1
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Chang L, Cui H, Li F, Job Zhang YHP, Zhang L. ATP regeneration by ATPases for in vitro biotransformation. Biotechnol Adv 2024; 73:108377. [PMID: 38763231 DOI: 10.1016/j.biotechadv.2024.108377] [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: 11/02/2023] [Revised: 04/10/2024] [Accepted: 05/12/2024] [Indexed: 05/21/2024]
Abstract
Adenosine triphosphate (ATP) regeneration is a significant step in both living cells and in vitro biotransformation (ivBT). Rotary motor ATP synthases (ATPases), which regenerate ATP in living cells, have been widely assembled in biomimetic structures for in vitro ATP synthesis. In this review, we present a comprehensive overview of ATPases, including the working principle, orientation and distribution density properties of ATPases, as well as the assembly strategies and applications of ATPase-based ATP regeneration modules. The original sources of ATPases for in vitro ATP regeneration include chromatophores, chloroplasts, mitochondria, and inverted Escherichia coli (E. coli) vesicles, which are readily accessible but unstable. Although significant advances have been made in the assembly methods for ATPase-artificial membranes in recent decades, it remains challenging to replicate the high density and orientation of ATPases observed in vivo using in vitro assembly methods. The use of bioproton pumps or chemicals for constructing proton motive forces (PMF) enables the versatility and potential of ATPase-based ATP regeneration modules. Additionally, overall robustness can be achieved via membrane component selection, such as polymers offering great mechanical stability, or by constructing a solid supporting matrix through layer-by-layer assembly techniques. Finally, the prospects of ATPase-based ATP regeneration modules can be expected with the technological development of ATPases and artificial membranes.
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Affiliation(s)
- Lijing Chang
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, PR China; In vitro Synthetic Biology Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, PR China
| | - Huijuan Cui
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, PR China; In vitro Synthetic Biology Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, PR China
| | - Fei Li
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, PR China; In vitro Synthetic Biology Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, PR China
| | - Yi-Heng P Job Zhang
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, PR China; In vitro Synthetic Biology Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Lingling Zhang
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, PR China; In vitro Synthetic Biology Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
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2
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Siggel M, Jensen RK, Maurer VJ, Mahamid J, Kosinski J. ColabSeg: An interactive tool for editing, processing, and visualizing membrane segmentations from cryo-ET data. J Struct Biol 2024; 216:108067. [PMID: 38367824 DOI: 10.1016/j.jsb.2024.108067] [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: 07/12/2023] [Revised: 01/17/2024] [Accepted: 02/03/2024] [Indexed: 02/19/2024]
Abstract
Cellular cryo-electron tomography (cryo-ET) has emerged as a key method to unravel the spatial and structural complexity of cells in their near-native state at unprecedented molecular resolution. To enable quantitative analysis of the complex shapes and morphologies of lipid membranes, the noisy three-dimensional (3D) volumes must be segmented. Despite recent advances, this task often requires considerable user intervention to curate the resulting segmentations. Here, we present ColabSeg, a Python-based tool for processing, visualizing, editing, and fitting membrane segmentations from cryo-ET data for downstream analysis. ColabSeg makes many well-established algorithms for point-cloud processing easily available to the broad community of structural biologists for applications in cryo-ET through its graphical user interface (GUI). We demonstrate the usefulness of the tool with a range of use cases and biological examples. Finally, for a large Mycoplasma pneumoniae dataset of 50 tomograms, we show how ColabSeg enables high-throughput membrane segmentation, which can be used as valuable training data for fully automated convolutional neural network (CNN)-based segmentation.
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Affiliation(s)
- Marc Siggel
- European Molecular Biology Laboratory (EMBL) Hamburg, Notkestrasse 85, Hamburg 20607, Germany; Centre of Structural Systems Biology (CSSB), Notkestrasse 85, Hamburg 20607, Germany
| | - Rasmus K Jensen
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL) Heidelberg, Meyerhofstrasse 1, Heidelberg 69117, Germany
| | - Valentin J Maurer
- European Molecular Biology Laboratory (EMBL) Hamburg, Notkestrasse 85, Hamburg 20607, Germany; Centre of Structural Systems Biology (CSSB), Notkestrasse 85, Hamburg 20607, Germany
| | - Julia Mahamid
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL) Heidelberg, Meyerhofstrasse 1, Heidelberg 69117, Germany; Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL) Heidelberg, Meyerhofstrasse 1, Heidelberg 69117, Germany
| | - Jan Kosinski
- European Molecular Biology Laboratory (EMBL) Hamburg, Notkestrasse 85, Hamburg 20607, Germany; Centre of Structural Systems Biology (CSSB), Notkestrasse 85, Hamburg 20607, Germany; Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL) Heidelberg, Meyerhofstrasse 1, Heidelberg 69117, Germany.
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3
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Brown CM, Marrink SJ. Modeling membranes in situ. Curr Opin Struct Biol 2024; 87:102837. [PMID: 38744147 DOI: 10.1016/j.sbi.2024.102837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 03/26/2024] [Accepted: 04/23/2024] [Indexed: 05/16/2024]
Abstract
Molecular dynamics simulations of cellular membranes have come a long way-from simple model lipid bilayers to multicomponent systems capturing the crowded and complex nature of real cell membranes. In this opinionated minireview, we discuss the current challenge to simulate the dynamics of membranes in their native environment, in situ, with the prospect of reaching the level of whole cells and cell organelles using an integrative modeling framework.
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Affiliation(s)
- Chelsea M Brown
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, the Netherlands. https://twitter.com/chelseabrowncg
| | - Siewert J Marrink
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, the Netherlands. s.j.marrinkrug.nl
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4
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Gaifas L, Kirchner MA, Timmins J, Gutsche I. Blik is an extensible 3D visualisation tool for the annotation and analysis of cryo-electron tomography data. PLoS Biol 2024; 22:e3002447. [PMID: 38687779 DOI: 10.1371/journal.pbio.3002447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Accepted: 04/02/2024] [Indexed: 05/02/2024] Open
Abstract
Powerful, workflow-agnostic and interactive visualisation is essential for the ad hoc, human-in-the-loop workflows typical of cryo-electron tomography (cryo-ET). While several tools exist for visualisation and annotation of cryo-ET data, they are often integrated as part of monolithic processing pipelines, or focused on a specific task and offering limited reusability and extensibility. With each software suite presenting its own pros and cons and tools tailored to address specific challenges, seamless integration between available pipelines is often a difficult task. As part of the effort to enable such flexibility and move the software ecosystem towards a more collaborative and modular approach, we developed blik, an open-source napari plugin for visualisation and annotation of cryo-ET data (source code: https://github.com/brisvag/blik). blik offers fast, interactive, and user-friendly 3D visualisation thanks to napari, and is built with extensibility and modularity at the core. Data is handled and exposed through well-established scientific Python libraries such as numpy arrays and pandas dataframes. Reusable components (such as data structures, file read/write, and annotation tools) are developed as independent Python libraries to encourage reuse and community contribution. By easily integrating with established image analysis tools-even outside of the cryo-ET world-blik provides a versatile platform for interacting with cryo-ET data. On top of core visualisation features-interactive and simultaneous visualisation of tomograms, particle picks, and segmentations-blik provides an interface for interactive tools such as manual, surface-based and filament-based particle picking, and image segmentation, as well as simple filtering tools. Additional self-contained napari plugins developed as part of this work also implement interactive plotting and selection based on particle features, and label interpolation for easier segmentation. Finally, we highlight the differences with existing software and showcase blik's applicability in biological research.
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Affiliation(s)
- Lorenzo Gaifas
- Institut de Biologie Structurale, Université Grenoble Alpes, CEA, CNRS, IBS, Grenoble, France
| | - Moritz A Kirchner
- Institut de Biologie Structurale, Université Grenoble Alpes, CEA, CNRS, IBS, Grenoble, France
| | - Joanna Timmins
- Institut de Biologie Structurale, Université Grenoble Alpes, CEA, CNRS, IBS, Grenoble, France
| | - Irina Gutsche
- Institut de Biologie Structurale, Université Grenoble Alpes, CEA, CNRS, IBS, Grenoble, France
- Department of Chemistry, Umeå University, Umeå, Sweden
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5
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Perez D, Dowlatshahi DP, Azaldegui CA, Dahlberg PD, Moerner WE. Exploring transient states of PAmKate to enable improved cryogenic single-molecule imaging. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.24.590965. [PMID: 38712218 PMCID: PMC11071506 DOI: 10.1101/2024.04.24.590965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Super-resolved cryogenic correlative light and electron microscopy is a powerful approach which combines the single-molecule specificity and sensitivity of fluorescence imaging with the nano-scale resolution of cryogenic electron tomography. Key to this method is active control over the emissive state of fluorescent labels to ensure sufficient sparsity to localize individual emitters. Recent work has identified fluorescent proteins (FPs) which photoactivate or photoswitch efficiently at cryogenic temperatures, but long on-times due to reduced quantum yield of photobleaching remains a challenge for imaging structures with a high density of localizations. In this work, we explore the photophysical properties of the red photoactivatable FP PAmKate and identify a 2-color process leading to enhanced turn-off of active emitters, improving localization rate. Specifically, after excitation of ground state molecules, we find a transient state forms with a lifetime of ~2 ms which can be bleached by exposure to a second wavelength. We measure the response of the transient state to different wavelengths, demonstrate how this mechanism can be used to improve imaging, and provide a blueprint for study of other FPs at cryogenic temperatures.
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Affiliation(s)
- Davis Perez
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Dara P Dowlatshahi
- Biosciences Division, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
- Department of Structural Biology, Stanford University, Stanford, California 94305, United States
| | - Christopher A Azaldegui
- Division of CryoEM and Bioimaging, Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Peter D Dahlberg
- Division of CryoEM and Bioimaging, Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - W E Moerner
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
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6
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Mehra HS, Wang X, Russell BP, Kulkarni N, Ferrari N, Larson B, Vinyard DJ. Assembly and Repair of Photosystem II in Chlamydomonas reinhardtii. PLANTS (BASEL, SWITZERLAND) 2024; 13:811. [PMID: 38592843 PMCID: PMC10975043 DOI: 10.3390/plants13060811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 03/05/2024] [Accepted: 03/07/2024] [Indexed: 04/11/2024]
Abstract
Oxygenic photosynthetic organisms use Photosystem II (PSII) to oxidize water and reduce plastoquinone. Here, we review the mechanisms by which PSII is assembled and turned over in the model green alga Chlamydomonas reinhardtii. This species has been used to make key discoveries in PSII research due to its metabolic flexibility and amenability to genetic approaches. PSII subunits originate from both nuclear and chloroplastic gene products in Chlamydomonas. Nuclear-encoded PSII subunits are transported into the chloroplast and chloroplast-encoded PSII subunits are translated by a coordinated mechanism. Active PSII dimers are built from discrete reaction center complexes in a process facilitated by assembly factors. The phosphorylation of core subunits affects supercomplex formation and localization within the thylakoid network. Proteolysis primarily targets the D1 subunit, which when replaced, allows PSII to be reactivated and completes a repair cycle. While PSII has been extensively studied using Chlamydomonas as a model species, important questions remain about its assembly and repair which are presented here.
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Affiliation(s)
| | | | | | | | | | | | - David J. Vinyard
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA; (H.S.M.); (X.W.); (B.P.R.); (N.K.); (N.F.); (B.L.)
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7
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Zeng X, Ding Y, Zhang Y, Uddin MR, Dabouei A, Xu M. DUAL: deep unsupervised simultaneous simulation and denoising for cryo-electron tomography. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.02.583135. [PMID: 38496657 PMCID: PMC10942334 DOI: 10.1101/2024.03.02.583135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
Recent biotechnological developments in cryo-electron tomography allow direct visualization of native sub-cellular structures with unprecedented details and provide essential information on protein functions/dysfunctions. Denoising can enhance the visualization of protein structures and distributions. Automatic annotation via data simulation can ameliorate the time-consuming manual labeling of large-scale datasets. Here, we combine the two major cryo-ET tasks together in DUAL, by a specific cyclic generative adversarial network with novel noise disentanglement. This enables end-to-end unsupervised learning that requires no labeled data for training. The denoising branch outperforms existing works and substantially improves downstream particle picking accuracy on benchmark datasets. The simulation branch provides learning-based cryo-ET simulation for the first time and generates synthetic tomograms indistinguishable from experimental ones. Through comprehensive evaluations, we showcase the effectiveness of DUAL in detecting macromolecular complexes across a wide range of molecular weights in experimental datasets. The versatility of DUAL is expected to empower cryo-ET researchers by improving visual interpretability, enhancing structural detection accuracy, expediting annotation processes, facilitating cross-domain model adaptability, and compensating for missing wedge artifacts. Our work represents a significant advancement in the unsupervised mining of protein structures in cryo-ET, offering a multifaceted tool that facilitates cryo-ET research.
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Affiliation(s)
- Xiangrui Zeng
- Ray and Stephanie Lane Computational Biology Department, Carnegie Mellon University, Pittsburgh, PA, 15213, USA
| | - Yizhe Ding
- Department of Statistics, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Yueqian Zhang
- School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Mostofa Rafid Uddin
- Ray and Stephanie Lane Computational Biology Department, Carnegie Mellon University, Pittsburgh, PA, 15213, USA
| | - Ali Dabouei
- Ray and Stephanie Lane Computational Biology Department, Carnegie Mellon University, Pittsburgh, PA, 15213, USA
| | - Min Xu
- Ray and Stephanie Lane Computational Biology Department, Carnegie Mellon University, Pittsburgh, PA, 15213, USA
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8
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Garty Y, Bussi Y, Levin-Zaidman S, Shimoni E, Kirchhoff H, Charuvi D, Nevo R, Reich Z. Thylakoid membrane stacking controls electron transport mode during the dark-to-light transition by adjusting the distances between PSI and PSII. NATURE PLANTS 2024; 10:512-524. [PMID: 38396112 DOI: 10.1038/s41477-024-01628-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 01/23/2024] [Indexed: 02/25/2024]
Abstract
The balance between linear electron transport (LET) and cyclic electron transport (CET) plays an essential role in plant adaptation and protection against photo-induced damage. This balance is largely maintained by phosphorylation-driven alterations in the PSII-LHCII assembly and thylakoid membrane stacking. During the dark-to-light transition, plants shift this balance from CET, which prevails to prevent overreduction of the electron transport chain and consequent photo-induced damage, towards LET, which enables efficient CO2 assimilation and biomass production. Using freeze-fracture cryo-scanning electron microscopy and transmission electron microscopy of Arabidopsis leaves, we reveal unique membrane regions possessing characteristics of both stacked and unstacked regions of the thylakoid network that form during this transition. A notable consequence of the morphological attributes of these regions, which we refer to as 'stacked thylakoid doublets', is an overall increase in the proximity and connectivity of the two photosystems (PSI and PSII) that drive LET. This, in turn, reduces diffusion distances and barriers for the mobile carriers that transfer electrons between the two PSs, thereby maximizing LET and optimizing the plant's ability to utilize light energy. The mechanics described here for the shift between CET and LET during the dark-to-light transition are probably also used during chromatic adaptation mediated by state transitions.
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Affiliation(s)
- Yuval Garty
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Yuval Bussi
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Smadar Levin-Zaidman
- Department of Chemical Research Support, Weizmann Institute of Science, Rehovot, Israel
| | - Eyal Shimoni
- Department of Chemical Research Support, Weizmann Institute of Science, Rehovot, Israel
| | - Helmut Kirchhoff
- Institute of Biological Chemistry, Washington State University, Pullman, WA, USA
| | - Dana Charuvi
- Institute of Plant Sciences, Agricultural Research Organization, Volcani Institute, Rishon LeZion, Israel
| | - Reinat Nevo
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel.
| | - Ziv Reich
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel.
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9
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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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10
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Mahapatra K, Mukherjee A, Suyal S, Dar MA, Bhagavatula L, Datta S. Regulation of chloroplast biogenesis, development, and signaling by endogenous and exogenous cues. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2024; 30:167-183. [PMID: 38623168 PMCID: PMC11016055 DOI: 10.1007/s12298-024-01427-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 02/07/2024] [Accepted: 02/27/2024] [Indexed: 04/17/2024]
Abstract
Chloroplasts are one of the defining features in most plants, primarily known for their unique property to carry out photosynthesis. Besides this, chloroplasts are also associated with hormone and metabolite productions. For this, biogenesis and development of chloroplast are required to be synchronized with the seedling growth to corroborate the maximum rate of photosynthesis following the emergence of seedlings. Chloroplast biogenesis and development are dependent on the signaling to and from the chloroplast, which are in turn regulated by several endogenous and exogenous cues. Light and hormones play a crucial role in chloroplast maturation and development. Chloroplast signaling involves a coordinated two-way connection between the chloroplast and nucleus, termed retrograde and anterograde signaling, respectively. Anterograde and retrograde signaling are involved in regulation at the transcriptional level and downstream modifications and are modulated by several metabolic and external cues. The communication between chloroplast and nucleus is essential for plants to develop strategies to cope with various stresses including high light or high heat. In this review, we have summarized several aspects of chloroplast development and its regulation through the interplay of various external and internal factors. We have also discussed the involvement of chloroplasts as sensors of various external environment stress factors including high light and temperature, and communicate via a series of retrograde signals to the nucleus, thus playing an essential role in plants' abiotic stress response.
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Affiliation(s)
- Kalyan Mahapatra
- Plant Cell and Developmental Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER), Bhopal, Madhya Pradesh 462066 India
| | - Arpan Mukherjee
- Plant Cell and Developmental Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER), Bhopal, Madhya Pradesh 462066 India
| | - Shikha Suyal
- Plant Cell and Developmental Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER), Bhopal, Madhya Pradesh 462066 India
| | - Mansoor Ali Dar
- Plant Cell and Developmental Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER), Bhopal, Madhya Pradesh 462066 India
| | | | - Sourav Datta
- Plant Cell and Developmental Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER), Bhopal, Madhya Pradesh 462066 India
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11
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Broderson M, Niyogi KK, Iwai M. Macroscale structural changes of thylakoid architecture during high light acclimation in Chlamydomonas reinhardtii. PHOTOSYNTHESIS RESEARCH 2024:10.1007/s11120-023-01067-1. [PMID: 38180578 DOI: 10.1007/s11120-023-01067-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 12/04/2023] [Indexed: 01/06/2024]
Abstract
Photoprotection mechanisms are ubiquitous among photosynthetic organisms. The photoprotection capacity of the green alga Chlamydomonas reinhardtii is correlated with protein levels of stress-related light-harvesting complex (LHCSR) proteins, which are strongly induced by high light (HL). However, the dynamic response of overall thylakoid structure during acclimation to growth in HL has not been fully understood. Here, we combined live-cell super-resolution microscopy and analytical membrane subfractionation to investigate macroscale structural changes of thylakoid membranes during HL acclimation in Chlamydomonas. Subdiffraction-resolution live-cell imaging revealed that the overall thylakoid structures became thinned and shrunken during HL acclimation. The stromal space around the pyrenoid also became enlarged. Analytical density-dependent membrane fractionation indicated that the structural changes were partly a consequence of membrane unstacking. The analysis of both an LHCSR loss-of-function mutant, npq4 lhcsr1, and a regulatory mutant that over-expresses LHCSR, spa1-1, showed that structural changes occurred independently of LHCSR protein levels, demonstrating that LHCSR was neither necessary nor sufficient to induce the thylakoid structural changes associated with HL acclimation. In contrast, stt7-9, a mutant lacking a kinase of major light-harvesting antenna proteins, had a slower thylakoid structural response to HL relative to all other lines tested but still showed membrane unstacking. These results indicate that neither LHCSR- nor antenna-phosphorylation-dependent HL acclimation are required for the observed macroscale structural changes of thylakoid membranes in HL conditions.
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Affiliation(s)
- Mimi Broderson
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA
- Howard Hughes Medical Institute, University of California, Berkeley, CA, 94720, USA
| | - Krishna K Niyogi
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA
- Howard Hughes Medical Institute, University of California, Berkeley, CA, 94720, USA
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Masakazu Iwai
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA.
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
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12
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Bos PR, Berentsen J, Wientjes E. Expansion microscopy resolves the thylakoid structure of spinach. PLANT PHYSIOLOGY 2023; 194:347-358. [PMID: 37792700 PMCID: PMC10756755 DOI: 10.1093/plphys/kiad526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 09/19/2023] [Accepted: 09/19/2023] [Indexed: 10/06/2023]
Abstract
The light-harvesting reactions of photosynthesis take place on the thylakoid membrane inside chloroplasts. The thylakoid membrane is folded into appressed membranes, the grana, and nonappressed membranes that interconnect the grana, the stroma lamellae. This folding is essential for the correct functioning of photosynthesis. Electron microscopy and atomic force microscopy are commonly used to study the thylakoid membrane, but these techniques have limitations in visualizing a complete chloroplast and its organization. To overcome this limitation, we applied expansion microscopy (ExM) on isolated chloroplasts. ExM is a technique that involves physically expanding a sample in a swellable hydrogel to enhance the spatial resolution of fluorescence microscopy. Using all-protein staining, we visualized the 3D structure of spinach (Spinacia oleracea) thylakoids in detail. We were able to resolve stroma lamellae that were 60 nm apart and observe their helical wrapping around the grana. Furthermore, we accurately measured the dimensions of grana from top views of chloroplasts, which allow for precise determination of the granum diameter. Our results demonstrate that ExM is a fast and reliable technique for studying thylakoid organization in great detail.
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Affiliation(s)
- Peter R Bos
- Laboratory of Biophysics, Wageningen University & Research, Wageningen 6700 ET, The Netherlands
| | - Jarne Berentsen
- Laboratory of Biophysics, Wageningen University & Research, Wageningen 6700 ET, The Netherlands
| | - Emilie Wientjes
- Laboratory of Biophysics, Wageningen University & Research, Wageningen 6700 ET, The Netherlands
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13
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Sanchez Carrillo IB, Hoffmann PC, Barff T, Beck M, Germain H. Preparing Arabidopsis thaliana root protoplasts for cryo electron tomography. FRONTIERS IN PLANT SCIENCE 2023; 14:1261180. [PMID: 37810374 PMCID: PMC10556516 DOI: 10.3389/fpls.2023.1261180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 09/04/2023] [Indexed: 10/10/2023]
Abstract
The use of protoplasts in plant biology has become a convenient tool for the application of transient gene expression. This model system has allowed the study of plant responses to biotic and abiotic stresses, protein location and trafficking, cell wall dynamics, and single-cell transcriptomics, among others. Although well-established protocols for isolating protoplasts from different plant tissues are available, they have never been used for studying plant cells using cryo electron microscopy (cryo-EM) and cryo electron tomography (cryo-ET). Here we describe a workflow to prepare root protoplasts from Arabidopsis thaliana plants for cryo-ET. The process includes protoplast isolation and vitrification on EM grids, and cryo-focused ion beam milling (cryo-FIB), with the aim of tilt series acquisition. The whole workflow, from growing the plants to the acquisition of the tilt series, may take a few months. Our protocol provides a novel application to use plant protoplasts as a tool for cryo-ET.
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Affiliation(s)
| | - Patrick C. Hoffmann
- Department of Molecular Sociology, Max-Planck-Institute for Biophysics, Frankfurt, Germany
| | - Teura Barff
- Department of Chemistry, Biochemistry, and Physics, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
| | - Martin Beck
- Department of Molecular Sociology, Max-Planck-Institute for Biophysics, Frankfurt, Germany
- Institute of Biochemistry, Goethe University Frankfurt, Frankfurt, Germany
| | - Hugo Germain
- Department of Chemistry, Biochemistry, and Physics, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
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14
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Findinier J, Grossman AR. Chlamydomonas: Fast tracking from genomics. JOURNAL OF PHYCOLOGY 2023; 59:644-652. [PMID: 37417760 DOI: 10.1111/jpy.13356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 06/06/2023] [Indexed: 07/08/2023]
Abstract
Elucidating biological processes has relied on the establishment of model organisms, many of which offer advantageous features such as rapid axenic growth, extensive knowledge of their physiological features and gene content, and the ease with which they can be genetically manipulated. The unicellular green alga Chlamydomonas reinhardtii has been an exemplary model that has enabled many scientific breakthroughs over the decades, especially in the fields of photosynthesis, cilia function and biogenesis, and the acclimation of photosynthetic organisms to their environment. Here, we discuss recent molecular/technological advances that have been applied to C. reinhardtii and how they have further fostered its development as a "flagship" algal system. We also explore the future promise of this alga in leveraging advances in the fields of genomics, proteomics, imaging, and synthetic biology for addressing critical future biological issues.
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Affiliation(s)
- Justin Findinier
- The Carnegie Institution for Science, Biosphere Science and Engineering, Stanford, California, USA
| | - Arthur R Grossman
- The Carnegie Institution for Science, Biosphere Science and Engineering, Stanford, California, USA
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15
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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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16
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Wilson S, Kim E, Ishii A, Ruban AV, Minagawa J. Overexpression of LHCSR and PsbS enhance light tolerance in Chlamydomonas reinhardtii. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2023; 244:112718. [PMID: 37156084 DOI: 10.1016/j.jphotobiol.2023.112718] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Revised: 04/17/2023] [Accepted: 05/01/2023] [Indexed: 05/10/2023]
Abstract
Nonphotochemical quenching (NPQ) is a crucial mechanism for fine-tuning light harvesting and protecting the photosystem II (PSII) reaction centres from excess light energy in plants and algae. This process is regulated by photoprotective proteins LHCSR1, LHCSR3, and PsbS in green algae, such as Chlamydomonas reinhardtii. The det1-2 phot mutant, which overexpresses these photoprotective proteins, resulting in a significantly higher NPQ response, has been recently discovered in C. reinhardtii. Here, we analysed the physiological impact of this response on algal cells and found that det1-2 phot was capable of efficient growth under high light intensities, where wild-type (WT) cells were unable to survive. The mutant exhibited a smaller PSII cross-section in the dark and showed a detachment of the peripheral light-harvesting complex II (LHCII) antenna in the NPQ state, as suggested by a rise in the chlorophyll fluorescence parameter of photochemical quenching in the dark (qPd > 1). Furthermore, fluorescence decay-associated spectra demonstrated a decreased excitation pressure on PSII, with excess energy being directed toward PSI. The amount of LHCSR1, LHCSR3, and PsbS in the mutant correlated with the magnitude of the protective NPQ response. Overall, the study suggests the mechanism by which the overexpression of photoprotective proteins in det1-2 phot brings about an efficient and effective photoprotective response, enabling the mutant to grow and survive under high light intensities that would otherwise be lethal for WT cells.
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Affiliation(s)
- Sam Wilson
- Department of Biochemistry, School of Biological and Behavioural Sciences, Queen Mary University of London, London E1 4NS, United Kingdom
| | - Eunchul Kim
- Division of Environmental Photobiology, National Institute for Basic Biology, Okazaki 444-8585, Japan; Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Japan
| | - Asako Ishii
- Division of Environmental Photobiology, National Institute for Basic Biology, Okazaki 444-8585, Japan; Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Japan
| | - Alexander V Ruban
- Department of Biochemistry, School of Biological and Behavioural Sciences, Queen Mary University of London, London E1 4NS, United Kingdom
| | - Jun Minagawa
- Division of Environmental Photobiology, National Institute for Basic Biology, Okazaki 444-8585, Japan; Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Japan.
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17
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Barad BA, Medina M, Fuentes D, Wiseman RL, Grotjahn DA. Quantifying organellar ultrastructure in cryo-electron tomography using a surface morphometrics pipeline. J Cell Biol 2023; 222:e202204093. [PMID: 36786771 PMCID: PMC9960335 DOI: 10.1083/jcb.202204093] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 09/22/2022] [Accepted: 01/17/2023] [Indexed: 02/15/2023] Open
Abstract
Cellular cryo-electron tomography (cryo-ET) enables three-dimensional reconstructions of organelles in their native cellular environment at subnanometer resolution. However, quantifying ultrastructural features of pleomorphic organelles in three dimensions is challenging, as is defining the significance of observed changes induced by specific cellular perturbations. To address this challenge, we established a semiautomated workflow to segment organellar membranes and reconstruct their underlying surface geometry in cryo-ET. To complement this workflow, we developed an open-source suite of ultrastructural quantifications, integrated into a single pipeline called the surface morphometrics pipeline. This pipeline enables rapid modeling of complex membrane structures and allows detailed mapping of inter- and intramembrane spacing, curvedness, and orientation onto reconstructed membrane meshes, highlighting subtle organellar features that are challenging to detect in three dimensions and allowing for statistical comparison across many organelles. To demonstrate the advantages of this approach, we combine cryo-ET with cryo-fluorescence microscopy to correlate bulk mitochondrial network morphology (i.e., elongated versus fragmented) with membrane ultrastructure of individual mitochondria in the presence and absence of endoplasmic reticulum (ER) stress. Using our pipeline, we demonstrate ER stress promotes adaptive remodeling of ultrastructural features of mitochondria including spacing between the inner and outer membranes, local curvedness of the inner membrane, and spacing between mitochondrial cristae. We show that differences in membrane ultrastructure correlate to mitochondrial network morphologies, suggesting that these two remodeling events are coupled. Our pipeline offers opportunities for quantifying changes in membrane ultrastructure on a single-cell level using cryo-ET, opening new opportunities to define changes in ultrastructural features induced by diverse types of cellular perturbations.
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Affiliation(s)
- Benjamin A. Barad
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Michaela Medina
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Daniel Fuentes
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - R. Luke Wiseman
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Danielle A. Grotjahn
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
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18
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Svoboda V, Oung HMO, Koochak H, Yarbrough R, Mckenzie SD, Puthiyaveetil S, Kirchhoff H. Quantification of energy-converting protein complexes in plant thylakoid membranes. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2023; 1864:148945. [PMID: 36442511 DOI: 10.1016/j.bbabio.2022.148945] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 11/15/2022] [Accepted: 11/22/2022] [Indexed: 11/27/2022]
Abstract
Knowledge about the exact abundance and ratio of photosynthetic protein complexes in thylakoid membranes is central to understanding structure-function relationships in energy conversion. Recent modeling approaches for studying light harvesting and electron transport reactions rely on quantitative information on the constituent complexes in thylakoid membranes. Over the last decades several quantitative methods have been established and refined, enabling precise stoichiometric information on the five main energy-converting building blocks in the thylakoid membrane: Light-harvesting complex II (LHCII), Photosystem II (PSII), Photosystem I (PSI), cytochrome b6f complex (cyt b6f complex), and ATPase. This paper summarizes a few quantitative spectroscopic and biochemical methods that are currently available for quantification of plant thylakoid protein complexes. Two new methods are presented for quantification of LHCII and the cyt b6f complex, which agree well with established methods. In addition, recent improvements in mass spectrometry (MS) allow deeper compositional information on thylakoid membranes. The comparison between mass spectrometric and more classical protein quantification methods shows similar quantities of complexes, confirming the potential of thylakoid protein complex quantification by MS. The quantitative information on PSII, PSI, and LHCII reveal that about one third of LHCII must be associated with PSI for a balanced light energy absorption by the two photosystems.
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Affiliation(s)
- Vaclav Svoboda
- Institute of Biological Chemistry, Washington State University, Pullman, WA, USA
| | - Hui Min Olivia Oung
- Institute of Biological Chemistry, Washington State University, Pullman, WA, USA
| | - Haniyeh Koochak
- Institute of Biological Chemistry, Washington State University, Pullman, WA, USA
| | - Robert Yarbrough
- Institute of Biological Chemistry, Washington State University, Pullman, WA, USA
| | - Steven D Mckenzie
- Department of Biochemistry and Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
| | - Sujith Puthiyaveetil
- Department of Biochemistry and Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
| | - Helmut Kirchhoff
- Institute of Biological Chemistry, Washington State University, Pullman, WA, USA.
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19
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Ho J, Kwan W, Li V, Theg SM. Characterization of thylakoid division using chloroplast dividing mutants in Arabidopsis. PHOTOSYNTHESIS RESEARCH 2023:10.1007/s11120-023-01002-4. [PMID: 36856939 DOI: 10.1007/s11120-023-01002-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 02/05/2023] [Indexed: 06/18/2023]
Abstract
Chloroplasts are double membrane bound organelles that are found in plants and algae. Their division requires a number of proteins to assemble into rings along the center of the organelle and to constrict in synchrony. Chloroplasts possess a third membrane system, the thylakoids, which house the majority of proteins responsible for the light-dependent reactions. The mechanism that allows chloroplasts to sort out and separate the intricate thylakoid membrane structures during organelle division remain unknown. By characterizing the sizes of thylakoids found in a number of different chloroplast division mutants in Arabidopsis, we show that thylakoids do not divide independently of the chloroplast division cycle. More specifically, we show that thylakoid division requires the formation of both the inner and the outer contractile rings of the chloroplast.
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Affiliation(s)
- Jonathan Ho
- Department of Plant Biology, University of California Davis, Davis, CA, 95616, USA
| | - Warren Kwan
- Department of Plant Biology, University of California Davis, Davis, CA, 95616, USA
| | - Vivian Li
- Department of Plant Biology, University of California Davis, Davis, CA, 95616, USA
| | - Steven M Theg
- Department of Plant Biology, University of California Davis, Davis, CA, 95616, USA.
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20
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Utschig LM, Zaluzec NJ, Malavath T, Ponomarenko NS, Tiede DM. Solar water splitting Pt-nanoparticle photosystem I thylakoid systems: Catalyst identification, location and oligomeric structure. BIOCHIMICA ET BIOPHYSICA ACTA (BBA) - BIOENERGETICS 2023; 1864:148974. [PMID: 37001790 DOI: 10.1016/j.bbabio.2023.148974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 03/10/2023] [Accepted: 03/25/2023] [Indexed: 03/31/2023]
Abstract
Photosynthetic conversion of light energy into chemical energy occurs in sheet-like membrane-bound compartments called thylakoids and is mediated by large integral membrane protein-pigment complexes called reaction centers (RCs). Oxygenic photosynthesis of higher plants, cyanobacteria and algae requires the symbiotic linking of two RCs, photosystem II (PSII) and photosystem I (PSI), to split water and assimilate carbon dioxide. Worldwide there is a large research investment in developing RC-based hybrids that utilize the highly evolved solar energy conversion capabilities of RCs to power catalytic reactions for solar fuel generation. Of particular interest is the solar-powered production of H2, a clean and renewable energy source that can replace carbon-based fossil fuels and help provide for ever-increasing global energy demands. Recently, we developed thylakoid membrane hybrids with abiotic catalysts and demonstrated that photosynthetic Z-scheme electron flow from the light-driven water oxidation at PSII can drive H2 production from PSI. One of these hybrid systems was created by self-assembling Pt-nanoparticles (PtNPs) with the stromal subunits of PSI that extend beyond the membrane plane in both spinach and cyanobacterial thylakoids. Using PtNPs as site-specific probe molecules, we report the electron microscopic (EM) imaging of oligomeric structure, location and organization of PSI in thylakoid membranes and provide the first direct visualization of photosynthetic Z-scheme solar water-splitting biohybrids for clean H2 production.
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21
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Caspy I, Fadeeva M, Mazor Y, Nelson N. Structure of Dunaliella photosystem II reveals conformational flexibility of stacked and unstacked supercomplexes. eLife 2023; 12:e81150. [PMID: 36799903 PMCID: PMC9949808 DOI: 10.7554/elife.81150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 02/16/2023] [Indexed: 02/18/2023] Open
Abstract
Photosystem II (PSII) generates an oxidant whose redox potential is high enough to enable water oxidation , a substrate so abundant that it assures a practically unlimited electron source for life on earth . Our knowledge on the mechanism of water photooxidation was greatly advanced by high-resolution structures of prokaryotic PSII . Here, we show high-resolution cryogenic electron microscopy (cryo-EM) structures of eukaryotic PSII from the green alga Dunaliella salina at two distinct conformations. The conformers are also present in stacked PSII, exhibiting flexibility that may be relevant to the grana formation in chloroplasts of the green lineage. CP29, one of PSII associated light-harvesting antennae, plays a major role in distinguishing the two conformations of the supercomplex. We also show that the stacked PSII dimer, a form suggested to support the organisation of thylakoid membranes , can appear in many different orientations providing a flexible stacking mechanism for the arrangement of grana stacks in thylakoids. Our findings provide a structural basis for the heterogenous nature of the eukaryotic PSII on multiple levels.
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Affiliation(s)
- Ido Caspy
- Department of Biochemistry and Molecular Biology, The George S. Wise Faculty of Life Sciences, Tel Aviv UniversityTel AvivIsrael
| | - Maria Fadeeva
- Department of Biochemistry and Molecular Biology, The George S. Wise Faculty of Life Sciences, Tel Aviv UniversityTel AvivIsrael
| | - Yuval Mazor
- School of Molecular Sciences, Arizona State UniversityTempeUnited States
- Biodesign Center for Applied Structural Discovery, Arizona State UniversityTempeUnited States
| | - Nathan Nelson
- Department of Biochemistry and Molecular Biology, The George S. Wise Faculty of Life Sciences, Tel Aviv UniversityTel AvivIsrael
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22
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Verhoeven D, van Amerongen H, Wientjes E. Single chloroplast in folio imaging sheds light on photosystem energy redistribution during state transitions. PLANT PHYSIOLOGY 2023; 191:1186-1198. [PMID: 36478277 PMCID: PMC9922397 DOI: 10.1093/plphys/kiac561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 11/04/2022] [Indexed: 06/17/2023]
Abstract
Oxygenic photosynthesis is driven by light absorption in photosystem I (PSI) and photosystem II (PSII). A balanced excitation pressure between PSI and PSII is required for optimal photosynthetic efficiency. State transitions serve to keep this balance. If PSII is overexcited in plants and green algae, a mobile pool of light-harvesting complex II (LHCII) associates with PSI, increasing its absorption cross-section and restoring the excitation balance. This is called state 2. Upon PSI overexcitation, this LHCII pool moves to PSII, leading to state 1. Whether the association/dissociation of LHCII with the photosystems occurs between thylakoid grana and thylakoid stroma lamellae during state transitions or within the same thylakoid region remains unclear. Furthermore, although state transitions are thought to be accompanied by changes in thylakoid macro-organization, this has never been observed directly in functional leaves. In this work, we used confocal fluorescence lifetime imaging to quantify state transitions in single Arabidopsis (Arabidopsis thaliana) chloroplasts in folio with sub-micrometer spatial resolution. The change in excitation-energy distribution between PSI and PSII was investigated at a range of excitation wavelengths between 475 and 665 nm. For all excitation wavelengths, the PSI/(PSI + PSII) excitation ratio was higher in state 2 than in state 1. We next imaged the local PSI/(PSI + PSII) excitation ratio for single chloroplasts in both states. The data indicated that LHCII indeed migrates between the grana and stroma lamellae during state transitions. Finally, fluorescence intensity images revealed that thylakoid macro-organization is largely unaffected by state transitions. This single chloroplast in folio imaging method will help in understanding how plants adjust their photosynthetic machinery to ever-changing light conditions.
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23
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Stevens JA, Grünewald F, van Tilburg PAM, König M, Gilbert BR, Brier TA, Thornburg ZR, Luthey-Schulten Z, Marrink SJ. Molecular dynamics simulation of an entire cell. Front Chem 2023; 11:1106495. [PMID: 36742032 PMCID: PMC9889929 DOI: 10.3389/fchem.2023.1106495] [Citation(s) in RCA: 26] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 01/09/2023] [Indexed: 01/19/2023] Open
Abstract
The ultimate microscope, directed at a cell, would reveal the dynamics of all the cell's components with atomic resolution. In contrast to their real-world counterparts, computational microscopes are currently on the brink of meeting this challenge. In this perspective, we show how an integrative approach can be employed to model an entire cell, the minimal cell, JCVI-syn3A, at full complexity. This step opens the way to interrogate the cell's spatio-temporal evolution with molecular dynamics simulations, an approach that can be extended to other cell types in the near future.
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Affiliation(s)
- Jan A. Stevens
- Molecular Dynamics Group, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, Netherlands
| | - Fabian Grünewald
- Molecular Dynamics Group, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, Netherlands
| | - P. A. Marco van Tilburg
- Molecular Dynamics Group, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, Netherlands
| | - Melanie König
- Molecular Dynamics Group, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, Netherlands
| | - Benjamin R. Gilbert
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Champaign, IL, United States
| | - Troy A. Brier
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Champaign, IL, United States
| | - Zane R. Thornburg
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Champaign, IL, United States
| | - Zaida Luthey-Schulten
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Champaign, IL, United States
| | - Siewert J. Marrink
- Molecular Dynamics Group, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, Netherlands,*Correspondence: Siewert J. Marrink,
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24
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Pyle E, Hutchings J, Zanetti G. Strategies for picking membrane-associated particles within subtomogram averaging workflows. Faraday Discuss 2022; 240:101-113. [PMID: 35924570 PMCID: PMC9642003 DOI: 10.1039/d2fd00022a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Cryo-electron tomography (cryo-ET) with subtomogram averaging (STA) has emerged as a key tool for determining macromolecular structure(s) in vitro and in situ. However, processing cryo-ET data with STA currently requires significant user expertise. Recent efforts have streamlined several steps in STA workflows; however, particle picking remains a time-consuming bottleneck for many projects and requires considerable user input. Here, we present several strategies for the time-efficient and accurate picking of membrane-associated particles using the COPII inner coat as a case study. We also discuss a range of particle cleaning solutions to remove both poor quality and false-positive particles from STA datasets. We provide a step-by-step guide and the necessary scripts for users to independently carry out the particle picking and cleaning strategies discussed.
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Affiliation(s)
- Euan Pyle
- Institute of Structural and Molecular Biology, Birkbeck CollegeMalet St.LondonWC1E 7HXUK
| | - Joshua Hutchings
- Division of Biological Sciences, University of California San DiegoLa JollaCAUSA
| | - Giulia Zanetti
- Institute of Structural and Molecular Biology, Birkbeck CollegeMalet St.LondonWC1E 7HXUK
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25
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Zhu XG, Hasanuzzaman M, Jajoo A, Lawson T, Lin R, Liu CM, Liu LN, Liu Z, Lu C, Moustakas M, Roach T, Song Q, Yin X, Zhang W. Improving photosynthesis through multidisciplinary efforts: The next frontier of photosynthesis research. FRONTIERS IN PLANT SCIENCE 2022; 13:967203. [PMID: 36247611 PMCID: PMC9563237 DOI: 10.3389/fpls.2022.967203] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Accepted: 08/18/2022] [Indexed: 06/07/2023]
Affiliation(s)
- Xin-Guang Zhu
- Center of Excellence for Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Mirza Hasanuzzaman
- Department of Agronomy, Faculty of Agriculture, Sher-e-Bangla Agricultural University, Dhaka, Bangladesh
| | - Anjana Jajoo
- School of Biotechnology, Devi Ahilya University, Indore, India
| | - Tracy Lawson
- School of Life Science, University of Essex, Colchester, United Kingdom
| | - Rongcheng Lin
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Chun-Ming Liu
- School of Advanced Agricultural Sciences, Peking University, Beijing, China
| | - Lu-Ning Liu
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Zhenfeng Liu
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Congming Lu
- School of Life Sciences, Shandong Agricultural University, Taian, China
| | - Michael Moustakas
- Department of Botany, School of Biology, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Thomas Roach
- Department of Botany, University of Innsbruck, Innsbruck, Austria
| | - Qingfeng Song
- Center of Excellence for Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Xinyou Yin
- Department of Plant Sciences, Centre for Crop Systems Analysis, Wageningen University & Research, Wageningen, Netherlands
| | - Wangfeng Zhang
- Department of Agronomy, Shihezi University, Shihezi, China
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26
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Liang Z, Yeung WT, Ma J, Mai KKK, Liu Z, Chong YLF, Cai X, Kang BH. Electron tomography of prolamellar bodies and their transformation into grana thylakoids in cryofixed Arabidopsis cotyledons. THE PLANT CELL 2022; 34:3830-3843. [PMID: 35876816 PMCID: PMC9516191 DOI: 10.1093/plcell/koac205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 07/05/2022] [Indexed: 06/15/2023]
Abstract
The para-crystalline structures of prolamellar bodies (PLBs) and light-induced etioplast-to-chloroplast transformation have been investigated via electron microscopy. However, such studies suffer from chemical fixation artifacts and limited volumes of 3D reconstruction. Here, we examined Arabidopsis thaliana cotyledon cells by electron tomography (ET) to visualize etioplasts and their conversion into chloroplasts. We employed scanning transmission ET to image large volumes and high-pressure freezing to improve sample preservation. PLB tubules were arranged in a zinc blende-type lattice-like carbon atoms in diamonds. Within 2 h after illumination, the lattice collapsed from the PLB exterior and the disorganized tubules merged to form thylakoid sheets (pre-granal thylakoids), which folded and overlapped with each other to create grana stacks. Since the nascent pre-granal thylakoids contained curved membranes in their tips, we examined the expression and localization of CURT1 (CURVATURE THYLAKOID1) proteins. CURT1A transcripts were most abundant in de-etiolating cotyledon samples, and CURT1A was concentrated at the PLB periphery. In curt1a etioplasts, PLB-associated thylakoids were swollen and failed to form grana stacks. In contrast, PLBs had cracks in their lattices in curt1c etioplasts. Our data provide evidence that CURT1A is required for pre-granal thylakoid assembly from PLB tubules during de-etiolation, while CURT1C contributes to cubic crystal growth in the dark.
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Affiliation(s)
| | - Wai-Tsun Yeung
- Centre for Cell and Developmental Biology, State Key Laboratory for Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Juncai Ma
- Centre for Cell and Developmental Biology, State Key Laboratory for Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Keith Ka Ki Mai
- Centre for Cell and Developmental Biology, State Key Laboratory for Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Zhongyuan Liu
- Centre for Cell and Developmental Biology, State Key Laboratory for Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Yau-Lun Felix Chong
- Department of Physics, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Xiaohao Cai
- School of Electronics and Computer Science, The University of Southampton, Southampton, UK
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27
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State transition is quiet around pyrenoid and LHCII phosphorylation is not essential for thylakoid deformation in Chlamydomonas 137c. Proc Natl Acad Sci U S A 2022; 119:e2122032119. [PMID: 36067315 PMCID: PMC9478649 DOI: 10.1073/pnas.2122032119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Photosynthetic organisms have developed a regulation mechanism called state transition (ST) to rapidly adjust the excitation balance between the two photosystems by light-harvesting complex II (LHCII) movement. Though many researchers have assumed coupling of the dynamic transformations of the thylakoid membrane with ST, evidence of that remains elusive. To clarify the above-mentioned coupling in a model organism Chlamydomonas, here we used two advanced microscope techniques, the excitation-spectral microscope (ESM) developed recently by us and the superresolution imaging based on structured-illumination microscopy (SIM). The ESM observation revealed ST-dependent spectral changes upon repeated ST inductions. Surprisingly, it clarified a less significant ST occurrence in the region surrounding the pyrenoid, which is a subcellular compartment specialized for the carbon-fixation reaction, than that in the other domains. Further, we found a species dependence of this phenomenon: 137c strain showed the significant intracellular inhomogeneity of ST occurrence, whereas 4A+ strain hardly did. On the other hand, the SIM observation resolved partially irreversible fine thylakoid transformations caused by the ST-inducing illumination. This fine, irreversible thylakoid transformation was also observed in the STT7 kinase-lacking mutant. This result revealed that the fine thylakoid transformation is not induced solely by the LHCII phosphorylation, suggesting the highly susceptible nature of the thylakoid ultrastructure to the photosynthetic light reactions.
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28
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Lamm L, Righetto RD, Wietrzynski W, Pöge M, Martinez-Sanchez A, Peng T, Engel BD. MemBrain: A deep learning-aided pipeline for detection of membrane proteins in Cryo-electron tomograms. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2022; 224:106990. [PMID: 35858496 DOI: 10.1016/j.cmpb.2022.106990] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 06/04/2022] [Accepted: 06/28/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND AND OBJECTIVE Cryo-electron tomography (cryo-ET) is an imaging technique that enables 3D visualization of the native cellular environment at sub-nanometer resolution, providing unpreceded insights into the molecular organization of cells. However, cryo-electron tomograms suffer from low signal-to-noise ratios and anisotropic resolution, which makes subsequent image analysis challenging. In particular, the efficient detection of membrane-embedded proteins is a problem still lacking satisfactory solutions. METHODS We present MemBrain - a new deep learning-aided pipeline that automatically detects membrane-bound protein complexes in cryo-electron tomograms. After subvolumes are sampled along a segmented membrane, each subvolume is assigned a score using a convolutional neural network (CNN), and protein positions are extracted by a clustering algorithm. Incorporating rotational subvolume normalization and using a tiny receptive field simplify the task of protein detection and thus facilitate the network training. RESULTS MemBrain requires only a small quantity of training labels and achieves excellent performance with only a single annotated membrane (F1 score: 0.88). A detailed evaluation shows that our fully trained pipeline outperforms existing classical computer vision-based and CNN-based approaches by a large margin (F1 score: 0.92 vs. max. 0.63). Furthermore, in addition to protein center positions, MemBrain can determine protein orientations, which has not been implemented by any existing CNN-based method to date. We also show that a pre-trained MemBrain program generalizes to tomograms acquired using different cryo-ET methods and depicting different types of cells. CONCLUSIONS MemBrain is a powerful and annotation-efficient tool for the detection of membrane protein complexes in cryo-ET data, with the potential to be used in a wide range of biological studies. It is generalizable to various kinds of tomograms, making it possible to use pretrained models for different tasks. Its efficiency in terms of required annotations also allows rapid training and fine-tuning of models. The corresponding code, pretrained models, and instructions for operating the MemBrain program can be found at: https://github.com/CellArchLab/MemBrain.
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Affiliation(s)
- Lorenz Lamm
- Helmholtz Pioneer Campus, Helmholtz Munich, 85764, Neuherberg, Germany; Helmholtz AI, Helmholtz Munich, 85764, Neuherberg, Germany
| | - Ricardo D Righetto
- Helmholtz Pioneer Campus, Helmholtz Munich, 85764, Neuherberg, Germany; Biozentrum, University of Basel, 4056, Basel, Switzerland
| | - Wojciech Wietrzynski
- Helmholtz Pioneer Campus, Helmholtz Munich, 85764, Neuherberg, Germany; Biozentrum, University of Basel, 4056, Basel, Switzerland
| | - Matthias Pöge
- Max Planck Institute of Biochemistry, 82152, Martinsried, Germany
| | - Antonio Martinez-Sanchez
- Department of Computer Science, Faculty of Sciences - Campus Llamaquique, University of Oviedo, 33007, Oviedo, Spain; Health Research Institute of Asturias (ISPA), Avenida Hospital Universitario s/n, 33011, Oviedo, Spain
| | - Tingying Peng
- Helmholtz AI, Helmholtz Munich, 85764, Neuherberg, Germany.
| | - Benjamin D Engel
- Helmholtz Pioneer Campus, Helmholtz Munich, 85764, Neuherberg, Germany; Biozentrum, University of Basel, 4056, Basel, Switzerland.
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29
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Jiang W, Wagner J, Du W, Plitzko J, Baumeister W, Beck F, Guo Q. A transformation clustering algorithm and its application in polyribosomes structural profiling. Nucleic Acids Res 2022; 50:9001-9011. [PMID: 35811088 PMCID: PMC9458451 DOI: 10.1093/nar/gkac547] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 06/01/2022] [Accepted: 06/10/2022] [Indexed: 12/26/2022] Open
Abstract
Improvements in cryo-electron tomography sample preparation, electron-microscopy instrumentations, and image processing algorithms have advanced the structural analysis of macromolecules in situ. Beyond such analyses of individual macromolecules, the study of their interactions with functionally related neighbors in crowded cellular habitats, i.e. ‘molecular sociology’, is of fundamental importance in biology. Here we present a NEighboring Molecule TOpology Clustering (NEMO-TOC) algorithm. We optimized this algorithm for the detection and profiling of polyribosomes, which play both constitutive and regulatory roles in gene expression. Our results suggest a model where polysomes are formed by connecting multiple nonstochastic blocks, in which translation is likely synchronized.
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Affiliation(s)
- Wenhong Jiang
- State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, School of Life Sciences, Peking University , Beijing 100871, China
| | - Jonathan Wagner
- Department of Structural Molecular Biology, Max Planck Institute of Biochemistry , Am Klopferspitz 18, 82152 Martinsried, Germany
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry , Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Wenjing Du
- State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, School of Life Sciences, Peking University , Beijing 100871, China
| | - Juergen Plitzko
- CryoEM Technology, Max Planck Institute of Biochemistry , Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Wolfgang Baumeister
- Department of Structural Molecular Biology, Max Planck Institute of Biochemistry , Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Florian Beck
- CryoEM Technology, Max Planck Institute of Biochemistry , Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Qiang Guo
- State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, School of Life Sciences, Peking University , Beijing 100871, China
- Changping Laboratory , Beijing, China
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30
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Revealing bacterial cell biology using cryo-electron tomography. Curr Opin Struct Biol 2022; 75:102419. [PMID: 35820259 DOI: 10.1016/j.sbi.2022.102419] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 05/28/2022] [Accepted: 05/30/2022] [Indexed: 11/21/2022]
Abstract
Visualizing macromolecules inside bacteria at a high spatial resolution has remained a challenge owing to their small size and limited resolution of optical microscopy techniques. Recent advances in cryo-electron tomography (cryo-ET) imaging methods have revealed the spatial and temporal assemblies of many macromolecules involved in different cellular processes in bacteria at a resolution of a few nanometers in their native milieu. Specifically, the application of cryo-focused ion beam (cryo-FIB) milling to thin bacterial specimens makes them amenable for high-resolution cryo-ET data collection. In this review, we highlight recent research in three emerging areas of bacterial cell biology that have benefited from the cryo-FIB-ET technology - cytoskeletal filament assembly, intracellular organelles, and multicellularity.
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31
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Arshad R, Saccon F, Bag P, Biswas A, Calvaruso C, Bhatti AF, Grebe S, Mascoli V, Mahbub M, Muzzopappa F, Polyzois A, Schiphorst C, Sorrentino M, Streckaité S, van Amerongen H, Aro EM, Bassi R, Boekema EJ, Croce R, Dekker J, van Grondelle R, Jansson S, Kirilovsky D, Kouřil R, Michel S, Mullineaux CW, Panzarová K, Robert B, Ruban AV, van Stokkum I, Wientjes E, Büchel C. A kaleidoscope of photosynthetic antenna proteins and their emerging roles. PLANT PHYSIOLOGY 2022; 189:1204-1219. [PMID: 35512089 PMCID: PMC9237682 DOI: 10.1093/plphys/kiac175] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 03/17/2022] [Indexed: 05/17/2023]
Abstract
Photosynthetic light-harvesting antennae are pigment-binding proteins that perform one of the most fundamental tasks on Earth, capturing light and transferring energy that enables life in our biosphere. Adaptation to different light environments led to the evolution of an astonishing diversity of light-harvesting systems. At the same time, several strategies have been developed to optimize the light energy input into photosynthetic membranes in response to fluctuating conditions. The basic feature of these prompt responses is the dynamic nature of antenna complexes, whose function readily adapts to the light available. High-resolution microscopy and spectroscopic studies on membrane dynamics demonstrate the crosstalk between antennae and other thylakoid membrane components. With the increased understanding of light-harvesting mechanisms and their regulation, efforts are focusing on the development of sustainable processes for effective conversion of sunlight into functional bio-products. The major challenge in this approach lies in the application of fundamental discoveries in light-harvesting systems for the improvement of plant or algal photosynthesis. Here, we underline some of the latest fundamental discoveries on the molecular mechanisms and regulation of light harvesting that can potentially be exploited for the optimization of photosynthesis.
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Affiliation(s)
- Rameez Arshad
- Department of Biophysics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Olomouc 783 71, Czech Republic
- Electron Microscopy Group, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen 9747 AG, The Netherlands
| | - Francesco Saccon
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, UK
| | - Pushan Bag
- Department of Plant Physiology, Umeå Plant Science Centre, Umeå University, Umeå 901 87, Sweden
| | - Avratanu Biswas
- Department of Physics and Astronomy and LaserLaB, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam 1081 HV, The Netherlands
| | - Claudio Calvaruso
- Institute for Molecular Biosciences, Goethe University of Frankfurt, Frankfurt 60438, Germany
| | - Ahmad Farhan Bhatti
- Laboratory of Biophysics, Wageningen University, Wageningen, the Netherlands
| | - Steffen Grebe
- Department of Life Technologies, MolecularPlant Biology, University of Turku, Turku FI–20520, Finland
| | - Vincenzo Mascoli
- Department of Physics and Astronomy and LaserLaB, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam 1081 HV, The Netherlands
| | - Moontaha Mahbub
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, UK
- Department of Botany, Jagannath University, Dhaka 1100, Bangladesh
| | - Fernando Muzzopappa
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif sur Yvette 1198, France
| | - Alexandros Polyzois
- Université de Paris, Faculté de Pharmacie de Paris, CiTCoM UMR 8038 CNRS, Paris 75006, France
| | | | - Mirella Sorrentino
- Photon Systems Instruments, spol. s.r.o., Drásov, Czech Republic
- Department of Agricultural Sciences, University of Naples Federico II, Naples 80138, Italy
| | - Simona Streckaité
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif sur Yvette 1198, France
| | | | - Eva-Mari Aro
- Department of Life Technologies, MolecularPlant Biology, University of Turku, Turku FI–20520, Finland
| | - Roberto Bassi
- Dipartimento di Biotecnologie, Università di Verona, Verona, Italy
| | - Egbert J Boekema
- Electron Microscopy Group, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen 9747 AG, The Netherlands
| | - Roberta Croce
- Department of Physics and Astronomy and LaserLaB, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam 1081 HV, The Netherlands
| | - Jan Dekker
- Department of Physics and Astronomy and LaserLaB, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam 1081 HV, The Netherlands
| | - Rienk van Grondelle
- Department of Physics and Astronomy and LaserLaB, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam 1081 HV, The Netherlands
| | - Stefan Jansson
- Department of Plant Physiology, Umeå Plant Science Centre, Umeå University, Umeå 901 87, Sweden
| | - Diana Kirilovsky
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif sur Yvette 1198, France
| | - Roman Kouřil
- Department of Biophysics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Olomouc 783 71, Czech Republic
| | - Sylvie Michel
- Université de Paris, Faculté de Pharmacie de Paris, CiTCoM UMR 8038 CNRS, Paris 75006, France
| | - Conrad W Mullineaux
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, UK
| | - Klára Panzarová
- Photon Systems Instruments, spol. s.r.o., Drásov, Czech Republic
| | - Bruno Robert
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif sur Yvette 1198, France
| | - Alexander V Ruban
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, UK
| | - Ivo van Stokkum
- Department of Physics and Astronomy and LaserLaB, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam 1081 HV, The Netherlands
| | - Emilie Wientjes
- Laboratory of Biophysics, Wageningen University, Wageningen, the Netherlands
| | - Claudia Büchel
- Institute for Molecular Biosciences, Goethe University of Frankfurt, Frankfurt 60438, Germany
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32
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Cackett L, Luginbuehl LH, Schreier TB, Lopez-Juez E, Hibberd JM. Chloroplast development in green plant tissues: the interplay between light, hormone, and transcriptional regulation. THE NEW PHYTOLOGIST 2022; 233:2000-2016. [PMID: 34729790 DOI: 10.1111/nph.17839] [Citation(s) in RCA: 45] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 10/09/2021] [Indexed: 05/20/2023]
Abstract
Chloroplasts are best known for their role in photosynthesis, but they also allow nitrogen and sulphur assimilation, amino acid, fatty acid, nucleotide and hormone synthesis. How chloroplasts develop is therefore relevant to these diverse and fundamental biological processes, but also to attempts at their rational redesign. Light is strictly required for chloroplast formation in all angiosperms and directly regulates the expression of hundreds of chloroplast-related genes. Light also modulates the levels of several hormones including brassinosteriods, cytokinins, auxins and gibberellins, which themselves control chloroplast development particularly during early stages of plant development. Transcription factors such as GOLDENLIKE1&2 (GLK1&2), GATA NITRATE-INDUCIBLE CARBON METABOLISM-INVOLVED (GNC) and CYTOKININ-RESPONSIVE GATA FACTOR 1 (CGA1) act downstream of both light and phytohormone signalling to regulate chloroplast development. Thus, in green tissues transcription factors, light signalling and hormone signalling form a complex network regulating the transcription of chloroplast- and photosynthesis-related genes to control the development and number of chloroplasts per cell. We use this conceptual framework to identify points of regulation that could be harnessed to modulate chloroplast abundance and increase photosynthetic efficiency of crops, and to highlight future avenues to overcome gaps in current knowledge.
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Affiliation(s)
- Lee Cackett
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK
| | - Leonie H Luginbuehl
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK
| | - Tina B Schreier
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK
| | - Enrique Lopez-Juez
- Department of Biological Sciences, Royal Holloway University of London, Egham, TW20 0EX, UK
| | - Julian M Hibberd
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK
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33
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Vermaas JV, Mayne CG, Shinn E, Tajkhorshid E. Assembly and Analysis of Cell-Scale Membrane Envelopes. J Chem Inf Model 2022; 62:602-617. [PMID: 34910495 PMCID: PMC8903035 DOI: 10.1021/acs.jcim.1c01050] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The march toward exascale computing will enable routine molecular simulation of larger and more complex systems, for example, simulation of entire viral particles, on the scale of approximately billions of atoms─a simulation size commensurate with a small bacterial cell. Anticipating the future hardware capabilities that will enable this type of research and paralleling advances in experimental structural biology, efforts are currently underway to develop software tools, procedures, and workflows for constructing cell-scale structures. Herein, we describe our efforts in developing and implementing an efficient and robust workflow for construction of cell-scale membrane envelopes and embedding membrane proteins into them. A new approach for construction of massive membrane structures that are stable during the simulations is built on implementing a subtractive assembly technique coupled with the development of a structure concatenation tool (fastmerge), which eliminates overlapping elements based on volumetric criteria rather than adding successive molecules to the simulation system. Using this approach, we have constructed two "protocells" consisting of MARTINI coarse-grained beads to represent cellular membranes, one the size of a cellular organelle and another the size of a small bacterial cell. The membrane envelopes constructed here remain whole during the molecular dynamics simulations performed and exhibit water flux only through specific proteins, demonstrating the success of our methodology in creating tight cell-like membrane compartments. Extended simulations of these cell-scale structures highlight the propensity for nonspecific interactions between adjacent membrane proteins leading to the formation of protein microclusters on the cell surface, an insight uniquely enabled by the scale of the simulations. We anticipate that the experiences and best practices presented here will form the basis for the next generation of cell-scale models, which will begin to address the addition of soluble proteins, nucleic acids, and small molecules essential to the function of a cell.
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Affiliation(s)
- Josh V. Vermaas
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401,;
| | - Christopher G. Mayne
- Theoretical and Computational Biophysics Group, NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology, Department of Biochemistry, and Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801
| | - Eric Shinn
- Theoretical and Computational Biophysics Group, NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology, Department of Biochemistry, and Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801
| | - Emad Tajkhorshid
- Theoretical and Computational Biophysics Group, NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology, Department of Biochemistry, and Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801,;
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34
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Foster HE, Ventura Santos C, Carter AP. A cryo-ET survey of microtubules and intracellular compartments in mammalian axons. J Cell Biol 2022; 221:e202103154. [PMID: 34878519 PMCID: PMC7612188 DOI: 10.1083/jcb.202103154] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 09/28/2021] [Accepted: 11/16/2021] [Indexed: 12/16/2022] Open
Abstract
The neuronal axon is packed with cytoskeletal filaments, membranes, and organelles, many of which move between the cell body and axon tip. Here, we used cryo-electron tomography to survey the internal components of mammalian sensory axons. We determined the polarity of the axonal microtubules (MTs) by combining subtomogram classification and visual inspection, finding MT plus and minus ends are structurally similar. Subtomogram averaging of globular densities in the MT lumen suggests they have a defined structure, which is surprising given they likely contain the disordered protein MAP6. We found the endoplasmic reticulum in axons is tethered to MTs through multiple short linkers. We surveyed membrane-bound cargos and describe unexpected internal features such as granules and broken membranes. In addition, we detected proteinaceous compartments, including numerous virus-like capsid particles. Our observations outline novel features of axonal cargos and MTs, providing a platform for identification of their constituents.
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35
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Kang BH, Anderson CT, Arimura SI, Bayer E, Bezanilla M, Botella MA, Brandizzi F, Burch-Smith TM, Chapman KD, Dünser K, Gu Y, Jaillais Y, Kirchhoff H, Otegui MS, Rosado A, Tang Y, Kleine-Vehn J, Wang P, Zolman BK. A glossary of plant cell structures: Current insights and future questions. THE PLANT CELL 2022; 34:10-52. [PMID: 34633455 PMCID: PMC8846186 DOI: 10.1093/plcell/koab247] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 09/29/2021] [Indexed: 05/03/2023]
Abstract
In this glossary of plant cell structures, we asked experts to summarize a present-day view of plant organelles and structures, including a discussion of outstanding questions. In the following short reviews, the authors discuss the complexities of the plant cell endomembrane system, exciting connections between organelles, novel insights into peroxisome structure and function, dynamics of mitochondria, and the mysteries that need to be unlocked from the plant cell wall. These discussions are focused through a lens of new microscopy techniques. Advanced imaging has uncovered unexpected shapes, dynamics, and intricate membrane formations. With a continued focus in the next decade, these imaging modalities coupled with functional studies are sure to begin to unravel mysteries of the plant cell.
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Affiliation(s)
- Byung-Ho Kang
- School of Life Sciences, Centre for Cell & Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Charles T Anderson
- Department of Biology and Center for Lignocellulose Structure and Formation, The Pennsylvania State University, University Park, Pennsylvania 16802 USA
| | - Shin-ichi Arimura
- Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo, Japan
| | - Emmanuelle Bayer
- Université de Bordeaux, CNRS, Laboratoire de Biogenèse Membranaire, UMR 5200, Villenave d'Ornon F-33140, France
| | - Magdalena Bezanilla
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755, USA
| | - Miguel A Botella
- Departamento de Biología Molecular y Bioquímica, Instituto de Hortifruticultura Subtropical y Mediterránea “La Mayora,” Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Universidad de Málaga, Málaga 29071, Spain
| | - Federica Brandizzi
- MSU-DOE Plant Research Lab, Michigan State University, East Lansing, Michigan 48824 USA
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824, USA
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, Michigan 48824, USA
| | - Tessa M Burch-Smith
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - Kent D Chapman
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, Texas 76203, USA
| | - Kai Dünser
- Faculty of Biology, Chair of Molecular Plant Physiology (MoPP) University of Freiburg, Freiburg 79104, Germany
- Center for Integrative Biological Signalling Studies (CIBSS), University of Freiburg, Freiburg 79104, Germany
| | - Yangnan Gu
- Department of Plant and Microbial Biology, Innovative Genomics Institute, University of California, Berkeley, California 94720, USA
| | - Yvon Jaillais
- Laboratoire Reproduction et Développement des Plantes (RDP), Université de Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRAE, Lyon, France
| | - Helmut Kirchhoff
- Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164, USA
| | - Marisa S Otegui
- Department of Botany and Center for Quantitative Cell Imaging, University of Wisconsin-Madison, Wisconsin 53706, USA
| | - Abel Rosado
- Department of Botany, University of British Columbia, Vancouver V6T1Z4, Canada
| | - Yu Tang
- Department of Plant and Microbial Biology, Innovative Genomics Institute, University of California, Berkeley, California 94720, USA
| | - Jürgen Kleine-Vehn
- Faculty of Biology, Chair of Molecular Plant Physiology (MoPP) University of Freiburg, Freiburg 79104, Germany
- Center for Integrative Biological Signalling Studies (CIBSS), University of Freiburg, Freiburg 79104, Germany
| | - Pengwei Wang
- Key Laboratory of Horticultural Plant Biology (MOE), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, China
| | - Bethany Karlin Zolman
- Department of Biology, University of Missouri, St. Louis, St. Louis, Missouri 63121, USA
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Ostermeier M, Heinz S, Hamm J, Zabret J, Rast A, Klingl A, Nowaczyk MM, Nickelsen J. Thylakoid attachment to the plasma membrane in Synechocystis sp. PCC 6803 requires the AncM protein. THE PLANT CELL 2022; 34:655-678. [PMID: 34665262 PMCID: PMC8846179 DOI: 10.1093/plcell/koab253] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 10/06/2021] [Indexed: 06/13/2023]
Abstract
Thylakoids are the highly specialized internal membrane systems that harbor the photosynthetic electron transport machinery in cyanobacteria and in chloroplasts. In Synechocystis sp. PCC 6803, thylakoid membranes (TMs) are arranged in peripheral sheets that occasionally converge on the plasma membrane (PM) to form thylakoid convergence membranes (TCMs). TCMs connect several thylakoid sheets and form local contact sites called thylapses between the two membrane systems, at which the early steps of photosystem II (PSII) assembly occur. The protein CurT is one of the main drivers of TCM formation known so far. Here, we identify, by whole-genome sequencing of a curT- suppressor strain, the protein anchor of convergence membranes (AncM) as a factor required for the attachment of thylakoids to the PM at thylapses. An ancM- mutant is shown to have a photosynthetic phenotype characterized by reductions in oxygen-evolution rate, PSII accumulation, and PS assembly. Moreover, the ancM- strain exhibits an altered thylakoid ultrastructure with additional sheets and TCMs detached from the PM. By combining biochemical studies with fluorescence and correlative light-electron microscopy-based approaches, we show that AncM is an integral membrane protein located in biogenic TCMs that form thylapses. These data suggest an antagonistic function of AncM and CurT in shaping TM ultrastructure.
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Affiliation(s)
- Matthias Ostermeier
- Department of Molecular Plant Science, LMU Munich, Planegg-Martinsried, 82152, Germany
| | - Steffen Heinz
- Department of Molecular Plant Science, LMU Munich, Planegg-Martinsried, 82152, Germany
| | - Julia Hamm
- Department of Molecular Plant Science, LMU Munich, Planegg-Martinsried, 82152, Germany
| | - Jure Zabret
- Department of Plant Biochemistry, Ruhr-University Bochum, Bochum 44801, Germany
| | - Anna Rast
- Department of Molecular Plant Science, LMU Munich, Planegg-Martinsried, 82152, Germany
| | - Andreas Klingl
- Department of Plant Development, LMU Munich, Planegg-Martinsried, 82152, Germany
| | - Marc M Nowaczyk
- Department of Plant Biochemistry, Ruhr-University Bochum, Bochum 44801, Germany
| | - Jörg Nickelsen
- Department of Molecular Plant Science, LMU Munich, Planegg-Martinsried, 82152, Germany
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37
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Nawrocki WJ, Liu X, Raber B, Hu C, de Vitry C, Bennett DIG, Croce R. Molecular origins of induction and loss of photoinhibition-related energy dissipation q I. SCIENCE ADVANCES 2021; 7:eabj0055. [PMID: 34936440 PMCID: PMC8694598 DOI: 10.1126/sciadv.abj0055] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Photosynthesis fuels life on Earth using sunlight as energy source. However, light has a simultaneous detrimental effect on the enzyme triggering photosynthesis and producing oxygen, photosystem II (PSII). Photoinhibition, the light-dependent decrease of PSII activity, results in a major limitation to aquatic and land photosynthesis and occurs upon all environmental stress conditions. In this work, we investigated the molecular origins of photoinhibition focusing on the paradoxical energy dissipation process of unknown nature coinciding with PSII damage. Integrating spectroscopic, biochemical, and computational approaches, we demonstrate that the site of this quenching process is the PSII reaction center. We propose that the formation of quenching and the closure of PSII stem from the same event. We lastly reveal the heterogeneity of PSII upon photoinhibition using structure-function modeling of excitation energy transfer. This work unravels the functional details of the damage-induced energy dissipation at the heart of photosynthesis.
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Affiliation(s)
- Wojciech J. Nawrocki
- Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, Netherlands
- LaserLaB Amsterdam, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, Netherlands
- Corresponding author. (W.J.N.); (R.C.)
| | - Xin Liu
- Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, Netherlands
- LaserLaB Amsterdam, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, Netherlands
| | - Bailey Raber
- Department of Chemistry, Southern Methodist University, P.O. Box 750314, Dallas, TX, USA
| | - Chen Hu
- Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, Netherlands
- LaserLaB Amsterdam, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, Netherlands
| | - Catherine de Vitry
- Institut de Biologie Physico-Chimique, UMR 7141, CNRS-Sorbonne Université, 75005 Paris, France
| | - Doran I. G. Bennett
- Department of Chemistry, Southern Methodist University, P.O. Box 750314, Dallas, TX, USA
| | - Roberta Croce
- Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, Netherlands
- LaserLaB Amsterdam, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, Netherlands
- Corresponding author. (W.J.N.); (R.C.)
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38
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Moebel E, Martinez-Sanchez A, Lamm L, Righetto RD, Wietrzynski W, Albert S, Larivière D, Fourmentin E, Pfeffer S, Ortiz J, Baumeister W, Peng T, Engel BD, Kervrann C. Deep learning improves macromolecule identification in 3D cellular cryo-electron tomograms. Nat Methods 2021; 18:1386-1394. [PMID: 34675434 DOI: 10.1038/s41592-021-01275-4] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 08/18/2021] [Indexed: 11/10/2022]
Abstract
Cryogenic electron tomography (cryo-ET) visualizes the 3D spatial distribution of macromolecules at nanometer resolution inside native cells. However, automated identification of macromolecules inside cellular tomograms is challenged by noise and reconstruction artifacts, as well as the presence of many molecular species in the crowded volumes. Here, we present DeepFinder, a computational procedure that uses artificial neural networks to simultaneously localize multiple classes of macromolecules. Once trained, the inference stage of DeepFinder is faster than template matching and performs better than other competitive deep learning methods at identifying macromolecules of various sizes in both synthetic and experimental datasets. On cellular cryo-ET data, DeepFinder localized membrane-bound and cytosolic ribosomes (roughly 3.2 MDa), ribulose 1,5-bisphosphate carboxylase-oxygenase (roughly 560 kDa soluble complex) and photosystem II (roughly 550 kDa membrane complex) with an accuracy comparable to expert-supervised ground truth annotations. DeepFinder is therefore a promising algorithm for the semiautomated analysis of a wide range of molecular targets in cellular tomograms.
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Affiliation(s)
- Emmanuel Moebel
- Serpico Project-Team, Centre Inria Rennes-Bretagne Atlantique and CNRS-UMR 144, Inria, CNRS, Institut Curie, PSL Research University, Campus Universitaire de Beaulieu, Rennes Cedex, France
| | - Antonio Martinez-Sanchez
- Department of Computer Science, Faculty of Sciences, University of Oviedo, Oviedo, Spain.,Health Research Institute of Asturias (ISPA), Avenida Hospital Universitario s/n, Oviedo, Spain.,Institute of Neuropathology, Cluster of Excellence 'Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells', University of Göttingen, Göttingen, Germany
| | - Lorenz Lamm
- Helmholtz Pioneer Campus, Helmholtz Zentrum München, Neuherberg, Germany.,Helmholtz AI, Helmholtz Zentrum München, Neuherberg, Germany
| | - Ricardo D Righetto
- Helmholtz Pioneer Campus, Helmholtz Zentrum München, Neuherberg, Germany
| | | | | | - Damien Larivière
- Fourmentin-Guilbert Scientific Foundation, Noisy-le-Grand, France
| | - Eric Fourmentin
- Fourmentin-Guilbert Scientific Foundation, Noisy-le-Grand, France
| | - Stefan Pfeffer
- Max Planck Institute of Biochemistry, Martinsried, Germany.,Zentrum für Molekulare Biologie der Universität Heidelberg, Heidelberg, Germany
| | - Julio Ortiz
- Max Planck Institute of Biochemistry, Martinsried, Germany.,Ernst Ruska-Centre, Wilhelm-Johnen-Straße, Jülich, Germany
| | | | - Tingying Peng
- Helmholtz AI, Helmholtz Zentrum München, Neuherberg, Germany
| | - Benjamin D Engel
- Helmholtz Pioneer Campus, Helmholtz Zentrum München, Neuherberg, Germany. .,Department of Chemistry, Technical University of Munich, Garching, Germany.
| | - Charles Kervrann
- Serpico Project-Team, Centre Inria Rennes-Bretagne Atlantique and CNRS-UMR 144, Inria, CNRS, Institut Curie, PSL Research University, Campus Universitaire de Beaulieu, Rennes Cedex, France.
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Ruban AV, Wilson S. The Mechanism of Non-Photochemical Quenching in Plants: Localization and Driving Forces. PLANT & CELL PHYSIOLOGY 2021; 62:1063-1072. [PMID: 33351147 DOI: 10.1093/pcp/pcaa155] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 11/25/2020] [Indexed: 05/20/2023]
Abstract
Non-photochemical chlorophyll fluorescence quenching (NPQ) remains one of the most studied topics of the 21st century in photosynthesis research. Over the past 30 years, profound knowledge has been obtained on the molecular mechanism of NPQ in higher plants. First, the largely overlooked significance of NPQ in protecting the reaction center of photosystem II (RCII) against damage, and the ways to assess its effectiveness are highlighted. Then, the key in vivo signals that can monitor the life of the major NPQ component, qE, are presented. Finally, recent knowledge on the site of qE and the possible molecular events that transmit ΔpH into the conformational change in the major LHCII [the major trimeric light harvesting complex of photosystem II (PSII)] antenna complex are discussed. Recently, number of reports on Arabidopsis mutants lacking various antenna components of PSII confirmed that the in vivo site of qE rests within the major trimeric LHCII complex. Experiments on biochemistry, spectroscopy, microscopy and molecular modeling suggest an interplay between thylakoid membrane geometry and the dynamics of LHCII, the PsbS (PSII subunit S) protein and thylakoid lipids. The molecular basis for the qE-related conformational change in the thylakoid membrane, including the possible onset of a hydrophobic mismatch between LHCII and lipids, potentiated by PsbS protein, begins to unfold.
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Affiliation(s)
- Alexander V Ruban
- Department of Biochemistry, School of Biological and Chemical Sciences, Queen Mary University of London, Fogg Building, Mile End Road, London E1 4NS, UK
| | - Sam Wilson
- Department of Biochemistry, School of Biological and Chemical Sciences, Queen Mary University of London, Fogg Building, Mile End Road, London E1 4NS, UK
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40
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Zhang XJ, Fujita Y, Tokutsu R, Minagawa J, Ye S, Shibata Y. High-Speed Excitation-Spectral Microscopy Uncovers In Situ Rearrangement of Light-Harvesting Apparatus in Chlamydomonas during State Transitions at Submicron Precision. PLANT & CELL PHYSIOLOGY 2021; 62:872-882. [PMID: 33822212 DOI: 10.1093/pcp/pcab047] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 03/31/2021] [Accepted: 04/01/2021] [Indexed: 06/12/2023]
Abstract
Photosynthetic organisms adjust to fluctuating natural light under physiological ambient conditions through flexible light-harvesting ability of light-harvesting complex II (LHCII). A process called state transition is an efficient regulation mechanism to balance the excitations between photosystem II (PSII) and photosystem I (PSI) by shuttling mobile LHCII between them. However, in situ observation of the migration of LHCII in vivo remains limited. In this study, we investigated the in vivo reversible changes in the intracellular distribution of the chlorophyll (Chl) fluorescence during the light-induced state transitions in Chlamydomonas reinhardtii. The newly developed noninvasive excitation-spectral microscope provided powerful spectral information about excitation-energy transfer between Chl-a and Chl-b. The excitation spectra were detected through the fluorescence emission in the 700-750-nm spectral range, where PSII makes the main contribution, though PSI still makes a non-negligible contribution at room temperature. The technique is sensitive to the Chl-b spectral component specifically bound to LHCII. Using a PSI-specific 685-nm component also provided visualization of the local relative concentration of PSI within a chloroplast at room temperature. The decrease in the relative intensity of the Chl-b band in state 2 was more conspicuous in the PSII-rich region than in the PSI-rich region, reflecting the dissociation of LHCII from PSII. We observed intracellular redistributions of the Chl-b-related light-harvesting abilities within a chloroplast during the state transitions. This observation implies the association of the state transitions with the morphological changes in the thylakoid membrane.
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Affiliation(s)
- Xian Jun Zhang
- Department of Chemistry, Graduate School of Sciences, Tohoku University, Sendai, 980-8578 Japan
| | - Yuki Fujita
- Department of Chemistry, Graduate School of Sciences, Tohoku University, Sendai, 980-8578 Japan
| | - Ryutaro Tokutsu
- Division of Environmental Photobiology, National Institute for Basic Biology, Okazaki, 444-8585 Japan
| | - Jun Minagawa
- Division of Environmental Photobiology, National Institute for Basic Biology, Okazaki, 444-8585 Japan
| | - Shen Ye
- Department of Chemistry, Graduate School of Sciences, Tohoku University, Sendai, 980-8578 Japan
| | - Yutaka Shibata
- Department of Chemistry, Graduate School of Sciences, Tohoku University, Sendai, 980-8578 Japan
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41
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Li M, Ma J, Li X, Sui SF. In situ cryo-ET structure of phycobilisome-photosystem II supercomplex from red alga. eLife 2021; 10:e69635. [PMID: 34515634 PMCID: PMC8437437 DOI: 10.7554/elife.69635] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 08/19/2021] [Indexed: 11/13/2022] Open
Abstract
Phycobilisome (PBS) is the main light-harvesting antenna in cyanobacteria and red algae. How PBS transfers the light energy to photosystem II (PSII) remains to be elucidated. Here we report the in situ structure of the PBS-PSII supercomplex from Porphyridium purpureum UTEX 2757 using cryo-electron tomography and subtomogram averaging. Our work reveals the organized network of hemiellipsoidal PBS with PSII on the thylakoid membrane in the native cellular environment. In the PBS-PSII supercomplex, each PBS interacts with six PSII monomers, of which four directly bind to the PBS, and two bind indirectly. Additional three 'connector' proteins also contribute to the connections between PBS and PSIIs. Two PsbO subunits from adjacent PSII dimers bind with each other, which may promote stabilization of the PBS-PSII supercomplex. By analyzing the interaction interface between PBS and PSII, we reveal that αLCM and ApcD connect with CP43 of PSII monomer and that αLCM also interacts with CP47' of the neighboring PSII monomer, suggesting the multiple light energy delivery pathways. The in situ structures illustrate the coupling pattern of PBS and PSII and the arrangement of the PBS-PSII supercomplex on the thylakoid, providing the near-native 3D structural information of the various energy transfer from PBS to PSII.
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Affiliation(s)
- Meijing Li
- Key Laboratory for Protein Sciences of Ministry of Education, Beijing Advanced Innovation Center for Structural Biology & Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua UniversityBeijingChina
| | - Jianfei Ma
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology & Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua UniversityBeijingChina
| | - Xueming Li
- Key Laboratory for Protein Sciences of Ministry of Education, Beijing Advanced Innovation Center for Structural Biology & Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua UniversityBeijingChina
| | - Sen-Fang Sui
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology & Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua UniversityBeijingChina
- Department of Biology, Southern University of Science and TechnologyGuangdongChina
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42
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Zhang J, Zhang D, Sun L, Ji G, Huang X, Niu T, Xu J, Ma C, Zhu Y, Gao N, Xu W, Sun F. VHUT-cryo-FIB, a method to fabricate frozen hydrated lamellae from tissue specimens for in situ cryo-electron tomography. J Struct Biol 2021; 213:107763. [PMID: 34174447 DOI: 10.1016/j.jsb.2021.107763] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 06/14/2021] [Accepted: 06/20/2021] [Indexed: 12/14/2022]
Abstract
Cryo-electron tomography (cryo-ET) provides a promising approach to study intact structures of macromolecules in situ, but the efficient preparation of high-quality cryosections represents a bottleneck. Although cryo-focused ion beam (cryo-FIB) milling has emerged for large and flat cryo-lamella preparation, its application to tissue specimens remains challenging. Here, we report an integrated workflow, VHUT-cryo-FIB, for efficiently preparing frozen hydrated tissue lamella that can be readily used in subsequent cryo-ET studies. The workflow includes vibratome slicing, high-pressure freezing, ultramicrotome cryo-trimming and cryo-FIB milling. Two strategies were developed for loading cryo-lamella via a side-entry cryo-holder or an FEI AutoGrid. The workflow was validated by using various tissue specimens, including rat skeletal muscle, rat liver and spinach leaf specimens, and in situ structures of ribosomes were obtained at nanometer resolution from the spinach and liver samples.
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Affiliation(s)
- Jianguo Zhang
- National Key Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; Center for Biological Imaging, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Danyang Zhang
- National Key Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing, China; Physical Science Laboratory, Huairou National Comprehensive Science Center, No. 5 Yanqi East Second Street, Beijing 101400, China
| | - Lei Sun
- Center for Biological Imaging, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Gang Ji
- University of Chinese Academy of Sciences, Beijing, China; Center for Biological Imaging, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiaojun Huang
- Center for Biological Imaging, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Tongxin Niu
- National Key Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; Center for Biological Imaging, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Jiashu Xu
- National Key Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing, China
| | - Chengying Ma
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing 100871, China
| | - Yun Zhu
- National Key Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing, China
| | - Ning Gao
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing 100871, China
| | - Wei Xu
- National Key Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; Center for Biological Imaging, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Fei Sun
- National Key Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing, China; Center for Biological Imaging, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; Physical Science Laboratory, Huairou National Comprehensive Science Center, No. 5 Yanqi East Second Street, Beijing 101400, China.
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43
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Dahlberg PD, Moerner WE. Cryogenic Super-Resolution Fluorescence and Electron Microscopy Correlated at the Nanoscale. Annu Rev Phys Chem 2021; 72:253-278. [PMID: 33441030 PMCID: PMC8877847 DOI: 10.1146/annurev-physchem-090319-051546] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/28/2023]
Abstract
We review the emerging method of super-resolved cryogenic correlative light and electron microscopy (srCryoCLEM). Super-resolution (SR) fluorescence microscopy and cryogenic electron tomography (CET) are both powerful techniques for observing subcellular organization, but each approach has unique limitations. The combination of the two brings the single-molecule sensitivity and specificity of SR to the detailed cellular context and molecular scale resolution of CET. The resulting correlative data is more informative than the sum of its parts. The correlative images can be used to pinpoint the positions of fluorescently labeled proteins in the high-resolution context of CET with nanometer-scale precision and/or to identify proteins in electron-dense structures. The execution of srCryoCLEM is challenging and the approach is best described as a method that is still in its infancy with numerous technical challenges. In this review, we describe state-of-the-art srCryoCLEM experiments, discuss the most pressing challenges, and give a brief outlook on future applications.
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Affiliation(s)
- Peter D Dahlberg
- Department of Chemistry, Stanford University, Stanford, California 94305, USA;
| | - W E Moerner
- Department of Chemistry, Stanford University, Stanford, California 94305, USA;
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44
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Liu Z, Gao J, Cui Y, Klumpe S, Xiang Y, Erdmann PS, Jiang L. Membrane imaging in the plant endomembrane system. PLANT PHYSIOLOGY 2021; 185:562-576. [PMID: 33793889 PMCID: PMC8133680 DOI: 10.1093/plphys/kiaa040] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 08/11/2020] [Indexed: 05/10/2023]
Abstract
Recent studies on membrane imaging in the plant endomembrane system by 2-D/3-D CLSM and TEM provide future perspectives of whole-cell ET and cryo-FIB-aided cryo-ET analysis.
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Affiliation(s)
- Zhiqi Liu
- State Key Laboratory of Agrobiotechnology, School of Life Sciences, Centre for Cell and Developmental Biology, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Jiayang Gao
- State Key Laboratory of Agrobiotechnology, School of Life Sciences, Centre for Cell and Developmental Biology, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Yong Cui
- State Key Laboratory of Agrobiotechnology, School of Life Sciences, Centre for Cell and Developmental Biology, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Sven Klumpe
- Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Yun Xiang
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Philipp S Erdmann
- Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
- Author for communication: (L.J.)
| | - Liwen Jiang
- State Key Laboratory of Agrobiotechnology, School of Life Sciences, Centre for Cell and Developmental Biology, The Chinese University of Hong Kong, Shatin, Hong Kong
- CUHK Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen 518057, China
- Author for communication: (L.J.)
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45
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Floris D, Kühlbrandt W. Molecular landscape of etioplast inner membranes in higher plants. NATURE PLANTS 2021; 7:514-523. [PMID: 33875833 PMCID: PMC8055535 DOI: 10.1038/s41477-021-00896-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 03/05/2021] [Indexed: 05/16/2023]
Abstract
Etioplasts are photosynthetically inactive plastids that accumulate when light levels are too low for chloroplast maturation. The etioplast inner membrane consists of a paracrystalline tubular lattice and peripheral, disk-shaped membranes, respectively known as the prolamellar body and prothylakoids. These distinct membrane regions are connected into one continuous compartment. To date, no structures of protein complexes in or at etioplast membranes have been reported. Here, we used electron cryo-tomography to explore the molecular membrane landscape of pea and maize etioplasts. Our tomographic reconstructions show that ATP synthase monomers are enriched in the prothylakoids, and plastid ribosomes in the tubular lattice. The entire tubular lattice is covered by regular helical arrays of a membrane-associated protein, which we identified as the 37-kDa enzyme, light-dependent protochlorophyllide oxidoreductase (LPOR). LPOR is the most abundant protein in the etioplast, where it is responsible for chlorophyll biosynthesis, photoprotection and defining the membrane geometry of the prolamellar body. Based on the 9-Å-resolution volume of the subtomogram average, we propose a structural model of membrane-associated LPOR.
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Affiliation(s)
- Davide Floris
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany.
| | - Werner Kühlbrandt
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany.
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46
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Barrett J, Girr P, Mackinder LCM. Pyrenoids: CO 2-fixing phase separated liquid organelles. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2021; 1868:118949. [PMID: 33421532 DOI: 10.1016/j.bbamcr.2021.118949] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 12/11/2020] [Accepted: 12/12/2020] [Indexed: 02/06/2023]
Abstract
Pyrenoids are non-membrane bound organelles found in chloroplasts of algae and hornwort plants that can be seen by light-microscopy. Pyrenoids are formed by liquid-liquid phase separation (LLPS) of Rubisco, the primary CO2 fixing enzyme, with an intrinsically disordered multivalent Rubisco-binding protein. Pyrenoids are the heart of algal and hornwort biophysical CO2 concentrating mechanisms, which accelerate photosynthesis and mediate about 30% of global carbon fixation. Even though LLPS may underlie the apparent convergent evolution of pyrenoids, our current molecular understanding of pyrenoid formation comes from a single example, the model alga Chlamydomonas reinhardtii. In this review, we summarise current knowledge about pyrenoid assembly, regulation and structural organization in Chlamydomonas and highlight evidence that LLPS is the general principle underlying pyrenoid formation across algal lineages and hornworts. Detailed understanding of the principles behind pyrenoid assembly, regulation and structural organization within diverse lineages will provide a fundamental understanding of this biogeochemically important organelle and help guide ongoing efforts to engineer pyrenoids into crops to increase photosynthetic performance and yields.2.
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Affiliation(s)
- James Barrett
- Department of Biology, University of York, York YO10 5DD, UK
| | - Philipp Girr
- Department of Biology, University of York, York YO10 5DD, UK
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47
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Burt A, Cassidy CK, Stansfeld PJ, Gutsche I. Alternative Architecture of the E. coli Chemosensory Array. Biomolecules 2021; 11:biom11040495. [PMID: 33806045 PMCID: PMC8064477 DOI: 10.3390/biom11040495] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 03/19/2021] [Accepted: 03/23/2021] [Indexed: 11/16/2022] Open
Abstract
Chemotactic responses in motile bacteria are the result of sophisticated signal transduction by large, highly organized arrays of sensory proteins. Despite tremendous progress in the understanding of chemosensory array structure and function, a structural basis for the heightened sensitivity of networked chemoreceptors is not yet complete. Here, we present cryo-electron tomography visualisations of native-state chemosensory arrays in E. coli minicells. Strikingly, these arrays appear to exhibit a p2-symmetric array architecture that differs markedly from the p6-symmetric architecture previously described in E. coli. Based on this data, we propose molecular models of this alternative architecture and the canonical p6-symmetric assembly. We evaluate our observations and each model in the context of previously published data, assessing the functional implications of an alternative architecture and effects for future studies.
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Affiliation(s)
- Alister Burt
- Institut de Biologie Structurale, Université Grenoble Alpes, CEA, CNRS, IBS, 71 Avenue des Martyrs, F-38044 Grenoble, France;
| | - C. Keith Cassidy
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK;
| | - Phillip J. Stansfeld
- Department of Chemistry, School of Life Sciences, University of Warwick, Gibbet Hill Campus, Coventry CV4 7AL, UK;
| | - Irina Gutsche
- Institut de Biologie Structurale, Université Grenoble Alpes, CEA, CNRS, IBS, 71 Avenue des Martyrs, F-38044 Grenoble, France;
- Correspondence:
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Pipitone R, Eicke S, Pfister B, Glauser G, Falconet D, Uwizeye C, Pralon T, Zeeman SC, Kessler F, Demarsy E. A multifaceted analysis reveals two distinct phases of chloroplast biogenesis during de-etiolation in Arabidopsis. eLife 2021; 10:e62709. [PMID: 33629953 PMCID: PMC7906606 DOI: 10.7554/elife.62709] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 02/04/2021] [Indexed: 11/18/2022] Open
Abstract
Light triggers chloroplast differentiation whereby the etioplast transforms into a photosynthesizing chloroplast and the thylakoid rapidly emerges. However, the sequence of events during chloroplast differentiation remains poorly understood. Using Serial Block Face Scanning Electron Microscopy (SBF-SEM), we generated a series of chloroplast 3D reconstructions during differentiation, revealing chloroplast number and volume and the extent of envelope and thylakoid membrane surfaces. Furthermore, we used quantitative lipid and whole proteome data to complement the (ultra)structural data, providing a time-resolved, multi-dimensional description of chloroplast differentiation. This showed two distinct phases of chloroplast biogenesis: an initial photosynthesis-enabling 'Structure Establishment Phase' followed by a 'Chloroplast Proliferation Phase' during cell expansion. Moreover, these data detail thylakoid membrane expansion during de-etiolation at the seedling level and the relative contribution and differential regulation of proteins and lipids at each developmental stage. Altogether, we establish a roadmap for chloroplast differentiation, a critical process for plant photoautotrophic growth and survival.
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Affiliation(s)
- Rosa Pipitone
- Plant Physiology Laboratory, University of NeuchâtelNeuchâtelSwitzerland
| | - Simona Eicke
- Institute of Molecular Plant Biology, Department of Biology, ETH ZurichZurichSwitzerland
| | - Barbara Pfister
- Institute of Molecular Plant Biology, Department of Biology, ETH ZurichZurichSwitzerland
| | - Gaetan Glauser
- Neuchâtel Platform of Analytical Chemistry, University of NeuchâtelNeuchâtelSwitzerland
| | - Denis Falconet
- Université Grenoble Alpes, CNRS, CEA, INRAE, IRIG-DBSCI-LPCVGrenobleFrance
| | - Clarisse Uwizeye
- Université Grenoble Alpes, CNRS, CEA, INRAE, IRIG-DBSCI-LPCVGrenobleFrance
| | - Thibaut Pralon
- Plant Physiology Laboratory, University of NeuchâtelNeuchâtelSwitzerland
| | - Samuel C Zeeman
- Institute of Molecular Plant Biology, Department of Biology, ETH ZurichZurichSwitzerland
| | - Felix Kessler
- Plant Physiology Laboratory, University of NeuchâtelNeuchâtelSwitzerland
| | - Emilie Demarsy
- Plant Physiology Laboratory, University of NeuchâtelNeuchâtelSwitzerland
- Department of Botany and Plant Biology, University of GenevaGenevaSwitzerland
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Morphological bases of phytoplankton energy management and physiological responses unveiled by 3D subcellular imaging. Nat Commun 2021; 12:1049. [PMID: 33594064 PMCID: PMC7886885 DOI: 10.1038/s41467-021-21314-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 01/12/2021] [Indexed: 01/31/2023] Open
Abstract
Eukaryotic phytoplankton have a small global biomass but play major roles in primary production and climate. Despite improved understanding of phytoplankton diversity and evolution, we largely ignore the cellular bases of their environmental plasticity. By comparative 3D morphometric analysis across seven distant phytoplankton taxa, we observe constant volume occupancy by the main organelles and preserved volumetric ratios between plastids and mitochondria. We hypothesise that phytoplankton subcellular topology is modulated by energy-management constraints. Consistent with this, shifting the diatom Phaeodactylum from low to high light enhances photosynthesis and respiration, increases cell-volume occupancy by mitochondria and the plastid CO2-fixing pyrenoid, and boosts plastid-mitochondria contacts. Changes in organelle architectures and interactions also accompany Nannochloropsis acclimation to different trophic lifestyles, along with respiratory and photosynthetic responses. By revealing evolutionarily-conserved topologies of energy-managing organelles, and their role in phytoplankton acclimation, this work deciphers phytoplankton responses at subcellular scales.
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Beyond X-rays: an overview of emerging structural biology methods. Emerg Top Life Sci 2021; 5:221-230. [DOI: 10.1042/etls20200272] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 12/27/2020] [Accepted: 01/20/2021] [Indexed: 11/17/2022]
Abstract
Structural biologists rely on X-ray crystallography as the main technique for determining the three-dimensional structures of macromolecules; however, in recent years, new methods that go beyond X-ray-based technologies are broadening the selection of tools to understand molecular structure and function. Simultaneously, national facilities are developing programming tools and maintaining personnel to aid novice structural biologists in de novo structure determination. The combination of X-ray free electron lasers (XFELs) and serial femtosecond crystallography (SFX) now enable time-resolved structure determination that allows for capture of dynamic processes, such as reaction mechanism and conformational flexibility. XFEL and SFX, along with microcrystal electron diffraction (MicroED), help side-step the need for large crystals for structural studies. Moreover, advances in cryogenic electron microscopy (cryo-EM) as a tool for structure determination is revolutionizing how difficult to crystallize macromolecules and/or complexes can be visualized at the atomic scale. This review aims to provide a broad overview of these new methods and to guide readers to more in-depth literature of these methods.
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