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Soubies E, Nogueron A, Pelletier F, Mangeat T, Leterrier C, Unser M, Sage D. Surpassing light inhomogeneities in structured-illumination microscopy with FlexSIM. J Microsc 2024; 296:94-106. [PMID: 39012071 DOI: 10.1111/jmi.13344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 06/03/2024] [Accepted: 06/29/2024] [Indexed: 07/17/2024]
Abstract
Super-resolution structured-illumination microscopy (SIM) is a powerful technique that allows one to surpass the diffraction limit by up to a factor two. Yet, its practical use is hampered by its sensitivity to imaging conditions which makes it prone to reconstruction artefacts. In this work, we present FlexSIM, a flexible SIM reconstruction method capable to handle highly challenging data. Specifically, we demonstrate the ability of FlexSIM to deal with the distortion of patterns, the high level of noise encountered in live imaging, as well as out-of-focus fluorescence. Moreover, we show that FlexSIM achieves state-of-the-art performance over a variety of open SIM datasets.
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Affiliation(s)
| | | | | | - Thomas Mangeat
- LITC Core Facility, Centre de Biologie Integrative, Université de Toulouse, CNRS, Toulouse, France
| | | | - Michael Unser
- Biomedical Imaging Group, EPFL, Lausanne, Switzerland
| | - Daniel Sage
- Biomedical Imaging Group, EPFL, Lausanne, Switzerland
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2
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Liu Y, Gong XT, Wang KN, He S, Wang Y, Lin Q, Liu Z, Yu X, Liu B. Dual-targeted fluorescent probe for tracking polarity and phase transition processes during lipophagy. MATERIALS HORIZONS 2024; 11:3287-3297. [PMID: 38842407 DOI: 10.1039/d4mh00190g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2024]
Abstract
Eukaryotic cells regulate various cellular processes through membrane-bound and membrane-less organelles, enabling active signal communication and material exchange. Lysosomes and lipid droplets are representative organelles, contributing to cell lipophagy when their interaction and metabolism are disrupted. Our limited understanding of the interacting behaviours and physicochemical properties of different organelles during lipophagy hinders accurate diagnosis and treatment of related diseases. In this contribution, we report a fluorescent probe, PTZ, engineered for dual-targeting of lipid droplets and lysosomes. PTZ can track liquid-liquid phase separation and respond to polarity shifts through ratiometric fluorescence emission, elucidating the lipophagy process from the perspective of organelle behavior and physicochemical properties. Leveraging on the multifunctionality of PTZ, we have successfully tracked the polarity and dynamic changes of lysosomes and lipid droplets during lipophagy. Furthermore, an unknown homogeneous transition of lipid droplets and lysosomes was discovered, which provided a new perspective for understanding lipophagy processes. And this work is expected to serve as a reference for diagnosis and treatment of lipophagy-related diseases.
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Affiliation(s)
- Yang Liu
- State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China.
| | - Xiao-Ting Gong
- Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117585, Singapore.
- Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou 350207, China
| | - Kang-Nan Wang
- State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China.
| | - Simeng He
- Department of Emergency Medicine, Qilu Hospital of Shandong University, Jinan 250012, China
| | - Yumeng Wang
- State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China.
| | - Qiaowen Lin
- State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China.
| | - Zhiqiang Liu
- State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China.
| | - Xiaoqiang Yu
- State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China.
| | - Bin Liu
- Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117585, Singapore.
- Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou 350207, China
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3
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Sun T, Zhao H, Hu L, Shao X, Lu Z, Wang Y, Ling P, Li Y, Zeng K, Chen Q. Enhanced optical imaging and fluorescent labeling for visualizing drug molecules within living organisms. Acta Pharm Sin B 2024; 14:2428-2446. [PMID: 38828150 PMCID: PMC11143489 DOI: 10.1016/j.apsb.2024.01.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 01/07/2024] [Accepted: 01/25/2024] [Indexed: 06/05/2024] Open
Abstract
The visualization of drugs in living systems has become key techniques in modern therapeutics. Recent advancements in optical imaging technologies and molecular design strategies have revolutionized drug visualization. At the subcellular level, super-resolution microscopy has allowed exploration of the molecular landscape within individual cells and the cellular response to drugs. Moving beyond subcellular imaging, researchers have integrated multiple modes, like optical near-infrared II imaging, to study the complex spatiotemporal interactions between drugs and their surroundings. By combining these visualization approaches, researchers gain supplementary information on physiological parameters, metabolic activity, and tissue composition, leading to a comprehensive understanding of drug behavior. This review focuses on cutting-edge technologies in drug visualization, particularly fluorescence imaging, and the main types of fluorescent molecules used. Additionally, we discuss current challenges and prospects in targeted drug research, emphasizing the importance of multidisciplinary cooperation in advancing drug visualization. With the integration of advanced imaging technology and molecular design, drug visualization has the potential to redefine our understanding of pharmacology, enabling the analysis of drug micro-dynamics in subcellular environments from new perspectives and deepening pharmacological research to the levels of the cell and organelles.
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Affiliation(s)
- Ting Sun
- School of Pharmaceutical Sciences, National Key Laboratory of Advanced Drug Delivery System, Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan 250062, China
- Institute of Biochemical and Biotechnological Drugs, School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan 250012, China
| | - Huanxin Zhao
- School of Pharmaceutical Sciences, National Key Laboratory of Advanced Drug Delivery System, Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan 250062, China
| | - Luyao Hu
- School of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China
| | - Xintian Shao
- School of Pharmaceutical Sciences, National Key Laboratory of Advanced Drug Delivery System, Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan 250062, China
- School of Life Sciences, Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan 250062, China
| | - Zhiyuan Lu
- School of Pharmaceutical Sciences, National Key Laboratory of Advanced Drug Delivery System, Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan 250062, China
| | - Yuli Wang
- Tianjin Pharmaceutical DA REN TANG Group Corporation Limited Traditional Chinese Pharmacy Research Institute, Tianjin 300457, China
- Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemistry Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Peixue Ling
- Institute of Biochemical and Biotechnological Drugs, School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan 250012, China
- Key Laboratory of Biopharmaceuticals, Postdoctoral Scientific Research Workstation, Shandong Academy of Pharmaceutical Science, Jinan 250098, China
| | - Yubo Li
- School of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China
| | - Kewu Zeng
- School of Pharmaceutical Sciences, National Key Laboratory of Advanced Drug Delivery System, Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan 250062, China
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Qixin Chen
- School of Pharmaceutical Sciences, National Key Laboratory of Advanced Drug Delivery System, Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan 250062, China
- Departments of Diagnostic Radiology, Surgery, Chemical and Biomolecular Engineering, and Biomedical Engineering, Yong Loo Lin School of Medicine and College of Design and Engineering, National University of Singapore, Singapore 119074, Singapore
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Keller D, Stinus S, Umlauf D, Gourbeyre E, Biot E, Olivier N, Mahou P, Beaurepaire E, Andrey P, Crabbe L. Non-random spatial organization of telomeres varies during the cell cycle and requires LAP2 and BAF. iScience 2024; 27:109343. [PMID: 38510147 PMCID: PMC10951912 DOI: 10.1016/j.isci.2024.109343] [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: 08/22/2023] [Revised: 11/30/2023] [Accepted: 02/22/2024] [Indexed: 03/22/2024] Open
Abstract
Spatial genome organization within the nucleus influences major biological processes and is impacted by the configuration of linear chromosomes. Here, we applied 3D spatial statistics and modeling on high-resolution telomere and centromere 3D-structured illumination microscopy images in cancer cells. We found a multi-scale organization of telomeres that dynamically evolved from a mixed clustered-and-regular distribution in early G1 to a purely regular distribution as cells progressed through the cell cycle. In parallel, our analysis revealed two pools of peripheral and internal telomeres, the proportions of which were inverted during the cell cycle. We then conducted a targeted screen using MadID to identify the molecular pathways driving or maintaining telomere anchoring to the nuclear envelope observed in early G1. Lamina-associated polypeptide (LAP) proteins were found transiently localized to telomeres in anaphase, a stage where LAP2α initiates the reformation of the nuclear envelope, and impacted telomere redistribution in the next interphase together with their partner barrier-to-autointegration factor (BAF).
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Affiliation(s)
- Debora Keller
- Molecular, Cellular and Developmental Biology Department (MCD), Centre de Biologie Intégrative (CBI), University of Toulouse, CNRS, UPS, 31062 Toulouse, France
- Laboratory for Optics and Biosciences, École polytechnique, CNRS, INSERM, IP Paris, 91128 Palaiseau, France
| | - Sonia Stinus
- Molecular, Cellular and Developmental Biology Department (MCD), Centre de Biologie Intégrative (CBI), University of Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - David Umlauf
- Molecular, Cellular and Developmental Biology Department (MCD), Centre de Biologie Intégrative (CBI), University of Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Edith Gourbeyre
- Molecular, Cellular and Developmental Biology Department (MCD), Centre de Biologie Intégrative (CBI), University of Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Eric Biot
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France
| | - Nicolas Olivier
- Laboratory for Optics and Biosciences, École polytechnique, CNRS, INSERM, IP Paris, 91128 Palaiseau, France
| | - Pierre Mahou
- Laboratory for Optics and Biosciences, École polytechnique, CNRS, INSERM, IP Paris, 91128 Palaiseau, France
| | - Emmanuel Beaurepaire
- Laboratory for Optics and Biosciences, École polytechnique, CNRS, INSERM, IP Paris, 91128 Palaiseau, France
| | - Philippe Andrey
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France
| | - Laure Crabbe
- Molecular, Cellular and Developmental Biology Department (MCD), Centre de Biologie Intégrative (CBI), University of Toulouse, CNRS, UPS, 31062 Toulouse, France
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5
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Wu Z, Zhang C, Sha J, Jing Z, He J, Bai Y, Wu J, Zhang S, Shi P. Ultrabright Xanthene Fluorescence Probe for Mitochondrial Super-Resolution Imaging. Anal Chem 2024; 96:5134-5142. [PMID: 38507805 DOI: 10.1021/acs.analchem.3c05154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/22/2024]
Abstract
Mitochondria are important organelles that provide energy for cellular physiological activities. Changes in their structures may indicate the occurrence of diseases, and the super-resolution imaging of mitochondria is of great significance. However, developing fluorescent probes for mitochondrial super-resolution visualization still remains challenging due to insufficient fluorescence brightness and poor stability. Herein, we rationally synthesized an ultrabright xanthene fluorescence probe Me-hNR for mitochondria-specific super-resolution imaging using structured illumination microscopy (SIM). The rigid structure of Me-hNR provided its ultrahigh fluorescence quantum yield of up to 0.92 and ultrahigh brightness of up to 16,000. Occupying the para-position of the O atom in the xanthene skeleton by utilizing the smallest methyl group ensured its excellent stability. The study of the photophysical process indicated that Me-hNR mainly emitted fluorescence via radiative decay, and nonradiative decay and inter-system crossing were rare due to the slow nonradiative decay rate and large energy gap (ΔEst = 0.55 eV). Owing to these excellent merits, Me-hNR can specifically light up mitochondria at ultralow concentrations down to 5 nM. The unprecedented spatial resolution for mitochondria with an fwhm of 174 nm was also achieved. Therefore, this ultrabright xanthene fluorescence probe has great potential in visualizing the structural changes of mitochondria and revealing the pathogenesis of related diseases using SIM.
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Affiliation(s)
- Ziyong Wu
- Shandong Provincial Key Laboratory of Detection Technology for Tumor Markers, School of Chemistry and Chemical Engineering, College of Medicine, Linyi University, Linyi 276000, P.R. China
| | - Chuangli Zhang
- Shandong Provincial Key Laboratory of Detection Technology for Tumor Markers, School of Chemistry and Chemical Engineering, College of Medicine, Linyi University, Linyi 276000, P.R. China
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials and CityU-CAS Joint Laboratory of Functional Materials and Devices, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P.R. China
| | - Jie Sha
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials and CityU-CAS Joint Laboratory of Functional Materials and Devices, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P.R. China
| | - Ziyang Jing
- Shandong Provincial Key Laboratory of Detection Technology for Tumor Markers, School of Chemistry and Chemical Engineering, College of Medicine, Linyi University, Linyi 276000, P.R. China
| | - Jing He
- Shandong Provincial Key Laboratory of Detection Technology for Tumor Markers, School of Chemistry and Chemical Engineering, College of Medicine, Linyi University, Linyi 276000, P.R. China
| | - Yang Bai
- Shandong Provincial Key Laboratory of Detection Technology for Tumor Markers, School of Chemistry and Chemical Engineering, College of Medicine, Linyi University, Linyi 276000, P.R. China
| | - Jiasheng Wu
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials and CityU-CAS Joint Laboratory of Functional Materials and Devices, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P.R. China
| | - Shusheng Zhang
- Shandong Provincial Key Laboratory of Detection Technology for Tumor Markers, School of Chemistry and Chemical Engineering, College of Medicine, Linyi University, Linyi 276000, P.R. China
| | - Pengfei Shi
- Shandong Provincial Key Laboratory of Detection Technology for Tumor Markers, School of Chemistry and Chemical Engineering, College of Medicine, Linyi University, Linyi 276000, P.R. China
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6
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Zhu FY, Mei LJ, Tian R, Li C, Wang YL, Xiang SL, Zhu MQ, Tang BZ. Recent advances in super-resolution optical imaging based on aggregation-induced emission. Chem Soc Rev 2024; 53:3350-3383. [PMID: 38406832 DOI: 10.1039/d3cs00698k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Super-resolution imaging has rapidly emerged as an optical microscopy technique, offering advantages of high optical resolution over the past two decades; achieving improved imaging resolution requires significant efforts in developing super-resolution imaging agents characterized by high brightness, high contrast and high sensitivity to fluorescence switching. Apart from technical requirements in optical systems and algorithms, super-resolution imaging relies on fluorescent dyes with special photophysical or photochemical properties. The concept of aggregation-induced emission (AIE) was proposed in 2001, coinciding with unprecedented advancements and innovations in super-resolution imaging technology. AIE probes offer many advantages, including high brightness in the aggregated state, low background signal, a larger Stokes shift, ultra-high photostability, and excellent biocompatibility, making them highly promising for applications in super-resolution imaging. In this review, we summarize the progress in implementation methods and provide insights into the mechanism of AIE-based super-resolution imaging, including fluorescence switching resulting from photochemically-converted aggregation-induced emission, electrostatically controlled aggregation-induced emission and specific binding-regulated aggregation-induced emission. Particularly, the aggregation-induced emission principle has been proposed to achieve spontaneous fluorescence switching, expanding the selection and application scenarios of super-resolution imaging probes. By combining the aggregation-induced emission principle and specific molecular design, we offer some comprehensive insights to facilitate the applications of AIEgens (AIE-active molecules) in super-resolution imaging.
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Affiliation(s)
- Feng-Yu Zhu
- Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, College of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China.
| | - Li-Jun Mei
- Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, College of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China.
| | - Rui Tian
- Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, College of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China.
| | - Chong Li
- Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, College of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China.
| | - Ya-Long Wang
- Key Laboratory of Biomedical Engineering of Hainan Province, School of Biomedical Engineering, Hainan University, Haikou, 570228, China
| | - Shi-Li Xiang
- Hubei Jiufengshan Laboratory, Wuhan, 430206, China
| | - Ming-Qiang Zhu
- Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, College of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China.
- Key Laboratory of Biomedical Engineering of Hainan Province, School of Biomedical Engineering, Hainan University, Haikou, 570228, China
| | - Ben Zhong Tang
- School of Science and Engineering, Shenzhen Institute of Aggregate Science and Technology, The Chinese University of Hong Kong, Shenzhen (CUHK-Shenzhen), Guangdong 518172, China.
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7
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Fabian-Morales E, Rodríguez A, Gudiño A, Herrera LA, Frias S. Profiling Chromosome Topological Features by Super-Resolution 3D Structured Illumination Microscopy. Methods Mol Biol 2024; 2825:213-237. [PMID: 38913312 DOI: 10.1007/978-1-0716-3946-7_12] [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] [Indexed: 06/25/2024]
Abstract
Three-dimensional structured illumination microscopy (3D-SIM) and fluorescence in situ hybridization on three-dimensional preserved cells (3D-FISH) have proven to be robust and efficient methodologies for analyzing nuclear architecture and profiling the genome's topological features. These methods have allowed the simultaneous visualization and evaluation of several target structures at super-resolution. In this chapter, we focus on the application of 3D-SIM for the visualization of 3D-FISH preparations of chromosomes in interphase, known as Chromosome Territories (CTs). We provide a workflow and detailed guidelines for sample preparation, image acquisition, and image analysis to obtain quantitative measurements for profiling chromosome topological features. In parallel, we address a practical example of these protocols in the profiling of CTs 9 and 22 involved in the translocation t(9;22) in Chronic Myeloid Leukemia (CML). The profiling of chromosome topological features described in this chapter allowed us to characterize a large-scale topological disruption of CTs 9 and 22 that correlates directly with patients' response to treatment and as a possible potential change in the inheritance systems. These findings open new insights into how the genome structure is associated with the response to cancer treatments, highlighting the importance of microscopy in analyzing the topological features of the genome.
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MESH Headings
- Humans
- In Situ Hybridization, Fluorescence/methods
- Imaging, Three-Dimensional/methods
- Translocation, Genetic
- Chromosomes/genetics
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/pathology
- Interphase/genetics
- Chromosomes, Human/genetics
- Image Processing, Computer-Assisted/methods
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Affiliation(s)
- Eunice Fabian-Morales
- Unidad de Aplicaciones Avanzadas en Microscopía (ADMiRA), Instituto Nacional de Cancerología (INCan), Red de Apoyo a la Investigación (RAI), Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico
- Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología (INCan), Mexico City, Mexico
- Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City, Mexico
| | - Alfredo Rodríguez
- Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City, Mexico
- Instituto Nacional de Pediatría (INP), Mexico City, Mexico
| | - Adriana Gudiño
- Unidad de Aplicaciones Avanzadas en Microscopía (ADMiRA), Instituto Nacional de Cancerología (INCan), Red de Apoyo a la Investigación (RAI), Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico
- Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología (INCan), Mexico City, Mexico
| | - Luis A Herrera
- Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología (INCan), Mexico City, Mexico.
- Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City, Mexico.
- Escuela de Medicina y Ciencias de la Salud, Instituto Tecnológico y de Estudios Superiores de Monterrey, Mexico City, Mexico.
| | - Sara Frias
- Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City, Mexico.
- Laboratorio de Citogenética, Instituto Nacional de Pediatría (INP), Mexico City, Mexico.
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Carden S, Vitiello E, Rosa E Silva I, Holder J, Quarantotti V, Kishore K, Roamio Franklin VN, D'Santos C, Ochi T, van Breugel M, Gergely F. Proteomic profiling of centrosomes across multiple mammalian cell and tissue types by an affinity capture method. Dev Cell 2023; 58:2393-2410.e9. [PMID: 37852252 DOI: 10.1016/j.devcel.2023.09.008] [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] [Received: 02/28/2023] [Revised: 07/27/2023] [Accepted: 09/25/2023] [Indexed: 10/20/2023]
Abstract
Centrosomes are the major microtubule-organizing centers in animals and play fundamental roles in many cellular processes. Understanding how their composition varies across diverse cell types and how it is altered in disease are major unresolved questions, yet currently available centrosome isolation protocols are cumbersome and time-consuming, and they lack scalability. Here, we report the development of centrosome affinity capture (CAPture)-mass spectrometry (MS), a powerful one-step purification method to obtain high-resolution centrosome proteomes from mammalian cells. Utilizing a synthetic peptide derived from CCDC61 protein, CAPture specifically isolates intact centrosomes. Importantly, as a bead-based affinity method, it enables rapid sample processing and multiplexing unlike conventional approaches. Our study demonstrates the power of CAPture-MS to elucidate cell-type-dependent heterogeneity in centrosome composition, dissect hierarchical interactions, and identify previously unknown centrosome components. Overall, CAPture-MS represents a transformative tool to unveil temporal, regulatory, cell-type- and tissue-specific changes in centrosome proteomes in health and disease.
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Affiliation(s)
- Sarah Carden
- CRUK Cambridge Institute, Li Ka Shing Centre, University of Cambridge, Cambridge, UK
| | - Elisa Vitiello
- Department of Biochemistry, University of Oxford, Oxford, UK
| | | | - James Holder
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Valentina Quarantotti
- CRUK Cambridge Institute, Li Ka Shing Centre, University of Cambridge, Cambridge, UK
| | - Kamal Kishore
- CRUK Cambridge Institute, Li Ka Shing Centre, University of Cambridge, Cambridge, UK
| | | | - Clive D'Santos
- CRUK Cambridge Institute, Li Ka Shing Centre, University of Cambridge, Cambridge, UK
| | - Takashi Ochi
- MRC Laboratory of Molecular Biology, Cambridge, UK; The Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, Leeds, UK.
| | - Mark van Breugel
- MRC Laboratory of Molecular Biology, Cambridge, UK; School of Biological & Behavioural Sciences, Queen Mary University of London, London, UK.
| | - Fanni Gergely
- CRUK Cambridge Institute, Li Ka Shing Centre, University of Cambridge, Cambridge, UK; Department of Biochemistry, University of Oxford, Oxford, UK.
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9
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Kraus F, Goodall EA, Smith IR, Jiang Y, Paoli JC, Adolf F, Zhang J, Paulo JA, Schulman BA, Harper JW. PARK15/FBXO7 is dispensable for PINK1/Parkin mitophagy in iNeurons and HeLa cell systems. EMBO Rep 2023; 24:e56399. [PMID: 37334901 PMCID: PMC10398645 DOI: 10.15252/embr.202256399] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 05/16/2023] [Accepted: 06/01/2023] [Indexed: 06/21/2023] Open
Abstract
The protein kinase PINK1 and ubiquitin ligase Parkin promote removal of damaged mitochondria via a feed-forward mechanism involving ubiquitin (Ub) phosphorylation (pUb), Parkin activation, and ubiquitylation of mitochondrial outer membrane proteins to support the recruitment of mitophagy receptors. The ubiquitin ligase substrate receptor FBXO7/PARK15 is mutated in an early-onset parkinsonian-pyramidal syndrome. Previous studies have proposed a role for FBXO7 in promoting Parkin-dependent mitophagy. Here, we systematically examine the involvement of FBXO7 in depolarization and mt UPR-dependent mitophagy in the well-established HeLa and induced-neurons cell systems. We find that FBXO7-/- cells have no demonstrable defect in: (i) kinetics of pUb accumulation, (ii) pUb puncta on mitochondria by super-resolution imaging, (iii) recruitment of Parkin and autophagy machinery to damaged mitochondria, (iv) mitophagic flux, and (v) mitochondrial clearance as quantified by global proteomics. Moreover, global proteomics of neurogenesis in the absence of FBXO7 reveals no obvious alterations in mitochondria or other organelles. These results argue against a general role for FBXO7 in Parkin-dependent mitophagy and point to the need for additional studies to define how FBXO7 mutations promote parkinsonian-pyramidal syndrome.
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Affiliation(s)
- Felix Kraus
- Department of Cell Biology, Blavatnik InstituteHarvard Medical SchoolBostonMAUSA
- Aligning Science Across Parkinson's (ASAP) Collaborative Research NetworkChevy ChaseMDUSA
| | - Ellen A Goodall
- Department of Cell Biology, Blavatnik InstituteHarvard Medical SchoolBostonMAUSA
- Aligning Science Across Parkinson's (ASAP) Collaborative Research NetworkChevy ChaseMDUSA
| | - Ian R Smith
- Department of Cell Biology, Blavatnik InstituteHarvard Medical SchoolBostonMAUSA
| | - Yizhi Jiang
- Department of Cell Biology, Blavatnik InstituteHarvard Medical SchoolBostonMAUSA
| | - Julia C Paoli
- Department of Cell Biology, Blavatnik InstituteHarvard Medical SchoolBostonMAUSA
| | - Frank Adolf
- Aligning Science Across Parkinson's (ASAP) Collaborative Research NetworkChevy ChaseMDUSA
- Department of Molecular Machines and SignalingMax Planck Institute of BiochemistryMartinsriedGermany
| | - Jiuchun Zhang
- Department of Cell Biology, Blavatnik InstituteHarvard Medical SchoolBostonMAUSA
| | - Joao A Paulo
- Department of Cell Biology, Blavatnik InstituteHarvard Medical SchoolBostonMAUSA
| | - Brenda A Schulman
- Aligning Science Across Parkinson's (ASAP) Collaborative Research NetworkChevy ChaseMDUSA
- Department of Molecular Machines and SignalingMax Planck Institute of BiochemistryMartinsriedGermany
| | - J Wade Harper
- Department of Cell Biology, Blavatnik InstituteHarvard Medical SchoolBostonMAUSA
- Aligning Science Across Parkinson's (ASAP) Collaborative Research NetworkChevy ChaseMDUSA
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10
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Liu Q, Zhou D, Zhang J, Ji C, Du K, Chen Y, Liu W, Kuang C. DMD-based compact SIM system with hexagonal-lattice-structured illumination. APPLIED OPTICS 2023; 62:5409-5415. [PMID: 37706857 DOI: 10.1364/ao.494214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 06/17/2023] [Indexed: 09/15/2023]
Abstract
In this study, we developed a novel, compact, and efficient structured illumination microscopy (SIM) system, to our best knowledge. A binary hexagonal lattice pattern was designed and implemented on a digital micromirror device (DMD), resulting in a projection-based structured-light generation. By leveraging the combination of the high-speed switching capability of the DMD with a high-speed CMOS camera, the system can capture 1024×1024 pixels images at a 200 fps frame rate when provided with sufficient illumination power. The loading of the hexagonal lattice pattern reduces the number of images required for reconstruction to seven, and by utilizing the DMD modulating characteristics on the illumination path, there is no need to use bulky mechanical structures for phase shifting. We designed a compact system with 110m m×150m m×170m m dimensions that displayed a 1.61 resolution enhancement for fluorescent particle and biological sample imaging.
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11
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Zhai R, Fang B, Lai Y, Peng B, Bai H, Liu X, Li L, Huang W. Small-molecule fluorogenic probes for mitochondrial nanoscale imaging. Chem Soc Rev 2023; 52:942-972. [PMID: 36514947 DOI: 10.1039/d2cs00562j] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Mitochondria are inextricably linked to the development of diseases and cell metabolism disorders. Super-resolution imaging (SRI) is crucial in enhancing our understanding of mitochondrial ultrafine structures and functions. In addition to high-precision instruments, super-resolution microscopy relies heavily on fluorescent materials with unique photophysical properties. Small-molecule fluorogenic probes (SMFPs) have excellent properties that make them ideal for mitochondrial SRI. This paper summarizes recent advances in the field of SMFPs, with a focus on the chemical and spectroscopic properties required for mitochondrial SRI. Finally, we discuss future challenges in this field, including the design principles of SMFPs and nanoscopic techniques.
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Affiliation(s)
- Rongxiu Zhai
- Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials & Engineering (IBME), Northwestern Polytechnical University, Xi'an 710072, China.
| | - Bin Fang
- Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials & Engineering (IBME), Northwestern Polytechnical University, Xi'an 710072, China. .,School of Materials Science and Engineering, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an 710072, China
| | - Yaqi Lai
- Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials & Engineering (IBME), Northwestern Polytechnical University, Xi'an 710072, China.
| | - Bo Peng
- Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials & Engineering (IBME), Northwestern Polytechnical University, Xi'an 710072, China.
| | - Hua Bai
- Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials & Engineering (IBME), Northwestern Polytechnical University, Xi'an 710072, China.
| | - Xiaowang Liu
- Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials & Engineering (IBME), Northwestern Polytechnical University, Xi'an 710072, China.
| | - Lin Li
- Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials & Engineering (IBME), Northwestern Polytechnical University, Xi'an 710072, China. .,The Institute of Flexible Electronics (IFE, Future Technologies), Xiamen University, Xiamen 361005, Fujian, China
| | - Wei Huang
- Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials & Engineering (IBME), Northwestern Polytechnical University, Xi'an 710072, China. .,The Institute of Flexible Electronics (IFE, Future Technologies), Xiamen University, Xiamen 361005, Fujian, China
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12
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Golmohammadzadeh M, Sexton DL, Parmar S, Tocheva EI. Advanced imaging techniques: Microscopy. ADVANCES IN APPLIED MICROBIOLOGY 2023; 122:1-25. [PMID: 37085191 DOI: 10.1016/bs.aambs.2023.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
For decades, bacteria were thought of as "bags" of enzymes, lacking organelles and significant subcellular structures. This stood in sharp contrast with eukaryotes, where intracellular compartmentalization and the role of large-scale order had been known for a long time. However, the emerging field of Bacterial Cell Biology has established that bacteria are in fact highly organized, with most macromolecular components having specific subcellular locations that can change depending on the cell's physiological state (Barry & Gitai, 2011; Lenz & Søgaard-Andersen, 2011; Thanbichler & Shapiro, 2008). For example, we now know that many processes in bacteria are orchestrated by cytoskeletal proteins, which polymerize into surprisingly diverse superstructures, such as rings, sheets, and tread-milling rods (Pilhofer & Jensen, 2013). These superstructures connect individual proteins, macromolecular assemblies, and even two neighboring cells, to affect essential higher-order processes including cell division, DNA segregation, and motility. Understanding these processes requires resolving the in vivo dynamics and ultrastructure at different functional stages of the cell, at macromolecular resolution and in 3-dimensions (3D). Fluorescence light microscopy (fLM) of tagged proteins is highly valuable for investigating protein localization and dynamics, and the resolution power of transmission electron microscopy (TEM) is required to elucidate the structure of macromolecular complexes in vivo and in vitro. This chapter summarizes the most recent advances in LM and TEM approaches that have revolutionized our knowledge and understanding of the microbial world.
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Affiliation(s)
- Mona Golmohammadzadeh
- Department of Microbiology and Immunology, Life Sciences Institute, Health Sciences Mall, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Danielle L Sexton
- Department of Microbiology and Immunology, Life Sciences Institute, Health Sciences Mall, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Shweta Parmar
- Department of Microbiology and Immunology, Life Sciences Institute, Health Sciences Mall, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Elitza I Tocheva
- Department of Microbiology and Immunology, Life Sciences Institute, Health Sciences Mall, The University of British Columbia, Vancouver, British Columbia, Canada.
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13
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Kokate SB, Ciuba K, Tran VD, Kumari R, Tojkander S, Engel U, Kogan K, Kumar S, Lappalainen P. Caldesmon controls stress fiber force-balance through dynamic cross-linking of myosin II and actin-tropomyosin filaments. Nat Commun 2022; 13:6032. [PMID: 36229430 PMCID: PMC9561149 DOI: 10.1038/s41467-022-33688-w] [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: 12/16/2021] [Accepted: 09/28/2022] [Indexed: 11/09/2022] Open
Abstract
Contractile actomyosin bundles are key force-producing and mechanosensing elements in muscle and non-muscle tissues. Whereas the organization of muscle myofibrils and mechanism regulating their contractility are relatively well-established, the principles by which myosin-II activity and force-balance are regulated in non-muscle cells have remained elusive. We show that Caldesmon, an important component of smooth muscle and non-muscle cell actomyosin bundles, is an elongated protein that functions as a dynamic cross-linker between myosin-II and tropomyosin-actin filaments. Depletion of Caldesmon results in aberrant lateral movement of myosin-II filaments along actin bundles, leading to irregular myosin distribution within stress fibers. This manifests as defects in stress fiber network organization and contractility, and accompanied problems in cell morphogenesis, migration, invasion, and mechanosensing. These results identify Caldesmon as critical factor that ensures regular myosin-II spacing within non-muscle cell actomyosin bundles, and reveal how stress fiber networks are controlled through dynamic cross-linking of tropomyosin-actin and myosin filaments.
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Affiliation(s)
- Shrikant B Kokate
- HiLIFE Institute of Biotechnology, University of Helsinki, P.O. Box 56, 00014, Helsinki, Finland
| | - Katarzyna Ciuba
- HiLIFE Institute of Biotechnology, University of Helsinki, P.O. Box 56, 00014, Helsinki, Finland.,Nencki Institute of Experimental Biology PAS, 3 Pasteur Street, 02-093, Warszawa, Poland
| | - Vivien D Tran
- Department of Bioengineering, University of California, Berkeley, CA, 94720, USA
| | - Reena Kumari
- HiLIFE Institute of Biotechnology, University of Helsinki, P.O. Box 56, 00014, Helsinki, Finland
| | - Sari Tojkander
- Faculty of Medicine and Health Technology, Tampere University, Kauppi Campus, Arvo Building, E318, Arvo Ylpön katu 34, 33520, Tampere, Finland
| | - Ulrike Engel
- Nikon Imaging Center at Heidelberg University and Centre for Organismal Studies (COS), Heidelberg University, Im Neuenheimer Feld 267, Heidelberg, 69120, Germany
| | - Konstantin Kogan
- HiLIFE Institute of Biotechnology, University of Helsinki, P.O. Box 56, 00014, Helsinki, Finland
| | - Sanjay Kumar
- Department of Bioengineering, University of California, Berkeley, CA, 94720, USA
| | - Pekka Lappalainen
- HiLIFE Institute of Biotechnology, University of Helsinki, P.O. Box 56, 00014, Helsinki, Finland.
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14
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Brown JM, De Ornellas S, Parisi E, Schermelleh L, Buckle VJ. RASER-FISH: non-denaturing fluorescence in situ hybridization for preservation of three-dimensional interphase chromatin structure. Nat Protoc 2022; 17:1306-1331. [PMID: 35379945 DOI: 10.1038/s41596-022-00685-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 01/10/2022] [Indexed: 11/09/2022]
Abstract
DNA fluorescence in situ hybridization (FISH) has been a central technique in advancing our understanding of how chromatin is organized within the nucleus. With the increasing resolution offered by super-resolution microscopy, the optimal maintenance of chromatin structure within the nucleus is essential for accuracy in measurements and interpretation of data. However, standard 3D-FISH requires potentially destructive heat denaturation in the presence of chaotropic agents such as formamide to allow access to the DNA strands for labeled FISH probes. To avoid the need to heat-denature, we developed Resolution After Single-strand Exonuclease Resection (RASER)-FISH, which uses exonuclease digestion to generate single-stranded target DNA for efficient probe binding over a 2 d process. Furthermore, RASER-FISH is easily combined with immunostaining of nuclear proteins or the detection of RNAs. Here, we provide detailed procedures for RASER-FISH in mammalian cultured cells to detect single loci, chromatin tracks and topologically associating domains with conventional and super-resolution 3D structured illumination microscopy. Moreover, we provide a validation and characterization of our method, demonstrating excellent preservation of chromatin structure and nuclear integrity, together with improved hybridization efficiency, compared with classic 3D-FISH protocols.
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Affiliation(s)
- Jill M Brown
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Oxford University, Oxford, UK
| | - Sara De Ornellas
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Oxford University, Oxford, UK
| | - Eva Parisi
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Oxford University, Oxford, UK
- School of Clinical Medicine, Addenbrooke's Hospital, Cambridge, UK
| | - Lothar Schermelleh
- Micron Oxford Advanced Bioimaging Unit, Department of Biochemistry, Oxford University, Oxford, UK
| | - Veronica J Buckle
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Oxford University, Oxford, UK.
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15
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Preston CC, Stoddard AC, Faustino RS. A Transient Mystery: Nucleolar Channel Systems. Results Probl Cell Differ 2022; 70:581-593. [PMID: 36348122 DOI: 10.1007/978-3-031-06573-6_20] [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] [Indexed: 06/16/2023]
Abstract
The nucleus is a complex organelle with functions beyond being a simple repository for genomic material. For example, its actions in biomechanical sensing, protein synthesis, and epigenomic regulation showcase how the nucleus integrates multiple signaling modalities to intricately regulate gene expression. This innate dynamism is underscored by subnuclear components that facilitate these roles, with elements of the nucleoskeleton, phase-separated nuclear bodies, and chromatin safeguarding by nuclear envelope proteins providing examples of this functional diversity. Among these, one of the lesser characterized nuclear organelles is the nucleolar channel system (NCS), first reported several decades ago in human endometrial biopsies. This tubular structure, believed to be derived from the inner nuclear membrane of the nuclear envelope, was first observed in secretory endometrial cells during a specific phase of the menstrual cycle. Reported as a consistent, yet transient, nuclear organelle, current interpretations of existing data suggest that it serves as a marker of a window for optimal implantation. In spite of this available data, the NCS remains incompletely characterized structurally and functionally, due in part to its transient spatial and temporal expression. As a further complication, evidence exists showing NCS expression in fetal tissue, suggesting that it may not act exclusively as a marker of uterine receptivity, but rather as a hormone sensor sensitive to estrogen and progesterone ratios. To gain a better understanding of the NCS, current technologies can be applied to profile rare cell populations or capture transient structural dynamics, for example, at a level of sensitivity and resolution not previously possible. Moving forward, advanced characterization of the NCS will shed light on an uncharacterized aspect of reproductive physiology, with the potential to refine assisted reproductive techniques.
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Affiliation(s)
- Claudia C Preston
- Biology Department, St. Mary's University of Minnesota, Winona, MN, USA
| | | | - Randolph S Faustino
- Genetics and Genomics Group, Sanford Research, Sioux Falls, SD, USA.
- Department of Pediatrics, Sanford School of Medicine of the University of South Dakota, Sioux Falls, SD, USA.
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16
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Miron E, Windo J, Ochs F, Schermelleh L. Replication Labeling Methods for Super-Resolution Imaging of Chromosome Territories and Chromatin Domains. Methods Mol Biol 2022; 2476:111-128. [PMID: 35635700 DOI: 10.1007/978-1-0716-2221-6_9] [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] [Indexed: 06/15/2023]
Abstract
Continuing progress in super-resolution microscopy enables the study of sub-chromosomal chromatin organization in single cells with unprecedented detail. Here we describe refined methods for pulse-chase replication labeling of individual chromosome territories (CTs) and replication domain units in mammalian cell nuclei, with specific focus on their application to three-dimensional structured illumination microscopy (3D-SIM). We provide detailed protocols for highly efficient electroporation-based delivery or scratch loading of cell-impermeable fluorescent nucleotides for live-cell studies. Furthermore, we describe the application of (2'S)-2'-deoxy-2'-fluoro-5-ethynyluridine (F-ara-EdU) and 5-vinyl-2'-deoxyuridine (VdU) for the in situ detection of segregated chromosome territories and sister chromatids with minimized cytotoxic side effects.
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Affiliation(s)
- Ezequiel Miron
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Joseph Windo
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Fena Ochs
- Department of Biochemistry, University of Oxford, Oxford, UK
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17
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Markaki Y, Gan Chong J, Wang Y, Jacobson EC, Luong C, Tan SYX, Jachowicz JW, Strehle M, Maestrini D, Banerjee AK, Mistry BA, Dror I, Dossin F, Schöneberg J, Heard E, Guttman M, Chou T, Plath K. Xist nucleates local protein gradients to propagate silencing across the X chromosome. Cell 2021; 184:6174-6192.e32. [PMID: 34813726 PMCID: PMC8671326 DOI: 10.1016/j.cell.2021.10.022] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 07/29/2021] [Accepted: 10/11/2021] [Indexed: 02/08/2023]
Abstract
The lncRNA Xist forms ∼50 diffraction-limited foci to transcriptionally silence one X chromosome. How this small number of RNA foci and interacting proteins regulate a much larger number of X-linked genes is unknown. We show that Xist foci are locally confined, contain ∼2 RNA molecules, and nucleate supramolecular complexes (SMACs) that include many copies of the critical silencing protein SPEN. Aggregation and exchange of SMAC proteins generate local protein gradients that regulate broad, proximal chromatin regions. Partitioning of numerous SPEN molecules into SMACs is mediated by their intrinsically disordered regions and essential for transcriptional repression. Polycomb deposition via SMACs induces chromatin compaction and the increase in SMACs density around genes, which propagates silencing across the X chromosome. Our findings introduce a mechanism for functional nuclear compartmentalization whereby crowding of transcriptional and architectural regulators enables the silencing of many target genes by few RNA molecules.
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Affiliation(s)
- Yolanda Markaki
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA.
| | - Johnny Gan Chong
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Yuying Wang
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Elsie C Jacobson
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Christy Luong
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Shawn Y X Tan
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Joanna W Jachowicz
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Mackenzie Strehle
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Davide Maestrini
- Department of Computational Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Abhik K Banerjee
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Bhaven A Mistry
- Department of Computational Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA; Claremont McKenna College, Claremont, CA 91711, USA
| | - Iris Dror
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Francois Dossin
- European Molecular Biology Laboratory, Director's Unit, Heidelberg 69117, Germany
| | - Johannes Schöneberg
- Departments of Pharmacology & Chemistry and Biochemistry, University of California San Diego, San Diego, CA 92093, USA
| | - Edith Heard
- European Molecular Biology Laboratory, Director's Unit, Heidelberg 69117, Germany
| | - Mitchell Guttman
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Tom Chou
- Department of Computational Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA.
| | - Kathrin Plath
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA.
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18
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Houlard M, Cutts EE, Shamim MS, Godwin J, Weisz D, Presser Aiden A, Lieberman Aiden E, Schermelleh L, Vannini A, Nasmyth K. MCPH1 inhibits Condensin II during interphase by regulating its SMC2-Kleisin interface. eLife 2021; 10:e73348. [PMID: 34850681 PMCID: PMC8673838 DOI: 10.7554/elife.73348] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 11/08/2021] [Indexed: 12/20/2022] Open
Abstract
Dramatic change in chromosomal DNA morphology between interphase and mitosis is a defining features of the eukaryotic cell cycle. Two types of enzymes, namely cohesin and condensin confer the topology of chromosomal DNA by extruding DNA loops. While condensin normally configures chromosomes exclusively during mitosis, cohesin does so during interphase. The processivity of cohesin's loop extrusion during interphase is limited by a regulatory factor called WAPL, which induces cohesin to dissociate from chromosomes via a mechanism that requires dissociation of its kleisin from the neck of SMC3. We show here that a related mechanism may be responsible for blocking condensin II from acting during interphase. Cells derived from patients affected by microcephaly caused by mutations in the MCPH1 gene undergo premature chromosome condensation. We show that deletion of Mcph1 in mouse embryonic stem cells unleashes an activity of condensin II that triggers formation of compact chromosomes in G1 and G2 phases, accompanied by enhanced mixing of A and B chromatin compartments, and this occurs even in the absence of CDK1 activity. Crucially, inhibition of condensin II by MCPH1 depends on the binding of a short linear motif within MCPH1 to condensin II's NCAPG2 subunit. MCPH1's ability to block condensin II's association with chromatin is abrogated by the fusion of SMC2 with NCAPH2, hence may work by a mechanism similar to cohesin. Remarkably, in the absence of both WAPL and MCPH1, cohesin and condensin II transform chromosomal DNAs of G2 cells into chromosomes with a solenoidal axis.
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Affiliation(s)
- Martin Houlard
- Department of Biochemistry, University of OxfordOxfordUnited Kingdom
| | - Erin E Cutts
- Division of Structural Biology, The Institute of Cancer ResearchLondonUnited Kingdom
| | - Muhammad S Shamim
- The Center for Genome Architecture, Department of Molecular and Human Genetics, Baylor College of MedicineHoustonUnited States
- Medical Scientist Training Program, Baylor College of Medicine, Department of Bioengineering, Rice UniversityHoustonUnited States
- Center for Theoretical Biological Physics, Rice UniversityHoustonUnited States
| | - Jonathan Godwin
- Department of Biochemistry, University of OxfordOxfordUnited Kingdom
| | - David Weisz
- The Center for Genome Architecture, Department of Molecular and Human Genetics, Baylor College of MedicineHoustonUnited States
- Center for Theoretical Biological Physics, Rice UniversityHoustonUnited States
| | - Aviva Presser Aiden
- The Center for Genome Architecture, Department of Molecular and Human Genetics, Baylor College of MedicineHoustonUnited States
- Center for Theoretical Biological Physics, Rice UniversityHoustonUnited States
| | - Erez Lieberman Aiden
- The Center for Genome Architecture, Department of Molecular and Human Genetics, Baylor College of MedicineHoustonUnited States
- Center for Theoretical Biological Physics, Rice UniversityHoustonUnited States
| | | | - Alessandro Vannini
- Division of Structural Biology, The Institute of Cancer ResearchLondonUnited Kingdom
- Human TechnopoleMilanItaly
| | - Kim Nasmyth
- Department of Biochemistry, University of OxfordOxfordUnited Kingdom
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19
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Blasiak J, Szczepańska J, Sobczuk A, Fila M, Pawlowska E. RIF1 Links Replication Timing with Fork Reactivation and DNA Double-Strand Break Repair. Int J Mol Sci 2021; 22:11440. [PMID: 34768871 PMCID: PMC8583789 DOI: 10.3390/ijms222111440] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 10/20/2021] [Accepted: 10/22/2021] [Indexed: 11/16/2022] Open
Abstract
Replication timing (RT) is a cellular program to coordinate initiation of DNA replication in all origins within the genome. RIF1 (replication timing regulatory factor 1) is a master regulator of RT in human cells. This role of RIF1 is associated with binding G4-quadruplexes and changes in 3D chromatin that may suppress origin activation over a long distance. Many effects of RIF1 in fork reactivation and DNA double-strand (DSB) repair (DSBR) are underlined by its interaction with TP53BP1 (tumor protein p53 binding protein). In G1, RIF1 acts antagonistically to BRCA1 (BRCA1 DNA repair associated), suppressing end resection and homologous recombination repair (HRR) and promoting non-homologous end joining (NHEJ), contributing to DSBR pathway choice. RIF1 is an important element of intra-S-checkpoints to recover damaged replication fork with the involvement of HRR. High-resolution microscopic studies show that RIF1 cooperates with TP53BP1 to preserve 3D structure and epigenetic markers of genomic loci disrupted by DSBs. Apart from TP53BP1, RIF1 interact with many other proteins, including proteins involved in DNA damage response, cell cycle regulation, and chromatin remodeling. As impaired RT, DSBR and fork reactivation are associated with genomic instability, a hallmark of malignant transformation, RIF1 has a diagnostic, prognostic, and therapeutic potential in cancer. Further studies may reveal other aspects of common regulation of RT, DSBR, and fork reactivation by RIF1.
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Affiliation(s)
- Janusz Blasiak
- Department of Molecular Genetics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland
| | - Joanna Szczepańska
- Department of Pediatric Dentistry, Medical University of Lodz, 92-216 Lodz, Poland;
| | - Anna Sobczuk
- Department of Gynaecology and Obstetrics, Medical University of Lodz, 93-338 Lodz, Poland;
| | - Michal Fila
- Department of Developmental Neurology and Epileptology, Polish Mother’s Memorial Hospital Research Institute, 93-338 Lodz, Poland;
| | - Elzbieta Pawlowska
- Department of Orthodontics, Medical University of Lodz, 92-217 Lodz, Poland;
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20
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Iwasaki YW, Sriswasdi S, Kinugasa Y, Adachi J, Horikoshi Y, Shibuya A, Iwasaki W, Tashiro S, Tomonaga T, Siomi H. Piwi-piRNA complexes induce stepwise changes in nuclear architecture at target loci. EMBO J 2021; 40:e108345. [PMID: 34337769 PMCID: PMC8441340 DOI: 10.15252/embj.2021108345] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 07/04/2021] [Accepted: 07/09/2021] [Indexed: 12/25/2022] Open
Abstract
PIWI‐interacting RNAs (piRNAs) are germline‐specific small RNAs that form effector complexes with PIWI proteins (Piwi–piRNA complexes) and play critical roles for preserving genomic integrity by repressing transposable elements (TEs). Drosophila Piwi transcriptionally silences specific targets through heterochromatin formation and increases histone H3K9 methylation (H3K9me3) and histone H1 deposition at these loci, with nuclear RNA export factor variant Nxf2 serving as a co‐factor. Using ChEP and DamID‐seq, we now uncover a Piwi/Nxf2‐dependent target association with nuclear lamins. Hi‐C analysis of Piwi or Nxf2‐depleted cells reveals decreased intra‐TAD and increased inter‐TAD interactions in regions harboring Piwi–piRNA target TEs. Using a forced tethering system, we analyze the functional effects of Piwi–piRNA/Nxf2‐mediated recruitment of piRNA target regions to the nuclear periphery. Removal of active histone marks is followed by transcriptional silencing, chromatin conformational changes, and H3K9me3 and H1 association. Our data show that the Piwi–piRNA pathway can induce stepwise changes in nuclear architecture and chromatin state at target loci for transcriptional silencing.
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Affiliation(s)
- Yuka W Iwasaki
- Department of Molecular Biology, Keio University School of Medicine, Tokyo, Japan.,Japan Science and Technology Agency (JST), Precursory Research for Embryonic Science and Technology (PRESTO), Saitama, Japan
| | - Sira Sriswasdi
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan.,Computational Molecular Biology Group, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.,Research Affairs, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Yasuha Kinugasa
- Department of Cellular Biology, Research Institute for Radiation Biology Medicine, Hiroshima University, Hiroshima, Japan
| | - Jun Adachi
- Laboratory of Proteome Research, National Institutes of Biomedical Innovation, Health and Nutrition, Osaka, Japan
| | - Yasunori Horikoshi
- Department of Cellular Biology, Research Institute for Radiation Biology Medicine, Hiroshima University, Hiroshima, Japan
| | - Aoi Shibuya
- Department of Molecular Biology, Keio University School of Medicine, Tokyo, Japan
| | - Wataru Iwasaki
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Satoshi Tashiro
- Department of Cellular Biology, Research Institute for Radiation Biology Medicine, Hiroshima University, Hiroshima, Japan
| | - Takeshi Tomonaga
- Laboratory of Proteome Research, National Institutes of Biomedical Innovation, Health and Nutrition, Osaka, Japan
| | - Haruhiko Siomi
- Department of Molecular Biology, Keio University School of Medicine, Tokyo, Japan
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21
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Adam N, Beattie TL, Riabowol K. Fluorescence microscopy methods for examining telomeres during cell aging. Ageing Res Rev 2021; 68:101320. [PMID: 33744488 DOI: 10.1016/j.arr.2021.101320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 02/24/2021] [Accepted: 03/08/2021] [Indexed: 10/21/2022]
Abstract
Telomeres are protective structures, composed of nucleic acids and a complex protein mixture, located at the end of the chromosomes. They play an important role in preventing genomic instability and ensuring cell health. Defects in telomere integrity result in cell dysfunction and the development of diseases, including neurodegenerative disorders, cancer and premature aging syndromes, among others. Loss of telomere integrity during normal cell aging also initiates DNA damage signals that culminate in the senescence phenotype. Fluorescence microscopy has allowed researchers to study the dynamics, shape, localization, and co-distribution of telomeres with proteins of interest. The microscopy tools to investigate these structures have evolved, making it possible to understand in greater detail the molecular mechanisms affecting telomeres that contribute to cell aging and the development of age-related diseases. Using human fibroblasts as an example, we will highlight several characteristics of telomeres that can be investigated using three different microscopy systems, including wide-field microscopy, and the two super-resolution techniques called 3D Structured Illumination Microscopy (3D-SIM) and direct Stochastic Optical Reconstruction Microscopy (dSTORM). In this review, we will also discuss their limitations and highlight their importance in answering telomere-related scientific questions.
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22
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Rodermund L, Coker H, Oldenkamp R, Wei G, Bowness J, Rajkumar B, Nesterova T, Susano Pinto DM, Schermelleh L, Brockdorff N. Time-resolved structured illumination microscopy reveals key principles of Xist RNA spreading. Science 2021; 372:372/6547/eabe7500. [PMID: 34112668 DOI: 10.1126/science.abe7500] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 05/07/2021] [Indexed: 01/23/2023]
Abstract
X-inactive specific transcript (Xist) RNA directs the process of X chromosome inactivation in mammals by spreading in cis along the chromosome from which it is transcribed and recruiting chromatin modifiers to silence gene transcription. To elucidate mechanisms of Xist RNA cis-confinement, we established a sequential dual-color labeling, super-resolution imaging approach to trace individual Xist RNA molecules over time, which enabled us to define fundamental parameters of spreading. We demonstrate a feedback mechanism linking Xist RNA synthesis and degradation and an unexpected physical coupling between preceding and newly synthesized Xist RNA molecules. Additionally, we find that the protein SPEN, a key factor for Xist-mediated gene silencing, has a distinct function in Xist RNA localization, stability, and coupling behaviors. Our results provide insights toward understanding the distinct dynamic properties of Xist RNA.
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Affiliation(s)
- Lisa Rodermund
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Heather Coker
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Roel Oldenkamp
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Guifeng Wei
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Joseph Bowness
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Bramman Rajkumar
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Tatyana Nesterova
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | | | | | - Neil Brockdorff
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK.
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23
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Cainero I, Cerutti E, Faretta M, Dellino GI, Pelicci PG, Bianchini P, Vicidomini G, Diaspro A, Lanzanò L. Chromatin investigation in the nucleus using a phasor approach to structured illumination microscopy. Biophys J 2021; 120:2566-2576. [PMID: 33940021 PMCID: PMC8390874 DOI: 10.1016/j.bpj.2021.04.027] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 04/14/2021] [Accepted: 04/26/2021] [Indexed: 12/17/2022] Open
Abstract
Chromatin in the nucleus is organized in functional sites at variable level of compaction. Structured illumination microscopy (SIM) can be used to generate three-dimensional super-resolution (SR) imaging of chromatin by changing in phase and in orientation a periodic line illumination pattern. The spatial frequency domain is the natural choice to process SIM raw data and to reconstruct an SR image. Using an alternative approach, we demonstrate that the additional spatial information encoded in the knowledge of the position of the illumination pattern can be efficiently decoded using a generalized version of separation of photon by lifetime tuning (SPLIT) that does not require lifetime measurements. In the resulting SPLIT-SIM, the SR image is obtained by isolating a fraction of the intensity corresponding to the center of the diffraction-limited point spread function. This extends the use of the SPLIT approach from stimulated emission depletion microscopy to SIM. The SPLIT-SIM algorithm is based only on phasor analysis and does not require deconvolution. We show that SPLIT-SIM can be used to generate SR images of chromatin organizational motifs with tunable resolution and can be a valuable tool for the imaging of functional sites in the nucleus.
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Affiliation(s)
- Isotta Cainero
- Nanoscopy and NIC@IIT, Istituto Italiano di Tecnologia, Genoa, Italy; Department of Physics, University of Genoa, Genoa, Italy
| | - Elena Cerutti
- Nanoscopy and NIC@IIT, Istituto Italiano di Tecnologia, Genoa, Italy; Department of Physics and Astronomy "Ettore Majorana", University of Catania, Catania, Italy
| | - Mario Faretta
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, Milan, Italy
| | - Gaetano Ivan Dellino
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, Milan, Italy; Department of Oncology and Hemato-Oncology, University of Milan, Milan, Italy
| | - Pier Giuseppe Pelicci
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, Milan, Italy; Department of Oncology and Hemato-Oncology, University of Milan, Milan, Italy
| | - Paolo Bianchini
- Nanoscopy and NIC@IIT, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Giuseppe Vicidomini
- Molecular Microscopy and Spectroscopy, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Alberto Diaspro
- Nanoscopy and NIC@IIT, Istituto Italiano di Tecnologia, Genoa, Italy; Department of Physics, University of Genoa, Genoa, Italy.
| | - Luca Lanzanò
- Nanoscopy and NIC@IIT, Istituto Italiano di Tecnologia, Genoa, Italy; Department of Physics and Astronomy "Ettore Majorana", University of Catania, Catania, Italy.
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24
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Rajakylä EK, Lehtimäki JI, Acheva A, Schaible N, Lappalainen P, Krishnan R, Tojkander S. Assembly of Peripheral Actomyosin Bundles in Epithelial Cells Is Dependent on the CaMKK2/AMPK Pathway. Cell Rep 2021; 30:4266-4280.e4. [PMID: 32209483 DOI: 10.1016/j.celrep.2020.02.096] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 12/02/2019] [Accepted: 12/26/2019] [Indexed: 12/13/2022] Open
Abstract
Defects in the maintenance of intercellular junctions are associated with loss of epithelial barrier function and consequent pathological conditions, including invasive cancers. Epithelial integrity is dependent on actomyosin bundles at adherens junctions, but the origin of these junctional bundles is incompletely understood. Here we show that peripheral actomyosin bundles can be generated from a specific actin stress fiber subtype, transverse arcs, through their lateral fusion at cell-cell contacts. Importantly, we find that assembly and maintenance of peripheral actomyosin bundles are dependent on the mechanosensitive CaMKK2/AMPK signaling pathway and that inhibition of this route leads to disruption of tension-maintaining actomyosin bundles and re-growth of stress fiber precursors. This results in redistribution of cellular forces, defects in monolayer integrity, and loss of epithelial identity. These data provide evidence that the mechanosensitive CaMKK2/AMPK pathway is critical for the maintenance of peripheral actomyosin bundles and thus dictates cell-cell junctions through cellular force distribution.
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Affiliation(s)
- Eeva Kaisa Rajakylä
- Section of Pathology, Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland
| | | | - Anna Acheva
- Section of Pathology, Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland
| | - Niccole Schaible
- Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Pekka Lappalainen
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Ramaswamy Krishnan
- Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Sari Tojkander
- Section of Pathology, Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland.
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25
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Wen G, Li S, Wang L, Chen X, Sun Z, Liang Y, Jin X, Xing Y, Jiu Y, Tang Y, Li H. High-fidelity structured illumination microscopy by point-spread-function engineering. LIGHT, SCIENCE & APPLICATIONS 2021; 10:70. [PMID: 33795640 PMCID: PMC8016956 DOI: 10.1038/s41377-021-00513-w] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 03/13/2021] [Accepted: 03/14/2021] [Indexed: 05/28/2023]
Abstract
Structured illumination microscopy (SIM) has become a widely used tool for insight into biomedical challenges due to its rapid, long-term, and super-resolution (SR) imaging. However, artifacts that often appear in SIM images have long brought into question its fidelity, and might cause misinterpretation of biological structures. We present HiFi-SIM, a high-fidelity SIM reconstruction algorithm, by engineering the effective point spread function (PSF) into an ideal form. HiFi-SIM can effectively reduce commonly seen artifacts without loss of fine structures and improve the axial sectioning for samples with strong background. In particular, HiFi-SIM is not sensitive to the commonly used PSF and reconstruction parameters; hence, it lowers the requirements for dedicated PSF calibration and complicated parameter adjustment, thus promoting SIM as a daily imaging tool.
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Affiliation(s)
- Gang Wen
- Jiangsu Key Laboratory of Medical Optics, CAS Center for Excellence in Molecular Cell Science, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, Jiangsu, 215163, China
- Academy for Engineering and Technology, Fudan University, Shanghai, 200433, China
| | - Simin Li
- Jiangsu Key Laboratory of Medical Optics, CAS Center for Excellence in Molecular Cell Science, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, Jiangsu, 215163, China
| | - Linbo Wang
- Jiangsu Key Laboratory of Medical Optics, CAS Center for Excellence in Molecular Cell Science, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, Jiangsu, 215163, China
| | - Xiaohu Chen
- Jiangsu Key Laboratory of Medical Optics, CAS Center for Excellence in Molecular Cell Science, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, Jiangsu, 215163, China
| | - Zhenglong Sun
- Jiangsu Key Laboratory of Medical Optics, CAS Center for Excellence in Molecular Cell Science, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, Jiangsu, 215163, China
| | - Yong Liang
- Jiangsu Key Laboratory of Medical Optics, CAS Center for Excellence in Molecular Cell Science, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, Jiangsu, 215163, China
| | - Xin Jin
- Jiangsu Key Laboratory of Medical Optics, CAS Center for Excellence in Molecular Cell Science, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, Jiangsu, 215163, China
| | - Yifan Xing
- The Center for Microbes, Development and Health, Key Laboratory of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Yaming Jiu
- The Center for Microbes, Development and Health, Key Laboratory of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Yuguo Tang
- Jiangsu Key Laboratory of Medical Optics, CAS Center for Excellence in Molecular Cell Science, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, Jiangsu, 215163, China.
| | - Hui Li
- Jiangsu Key Laboratory of Medical Optics, CAS Center for Excellence in Molecular Cell Science, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, Jiangsu, 215163, China.
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26
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Ercilla A, Benada J, Amitash S, Zonderland G, Baldi G, Somyajit K, Ochs F, Costanzo V, Lukas J, Toledo L. Physiological Tolerance to ssDNA Enables Strand Uncoupling during DNA Replication. Cell Rep 2021; 30:2416-2429.e7. [PMID: 32075739 DOI: 10.1016/j.celrep.2020.01.067] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 12/17/2019] [Accepted: 01/22/2020] [Indexed: 12/20/2022] Open
Abstract
It has been long assumed that normally leading strand synthesis must proceed coordinated with the lagging strand to prevent strand uncoupling and the pathological accumulation of single-stranded DNA (ssDNA) in the cell, a dogma recently challenged by in vitro studies in prokaryotes. Here, we report that human DNA polymerases can function independently at each strand in vivo and that the resulting strand uncoupling is supported physiologically by a cellular tolerance to ssDNA. Active forks rapidly accumulate ssDNA at the lagging strand when POLA1 is inhibited without triggering a stress response, despite ssDNA formation being considered a hallmark of replication stress. Acute POLA1 inhibition causes a lethal RPA exhaustion, but cells can duplicate their DNA with limited POLA1 activity and exacerbated strand uncoupling as long as RPA molecules suffice to protect the elevated ssDNA. Although robust, this uncoupled mode of DNA replication is also an in-built weakness that can be targeted for cancer treatment.
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Affiliation(s)
- Amaia Ercilla
- Center for Chromosome Stability, Institute for Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark
| | - Jan Benada
- Center for Chromosome Stability, Institute for Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark
| | - Sampath Amitash
- Center for Chromosome Stability, Institute for Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark
| | - Gijs Zonderland
- Center for Chromosome Stability, Institute for Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark
| | - Giorgio Baldi
- DNA Metabolism Laboratory, FIRC Institute for Molecular Oncology (IFOM), Milan 20139, Italy
| | - Kumar Somyajit
- Protein Signaling Program, Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark
| | - Fena Ochs
- Protein Signaling Program, Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark
| | - Vincenzo Costanzo
- DNA Metabolism Laboratory, FIRC Institute for Molecular Oncology (IFOM), Milan 20139, Italy
| | - Jiri Lukas
- Protein Signaling Program, Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark
| | - Luis Toledo
- Center for Chromosome Stability, Institute for Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark.
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27
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Lehtimäki JI, Rajakylä EK, Tojkander S, Lappalainen P. Generation of stress fibers through myosin-driven reorganization of the actin cortex. eLife 2021; 10:60710. [PMID: 33506761 PMCID: PMC7877910 DOI: 10.7554/elife.60710] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 01/27/2021] [Indexed: 12/26/2022] Open
Abstract
Contractile actomyosin bundles, stress fibers, govern key cellular processes including migration, adhesion, and mechanosensing. Stress fibers are thus critical for developmental morphogenesis. The most prominent actomyosin bundles, ventral stress fibers, are generated through coalescence of pre-existing stress fiber precursors. However, whether stress fibers can assemble through other mechanisms has remained elusive. We report that stress fibers can also form without requirement of pre-existing actomyosin bundles. These structures, which we named cortical stress fibers, are embedded in the cell cortex and assemble preferentially underneath the nucleus. In this process, non-muscle myosin II pulses orchestrate the reorganization of cortical actin meshwork into regular bundles, which promote reinforcement of nascent focal adhesions, and subsequent stabilization of the cortical stress fibers. These results identify a new mechanism by which stress fibers can be generated de novo from the actin cortex and establish role for stochastic myosin pulses in the assembly of functional actomyosin bundles.
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Affiliation(s)
- Jaakko I Lehtimäki
- HiLIFE Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Eeva Kaisa Rajakylä
- Section of Pathology, Department of Veterinary Biosciences, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Sari Tojkander
- Section of Pathology, Department of Veterinary Biosciences, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Pekka Lappalainen
- HiLIFE Institute of Biotechnology, University of Helsinki, Helsinki, Finland
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28
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Schneider F, Colin-York H, Fritzsche M. Quantitative Bio-Imaging Tools to Dissect the Interplay of Membrane and Cytoskeletal Actin Dynamics in Immune Cells. Front Immunol 2021; 11:612542. [PMID: 33505401 PMCID: PMC7829180 DOI: 10.3389/fimmu.2020.612542] [Citation(s) in RCA: 3] [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: 09/30/2020] [Accepted: 11/23/2020] [Indexed: 12/13/2022] Open
Abstract
Cellular function is reliant on the dynamic interplay between the plasma membrane and the actin cytoskeleton. This critical relationship is of particular importance in immune cells, where both the cytoskeleton and the plasma membrane work in concert to organize and potentiate immune signaling events. Despite their importance, there remains a critical gap in understanding how these respective dynamics are coupled, and how this coupling in turn may influence immune cell function from the bottom up. In this review, we highlight recent optical technologies that could provide strategies to investigate the simultaneous dynamics of both the cytoskeleton and membrane as well as their interplay, focusing on current and future applications in immune cells. We provide a guide of the spatio-temporal scale of each technique as well as highlighting novel probes and labels that have the potential to provide insights into membrane and cytoskeletal dynamics. The quantitative biophysical tools presented here provide a new and exciting route to uncover the relationship between plasma membrane and cytoskeletal dynamics that underlies immune cell function.
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Affiliation(s)
- Falk Schneider
- Medical Research Council (MRC) Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Huw Colin-York
- Medical Research Council (MRC) Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
- Kennedy Institute for Rheumatology, University of Oxford, Oxford, United Kingdom
| | - Marco Fritzsche
- Medical Research Council (MRC) Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
- Kennedy Institute for Rheumatology, University of Oxford, Oxford, United Kingdom
- Rosalind Franklin Institute, Harwell Campus, Didcot, United Kingdom
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29
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Fischl H, McManus D, Oldenkamp R, Schermelleh L, Mellor J, Jagannath A, Furger A. Cold-induced chromatin compaction and nuclear retention of clock mRNAs resets the circadian rhythm. EMBO J 2020; 39:e105604. [PMID: 33034091 PMCID: PMC7667876 DOI: 10.15252/embj.2020105604] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 08/28/2020] [Accepted: 08/29/2020] [Indexed: 12/22/2022] Open
Abstract
Cooling patients to sub‐physiological temperatures is an integral part of modern medicine. We show that cold exposure induces temperature‐specific changes to the higher‐order chromatin and gene expression profiles of human cells. These changes are particularly dramatic at 18°C, a temperature synonymous with that experienced by patients undergoing controlled deep hypothermia during surgery. Cells exposed to 18°C exhibit largely nuclear‐restricted transcriptome changes. These include the nuclear accumulation of mRNAs encoding components of the negative limbs of the core circadian clock, most notably REV‐ERBα. This response is accompanied by compaction of higher‐order chromatin and hindrance of mRNPs from engaging nuclear pores. Rewarming reverses chromatin compaction and releases the transcripts into the cytoplasm, triggering a pulse of negative limb gene proteins that reset the circadian clock. We show that cold‐induced upregulation of REV‐ERBα is sufficient to trigger this reset. Our findings uncover principles of the cellular cold response that must be considered for current and future applications involving therapeutic deep hypothermia.
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Affiliation(s)
- Harry Fischl
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - David McManus
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Roel Oldenkamp
- Department of Biochemistry, University of Oxford, Oxford, UK
| | | | - Jane Mellor
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Aarti Jagannath
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - André Furger
- Department of Biochemistry, University of Oxford, Oxford, UK
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30
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A protein assembly mediates Xist localization and gene silencing. Nature 2020; 587:145-151. [PMID: 32908311 PMCID: PMC7644664 DOI: 10.1038/s41586-020-2703-0] [Citation(s) in RCA: 103] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Accepted: 06/17/2020] [Indexed: 12/22/2022]
Abstract
Nuclear compartments play diverse roles in regulating gene expression, yet the molecular forces and components driving compartment formation remain largely unclear1. The long non-coding RNA Xist establishes an intra-chromosomal compartment by localizing at a high concentration in a territory spatially close to its transcription locus2 and binding diverse proteins3–5 to achieve X-chromosome inactivation (XCI)6,7. The XCI-process therefore serves as paradigm for understanding how RNA-mediated recruitment of diffusible proteins induces a functional compartment. Interestingly, the properties of the inactive X (Xi)-compartment change over time because upon initial Xist spreading and transcriptional shutoff a state is reached where gene silencing remains stable even if Xist is turned off8. Here, we show that the Xist RNA-binding-proteins (RBPs) PTBP19, MATR310, TDP4311, and CELF112 assemble on the multivalent E-repeat-element of Xist7 and, via self-aggregation and heterotypic protein-protein interactions, form a condensate1 in the Xi. This condensate is required for gene silencing and anchoring of Xist to the Xi-territory and can be sustained in the absence of Xist. Notably, these E-repeat-binding RBPs become essential coincident with transition to the Xist-independent XCI-phase8, indicating that the condensate seeded by the E-repeat underlies the developmental switch from Xist-dependence to Xist-independence. Taken together, our data reveal that Xist forms the Xi-compartment by seeding a heteromeric condensate consisting of ubiquitous RBPs and uncover an unanticipated mechanism for heritable gene silencing.
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31
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Miron E, Oldenkamp R, Brown JM, Pinto DMS, Xu CS, Faria AR, Shaban HA, Rhodes JDP, Innocent C, de Ornellas S, Hess HF, Buckle V, Schermelleh L. Chromatin arranges in chains of mesoscale domains with nanoscale functional topography independent of cohesin. SCIENCE ADVANCES 2020; 6:eaba8811. [PMID: 32967822 PMCID: PMC7531892 DOI: 10.1126/sciadv.aba8811] [Citation(s) in RCA: 90] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 08/06/2020] [Indexed: 05/05/2023]
Abstract
Three-dimensional (3D) chromatin organization plays a key role in regulating mammalian genome function; however, many of its physical features at the single-cell level remain underexplored. Here, we use live- and fixed-cell 3D super-resolution and scanning electron microscopy to analyze structural and functional nuclear organization in somatic cells. We identify chains of interlinked ~200- to 300-nm-wide chromatin domains (CDs) composed of aggregated nucleosomes that can overlap with individual topologically associating domains and are distinct from a surrounding RNA-populated interchromatin compartment. High-content mapping uncovers confinement of cohesin and active histone modifications to surfaces and enrichment of repressive modifications toward the core of CDs in both hetero- and euchromatic regions. This nanoscale functional topography is temporarily relaxed in postreplicative chromatin but remarkably persists after ablation of cohesin. Our findings establish CDs as physical and functional modules of mesoscale genome organization.
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Affiliation(s)
- Ezequiel Miron
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Roel Oldenkamp
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Jill M Brown
- MRC Weatherall Institute of Molecular Medicine, Haematology Unit, University of Oxford, Oxford OX3 9DS, UK
| | - David M S Pinto
- Micron Oxford Advanced Bioimaging Unit, University of Oxford, Oxford OX1 3QU, UK
| | - C Shan Xu
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Ana R Faria
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Haitham A Shaban
- Spectroscopy Department, Physics Division, National Research Centre, 12622 Dokki, Cairo, Egypt
| | - James D P Rhodes
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | | | - Sara de Ornellas
- MRC Weatherall Institute of Molecular Medicine, Haematology Unit, University of Oxford, Oxford OX3 9DS, UK
| | - Harald F Hess
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Veronica Buckle
- MRC Weatherall Institute of Molecular Medicine, Haematology Unit, University of Oxford, Oxford OX3 9DS, UK
| | - Lothar Schermelleh
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK.
- Micron Oxford Advanced Bioimaging Unit, University of Oxford, Oxford OX1 3QU, UK
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32
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Schubert V, Neumann P, Marques A, Heckmann S, Macas J, Pedrosa-Harand A, Schubert I, Jang TS, Houben A. Super-Resolution Microscopy Reveals Diversity of Plant Centromere Architecture. Int J Mol Sci 2020; 21:E3488. [PMID: 32429054 PMCID: PMC7278974 DOI: 10.3390/ijms21103488] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 05/11/2020] [Accepted: 05/11/2020] [Indexed: 12/20/2022] Open
Abstract
Centromeres are essential for proper chromosome segregation to the daughter cells during mitosis and meiosis. Chromosomes of most eukaryotes studied so far have regional centromeres that form primary constrictions on metaphase chromosomes. These monocentric chromosomes vary from point centromeres to so-called "meta-polycentromeres", with multiple centromere domains in an extended primary constriction, as identified in Pisum and Lathyrus species. However, in various animal and plant lineages centromeres are distributed along almost the entire chromosome length. Therefore, they are called holocentromeres. In holocentric plants, centromere-specific proteins, at which spindle fibers usually attach, are arranged contiguously (line-like), in clusters along the chromosomes or in bands. Here, we summarize findings of ultrastructural investigations using immunolabeling with centromere-specific antibodies and super-resolution microscopy to demonstrate the structural diversity of plant centromeres. A classification of the different centromere types has been suggested based on the distribution of spindle attachment sites. Based on these findings we discuss the possible evolution and advantages of holocentricity, and potential strategies to segregate holocentric chromosomes correctly.
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Affiliation(s)
- Veit Schubert
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, 06466 Seeland, Germany; (S.H.); (I.S.); (A.H.)
| | - Pavel Neumann
- Biology Centre, Czech Academy of Sciences, 37005 České Budějovice, Czech Republic; (P.N.); (J.M.); (T.-S.J.)
| | - André Marques
- Department of Chromosome Biology, Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany;
| | - Stefan Heckmann
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, 06466 Seeland, Germany; (S.H.); (I.S.); (A.H.)
| | - Jiri Macas
- Biology Centre, Czech Academy of Sciences, 37005 České Budějovice, Czech Republic; (P.N.); (J.M.); (T.-S.J.)
| | - Andrea Pedrosa-Harand
- Department of Botany, Federal University of Pernambuco (UFPE), Recife 50670-901, Pernambuco, Brazil;
| | - Ingo Schubert
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, 06466 Seeland, Germany; (S.H.); (I.S.); (A.H.)
| | - Tae-Soo Jang
- Biology Centre, Czech Academy of Sciences, 37005 České Budějovice, Czech Republic; (P.N.); (J.M.); (T.-S.J.)
- Department of Biological Sciences, Chungnam National University, Daejeon 34134, Korea
| | - Andreas Houben
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, 06466 Seeland, Germany; (S.H.); (I.S.); (A.H.)
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Abstract
Mitochondria are essential for eukaryotic life. These double-membrane organelles often form highly dynamic tubular networks interacting with many cellular structures. Their highly convoluted contiguous inner membrane compartmentalizes the organelle, which is crucial for mitochondrial function. Since the diameter of the mitochondrial tubules is generally close to the diffraction limit of light microscopy, it is often challenging, if not impossible, to visualize submitochondrial structures or protein distributions using conventional light microscopy. This renders super-resolution microscopy particularly valuable, and attractive, for studying mitochondria. Super-resolution microscopy encompasses a diverse set of approaches that extend resolution, as well as nanoscopy techniques that can even overcome the diffraction limit. In this review, we provide an overview of recent studies using super-resolution microscopy to investigate mitochondria, discuss the strengths and opportunities of the various methods in addressing specific questions in mitochondrial biology, and highlight potential future developments.
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Affiliation(s)
- Stefan Jakobs
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany;
- Clinic of Neurology, University Medical Center Göttingen, 37075 Göttingen, Germany
| | - Till Stephan
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany;
- Clinic of Neurology, University Medical Center Göttingen, 37075 Göttingen, Germany
| | - Peter Ilgen
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany;
- Clinic of Neurology, University Medical Center Göttingen, 37075 Göttingen, Germany
| | - Christian Brüser
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany;
- Clinic of Neurology, University Medical Center Göttingen, 37075 Göttingen, Germany
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Maiser A, Dillinger S, Längst G, Schermelleh L, Leonhardt H, Németh A. Super-resolution in situ analysis of active ribosomal DNA chromatin organization in the nucleolus. Sci Rep 2020; 10:7462. [PMID: 32366902 PMCID: PMC7198602 DOI: 10.1038/s41598-020-64589-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 04/01/2020] [Indexed: 12/21/2022] Open
Abstract
Ribosomal RNA (rRNA) transcription by RNA polymerase I (Pol I) is the first key step of ribosome biogenesis. While the molecular mechanisms of rRNA transcription regulation have been elucidated in great detail, the functional organization of the multicopy rRNA gene clusters (rDNA) in the nucleolus is less well understood. Here we apply super-resolution 3D structured illumination microscopy (3D-SIM) to investigate the spatial organization of transcriptionally competent active rDNA chromatin at size scales well below the diffraction limit by optical microscopy. We identify active rDNA chromatin units exhibiting uniformly ring-shaped conformations with diameters of ~240 nm in mouse and ~170 nm in human fibroblasts, consistent with rDNA looping. The active rDNA chromatin units are clearly separated from each other and from the surrounding areas of rRNA processing. Simultaneous imaging of all active genes bound by Pol I and the architectural chromatin protein Upstream Binding Transcription Factor (UBF) reveals a random spatial orientation of regular repeats of rDNA coding sequences within the nucleoli. These observations imply rDNA looping and exclude potential formation of systematic spatial assemblies of the well-ordered repetitive arrays of transcription units. Collectively, this study uncovers key features of the 3D organization of active rDNA chromatin units and their nucleolar clusters providing a spatial framework of nucleolar chromatin organization at unprecedented detail.
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Affiliation(s)
- Andreas Maiser
- Department of Biology II, Ludwig-Maximilians-Universität München, München, Germany
| | - Stefan Dillinger
- Department of Biochemistry III, University of Regensburg, Regensburg, Germany
| | - Gernot Längst
- Department of Biochemistry III, University of Regensburg, Regensburg, Germany
| | - Lothar Schermelleh
- Micron Advanced Bioimaging Unit, Department of Biochemistry, University of Oxford, Oxford, UK
| | - Heinrich Leonhardt
- Department of Biology II, Ludwig-Maximilians-Universität München, München, Germany
| | - Attila Németh
- Department of Biochemistry III, University of Regensburg, Regensburg, Germany.
- Institute of Neuropathology, Justus Liebig University, Giessen, Germany.
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35
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A Modified Magnified Analysis of Proteome (MAP) Method for Super-Resolution Cell Imaging that Retains Fluorescence. Sci Rep 2020; 10:4186. [PMID: 32144302 PMCID: PMC7060248 DOI: 10.1038/s41598-020-61156-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 02/21/2020] [Indexed: 12/03/2022] Open
Abstract
Biological systems consist of a variety of distinct cell types that form functional networks. Super-resolution imaging of individual cells is required for better understanding of these complex systems. Direct visualization of 3D subcellular and nano-scale structures in cells is helpful for the interpretation of biological interactions and system-level responses. Here we introduce a modified magnified analysis of proteome (MAP) method for cell super-resolution imaging (Cell-MAP) which preserves cell fluorescence. Cell-MAP expands cells more than four-fold while preserving their overall architecture and three-dimensional proteome organization after hydrogel embedding. In addition, Optimized-Cell-MAP completely preserves fluorescence and successfully allows for the observation of tagged small molecular probes containing peptides and microRNAs. Optimized-Cell-MAP further successfully applies to the study of structural characteristics and the identification of small molecules and organelles in mammalian cells. These results may give rise to many other applications related to the structural and molecular analysis of smaller assembled biological systems.
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36
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Organization of the Escherichia coli Chromosome by a MukBEF Axial Core. Mol Cell 2020; 78:250-260.e5. [PMID: 32097603 PMCID: PMC7163298 DOI: 10.1016/j.molcel.2020.02.003] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 12/03/2019] [Accepted: 02/03/2020] [Indexed: 01/22/2023]
Abstract
Structural maintenance of chromosomes (SMC) complexes organize chromosomes ubiquitously, thereby contributing to their faithful segregation. We demonstrate that under conditions of increased chromosome occupancy of the Escherichia coli SMC complex, MukBEF, the chromosome is organized as a series of loops around a thin (<130 nm) MukBEF axial core, whose length is ∼1,100 times shorter than the chromosomal DNA. The linear order of chromosomal loci is maintained in the axial cores, whose formation requires MukBEF ATP hydrolysis. Axial core structure in non-replicating chromosomes is predominantly linear (1 μm) but becomes circular (1.5 μm) in the absence of MatP because of its failure to displace MukBEF from the 800 kbp replication termination region (ter). Displacement of MukBEF from ter by MatP in wild-type cells directs MukBEF colocalization with the replication origin. We conclude that MukBEF individualizes and compacts the chromosome lengthwise, demonstrating a chromosome organization mechanism similar to condensin in mitotic chromosome formation. MukBEF forms a chromosome axial core dependent on ATP hydrolysis MukBEF compacts the chromosome lengthwise while avoiding links between replichores MatP determines the shape of the axial core by displacing MukBEF from ter The displacement by MatP directs MukBEF colocalization with the replication origin
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37
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Otterstrom J, Castells-Garcia A, Vicario C, Gomez-Garcia PA, Cosma MP, Lakadamyali M. Super-resolution microscopy reveals how histone tail acetylation affects DNA compaction within nucleosomes in vivo. Nucleic Acids Res 2019; 47:8470-8484. [PMID: 31287868 PMCID: PMC6895258 DOI: 10.1093/nar/gkz593] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 05/31/2019] [Accepted: 07/04/2019] [Indexed: 01/28/2023] Open
Abstract
Chromatin organization is crucial for regulating gene expression. Previously, we showed that nucleosomes form groups, termed clutches. Clutch size correlated with the pluripotency grade of mouse embryonic stem cells and human induced pluripotent stem cells. Recently, it was also shown that regions of the chromatin containing activating epigenetic marks were composed of small and dispersed chromatin nanodomains with lower DNA density compared to the larger silenced domains. Overall, these results suggest that clutch size may regulate DNA packing density and gene activity. To directly test this model, we carried out 3D, two-color super-resolution microscopy of histones and DNA with and without increased histone tail acetylation. Our results showed that lower percentage of DNA was associated with nucleosome clutches in hyperacetylated cells. We further showed that the radius and compaction level of clutch-associated DNA decreased in hyperacetylated cells, especially in regions containing several neighboring clutches. Importantly, this change was independent of clutch size but dependent on the acetylation state of the clutch. Our results directly link the epigenetic state of nucleosome clutches to their DNA packing density. Our results further provide in vivo support to previous in vitro models that showed a disruption of nucleosome-DNA interactions upon hyperacetylation.
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Affiliation(s)
- Jason Otterstrom
- ICFO-Institute of Photonic Sciences, Barcelona Institute of Science and Technology, Barcelona
| | - Alvaro Castells-Garcia
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona 08003, Spain
| | - Chiara Vicario
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona 08003, Spain
| | - Pablo A Gomez-Garcia
- ICFO-Institute of Photonic Sciences, Barcelona Institute of Science and Technology, Barcelona.,Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona 08003, Spain
| | - Maria Pia Cosma
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona 08003, Spain.,Universitat Pompeu Fabra (UPF), Barcelona, Spain.,ICREA, Pg. Lluis Companys 23, Barcelona 08010, Spain.,Guangzhou Regenerative Medicine and Health Guangdong Laboratory (GRMH-GDL), Guangzhou 510005, China.,Key Laboratory of Regenerative Biology and Guangdong Provincial Key Laboratory of Stem Cells and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Science, Guangzhou 510530, China
| | - Melike Lakadamyali
- ICFO-Institute of Photonic Sciences, Barcelona Institute of Science and Technology, Barcelona.,Perelman School of Medicine, Department of Physiology, University of Pennsylvania, Clinical Research Building, 415 Curie Boulevard, Philadelphia, PA 19104, USA
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38
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Ochs F, Karemore G, Miron E, Brown J, Sedlackova H, Rask MB, Lampe M, Buckle V, Schermelleh L, Lukas J, Lukas C. Stabilization of chromatin topology safeguards genome integrity. Nature 2019; 574:571-574. [DOI: 10.1038/s41586-019-1659-4] [Citation(s) in RCA: 104] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 09/10/2019] [Indexed: 11/10/2022]
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39
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Adaptive wavefront correction structured illumination holographic tomography. Sci Rep 2019; 9:10489. [PMID: 31324823 PMCID: PMC6642122 DOI: 10.1038/s41598-019-46951-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 06/13/2019] [Indexed: 01/10/2023] Open
Abstract
In this study, a novel adaptive wavefront correction (AWC) technique is implemented on a compactly developed structured illumination holographic tomography (SI-HT) system. We propose a mechanical movement-free compact scanning architecture for SI-HT systems with AWC, implemented by designing and displaying a series of computer-generated holograms (CGH) composed of blazed grating with phase Fresnel lens on a phase-only spatial light modulator (SLM). In the proposed SI-HT, the aberrations of the optical system are sensed by digital holography and are used to design the CGH-based AWC to compensate the phase aberrations of the tomographic imaging system. The proposed method was validated using a standard Siemens star target, its potential application was demonstrated using a live candida rugosa sample, and its label-free three-dimensional refractive index profile was generated at its subcellular level. The experimental results obtained reveal the ability of the proposed method to enhance the imaging performance in both lateral and axial directions.
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40
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Zhang Y, Lang S, Wang H, Liao J, Gong Y. Super-resolution algorithm based on Richardson-Lucy deconvolution for three-dimensional structured illumination microscopy. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2019; 36:173-178. [PMID: 30874094 DOI: 10.1364/josaa.36.000173] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 12/11/2018] [Indexed: 05/21/2023]
Abstract
Three-dimensional structured illumination microscopy (3D-SIM) is a wide-field super-resolution technique in fluorescent imaging that can double the resolution beyond its classical limit. We introduce, to the best of our knowledge, a new 3D reconstruction algorithm based on the Richardson-Lucy deconvolution. The 3D-SIM imaging principle and the reconstruction steps are demonstrated in detail. Microspheres and biological specimen are used to present the performance of this method. The background of the out-of-focus portion is effectively suppressed, and true optical sectioning and super-resolution can be achieved simultaneously. For the custom-built 3D-SIM and this reconstruction algorithm, the measured resolution was 99.5±5 nm laterally and 294±9 nm axially.
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41
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Schermelleh L, Ferrand A, Huser T, Eggeling C, Sauer M, Biehlmaier O, Drummen GPC. Super-resolution microscopy demystified. Nat Cell Biol 2019; 21:72-84. [PMID: 30602772 DOI: 10.1038/s41556-018-0251-8] [Citation(s) in RCA: 553] [Impact Index Per Article: 110.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Accepted: 11/12/2018] [Indexed: 02/08/2023]
Abstract
Super-resolution microscopy (SRM) bypasses the diffraction limit, a physical barrier that restricts the optical resolution to roughly 250 nm and was previously thought to be impenetrable. SRM techniques allow the visualization of subcellular organization with unprecedented detail, but also confront biologists with the challenge of selecting the best-suited approach for their particular research question. Here, we provide guidance on how to use SRM techniques advantageously for investigating cellular structures and dynamics to promote new discoveries.
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Affiliation(s)
- Lothar Schermelleh
- Micron Oxford Advanced Bioimaging Unit, Department of Biochemistry, University of Oxford, Oxford, UK.
| | - Alexia Ferrand
- Imaging Core Facility, Biozentrum, University of Basel, Basel, Switzerland
| | - Thomas Huser
- Biomolecular Photonics, Department of Physics, University of Bielefeld, Bielefeld, Germany
| | - Christian Eggeling
- MRC Human Immunology Unit and Wolfson Imaging Centre Oxford, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
- Institute for Applied Optics, Friedrich-Schiller-University Jena & Leibniz Institute of Photonic Technology, Jena, Germany
| | - Markus Sauer
- Department of Biotechnology & Biophysics, Biocenter, Julius Maximilian University of Würzburg, Würzburg, Germany
| | - Oliver Biehlmaier
- Imaging Core Facility, Biozentrum, University of Basel, Basel, Switzerland
| | - Gregor P C Drummen
- Advanced Bio-Imaging Program, Bio&Nano Solutions‒LAB3BIO, Bielefeld, Germany.
- ICON-Europe.org, Exxilon Scientific Events, Steinhagen, Germany.
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42
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Vavrdová T, Šamajová O, Křenek P, Ovečka M, Floková P, Šnaurová R, Šamaj J, Komis G. Multicolour three dimensional structured illumination microscopy of immunolabeled plant microtubules and associated proteins. PLANT METHODS 2019; 15:22. [PMID: 30899319 PMCID: PMC6408805 DOI: 10.1186/s13007-019-0406-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 02/26/2019] [Indexed: 05/04/2023]
Abstract
BACKGROUND In the present work, we provide an account of structured illumination microscopy (SIM) imaging of fixed and immunolabeled plant probes. We take advantage of SIM, to superresolve intracellular structures at a considerable z-range and circumvent its low temporal resolution capacity during the study of living samples. Further, we validate the protocol for the imaging of fixed transgenic material expressing fluorescent protein-based markers of different subcellular structures. RESULTS Focus is given on 3D imaging of bulky subcellular structures, such as mitotic and cytokinetic microtubule arrays as well as on the performance of SIM using multichannel imaging and the quantitative correlations that can be deduced. As a proof of concept, we provide a superresolution output on the organization of cortical microtubules in wild-type and mutant Arabidopsis cells, including aberrant preprophase microtubule bands and phragmoplasts in a cytoskeletal mutant devoid of the p60 subunit of the microtubule severing protein KATANIN and refined details of cytoskeletal aberrations in the mitogen activated protein kinase (MAPK) mutant mpk4. We further demonstrate, in a qualitative and quantitative manner, colocalizations between MPK6 and unknown dually phosphorylated and activated MAPK species and we follow the localization of the microtubule associated protein 65-3 (MAP65-3) in telophase and cytokinetic microtubular arrays. CONCLUSIONS 3D SIM is a powerful, versatile and adaptable microscopy method for elucidating spatial relationships between subcellular compartments. Improved methods of sample preparation aiming to the compensation of refractive index mismatches, allow the use of 3D SIM in the documentation of complex plant cell structures, such as microtubule arrays and the elucidation of their interactions with microtubule associated proteins.
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Affiliation(s)
- T. Vavrdová
- Department of Cell Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University Olomouc, Olomouc, Czech Republic
| | - O. Šamajová
- Department of Cell Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University Olomouc, Olomouc, Czech Republic
| | - P. Křenek
- Department of Cell Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University Olomouc, Olomouc, Czech Republic
| | - M. Ovečka
- Department of Cell Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University Olomouc, Olomouc, Czech Republic
| | - P. Floková
- Department of Cell Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University Olomouc, Olomouc, Czech Republic
| | - R. Šnaurová
- Department of Cell Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University Olomouc, Olomouc, Czech Republic
| | - J. Šamaj
- Department of Cell Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University Olomouc, Olomouc, Czech Republic
| | - G. Komis
- Department of Cell Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University Olomouc, Olomouc, Czech Republic
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43
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Chen Y, Liu W, Zhang Z, Zheng C, Huang Y, Cao R, Zhu D, Xu L, Zhang M, Zhang YH, Fan J, Jin L, Xu Y, Kuang C, Liu X. Multi-color live-cell super-resolution volume imaging with multi-angle interference microscopy. Nat Commun 2018; 9:4818. [PMID: 30446673 PMCID: PMC6240104 DOI: 10.1038/s41467-018-07244-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 10/23/2018] [Indexed: 12/17/2022] Open
Abstract
Imaging and tracking of near-surface three-dimensional volumetric nanoscale dynamic processes of live cells remains a challenging problem. In this paper, we propose a multi-color live-cell near-surface-volume super-resolution microscopy method that combines total internal reflection fluorescence structured illumination microscopy with multi-angle evanescent light illumination. We demonstrate that our approach of multi-angle interference microscopy is perfectly adapted to studying subcellular dynamics of mitochondria and microtubule architectures during cell migration. 3D super-resolution imaging of dynamic processes in live cells is still challenging, especially in a large field of view. Here the authors combine SIM with multi-angle evanescent light illumination and achieve improved lateral and axial resolution, with stack acquisition time in the range of 1–2 s.
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Affiliation(s)
- Youhua Chen
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, 310027, China.,Shanxi Provincial Key Laboratory for Biomedical Imaging and Big Data, North University of China, Taiyuan, Shanxi, 030051, China
| | - Wenjie Liu
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, 310027, China
| | - Zhimin Zhang
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, 310027, China
| | - Cheng Zheng
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, 310027, China
| | - Yujia Huang
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, 310027, China
| | - Ruizhi Cao
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, 310027, China
| | - Dazhao Zhu
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, 310027, China
| | - Liang Xu
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, 310027, China
| | - Meng Zhang
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei, 430074, China
| | - Yu-Hui Zhang
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan, Hubei, 430074, China
| | - Jiannan Fan
- Key Laboratory for Biomedical Engineering of Ministry of Education, Department of Biomedical Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Luhong Jin
- Key Laboratory for Biomedical Engineering of Ministry of Education, Department of Biomedical Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Yingke Xu
- Key Laboratory for Biomedical Engineering of Ministry of Education, Department of Biomedical Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Cuifang Kuang
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, 310027, China. .,Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi, 030006, China.
| | - Xu Liu
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, 310027, China. .,Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi, 030006, China.
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44
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Mitrea DM, Chandra B, Ferrolino MC, Gibbs EB, Tolbert M, White MR, Kriwacki RW. Methods for Physical Characterization of Phase-Separated Bodies and Membrane-less Organelles. J Mol Biol 2018; 430:4773-4805. [PMID: 30017918 PMCID: PMC6503534 DOI: 10.1016/j.jmb.2018.07.006] [Citation(s) in RCA: 105] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 07/04/2018] [Accepted: 07/09/2018] [Indexed: 12/17/2022]
Abstract
Membrane-less organelles are cellular structures which arise through the phenomenon of phase separation. This process enables compartmentalization of specific sets of macromolecules (e.g., proteins, nucleic acids), thereby regulating cellular processes by increasing local concentration, and modulating the structure and dynamics of their constituents. Understanding the connection between structure, material properties and function of membrane-less organelles requires inter-disciplinary approaches, which address length and timescales that span several orders of magnitude (e.g., Ångstroms to micrometer, picoseconds to hours). In this review, we discuss the wide variety of methods that have been applied to characterize the morphology, rheology, structure and dynamics of membrane-less organelles and their components, in vitro and in live cells.
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Affiliation(s)
- Diana M Mitrea
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
| | - Bappaditya Chandra
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Mylene C Ferrolino
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Eric B Gibbs
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Michele Tolbert
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Michael R White
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Richard W Kriwacki
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA; Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Sciences Center, Memphis, TN 38163, USA.
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45
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Szczurek A, Contu F, Hoang A, Dobrucki J, Mai S. Aqueous mounting media increasing tissue translucence improve image quality in Structured Illumination Microscopy of thick biological specimen. Sci Rep 2018; 8:13971. [PMID: 30228281 PMCID: PMC6143540 DOI: 10.1038/s41598-018-32191-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 08/14/2018] [Indexed: 01/08/2023] Open
Abstract
Structured Illumination Microscopy (SIM) is a super-resolution microscopy method that has significantly advanced studies of cellular structures. It relies on projection of illumination patterns onto a fluorescently labelled biological sample. The information derived from the sample is then shifted to a detectable band, and in the process of image calculation in Fourier space the resolution is doubled. Refractive index homogeneity along the optical path is crucial to maintain a highly modulated illumination pattern necessary for high-quality SIM. This applies in particular to thick samples consisting of large cells and tissues. Surprisingly, sample mounting media for SIM have not undergone a significant evolution for almost a decade. Through identification and systematic evaluation of a number of non-hazardous, water-soluble chemical components of mounting media, we demonstrate an unprecedented improvement in SIM-image quality. Mounting solutions presented in this research are capable of reducing abundant light scattering which constitutes the limiting factor in 3D-SIM imaging of large Hodgkin's lymphoma and embryonic stem cells as well as 10 µm tissue sections. Moreover, we demonstrate usefulness of some of the media in single molecule localisation microscopy. The results presented here are of importance for standardisation of 3D-SIM data acquisition pipelines for an expanding community of users.
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Affiliation(s)
- Aleksander Szczurek
- University of Manitoba, Cancer Care Manitoba, Winnipeg, 675 McDermot Ave, R3E 0V9, Canada
- Department of Cell Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Gronostajowa 7, 30-387, Poland
| | - Fabio Contu
- University of Manitoba, Cancer Care Manitoba, Winnipeg, 675 McDermot Ave, R3E 0V9, Canada
- University of Cagliari, Unit of Biology and Genetics, Department of Biomedical Sciences, S. P. Monserrato, Sestu Km 0.700, Cagliari, 09042, Italy
| | - Agnieszka Hoang
- Department of Cell Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Gronostajowa 7, 30-387, Poland
| | - Jurek Dobrucki
- Department of Cell Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Gronostajowa 7, 30-387, Poland
| | - Sabine Mai
- University of Manitoba, Cancer Care Manitoba, Winnipeg, 675 McDermot Ave, R3E 0V9, Canada.
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Accurate and fiducial-marker-free correction for three-dimensional chromatic shift in biological fluorescence microscopy. Sci Rep 2018; 8:7583. [PMID: 29765093 PMCID: PMC5954143 DOI: 10.1038/s41598-018-25922-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 05/02/2018] [Indexed: 11/09/2022] Open
Abstract
Correction of chromatic shift is necessary for precise registration of multicolor fluorescence images of biological specimens. New emerging technologies in fluorescence microscopy with increasing spatial resolution and penetration depth have prompted the need for more accurate methods to correct chromatic aberration. However, the amount of chromatic shift of the region of interest in biological samples often deviates from the theoretical prediction because of unknown dispersion in the biological samples. To measure and correct chromatic shift in biological samples, we developed a quadrisection phase correlation approach to computationally calculate translation, rotation, and magnification from reference images. Furthermore, to account for local chromatic shifts, images are split into smaller elements, for which the phase correlation between channels is measured individually and corrected accordingly. We implemented this method in an easy-to-use open-source software package, called Chromagnon, that is able to correct shifts with a 3D accuracy of approximately 15 nm. Applying this software, we quantified the level of uncertainty in chromatic shift correction, depending on the imaging modality used, and for different existing calibration methods, along with the proposed one. Finally, we provide guidelines to choose the optimal chromatic shift registration method for any given situation.
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Superresolution imaging of individual replication forks reveals unexpected prodrug resistance mechanism. Proc Natl Acad Sci U S A 2018; 115:E1366-E1373. [PMID: 29378947 DOI: 10.1073/pnas.1714790115] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Many drugs require extensive metabolism en route to their targets. High-resolution visualization of prodrug metabolism should therefore utilize analogs containing a small modification that does not interfere with its metabolism or mode of action. In addition to serving as mechanistic probes, such analogs provide candidates for theranostics when applied in both therapeutic and diagnostic modalities. Here a traceable mimic of the widely used anticancer prodrug cytarabine (ara-C) was generated by converting a single hydroxyl group to azide, giving "AzC." This compound exhibited the same biological profile as ara-C in cell cultures and zebrafish larvae. Using azide-alkyne "click" reactions, we uncovered an apparent contradiction: drug-resistant cells incorporated relatively large quantities of AzC into their genomes and entered S-phase arrest, whereas drug-sensitive cells incorporated only small quantities of AzC. Fluorescence microscopy was used to elucidate structural features associated with drug resistance by characterizing the architectures of stalled DNA replication foci containing AzC, EdU, γH2AX, and proliferating cell nuclear antigen (PCNA). Three-color superresolution imaging revealed replication foci containing one, two, or three partially resolved replication forks. Upon removing AzC from the media, resumption of DNA synthesis and completion of the cell cycle occurred before complete removal of AzC from genomes in vitro and in vivo. These results revealed an important mechanism for the low toxicity of ara-C toward normal tissues and drug-resistant cancer cells, where its efficient incorporation into DNA gives rise to highly stable, stalled replication forks that limit further incorporation of the drug, yet allow for the resumption of DNA synthesis and cellular division following treatment.
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48
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Hirano Y, Kinugasa Y, Asakawa H, Chikashige Y, Obuse C, Haraguchi T, Hiraoka Y. Lem2 is retained at the nuclear envelope through its interaction with Bqt4 in fission yeast. Genes Cells 2018; 23:122-135. [PMID: 29292846 DOI: 10.1111/gtc.12557] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 12/04/2017] [Indexed: 12/31/2022]
Abstract
Inner nuclear membrane (INM) proteins are thought to play important roles in modulating nuclear organization and function through their interactions with chromatin. However, these INM proteins share redundant functions in metazoans that pose difficulties for functional studies. The fission yeast Schizosaccharomyces pombe exhibits a relatively small number of INM proteins, and molecular genetic tools are available to separate their redundant functions. In S. pombe, it has been reported that among potentially redundant INM proteins, Lem2 displays a unique genetic interaction with another INM protein, Bqt4, which is involved in anchoring telomeres to the nuclear envelope. Double mutations in the lem2 and bqt4 genes confer synthetic lethality during vegetative growth. Here, we show that Lem2 is retained at the nuclear envelope through its interaction with Bqt4, as the loss of Bqt4 results in the exclusive accumulation of Lem2 to the spindle pole body (SPB). An N-terminal nucleoplasmic region of Lem2 bears affinity to both Bqt4 and the SPB in a competitive manner. In contrast, the synthetic lethality of the lem2 bqt4 double mutant is suppressed by the C-terminal region of Lem2. These results indicate that the N-terminal and C-terminal domains of Lem2 show independent functions with respect to Bqt4.
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Affiliation(s)
- Yasuhiro Hirano
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | - Yasuha Kinugasa
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | - Haruhiko Asakawa
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | - Yuji Chikashige
- Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology, Kobe, Japan
| | - Chikashi Obuse
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka, Japan.,Graduate School of Life Science, Hokkaido University, Sapporo, Japan
| | - Tokuko Haraguchi
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan.,Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology, Kobe, Japan
| | - Yasushi Hiraoka
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan.,Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology, Kobe, Japan
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49
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Halpern AR, Alas GCM, Chozinski TJ, Paredez AR, Vaughan JC. Hybrid Structured Illumination Expansion Microscopy Reveals Microbial Cytoskeleton Organization. ACS NANO 2017; 11:12677-12686. [PMID: 29165993 PMCID: PMC5752594 DOI: 10.1021/acsnano.7b07200] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Recently developed tissue-hydrogel methods for specimen expansion now enable researchers to perform super-resolution microscopy with ∼65 nm lateral resolution using ordinary microscopes, standard fluorescent probes, and inexpensive reagents. Here we use the combination of specimen expansion and the optical super-resolution microscopy technique structured illumination microscopy (SIM) to extend the spatial resolution to ∼30 nm. We apply this hybrid method, which we call ExSIM, to study the cytoskeleton of the important human pathogen Giardia lamblia including the adhesive disc and flagellar axonemes. We determined the localization of two recently identified disc-associated proteins, including DAP86676 , which localizes to disc microribbons, and the functionally unknown DAP16263 , which primarily localizes to dorsal microtubules of the disc overlap zone and the paraflagellar rod of ventral axonemes. Based on its strong performance in revealing known and unknown details of the ultrastructure of Giardia, we find that ExSIM is a simple, rapid, and powerful super-resolution method for the study of fixed specimens, and it should be broadly applicable to other biological systems of interest.
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Affiliation(s)
- Aaron R. Halpern
- Department of Chemistry, University of Washington, Seattle, Washington, USA
| | - Germain C. M. Alas
- Department of Biology, University of Washington, Seattle, Washington, USA
| | - Tyler J. Chozinski
- Department of Chemistry, University of Washington, Seattle, Washington, USA
| | - Alexander R. Paredez
- Department of Biology, University of Washington, Seattle, Washington, USA
- Corresponding Authors A. R. Paredez (); J. C. Vaughan ()
| | - Joshua C. Vaughan
- Department of Chemistry, University of Washington, Seattle, Washington, USA
- Department of Physiology and Biophysics, University of Washington, Seattle, Washington, USA
- Corresponding Authors A. R. Paredez (); J. C. Vaughan ()
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50
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Lengefeld J, Yen E, Chen X, Leary A, Vogel J, Barral Y. Spatial cues and not spindle pole maturation drive the asymmetry of astral microtubules between new and preexisting spindle poles. Mol Biol Cell 2017; 29:10-28. [PMID: 29142076 PMCID: PMC5746063 DOI: 10.1091/mbc.e16-10-0725] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 10/31/2017] [Accepted: 11/07/2017] [Indexed: 11/17/2022] Open
Abstract
The distinct behavior of the spindle pole bodies (SPBs) during spindle orientation in yeast metaphase does not result from them being differently mature, but astral microtubule organization correlates with the subcellular position rather than the age of the SPBs. In many asymmetrically dividing cells, the microtubule-organizing centers (MTOCs; mammalian centrosome and yeast spindle pole body [SPB]) nucleate more astral microtubules on one of the two spindle poles than the other. This differential activity generally correlates with the age of MTOCs and contributes to orienting the mitotic spindle within the cell. The asymmetry might result from the two MTOCs being in distinctive maturation states. We investigated this model in budding yeast. Using fluorophores with different maturation kinetics to label the outer plaque components of the SPB, we found that the Cnm67 protein is mobile, whereas Spc72 is not. However, these two proteins were rapidly as abundant on both SPBs, indicating that SPBs mature more rapidly than anticipated. Superresolution microscopy confirmed this finding for Spc72 and for the γ-tubulin complex. Moreover, astral microtubule number and length correlated with the subcellular localization of SPBs rather than their age. Kar9-dependent orientation of the spindle drove the differential activity of the SPBs in astral microtubule organization rather than intrinsic differences between the spindle poles. Together, our data establish that Kar9 and spatial cues, rather than the kinetics of SPB maturation, control the asymmetry of astral microtubule organization between the preexisting and new SPBs.
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Affiliation(s)
- Jette Lengefeld
- Department of Biology, Institute of Biochemistry, ETH Zurich, 8093 Zurich, Switzerland
| | - Eric Yen
- Department of Biology, McGill University, Montreal, QC H3G 0B1, Canada
| | - Xiuzhen Chen
- Department of Biology, Institute of Biochemistry, ETH Zurich, 8093 Zurich, Switzerland
| | - Allen Leary
- Department of Biology, McGill University, Montreal, QC H3G 0B1, Canada
| | - Jackie Vogel
- Department of Biology, McGill University, Montreal, QC H3G 0B1, Canada
| | - Yves Barral
- Department of Biology, Institute of Biochemistry, ETH Zurich, 8093 Zurich, Switzerland
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