1
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Zheng T, Cai S. Recent technical advances in cellular cryo-electron tomography. Int J Biochem Cell Biol 2024; 175:106648. [PMID: 39181502 DOI: 10.1016/j.biocel.2024.106648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Revised: 08/20/2024] [Accepted: 08/20/2024] [Indexed: 08/27/2024]
Abstract
Understanding the in situ structure, organization, and interactions of macromolecules is essential for elucidating their functions and mechanisms of action. Cellular cryo-electron tomography (cryo-ET) is a cutting-edge technique that reveals in situ molecular-resolution architectures of macromolecules in their lifelike states. It also provides insights into the three-dimensional distribution of macromolecules and their spatial relationships with various subcellular structures. Thus, cellular cryo-ET bridges the gap between structural biology and cell biology. With rapid advancements, this technique achieved substantial improvements in throughput, automation, and resolution. This review presents the fundamental principles and methodologies of cellular cryo-ET, highlighting recent developments in sample preparation, data collection, and image processing. We also discuss emerging trends and potential future directions. As cellular cryo-ET continues to develop, it is set to play an increasingly vital role in structural cell biology.
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Affiliation(s)
- Tianyu Zheng
- Department of Chemical Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China; Institute for Biological Electron Microscopy, Southern University of Science and Technology, Shenzhen 518055, China
| | - Shujun Cai
- Department of Chemical Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China; Institute for Biological Electron Microscopy, Southern University of Science and Technology, Shenzhen 518055, China.
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2
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Semchonok DA, Kyrilis FL, Hamdi F, Kastritis PL. Cryo-EM of a heterogeneous biochemical fraction elucidates multiple protein complexes from a multicellular thermophilic eukaryote. J Struct Biol X 2023; 8:100094. [PMID: 37638207 PMCID: PMC10451023 DOI: 10.1016/j.yjsbx.2023.100094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 07/27/2023] [Accepted: 08/07/2023] [Indexed: 08/29/2023] Open
Abstract
Biomolecular complexes and their interactions govern cellular structure and function. Understanding their architecture is a prerequisite for dissecting the cell's inner workings, but their higher-order assembly is often transient and challenging for structural analysis. Here, we performed cryo-EM on a single, highly heterogeneous biochemical fraction derived from Chaetomium thermophilum cell extracts to visualize the biomolecular content of the multicellular eukaryote. After cryo-EM single-particle image processing, results showed that a simultaneous three-dimensional structural characterization of multiple chemically diverse biomacromolecules is feasible. Namely, the thermophilic, eukaryotic complexes of (a) ATP citrate-lyase, (b) Hsp90, (c) 20S proteasome, (d) Hsp60 and (e) UDP-glucose pyrophosphorylase were characterized. In total, all five complexes have been structurally dissected in a thermophilic eukaryote in a total imaged sample area of 190.64 μm2, and two, in particular, 20S proteasome and Hsp60, exhibit side-chain resolution features. The C. thermophilum Hsp60 near-atomic model was resolved at 3.46 Å (FSC = 0.143) and shows a hinge-like conformational change of its equatorial domain, highly similar to the one previously shown for its bacterial orthologue, GroEL. This work demonstrates that cryo-EM of cell extracts will greatly accelerate the structural analysis of cellular complexes and provide unprecedented opportunities to annotate architectures of biomolecules in a holistic approach.
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Affiliation(s)
- Dmitry A. Semchonok
- Interdisciplinary Research Center HALOmem, Charles Tanford Protein Center, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Straße 3a, Halle/Saale, Germany
| | - Fotis L. Kyrilis
- Interdisciplinary Research Center HALOmem, Charles Tanford Protein Center, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Straße 3a, Halle/Saale, Germany
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Straße 3, Halle/Saale, Germany
- Institute of Chemical Biology, National Hellenic Research Foundation, Athens, Greece
| | - Farzad Hamdi
- Interdisciplinary Research Center HALOmem, Charles Tanford Protein Center, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Straße 3a, Halle/Saale, Germany
| | - Panagiotis L. Kastritis
- Interdisciplinary Research Center HALOmem, Charles Tanford Protein Center, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Straße 3a, Halle/Saale, Germany
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Straße 3, Halle/Saale, Germany
- Institute of Chemical Biology, National Hellenic Research Foundation, Athens, Greece
- Biozentrum, Martin Luther University Halle-Wittenberg, Weinbergweg 22, Halle/Saale, Germany
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3
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Tan ZY, Cai S, Noble AJ, Chen JK, Shi J, Gan L. Heterogeneous non-canonical nucleosomes predominate in yeast cells in situ. eLife 2023; 12:RP87672. [PMID: 37503920 PMCID: PMC10382156 DOI: 10.7554/elife.87672] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/29/2023] Open
Abstract
Nuclear processes depend on the organization of chromatin, whose basic units are cylinder-shaped complexes called nucleosomes. A subset of mammalian nucleosomes in situ (inside cells) resembles the canonical structure determined in vitro 25 years ago. Nucleosome structure in situ is otherwise poorly understood. Using cryo-electron tomography (cryo-ET) and 3D classification analysis of budding yeast cells, here we find that canonical nucleosomes account for less than 10% of total nucleosomes expected in situ. In a strain in which H2A-GFP is the sole source of histone H2A, class averages that resemble canonical nucleosomes both with and without GFP densities are found ex vivo (in nuclear lysates), but not in situ. These data suggest that the budding yeast intranuclear environment favors multiple non-canonical nucleosome conformations. Using the structural observations here and the results of previous genomics and biochemical studies, we propose a model in which the average budding yeast nucleosome's DNA is partially detached in situ.
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Affiliation(s)
- Zhi Yang Tan
- Department of Biological Sciences and Center for BioImaging Sciences, National University of SingaporeSingaporeSingapore
| | - Shujun Cai
- Department of Biological Sciences and Center for BioImaging Sciences, National University of SingaporeSingaporeSingapore
| | - Alex J Noble
- National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology CenterNew YorkUnited States
| | - Jon K Chen
- Department of Biological Sciences and Center for BioImaging Sciences, National University of SingaporeSingaporeSingapore
| | - Jian Shi
- Department of Biological Sciences and Center for BioImaging Sciences, National University of SingaporeSingaporeSingapore
| | - Lu Gan
- Department of Biological Sciences and Center for BioImaging Sciences, National University of SingaporeSingaporeSingapore
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4
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Are extraordinary nucleosome structures more ordinary than we thought? Chromosoma 2023:10.1007/s00412-023-00791-w. [PMID: 36917245 DOI: 10.1007/s00412-023-00791-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 03/02/2023] [Accepted: 03/03/2023] [Indexed: 03/16/2023]
Abstract
The nucleosome is a DNA-protein assembly that is the basic unit of chromatin. A nucleosome can adopt various structures. In the canonical nucleosome structure, 145-147 bp of DNA is wrapped around a histone heterooctamer. The strong histone-DNA interactions cause the DNA to be inaccessible for nuclear processes such as transcription. Therefore, the canonical nucleosome structure has to be altered into different, non-canonical structures to increase DNA accessibility. While it is recognised that non-canonical structures do exist, these structures are not well understood. In this review, we discuss both the evidence for various non-canonical nucleosome structures in the nucleus and the factors that are believed to induce these structures. The wide range of non-canonical structures is likely to regulate the amount of accessible DNA, and thus have important nuclear functions.
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5
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Zhang M, Celis CD, Liu J, Bustamante C, Ren G. Conformational Change of Nucleosome Arrays prior to Phase Separation. RESEARCH SQUARE 2023:rs.3.rs-2460504. [PMID: 36711774 PMCID: PMC9882673 DOI: 10.21203/rs.3.rs-2460504/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Chromatin phase transition serves as a regulatory mechanism for eukaryotic transcription. Understanding this process requires the characterization of the nucleosome array structure in response to external stimuli prior to phase separation. However, the intrinsic flexibility and heterogeneity hinders the arrays' structure determination. Here we exploit advances in cryogenic electron tomography (cryo-ET) to determine the three-dimensional (3D) structure of each individual particle of mono-, di-, tri-, and tetranucleosome arrays. Statistical analysis reveals the ionic strength changes the angle between the DNA linker and nucleosome core particle (NCP), which regulate the overall morphology of nucleosome arrays. The finding that one-third of the arrays in the presence of H1 contain an NCP invaded by foreign DNA suggests an alternative function of H1 in constructing nucleosomal networks. The new insights into the nucleosome conformational changes prior to the intermolecular interaction stage extends our understanding of chromatin phase separation regulation.
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Affiliation(s)
- Meng Zhang
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, USA
- Applied Science and Technology Graduate Group, University of California, Berkeley, USA
- California Institute for Quantitative Biosciences, University of California, Berkeley, USA
| | - César-Díaz Celis
- California Institute for Quantitative Biosciences, University of California, Berkeley, USA
- Howard Hughes Medical Institute, University of California, Berkeley, USA
| | - Jianfang Liu
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, USA
| | - Carlos Bustamante
- Applied Science and Technology Graduate Group, University of California, Berkeley, USA
- California Institute for Quantitative Biosciences, University of California, Berkeley, USA
- Howard Hughes Medical Institute, University of California, Berkeley, USA
- Department of Chemistry, University of California, Berkeley, USA
- Department of Physics, University of California, Berkeley, USA
- Department of Molecular and Cell Biology, University of California, Berkeley, USA
- Molecular Biophysics and Integrative Bioimaging Division, Lawrence Berkeley National Laboratory, USA
- Kavli Energy Nanoscience Institute, University of California, Berkeley, USA
| | - Gang Ren
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, USA
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6
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Kim W, Yoon DK. Electron microscopy analysis of soft materials with
freeze‐fracture
techniques. B KOREAN CHEM SOC 2022. [DOI: 10.1002/bkcs.12647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Wantae Kim
- Department of Chemistry Korea Advanced Institute of Science and Technology (KAIST) Daejeon Republic of Korea
| | - Dong Ki Yoon
- Department of Chemistry Korea Advanced Institute of Science and Technology (KAIST) Daejeon Republic of Korea
- KAIST Institute for Nanocentry Korea Advanced Institute of Science and Technology (KAIST) Daejeon Republic of Korea
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7
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Yang Z, Zhang Z, Zhao Y, Ye Q, Li X, Meng L, Long J, Zhang S, Zhang L. Organelle Interaction and Drug Discovery: Towards Correlative Nanoscopy and Molecular Dynamics Simulation. Front Pharmacol 2022; 13:935898. [PMID: 35795548 PMCID: PMC9251060 DOI: 10.3389/fphar.2022.935898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 06/01/2022] [Indexed: 11/23/2022] Open
Abstract
The inter-organelle interactions, including the cytomembrane, endoplasmic reticulum, mitochondrion, lysosome, dictyosome, and nucleus, play the important roles in maintaining the normal function and homeostasis of cells. Organelle dysfunction can lead to a range of diseases (e.g., Alzheimer's disease (AD), Parkinson's disease (PD), and cancer), and provide a new perspective for drug discovery. With the development of imaging techniques and functional fluorescent probes, a variety of algorithms and strategies have been developed for the ever-improving estimation of subcellular structures, organelle interaction, and organelle-related drug discovery with accounting for the dynamic structures of organelles, such as the nanoscopy technology and molecular dynamics (MD) simulations. Accordingly, this work summarizes a series of state-of-the-art examples of the recent progress in this rapidly changing field and uncovering the drug screening based on the structures and interactions of organelles. Finally, we propose the future outlook for exciting applications of organelle-related drug discovery, with the cooperation of nanoscopy and MD simulations.
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Affiliation(s)
- Zhiwei Yang
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Physics, Xi’an Jiaotong University, Xi’an, China
- School of Life Science and Technology, Xi’an Jiaotong University, Xi’an, China
| | - Zichen Zhang
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Physics, Xi’an Jiaotong University, Xi’an, China
| | - Yizhen Zhao
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Physics, Xi’an Jiaotong University, Xi’an, China
| | - Qiushi Ye
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Physics, Xi’an Jiaotong University, Xi’an, China
| | - Xuhua Li
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Physics, Xi’an Jiaotong University, Xi’an, China
| | - Lingjie Meng
- School of Chemistry, Xi’an Jiaotong University, Xi’an, China
- Instrumental Analysis Center, Xi’an Jiaotong University, Xi’an, China
| | - Jiangang Long
- School of Life Science and Technology, Xi’an Jiaotong University, Xi’an, China
| | - Shengli Zhang
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Physics, Xi’an Jiaotong University, Xi’an, China
| | - Lei Zhang
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Physics, Xi’an Jiaotong University, Xi’an, China
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8
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Ma OX, Chong WG, Lee JKE, Cai S, Siebert CA, Howe A, Zhang P, Shi J, Surana U, Gan L. Cryo-ET detects bundled triple helices but not ladders in meiotic budding yeast. PLoS One 2022; 17:e0266035. [PMID: 35421110 PMCID: PMC9009673 DOI: 10.1371/journal.pone.0266035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 03/13/2022] [Indexed: 11/19/2022] Open
Abstract
In meiosis, cells undergo two sequential rounds of cell division, termed meiosis I and meiosis II. Textbook models of the meiosis I substage called pachytene show that nuclei have conspicuous 100-nm-wide, ladder-like synaptonemal complexes and ordered chromatin loops. It remains unknown if these cells have any other large, meiosis-related intranuclear structures. Here we present cryo-ET analysis of frozen-hydrated budding yeast cells before, during, and after pachytene. We found no cryo-ET densities that resemble dense ladder-like structures or ordered chromatin loops. Instead, we found large numbers of 12-nm-wide triple-helices that pack into ordered bundles. These structures, herein called meiotic triple helices (MTHs), are present in meiotic cells, but not in interphase cells. MTHs are enriched in the nucleus but not enriched in the cytoplasm. Bundles of MTHs form at the same timeframe as synaptonemal complexes (SCs) in wild-type cells and in mutant cells that are unable to form SCs. These results suggest that in yeast, SCs coexist with previously unreported large, ordered assemblies.
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Affiliation(s)
- Olivia X. Ma
- Department of Biological Sciences and Centre for BioImaging Sciences, National University of Singapore, Singapore, Singapore
| | - Wen Guan Chong
- Department of Biological Sciences and Centre for BioImaging Sciences, National University of Singapore, Singapore, Singapore
| | - Joy K. E. Lee
- Department of Biological Sciences and Centre for BioImaging Sciences, National University of Singapore, Singapore, Singapore
| | - Shujun Cai
- Department of Biological Sciences and Centre for BioImaging Sciences, National University of Singapore, Singapore, Singapore
| | - C. Alistair Siebert
- Diamond Light Source Ltd, Harwell Science & Innovation Campus, Didcot, Oxfordshire, United Kingdom
| | - Andrew Howe
- Diamond Light Source Ltd, Harwell Science & Innovation Campus, Didcot, Oxfordshire, United Kingdom
| | - Peijun Zhang
- Diamond Light Source Ltd, Harwell Science & Innovation Campus, Didcot, Oxfordshire, United Kingdom
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Jian Shi
- Department of Biological Sciences and Centre for BioImaging Sciences, National University of Singapore, Singapore, Singapore
| | - Uttam Surana
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Proteos, Singapore
- Bioprocessing Technology Institute, A*STAR, Singapore, Singapore
- Biotransformation Innovation Platform, A*STAR, Singapore, Singapore
- Department of Pharmacology, National University of Singapore, Singapore, Singapore
| | - Lu Gan
- Department of Biological Sciences and Centre for BioImaging Sciences, National University of Singapore, Singapore, Singapore
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9
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Wang Y, Huo T, Tseng YJ, Dang L, Yu Z, Yu W, Foulks Z, Murdaugh RL, Ludtke SJ, Nakada D, Wang Z. Using Cryo-ET to distinguish platelets during pre-acute myeloid leukemia from steady state hematopoiesis. Commun Biol 2022; 5:72. [PMID: 35058565 PMCID: PMC8776871 DOI: 10.1038/s42003-022-03009-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 12/28/2021] [Indexed: 11/30/2022] Open
Abstract
Early diagnosis of acute myeloid leukemia (AML) in the pre-leukemic stage remains a clinical challenge, as pre-leukemic patients show no symptoms, lacking any known morphological or numerical abnormalities in blood cells. Here, we demonstrate that platelets with structurally abnormal mitochondria emerge at the pre-leukemic phase of AML, preceding detectable changes in blood cell counts or detection of leukemic blasts in blood. We visualized frozen-hydrated platelets from mice at different time points during AML development in situ using electron cryo-tomography (cryo-ET) and identified intracellular organelles through an unbiased semi-automatic process followed by quantitative measurement. A large proportion of platelets exhibited changes in the overall shape and depletion of organelles in AML. Notably, 23% of platelets in pre-leukemic cells exhibit abnormal, round mitochondria with unfolded cristae, accompanied by a significant drop in ATP levels and altered expression of metabolism-related gene signatures. Our study demonstrates that detectable structural changes in pre-leukemic platelets may serve as a biomarker for the early diagnosis of AML.
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Affiliation(s)
- Yuewei Wang
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
- Department of Vascular Surgery, the Affiliated Hospital of Qingdao University, Qingdao, China
| | - Tong Huo
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Yu-Jung Tseng
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Graduate Program in Translational Biology and Molecular Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Lan Dang
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Zhili Yu
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Wenjuan Yu
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
- Department of Pathology, the Affiliated Hospital of Qingdao University, Qingdao, China
| | - Zachary Foulks
- Department of Chemistry, Missouri University of Science and Technology, Rolla, MO, USA
- The summer undergraduate research program (SMART program), Baylor College of Medicine, Houston, TX, USA
| | - Rebecca L Murdaugh
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Graduate Program in Developmental Biology, Baylor College of Medicine, Houston, TX, USA
| | - Steven J Ludtke
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
- CryoEM/ET core, Baylor College of Medicine, Houston, TX, USA
| | - Daisuke Nakada
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
- Graduate Program in Translational Biology and Molecular Medicine, Baylor College of Medicine, Houston, TX, USA.
- Graduate Program in Developmental Biology, Baylor College of Medicine, Houston, TX, USA.
- Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, USA.
| | - Zhao Wang
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA.
- CryoEM/ET core, Baylor College of Medicine, Houston, TX, USA.
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA.
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10
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Leung MR, Ravi RT, Gadella BM, Zeev-Ben-Mordehai T. Membrane Remodeling and Matrix Dispersal Intermediates During Mammalian Acrosomal Exocytosis. Front Cell Dev Biol 2021; 9:765673. [PMID: 34957098 PMCID: PMC8708559 DOI: 10.3389/fcell.2021.765673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 10/19/2021] [Indexed: 11/13/2022] Open
Abstract
To become fertilization-competent, mammalian sperm must undergo a complex series of biochemical and morphological changes in the female reproductive tract. These changes, collectively called capacitation, culminate in the exocytosis of the acrosome, a large vesicle overlying the nucleus. Acrosomal exocytosis is not an all-or-nothing event but rather a regulated process in which vesicle cargo disperses gradually. However, the structural mechanisms underlying this controlled release remain undefined. In addition, unlike other exocytotic events, fusing membranes are shed as vesicles; the cell thus loses the entire anterior two-thirds of its plasma membrane and yet remains intact, while the remaining nonvesiculated plasma membrane becomes fusogenic. Precisely how cell integrity is maintained throughout this drastic vesiculation process is unclear, as is how it ultimately leads to the acquisition of fusion competence. Here, we use cryoelectron tomography to visualize these processes in unfixed, unstained, fully hydrated sperm. We show that paracrystalline structures within the acrosome disassemble during capacitation and acrosomal exocytosis, representing a plausible mechanism for gradual dispersal of the acrosomal matrix. We find that the architecture of the sperm head supports an atypical membrane fission-fusion pathway that maintains cell integrity. Finally, we detail how the acrosome reaction transforms both the micron-scale topography and the nanoscale protein landscape of the sperm surface, thus priming the sperm for fertilization.
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Affiliation(s)
- Miguel Ricardo Leung
- Bijvoet Centre for Biomolecular Research, Utrecht University, Utrecht, Netherlands.,The Division of Structural Biology, Wellcome Centre for Human Genetics, The University of Oxford, Oxford, United Kingdom
| | - Ravi Teja Ravi
- Bijvoet Centre for Biomolecular Research, Utrecht University, Utrecht, Netherlands
| | - Bart M Gadella
- Department of Farm and Animal Health and Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
| | - Tzviya Zeev-Ben-Mordehai
- Bijvoet Centre for Biomolecular Research, Utrecht University, Utrecht, Netherlands.,The Division of Structural Biology, Wellcome Centre for Human Genetics, The University of Oxford, Oxford, United Kingdom
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11
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Jiménez-Ortigosa C, Jiang J, Chen M, Kuang X, Healey KR, Castellano P, Boparai N, Ludtke SJ, Perlin DS, Dai W. Cryo-Electron Tomography of Candida glabrata Plasma Membrane Proteins. J Fungi (Basel) 2021; 7:120. [PMID: 33562124 PMCID: PMC7914498 DOI: 10.3390/jof7020120] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 02/01/2021] [Accepted: 02/02/2021] [Indexed: 12/18/2022] Open
Abstract
Fungal plasma membrane proteins have long been recognized as targets for the development of antifungal agents. Despite recent progress in experimental approaches and computational structural predictions, our knowledge of the structural dynamics and spatial distribution of these membrane proteins in the context of their native lipid environment remains limited. By applying cryo-electron tomography (cryoET) and subtomogram analysis, we aim to characterize the structural characteristics and spatial distribution of membrane proteins present in Candida glabrata plasma membranes. This study has resulted in the identification of the membrane-embedded structure of the fungal H+-ATPase, Pma1. Tomograms of the plasma membrane revealed that Pma1 complexes are heterogeneously distributed as hexamers that cluster into distinct membrane microdomains. This study characterizes fungal membrane proteins in the native cellular landscape and highlights the unique potential of cryoET to advance our understanding of cellular biology and biological systems.
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Affiliation(s)
- Cristina Jiménez-Ortigosa
- Hackensack Meridian Health-Center for Discovery and Innovation, 111 Ideation Way, Nutley, NJ 07110, USA;
| | - Jennifer Jiang
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, 604 Allison Road, Piscataway, NJ 08854, USA; (J.J.); (X.K.); (P.C.); (N.B.)
- Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, 174 Frelinghuysen Road, Piscataway, NJ 08854, USA
| | - Muyuan Chen
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA; (M.C.); (S.J.L.)
| | - Xuyuan Kuang
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, 604 Allison Road, Piscataway, NJ 08854, USA; (J.J.); (X.K.); (P.C.); (N.B.)
- Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, 174 Frelinghuysen Road, Piscataway, NJ 08854, USA
- Department of Hyperbaric Oxygen, Central South University, Changsha 410008, China
| | - Kelley R. Healey
- Department of Biology, William Paterson University, 300 Pompton Road, Wayne, NJ 07470, USA;
| | - Paul Castellano
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, 604 Allison Road, Piscataway, NJ 08854, USA; (J.J.); (X.K.); (P.C.); (N.B.)
- Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, 174 Frelinghuysen Road, Piscataway, NJ 08854, USA
| | - Nikpreet Boparai
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, 604 Allison Road, Piscataway, NJ 08854, USA; (J.J.); (X.K.); (P.C.); (N.B.)
- Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, 174 Frelinghuysen Road, Piscataway, NJ 08854, USA
| | - Steven J. Ludtke
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA; (M.C.); (S.J.L.)
| | - David S. Perlin
- Hackensack Meridian Health-Center for Discovery and Innovation, 111 Ideation Way, Nutley, NJ 07110, USA;
| | - Wei Dai
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, 604 Allison Road, Piscataway, NJ 08854, USA; (J.J.); (X.K.); (P.C.); (N.B.)
- Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, 174 Frelinghuysen Road, Piscataway, NJ 08854, USA
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12
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Leung MR, Zeev-Ben-Mordehai T. Cryo-electron microscopy of cholinesterases, present and future. J Neurochem 2020; 158:1236-1243. [PMID: 33222205 PMCID: PMC8518539 DOI: 10.1111/jnc.15245] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 10/30/2020] [Accepted: 11/11/2020] [Indexed: 02/06/2023]
Abstract
Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) exist in a variety of oligomeric forms, each with defined cellular and subcellular distributions. Although crystal structures of AChE and BChE have been available for many years, structures of the physiologically relevant ChE tetramer were only recently solved by cryo‐electron microscopy (cryo‐EM) single‐particle analysis. Here, we briefly review how these structures contribute to our understanding of cholinesterase oligomerization, highlighting the advantages of using cryo‐EM to resolve structures of protein assemblies that cannot be expressed recombinantly. We argue that the next frontier in cholinesterase structural biology is to image membrane‐anchored ChE oligomers directly in their native environment—the cell.
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Affiliation(s)
- Miguel Ricardo Leung
- Cryo-Electron Microscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands.,The Division of Structural Biology, Wellcome Centre for Human Genetics, The University of Oxford, Oxford, UK
| | - Tzviya Zeev-Ben-Mordehai
- Cryo-Electron Microscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands.,The Division of Structural Biology, Wellcome Centre for Human Genetics, The University of Oxford, Oxford, UK
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Ng CT, Ladinsky MS, Gan L. Serial Cryomicrotomy of Saccharomyces cerevisiae for Serial Electron Cryotomography. Bio Protoc 2020; 10:e3831. [PMID: 33659481 DOI: 10.21769/bioprotoc.3831] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 09/18/2020] [Accepted: 09/28/2020] [Indexed: 11/02/2022] Open
Abstract
Electron cryotomography (cryo-ET) is an increasingly popular technique to study cellular structures and macromolecules in situ. Due to poor penetration of electrons through thick biological samples, the vitreously frozen samples for cryo-ET need to be thin. For frozen-hydrated cells, such samples can be produced either by cryomicrotomy or cryo-FIB-milling. As a result, a tomogram of such a sample contains information of a small fraction of the entire cell volume, making it challenging to image rare structures in the cell or to determine the distribution of scattered structures. Here, we describe the tools and workflow that we designed to facilitate serial cryomicrotomy, which makes possible the exploration of a larger volume of individual cells at molecular resolution. We successfully used serial cryomicrotomy to locate and image the Dam1/DASH complex located at microtubule plus ends inside mitotic Saccharomyces cerevisiae cells.
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Affiliation(s)
- Cai Tong Ng
- Centre of BioImaging Sciences, Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Mark S Ladinsky
- Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, USA
| | - Lu Gan
- Centre of BioImaging Sciences, Department of Biological Sciences, National University of Singapore, Singapore, Singapore
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