a HeLa cell tomogram demonstrates that DeePiCt achieves high-quality predictions in unseen datasets from different biological species in a matter of minutes. The comprehensively annotated experimental data and pre-trained networks are provided for immediate use by the community.
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Affiliation(s)
- Irene de Teresa-Trueba
- grid.4709.a0000 0004 0495 846XStructural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany ,Present Address: Computer Science and Artificial Intelligence Lab, ENGIE Lab Crigen, Stains, France
| | - Sara K. Goetz
- grid.4709.a0000 0004 0495 846XStructural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany ,grid.7700.00000 0001 2190 4373Collaboration for Joint PhD Degree between EMBL and Heidelberg University, Faculty of Biosciences, Heidelberg, Germany
| | - Alexander Mattausch
- grid.4709.a0000 0004 0495 846XStructural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany ,grid.7700.00000 0001 2190 4373Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Heidelberg, Germany
| | - Frosina Stojanovska
- grid.4709.a0000 0004 0495 846XStructural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany ,grid.7700.00000 0001 2190 4373Collaboration for Joint PhD Degree between EMBL and Heidelberg University, Faculty of Biosciences, Heidelberg, Germany
| | - Christian E. Zimmerli
- grid.4709.a0000 0004 0495 846XStructural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany ,grid.419494.50000 0001 1018 9466Present Address: Department of Molecular Sociology, Max Planck Institute of Biophysics, Frankfurt, Germany
| | - Mauricio Toro-Nahuelpan
- grid.4709.a0000 0004 0495 846XStructural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany ,Present Address: Santiago GmbH & Co. KG, Willich, Germany
| | - Dorothy W. C. Cheng
- grid.7700.00000 0001 2190 4373Collaboration for Joint PhD Degree between EMBL and Heidelberg University, Faculty of Biosciences, Heidelberg, Germany ,grid.4709.a0000 0004 0495 846XCell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Fergus Tollervey
- grid.4709.a0000 0004 0495 846XStructural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany ,grid.7700.00000 0001 2190 4373Collaboration for Joint PhD Degree between EMBL and Heidelberg University, Faculty of Biosciences, Heidelberg, Germany
| | - Constantin Pape
- grid.4709.a0000 0004 0495 846XCell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany ,grid.7450.60000 0001 2364 4210Present Address: Institute for Computer Science, Universität Göttingen, Göttingen, Germany
| | - Martin Beck
- grid.4709.a0000 0004 0495 846XStructural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany ,grid.4709.a0000 0004 0495 846XCell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany ,grid.419494.50000 0001 1018 9466Present Address: Department of Molecular Sociology, Max Planck Institute of Biophysics, Frankfurt, Germany
| | - Alba Diz-Muñoz
- grid.4709.a0000 0004 0495 846XCell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Anna Kreshuk
- grid.4709.a0000 0004 0495 846XCell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Julia Mahamid
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany. .,Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany.
| | - Judith B. Zaugg
- grid.4709.a0000 0004 0495 846XStructural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany ,grid.4709.a0000 0004 0495 846XGenome Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
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45
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Klykov O, Bobe D, Paraan M, Johnston JD, Potter CS, Carragher B, Kopylov M, Noble AJ. In situ cryo-FIB/SEM Specimen Preparation Using the Waffle Method. Bio Protoc 2022; 12:4544. [PMID: 36618877 PMCID: PMC9795037 DOI: 10.21769/bioprotoc.4544] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 10/24/2022] [Accepted: 09/09/2022] [Indexed: 11/06/2022] Open
Abstract
Cryo-focused ion beam (FIB) milling of vitrified specimens is emerging as a powerful method for in situ specimen preparation. It allows for the preservation of native and near-native conditions in cells, and can reveal the molecular structure of protein complexes when combined with cryo-electron tomography (cryo-ET) and sub-tomogram averaging. Cryo-FIB milling is often performed on plunge-frozen specimens of limited thickness. However, this approach may have several disadvantages, including low throughput for cells that are small, or at low concentration, or poorly distributed across accessible areas of the grid, as well as for samples that may adopt a preferred orientation. Here, we present a detailed description of the "Waffle Method" protocol for vitrifying thick specimens followed by a semi-automated milling procedure using the Thermo Fisher Scientific (TFS) Aquilos 2 cryo-FIB/scanning electron microscope (SEM) instrument and AutoTEM Cryo software to produce cryo-lamellae. With this protocol, cryo-lamellae may be generated from specimens, such as microsporidia spores, yeast, bacteria, and mammalian cells, as well as purified proteins and protein complexes. An experienced lab can perform the entire protocol presented here within an 8-hour working day, resulting in two to three cryo-lamellae with target thicknesses of 100-200 nm and dimensions of approximately 12 μm width and 15-20 μm length. For cryo-FIB/SEMs with particularly low-contamination chambers, the protocol can be extended to overnight milling, resulting in up to 16 cryo-lamellae in 24 h. Graphical abstract.
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Affiliation(s)
- Oleg Klykov
- National Center for In-situ Tomographic Ultramicroscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, USA
,
*For correspondence:
;
| | - Daija Bobe
- National Center for In-situ Tomographic Ultramicroscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, USA
,
*For correspondence:
;
| | - Mohammadreza Paraan
- National Center for In-situ Tomographic Ultramicroscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, USA
| | - Jake D. Johnston
- National Center for In-situ Tomographic Ultramicroscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, USA
,
Department of Physiology and Cellular Biophysics, Columbia University, New York, NY, USA
| | - Clinton S. Potter
- National Center for In-situ Tomographic Ultramicroscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, USA
,
Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA; *Contributed equally to this work
| | - Bridget Carragher
- National Center for In-situ Tomographic Ultramicroscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, USA
,
Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA; *Contributed equally to this work
| | - Mykhailo Kopylov
- National Center for In-situ Tomographic Ultramicroscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, USA
| | - Alex J. Noble
- National Center for In-situ Tomographic Ultramicroscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, USA
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46
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Franken LE, Rosch R, Laugks U, Grünewald K. Protocol for live-cell fluorescence-guided cryoFIB-milling and electron cryo-tomography of virus-infected cells. STAR Protoc 2022; 3:101696. [PMID: 36149798 PMCID: PMC9508610 DOI: 10.1016/j.xpro.2022.101696] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 07/13/2022] [Accepted: 08/17/2022] [Indexed: 01/25/2023] Open
Abstract
Here, we present a protocol for assessing virus-infected cells using electron cryo-tomography (cryoET). It includes the basic workflows of seeding cells, plunge-freezing, clipping, cryo-focused ion beam milling (cryoFIB-milling), and cryoET, as well as two optional modules: micropatterning and live-cell fluorescence microscopy. We use an A549 human cell line and the virus HAdV5-pIX-mcherry in this protocol, but the comprehensive workflow can be easily transferred to other cell types and different types of virus infection or treatment. For complete details on the use and execution of this protocol, please refer to Pfitzner et al. (2021).
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Affiliation(s)
- Linda E. Franken
- Leibniz Institute of Virology (LIV), Martinistraße 52, 20251 Hamburg, Germany,Centre for Structural Systems Biology, Notkestraße 85, 22607 Hamburg, Germany,Corresponding author
| | - Rene Rosch
- Leibniz Institute of Virology (LIV), Martinistraße 52, 20251 Hamburg, Germany,Centre for Structural Systems Biology, Notkestraße 85, 22607 Hamburg, Germany,Universität Hamburg, Institute for Biochemistry and Molecular Biology, Martin-Luther-King-Platz 6, 20146 Hamburg, Germany
| | - Ulrike Laugks
- Centre for Structural Systems Biology, Notkestraße 85, 22607 Hamburg, Germany,Universität Hamburg, Institute for Biochemistry and Molecular Biology, Martin-Luther-King-Platz 6, 20146 Hamburg, Germany
| | - Kay Grünewald
- Leibniz Institute of Virology (LIV), Martinistraße 52, 20251 Hamburg, Germany,Centre for Structural Systems Biology, Notkestraße 85, 22607 Hamburg, Germany,Universität Hamburg, Institute for Biochemistry and Molecular Biology, Martin-Luther-King-Platz 6, 20146 Hamburg, Germany,Corresponding author
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47
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Varsano N, Wolf SG. Electron microscopy of cellular ultrastructure in three dimensions. Curr Opin Struct Biol 2022; 76:102444. [PMID: 36041268 DOI: 10.1016/j.sbi.2022.102444] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 07/05/2022] [Accepted: 07/19/2022] [Indexed: 11/03/2022]
Abstract
Electron microscopy in three dimensions (3D) of cells and tissues can be essential for understanding the ultrastructural aspects of biological processes. The quest for 3D information reveals challenges at many stages of the workflow, from sample preparation, to imaging, data analysis and segmentation. Here, we outline several available methods, including volume SEM imaging, cryo-TEM and cryo-STEM tomography, each one occupying a different domain in the basic tradeoff between field-of-view and resolution. We discuss the considerations for choosing a suitable method depending on research needs and highlight recent developments that are essential for making 3D volume imaging of cells and tissues a standard tool for cellular and structural biologists.
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Affiliation(s)
- Neta Varsano
- Department of Chemical Research Support, Weizmann Institute of Science, 234 Herzl St., Rehovot 76100, Israel
| | - Sharon Grayer Wolf
- Department of Chemical Research Support, Weizmann Institute of Science, 234 Herzl St., Rehovot 76100, Israel.
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48
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Abstract
The three-dimensional organization of biomolecules important for the functioning of all living systems can be determined by cryo-electron tomography imaging under native biological contexts. Cryo-electron tomography is continually expanding and evolving, and the development of new methods that use the latest technology for sample thinning is enabling the visualization of ever larger and more complex biological systems, allowing imaging across scales. Quantitative cryo-electron tomography possesses the capability of visualizing the impact of molecular and environmental perturbations in subcellular structure and function to understand fundamental biological processes. This review provides an overview of current hardware and software developments that allow quantitative cryo-electron tomography studies and their limitations and how overcoming them may allow us to unleash the full power of cryo-electron tomography.
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Affiliation(s)
- Paula P. Navarro
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, United States
- Department of Genetics, Harvard Medical School, Boston, MA, United States
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49
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van den Dries K, Fransen J, Cambi A. Fluorescence CLEM in biology: historic developments and current super-resolution applications. FEBS Lett 2022; 596:2486-2496. [PMID: 35674424 DOI: 10.1002/1873-3468.14421] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 05/24/2022] [Accepted: 05/25/2022] [Indexed: 11/12/2022]
Abstract
Correlative light and electron microscopy (CLEM) is a powerful imaging approach that allows the direct correlation of information obtained on a light and an electron microscope. There is a growing interest in the application of CLEM in biology, mainly attributable to technical advances in field of fluorescence microscopy in the past two decades. In this review, we summarize the important developments in CLEM for biological applications, focusing on the combination of fluorescence microscopy and electron microscopy. We first provide a brief overview of the early days of fluorescence CLEM usage starting with the initial rise in the late 1970s and the subsequent optimization of CLEM workflows during the following two decades. Next, we describe how the engineering of fluorescent proteins and the development of super-resolution fluorescence microscopy have significantly renewed the interest in CLEM resulting in the present application of fluorescence CLEM in many different areas of cellular and molecular biology. Lastly, we present the promises and challenges for the future of fluorescence CLEM discussing novel workflows, probe development and quantification possibilities.
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Affiliation(s)
- Koen van den Dries
- Department of Cell Biology, Radboud Institute for Molecular Life Sciences, Radboudumc, Nijmegen, The Netherlands
| | - Jack Fransen
- Department of Cell Biology, Radboud Institute for Molecular Life Sciences, Radboudumc, Nijmegen, The Netherlands.,Microscopic Imaging Center, Radboud Institute for Molecular Life Sciences, Radboudumc, Nijmegen, The Netherlands
| | - Alessandra Cambi
- Department of Cell Biology, Radboud Institute for Molecular Life Sciences, Radboudumc, Nijmegen, The Netherlands
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50
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Schneider J, Jasnin M. Capturing actin assemblies in cells using in situ cryo-electron tomography. Eur J Cell Biol 2022; 101:151224. [PMID: 35500467 DOI: 10.1016/j.ejcb.2022.151224] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 04/05/2022] [Accepted: 04/07/2022] [Indexed: 11/21/2022] Open
Abstract
Actin contributes to an exceptionally wide range of cellular processes through the assembly and disassembly of highly dynamic and ordered structures. Visualizing these structures in cells can help us understand how the molecular players of the actin machinery work together to produce force-generating systems. In recent years, cryo-electron tomography (cryo-ET) has become the method of choice for structural analysis of the cell interior at the molecular scale. Here we review advances in cryo-ET workflows that have enabled this transformation, especially the automation of sample preparation procedures, data collection, and processing. We discuss new structural analyses of dynamic actin assemblies in cryo-preserved cells, which have provided mechanistic insights into actin assembly and function at the nanoscale. Finally, we highlight the latest visual proteomics studies of actin filaments and their interactors reaching sub-nanometer resolutions in cells.
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Affiliation(s)
- Jonathan Schneider
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Marion Jasnin
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany.
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