1
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Kono Y, Shimi T. Crosstalk between mitotic reassembly and repair of the nuclear envelope. Nucleus 2024; 15:2352203. [PMID: 38780365 PMCID: PMC11123513 DOI: 10.1080/19491034.2024.2352203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 05/01/2024] [Indexed: 05/25/2024] Open
Abstract
In eukaryotic cells, the nuclear envelope (NE) is a membrane partition between the nucleus and the cytoplasm to compartmentalize nuclear contents. It plays an important role in facilitating nuclear functions including transcription, DNA replication and repair. In mammalian cells, the NE breaks down and then reforms during cell division, and in interphase it is restored shortly after the NE rupture induced by mechanical force. In this way, the partitioning effect is regulated through dynamic processes throughout the cell cycle. A failure in rebuilding the NE structure triggers the mixing of nuclear and cytoplasmic contents, leading to catastrophic consequences for the nuclear functions. Whereas the precise details of molecular mechanisms for NE reformation during cell division and NE restoration in interphase are still being investigated, here, we mostly focus on mammalian cells to describe key aspects that have been identified and to discuss the crosstalk between them.
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Affiliation(s)
- Yohei Kono
- Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kanazawa, Japan
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | - Takeshi Shimi
- Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kanazawa, Japan
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2
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Keuper K, Bartek J, Maya-Mendoza A. The nexus of nuclear envelope dynamics, circular economy and cancer cell pathophysiology. Eur J Cell Biol 2024; 103:151394. [PMID: 38340500 DOI: 10.1016/j.ejcb.2024.151394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Revised: 02/01/2024] [Accepted: 02/02/2024] [Indexed: 02/12/2024] Open
Abstract
The nuclear envelope (NE) is a critical component in maintaining the function and structure of the eukaryotic nucleus. The NE and lamina are disassembled during each cell cycle to enable an open mitosis. Nuclear architecture construction and deconstruction is a prime example of a circular economy, as it fulfills a highly efficient recycling program bound to continuous assessment of the quality and functionality of the building blocks. Alterations in the nuclear dynamics and lamina structure have emerged as important contributors to both oncogenic transformation and cancer progression. However, the knowledge of the NE breakdown and reassembly is still limited to a fraction of participating proteins and complexes. As cancer cells contain highly diverse nuclei in terms of DNA content, but also in terms of nuclear number, size, and shape, it is of great interest to understand the intricate relationship between these nuclear features in cancer cell pathophysiology. In this review, we provide insights into how those NE dynamics are regulated, and how lamina destabilization processes may alter the NE circular economy. Moreover, we expand the knowledge of the lamina-associated domain region by using strategic algorithms, including Artificial Intelligence, to infer protein associations, assess their function and location, and predict cancer-type specificity with implications for the future of cancer diagnosis, prognosis and treatment. Using this approach we identified NUP98 and MECP2 as potential proteins that exhibit upregulation in Acute Myeloid Leukemia (LAML) patients with implications for early diagnosis.
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Affiliation(s)
- Kristina Keuper
- DNA Replication and Cancer Group, Danish Cancer Institute, Copenhagen, Denmark; Genome Integrity Group, Danish Cancer Institute, Copenhagen, Denmark
| | - Jiri Bartek
- Genome Integrity Group, Danish Cancer Institute, Copenhagen, Denmark; Division of Genome Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SciLifeLab, Stockholm, Sweden
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3
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Bihani A, Avvaru AK, Mishra RK. Biochemical Deconstruction and Reconstruction of Nuclear Matrix Reveals the Layers of Nuclear Organization. Mol Cell Proteomics 2023; 22:100671. [PMID: 37863319 PMCID: PMC10687341 DOI: 10.1016/j.mcpro.2023.100671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 10/11/2023] [Accepted: 10/15/2023] [Indexed: 10/22/2023] Open
Abstract
Nuclear matrix (NuMat) is the fraction of the eukaryotic nucleus insoluble to detergents and high-salt extractions that manifests as a pan-nuclear fiber-granule network. NuMat consists of ribonucleoprotein complexes, members of crucial nuclear functional modules, and DNA fragments. Although NuMat captures the organization of nonchromatin nuclear space, very little is known about components organization within NuMat. To understand the organization of NuMat components, we subfractionated it with increasing concentrations of the chaotrope guanidinium hydrochloride (GdnHCl) and analyzed the proteomic makeup of the fractions. We observe that the solubilization of proteins at different concentrations of GdnHCl is finite and independent of the broad biophysical properties of the protein sequences. Looking at the extraction pattern of the nuclear envelope and nuclear pore complex, we surmise that this fractionation represents easily solubilized/loosely bound and difficultly solubilized/tightly bound components of NuMat. Microscopic analyses of the localization of key NuMat proteins across sequential GdnHCl extractions of in situ NuMat further elaborate on the divergent extraction patterns. Furthermore, we solubilized NuMat in 8M GdnHCl and upon removal of GdnHCl through dialysis, en masse renaturation leads to RNA-dependent self-assembly of fibrous structures. The major proteome component of the self-assembled fibers comes from the difficultly solubilized, tightly bound component. This fractionation of the NuMat reveals different organizational levels within it which may reflect the structural and functional organization of nuclear architecture.
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Affiliation(s)
- Ashish Bihani
- CSIR - Centre for Cellular and Molecular Biology (CCMB), Hyderabad, India.
| | - Akshay K Avvaru
- CSIR - Centre for Cellular and Molecular Biology (CCMB), Hyderabad, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Rakesh K Mishra
- CSIR - Centre for Cellular and Molecular Biology (CCMB), Hyderabad, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India; Tata Institute for Genetics and Society (TIGS), Bengaluru, India.
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4
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Liu HF, Zhou Y, Huang Q, Piland J, Jin W, Mandel J, Du X, Martin J, Bartesaghi A. nextPYP: a comprehensive and scalable platform for characterizing protein variability in situ using single-particle cryo-electron tomography. Nat Methods 2023; 20:1909-1919. [PMID: 37884796 PMCID: PMC10703682 DOI: 10.1038/s41592-023-02045-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 09/12/2023] [Indexed: 10/28/2023]
Abstract
Single-particle cryo-electron tomography is an emerging technique capable of determining the structure of proteins imaged within the native context of cells at molecular resolution. While high-throughput techniques for sample preparation and tilt-series acquisition are beginning to provide sufficient data to allow structural studies of proteins at physiological concentrations, the complex data analysis pipeline and the demanding storage and computational requirements pose major barriers for the development and broader adoption of this technology. Here, we present a scalable, end-to-end framework for single-particle cryo-electron tomography data analysis from on-the-fly pre-processing of tilt series to high-resolution refinement and classification, which allows efficient analysis and visualization of datasets with hundreds of tilt series and hundreds of thousands of particles. We validate our approach using in vitro and cellular datasets, demonstrating its effectiveness at achieving high-resolution and revealing conformational heterogeneity in situ. The framework is made available through an intuitive and easy-to-use computer application, nextPYP ( http://nextpyp.app ).
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Affiliation(s)
- Hsuan-Fu Liu
- Department of Biochemistry, Duke University, Durham, NC, USA
| | - Ye Zhou
- Department of Computer Science, Duke University, Durham, NC, USA
| | - Qinwen Huang
- Department of Computer Science, Duke University, Durham, NC, USA
| | - Jonathan Piland
- Department of Electrical and Computer Engineering, Duke University, Durham, NC, USA
| | - Weisheng Jin
- Department of Computer Science, Duke University, Durham, NC, USA
| | - Justin Mandel
- Department of Computer Science, Duke University, Durham, NC, USA
| | - Xiaochen Du
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Jeffrey Martin
- Department of Computer Science, Duke University, Durham, NC, USA
| | - Alberto Bartesaghi
- Department of Biochemistry, Duke University, Durham, NC, USA.
- Department of Computer Science, Duke University, Durham, NC, USA.
- Department of Electrical and Computer Engineering, Duke University, Durham, NC, USA.
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5
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Rush C, Jiang Z, Tingey M, Feng F, Yang W. Unveiling the complexity: assessing models describing the structure and function of the nuclear pore complex. Front Cell Dev Biol 2023; 11:1245939. [PMID: 37876551 PMCID: PMC10591098 DOI: 10.3389/fcell.2023.1245939] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Accepted: 09/19/2023] [Indexed: 10/26/2023] Open
Abstract
The nuclear pore complex (NPC) serves as a pivotal subcellular structure, acting as a gateway that orchestrates nucleocytoplasmic transport through a selectively permeable barrier. Nucleoporins (Nups), particularly those containing phenylalanine-glycine (FG) motifs, play indispensable roles within this barrier. Recent advancements in technology have significantly deepened our understanding of the NPC's architecture and operational intricacies, owing to comprehensive investigations. Nevertheless, the conspicuous presence of intrinsically disordered regions within FG-Nups continues to present a formidable challenge to conventional static characterization techniques. Historically, a multitude of strategies have been employed to unravel the intricate organization and behavior of FG-Nups within the NPC. These endeavors have given rise to multiple models that strive to elucidate the structural layout and functional significance of FG-Nups. Within this exhaustive review, we present a comprehensive overview of these prominent models, underscoring their proposed dynamic and structural attributes, supported by pertinent research. Through a comparative analysis, we endeavor to shed light on the distinct characteristics and contributions inherent in each model. Simultaneously, it remains crucial to acknowledge the scarcity of unequivocal validation for any of these models, as substantiated by empirical evidence.
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Affiliation(s)
| | | | | | | | - Weidong Yang
- Department of Biology, Temple University, Philadelphia, PA, United States
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6
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Nie Y, Fu G, Leng Y. Nuclear Delivery of Nanoparticle-Based Drug Delivery Systems by Nuclear Localization Signals. Cells 2023; 12:1637. [PMID: 37371107 DOI: 10.3390/cells12121637] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 05/31/2023] [Accepted: 06/13/2023] [Indexed: 06/29/2023] Open
Abstract
Nanomedicine 2.0 refers to the next generation of nanotechnology-based medical therapies and diagnostic tools. This field focuses on the development of more sophisticated and precise nanoparticles (NPs) for targeted drug delivery, imaging, and sensing. It has been established that the nuclear delivery of NP-loaded drugs can increase their therapeutic efficacy. To effectively direct the NPs to the nucleus, the attachment of nuclear localization signals (NLSs) to NPs has been employed in many applications. In this review, we will provide an overview of the structure of nuclear pore complexes (NPCs) and the classic nuclear import mechanism. Additionally, we will explore various nanoparticles, including their synthesis, functionalization, drug loading and release mechanisms, nuclear targeting strategies, and potential applications. Finally, we will highlight the challenges associated with developing nucleus-targeted nanoparticle-based drug delivery systems (NDDSs) and provide insights into the future of NDDSs.
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Affiliation(s)
- Yuhan Nie
- Innovation and Integration Center of New Laser Technology, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
| | - Guo Fu
- Innovation and Integration Center of New Laser Technology, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
| | - Yuxin Leng
- State Key Laboratory of High Field Laser Physics and CAS Center for Excellence in Ultra-Intense Laser Science, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
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7
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Vial A, Costa L, Dosset P, Rosso P, Boutières G, Faklaris O, Haschke H, Milhiet PE, Doucet CM. Structure and mechanics of the human nuclear pore complex basket using correlative AFM-fluorescence superresolution microscopy. NANOSCALE 2023; 15:5756-5770. [PMID: 36786384 DOI: 10.1039/d2nr06034e] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Nuclear pore complexes (NPCs) are the only gateways between the nucleus and cytoplasm in eukaryotic cells. They restrict free diffusion to molecules below 5 nm while facilitating the active transport of selected cargoes, sometimes as large as the pore itself. This versatility implies an important pore plasticity. Recently, cryo-EM and AI-based protein modeling of human NPC revealed with acute precision how most constituents are arranged. But the basket, a fish trap-like structure capping the nucleoplasmic side of the pore, remains poorly resolved. Here by atomic force microscopy (AFM) coupled to single molecule localization microscopy (SMLM) we revealed that the basket is very soft and explores a large conformational landscape: apart from its canonical basket shape, it dives into the central pore channel or opens, with filaments reaching to the pore sides. Our observations highlight how this structure can adapt and let morphologically diverse cargoes shuttle through NPCs.
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Affiliation(s)
- Anthony Vial
- CBS (Centre de Biologie Structurale), Univ Montpellier, CNRS, INSERM, Montpellier, France.
| | - Luca Costa
- CBS (Centre de Biologie Structurale), Univ Montpellier, CNRS, INSERM, Montpellier, France.
| | - Patrice Dosset
- CBS (Centre de Biologie Structurale), Univ Montpellier, CNRS, INSERM, Montpellier, France.
| | - Pietro Rosso
- CBS (Centre de Biologie Structurale), Univ Montpellier, CNRS, INSERM, Montpellier, France.
| | - Gaëlle Boutières
- CBS (Centre de Biologie Structurale), Univ Montpellier, CNRS, INSERM, Montpellier, France.
| | - Orestis Faklaris
- MRI, Biocampus, University of Montpellier, CNRS, INSERM, Montpellier, France
| | | | | | - Christine M Doucet
- CBS (Centre de Biologie Structurale), Univ Montpellier, CNRS, INSERM, Montpellier, France.
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8
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Tai L, Yin G, Sun F, Zhu Y. Cryo-electron microscopy reveals the structure of the nuclear pore complex. J Mol Biol 2023; 435:168051. [PMID: 36933820 DOI: 10.1016/j.jmb.2023.168051] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 03/07/2023] [Accepted: 03/09/2023] [Indexed: 03/18/2023]
Abstract
The nuclear pore complex (NPC) is a giant protein assembly that penetrates the double layers of the nuclear membrane. The overall structure of the NPC has approximately eightfold symmetry and is formed by approximately 30 nucleoporins. The great size and complexity of the NPC have hindered the study of its structure for many years until recent breakthroughs were achieved by integrating the latest high-resolution cryo-electron microscopy (cryo-EM), the emerging artificial intelligence-based modeling and all other available structural information from crystallography and mass spectrometry. Here, we review our latest knowledge of the NPC architecture and the history of its structural study from in vitro to in situ with progressively improved resolutions by cryo-EM, with a particular focus on the latest subnanometer-resolution structural studies. The future directions for structural studies of NPCs are also discussed.
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Affiliation(s)
- Linhua Tai
- National Key Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Guoliang Yin
- National Key Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Fei Sun
- National Key Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China; Center for Biological Imaging, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou, Guangdong 510005, China.
| | - Yun Zhu
- National Key Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
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9
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Wang C, Wojtynek M, Medalia O. Structural investigation of eukaryotic cells: From the periphery to the interior by cryo-electron tomography. Adv Biol Regul 2023; 87:100923. [PMID: 36280452 DOI: 10.1016/j.jbior.2022.100923] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 10/05/2022] [Accepted: 10/10/2022] [Indexed: 11/06/2022]
Abstract
Cryo-electron tomography (cryo-ET) combines a close-to-life preservation of the cell with high-resolution three-dimensional (3D) imaging. This allows to study the molecular architecture of the cellular landscape and provides unprecedented views on biological processes and structures. In this review we mainly focus on the application of cryo-ET to visualize and structurally characterize eukaryotic cells - from the periphery to the cellular interior. We discuss strategies that can be employed to investigate the structure of challenging targets in their cellular environment as well as the application of complimentary approaches in conjunction with cryo-ET.
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Affiliation(s)
- Chunyang Wang
- Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Matthias Wojtynek
- Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Ohad Medalia
- Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland.
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10
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Tingey M, Li Y, Yu W, Young A, Yang W. Spelling out the roles of individual nucleoporins in nuclear export of mRNA. Nucleus 2022; 13:170-193. [PMID: 35593254 PMCID: PMC9132428 DOI: 10.1080/19491034.2022.2076965] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 05/08/2022] [Accepted: 05/09/2022] [Indexed: 11/01/2022] Open
Abstract
The Nuclear Pore Complex (NPC) represents a critical passage through the nuclear envelope for nuclear import and export that impacts nearly every cellular process at some level. Recent technological advances in the form of Auxin Inducible Degron (AID) strategies and Single-Point Edge-Excitation sub-Diffraction (SPEED) microscopy have enabled us to provide new insight into the distinct functions and roles of nuclear basket nucleoporins (Nups) upon nuclear docking and export for mRNAs. In this paper, we provide a review of our recent findings as well as an assessment of new techniques, updated models, and future perspectives in the studies of mRNA's nuclear export.
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Affiliation(s)
- Mark Tingey
- Department of Biology, Temple University, Philadelphia, Pennsylvania, USA
| | - Yichen Li
- Department of Genetics, Yale School of Medicine, Yale University, New Haven, Connecticut, USA
| | - Wenlan Yu
- Department of Biology, Temple University, Philadelphia, Pennsylvania, USA
| | - Albert Young
- Department of Biology, Temple University, Philadelphia, Pennsylvania, USA
| | - Weidong Yang
- Department of Biology, Temple University, Philadelphia, Pennsylvania, USA
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11
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Dubey AK, Kumar P, Mandal D, Ravichandiran V, Singh SK. An introduction to dynamic nucleoporins in Leishmania species: Novel targets for tropical-therapeutics. J Parasit Dis 2022; 46:1176-1191. [PMID: 36457769 PMCID: PMC9606170 DOI: 10.1007/s12639-022-01515-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 06/20/2022] [Indexed: 11/28/2022] Open
Abstract
As an ailment, leishmaniasis is still an incessant challenge in neglected tropical diseases and neglected infections of poverty worldwide. At present, the diagnosis and treatment to combat Leishmania tropical infections are not substantial remedies and require advanced & specific research. Therefore, there is a need for a potential novel target to overcome established medicament modalities' limitations in pathogenicity. In this review, we proposed a few ab initio findings in nucleoporins of nuclear pore complex in Leishmania sp. concerning other infectious protists. So, through structural analysis and dynamics studies, we hypothesize the nuclear pore molecular machinery & functionality. The gatekeepers Nups, export of mRNA, mitotic spindle formation are salient features in cellular mechanics and this is regulated by dynamic nucleoporins. Here, diverse studies suggest that Nup93/NIC96, Nup155/Nup144, Mlp1/Mlp2/Tpr of Leishmania Species can be a picked out marker for diagnostic, immune-modulation, and novel drug targets. In silico prediction of nucleoporin-functional interactors such as NUP54/57, RNA helicase, Ubiquitin-protein ligase, Exportin 1, putative T-lymphocyte triggering factor, and 9 uncharacterized proteins suggest few more noble targets. The novel drug targeting to importins/exportins of Leishmania sp. and defining mechanism of Leptomycin-B, SINE compounds, Curcumins, Selinexor can be an arc-light in therapeutics. The essence of the review in Leishmania's nucleoporins is to refocus our research on noble molecular targets for tropical therapeutics. Supplementary Information The online version contains supplementary material available at 10.1007/s12639-022-01515-0.
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Affiliation(s)
- Amit Kumar Dubey
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research (NIPER), Hajipur, Vaishali, Bihar 844102 India
- Parasite Immunology Lab, Microbiology Department, Indian Council of Medical Research (ICMR)-Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Patna, Bihar 800007 India
| | - Prakash Kumar
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research (NIPER), Hajipur, Vaishali, Bihar 844102 India
| | - Debabrata Mandal
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research (NIPER), Hajipur, Vaishali, Bihar 844102 India
| | - V. Ravichandiran
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research (NIPER), Hajipur, Vaishali, Bihar 844102 India
| | - Shubhankar Kumar Singh
- Parasite Immunology Lab, Microbiology Department, Indian Council of Medical Research (ICMR)-Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Patna, Bihar 800007 India
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12
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Youden B, Jiang R, Carrier AJ, Servos MR, Zhang X. A Nanomedicine Structure-Activity Framework for Research, Development, and Regulation of Future Cancer Therapies. ACS NANO 2022; 16:17497-17551. [PMID: 36322785 DOI: 10.1021/acsnano.2c06337] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Despite their clinical success in drug delivery applications, the potential of theranostic nanomedicines is hampered by mechanistic uncertainty and a lack of science-informed regulatory guidance. Both the therapeutic efficacy and the toxicity of nanoformulations are tightly controlled by the complex interplay of the nanoparticle's physicochemical properties and the individual patient/tumor biology; however, it can be difficult to correlate such information with observed outcomes. Additionally, as nanomedicine research attempts to gradually move away from large-scale animal testing, the need for computer-assisted solutions for evaluation will increase. Such models will depend on a clear understanding of structure-activity relationships. This review provides a comprehensive overview of the field of cancer nanomedicine and provides a knowledge framework and foundational interaction maps that can facilitate future research, assessments, and regulation. By forming three complementary maps profiling nanobio interactions and pathways at different levels of biological complexity, a clear picture of a nanoparticle's journey through the body and the therapeutic and adverse consequences of each potential interaction are presented.
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Affiliation(s)
- Brian Youden
- Department of Biology, University of Waterloo, 200 University Ave. W, Waterloo, Ontario N2L 3G1, Canada
| | - Runqing Jiang
- Department of Biology, University of Waterloo, 200 University Ave. W, Waterloo, Ontario N2L 3G1, Canada
- Department of Medical Physics, Grand River Regional Cancer Centre, Kitchener, Ontario N2G 1G3, Canada
| | - Andrew J Carrier
- Department of Chemistry, Cape Breton University, 1250 Grand Lake Road, Sydney, Nova Scotia B1P 6L2, Canada
| | - Mark R Servos
- Department of Biology, University of Waterloo, 200 University Ave. W, Waterloo, Ontario N2L 3G1, Canada
| | - Xu Zhang
- Department of Biology, University of Waterloo, 200 University Ave. W, Waterloo, Ontario N2L 3G1, Canada
- Department of Chemistry, Cape Breton University, 1250 Grand Lake Road, Sydney, Nova Scotia B1P 6L2, Canada
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13
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Tai L, Zhu Y, Ren H, Huang X, Zhang C, Sun F. 8 Å structure of the outer rings of the Xenopus laevis nuclear pore complex obtained by cryo-EM and AI. Protein Cell 2022; 13:760-777. [PMID: 35015240 PMCID: PMC9233733 DOI: 10.1007/s13238-021-00895-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 11/16/2021] [Indexed: 11/27/2022] Open
Abstract
The nuclear pore complex (NPC), one of the largest protein complexes in eukaryotes, serves as a physical gate to regulate nucleocytoplasmic transport. Here, we determined the 8 Å resolution cryo-electron microscopic (cryo-EM) structure of the outer rings containing nuclear ring (NR) and cytoplasmic ring (CR) from the Xenopus laevis NPC, with local resolutions reaching 4.9 Å. With the aid of AlphaFold2, we managed to build a pseudoatomic model of the outer rings, including the Y complexes and flanking components. In this most comprehensive and accurate model of outer rings to date, the almost complete Y complex structure exhibits much tighter interaction in the hub region. In addition to two copies of Y complexes, each asymmetric subunit in CR contains five copies of Nup358, two copies of the Nup214 complex, two copies of Nup205 and one copy of newly identified Nup93, while that in NR contains one copy of Nup205, one copy of ELYS and one copy of Nup93. These in-depth structural features represent a great advance in understanding the assembly of NPCs.
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Affiliation(s)
- Linhua Tai
- National Key Laboratory of Biomacromolecules, Institute of Biophysics, CAS Center for Excellence in Biomacromolecules, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yun Zhu
- National Key Laboratory of Biomacromolecules, Institute of Biophysics, CAS Center for Excellence in Biomacromolecules, Chinese Academy of Sciences, Beijing, 100101, China
| | - He Ren
- The Ministry of Education Key Laboratory of Cell Proliferation and Differentiation and the State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing, 100871, China
| | - Xiaojun Huang
- National Key Laboratory of Biomacromolecules, Institute of Biophysics, CAS Center for Excellence in Biomacromolecules, Chinese Academy of Sciences, Beijing, 100101, China
- Center for Biological Imaging, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Chuanmao Zhang
- The Ministry of Education Key Laboratory of Cell Proliferation and Differentiation and the State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing, 100871, China.
| | - Fei Sun
- National Key Laboratory of Biomacromolecules, Institute of Biophysics, CAS Center for Excellence in Biomacromolecules, Chinese Academy of Sciences, Beijing, 100101, China.
- Center for Biological Imaging, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
- Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou, 510005, China.
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14
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Hahn L, Carvalho P. Making and breaking the inner nuclear membrane proteome. Curr Opin Cell Biol 2022; 78:102115. [PMID: 35870351 DOI: 10.1016/j.ceb.2022.102115] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 06/12/2022] [Accepted: 06/17/2022] [Indexed: 01/31/2023]
Abstract
The nuclear envelope (NE) is the defining feature of eukaryotic cells, separating the nucleus from the cytoplasm. It has a complex architecture consisting of two lipid bilayers that, despite being continuous between them and with the endoplasmic reticulum, have different protein compositions consistent with their distinct functions. In particular, the unique composition of the inner nuclear membrane (INM), facing the nucleoplasm and its underlying nuclear lamina, is critical for the organisation and function of nuclear processes, from cell fate to gene regulation and DNA repair. Mutations in INM proteins affecting this organisation are associated with muscular dystrophies and premature ageing syndromes highlighting the role of INM architecture in cell homeostasis. Here, we discuss recent progress in understanding how specific proteins concentrate at the INM, as well as the quality control mechanisms involved in remodelling and maintaining INM protein homeostasis.
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Affiliation(s)
- Lilli Hahn
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Pedro Carvalho
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK.
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15
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Tingey M, Li Y, Yang W. Selective Degradation and Quantification of Nucleoporins in the Nuclear Pore by Auxin-Inducible Degrons and Single-Molecule Microscopy. Curr Protoc 2022; 2:e520. [PMID: 36063146 PMCID: PMC9454236 DOI: 10.1002/cpz1.520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
There is a significant current question regarding the viable copy numbers of nucleoporins required for the function of the nuclear pore complex (NPC) in eukaryotic cells. The NPC consists of approximately 30 different nucleoporins in an eight-fold symmetry, meaning that there are multiple duplicates of each nucleoporin present within the nuclear pore. We recently developed a method that combines auxin-inducible degrons and single-molecule super-resolution microscopy to evaluate the copy number of nuclear basket nucleoporins required for the successful function of the NPC. Here, we describe the theory behind this auxin-inducible degron and single-molecule super-resolution microscopy method, and we detail a step-by-step process to selectively degrade nucleoporins either completely or in a stepwise manner. © 2022 Wiley Periodicals LLC. Basic Protocol 1: Degradation of target nucleoporins Basic Protocol 2: Quantification of nucleoporin copy number via narrow-field fluorescence microscopy.
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Affiliation(s)
- Mark Tingey
- Department of Biology, Temple University, Philadelphia, Pennsylvania, USA
| | - Yichen Li
- Yale School of Medicine, Yale University, New Haven, Connecticut, USA
| | - Weidong Yang
- Department of Biology, Temple University, Philadelphia, Pennsylvania, USA
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16
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Mosalaganti S, Obarska-Kosinska A, Siggel M, Taniguchi R, Turoňová B, Zimmerli CE, Buczak K, Schmidt FH, Margiotta E, Mackmull MT, Hagen WJH, Hummer G, Kosinski J, Beck M. AI-based structure prediction empowers integrative structural analysis of human nuclear pores. Science 2022; 376:eabm9506. [PMID: 35679397 DOI: 10.1126/science.abm9506] [Citation(s) in RCA: 142] [Impact Index Per Article: 71.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
INTRODUCTION The eukaryotic nucleus pro-tects the genome and is enclosed by the two membranes of the nuclear envelope. Nuclear pore complexes (NPCs) perforate the nuclear envelope to facilitate nucleocytoplasmic transport. With a molecular weight of ∼120 MDa, the human NPC is one of the larg-est protein complexes. Its ~1000 proteins are taken in multiple copies from a set of about 30 distinct nucleoporins (NUPs). They can be roughly categorized into two classes. Scaf-fold NUPs contain folded domains and form a cylindrical scaffold architecture around a central channel. Intrinsically disordered NUPs line the scaffold and extend into the central channel, where they interact with cargo complexes. The NPC architecture is highly dynamic. It responds to changes in nuclear envelope tension with conforma-tional breathing that manifests in dilation and constriction movements. Elucidating the scaffold architecture, ultimately at atomic resolution, will be important for gaining a more precise understanding of NPC function and dynamics but imposes a substantial chal-lenge for structural biologists. RATIONALE Considerable progress has been made toward this goal by a joint effort in the field. A synergistic combination of complementary approaches has turned out to be critical. In situ structural biology techniques were used to reveal the overall layout of the NPC scaffold that defines the spatial reference for molecular modeling. High-resolution structures of many NUPs were determined in vitro. Proteomic analysis and extensive biochemical work unraveled the interaction network of NUPs. Integra-tive modeling has been used to combine the different types of data, resulting in a rough outline of the NPC scaffold. Previous struc-tural models of the human NPC, however, were patchy and limited in accuracy owing to several challenges: (i) Many of the high-resolution structures of individual NUPs have been solved from distantly related species and, consequently, do not comprehensively cover their human counterparts. (ii) The scaf-fold is interconnected by a set of intrinsically disordered linker NUPs that are not straight-forwardly accessible to common structural biology techniques. (iii) The NPC scaffold intimately embraces the fused inner and outer nuclear membranes in a distinctive topol-ogy and cannot be studied in isolation. (iv) The conformational dynamics of scaffold NUPs limits the resolution achievable in structure determination. RESULTS In this study, we used artificial intelligence (AI)-based prediction to generate an exten-sive repertoire of structural models of human NUPs and their subcomplexes. The resulting models cover various domains and interfaces that so far remained structurally uncharac-terized. Benchmarking against previous and unpublished x-ray and cryo-electron micros-copy structures revealed unprecedented accu-racy. We obtained well-resolved cryo-electron tomographic maps of both the constricted and dilated conformational states of the hu-man NPC. Using integrative modeling, we fit-ted the structural models of individual NUPs into the cryo-electron microscopy maps. We explicitly included several linker NUPs and traced their trajectory through the NPC scaf-fold. We elucidated in great detail how mem-brane-associated and transmembrane NUPs are distributed across the fusion topology of both nuclear membranes. The resulting architectural model increases the structural coverage of the human NPC scaffold by about twofold. We extensively validated our model against both earlier and new experimental data. The completeness of our model has enabled microsecond-long coarse-grained molecular dynamics simulations of the NPC scaffold within an explicit membrane en-vironment and solvent. These simulations reveal that the NPC scaffold prevents the constriction of the otherwise stable double-membrane fusion pore to small diameters in the absence of membrane tension. CONCLUSION Our 70-MDa atomically re-solved model covers >90% of the human NPC scaffold. It captures conforma-tional changes that occur during dilation and constriction. It also reveals the precise anchoring sites for intrinsically disordered NUPs, the identification of which is a prerequisite for a complete and dy-namic model of the NPC. Our study exempli-fies how AI-based structure prediction may accelerate the elucidation of subcellular ar-chitecture at atomic resolution. [Figure: see text].
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Affiliation(s)
- Shyamal Mosalaganti
- Department of Molecular Sociology, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany.,Structural and Computational Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany.,Life Sciences Institute and Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Agnieszka Obarska-Kosinska
- Department of Molecular Sociology, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany.,European Molecular Biology Laboratory Hamburg, 22607 Hamburg, Germany
| | - Marc Siggel
- European Molecular Biology Laboratory Hamburg, 22607 Hamburg, Germany.,Department of Theoretical Biophysics, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany.,Centre for Structural Systems Biology, 22607 Hamburg, Germany
| | - Reiya Taniguchi
- Department of Molecular Sociology, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany.,Structural and Computational Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Beata Turoňová
- Department of Molecular Sociology, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany.,Structural and Computational Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Christian E Zimmerli
- Department of Molecular Sociology, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany.,Structural and Computational Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Katarzyna Buczak
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Florian H Schmidt
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Erica Margiotta
- Department of Molecular Sociology, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany.,Structural and Computational Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Marie-Therese Mackmull
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Wim J H Hagen
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Gerhard Hummer
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany.,Institute of Biophysics, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany
| | - Jan Kosinski
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany.,European Molecular Biology Laboratory Hamburg, 22607 Hamburg, Germany.,Centre for Structural Systems Biology, 22607 Hamburg, Germany
| | - Martin Beck
- Department of Molecular Sociology, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany.,Structural and Computational Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
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17
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Dultz E, Wojtynek M, Medalia O, Onischenko E. The Nuclear Pore Complex: Birth, Life, and Death of a Cellular Behemoth. Cells 2022; 11:1456. [PMID: 35563762 PMCID: PMC9100368 DOI: 10.3390/cells11091456] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 04/22/2022] [Accepted: 04/23/2022] [Indexed: 02/01/2023] Open
Abstract
Nuclear pore complexes (NPCs) are the only transport channels that cross the nuclear envelope. Constructed from ~500-1000 nucleoporin proteins each, they are among the largest macromolecular assemblies in eukaryotic cells. Thanks to advances in structural analysis approaches, the construction principles and architecture of the NPC have recently been revealed at submolecular resolution. Although the overall structure and inventory of nucleoporins are conserved, NPCs exhibit significant compositional and functional plasticity even within single cells and surprising variability in their assembly pathways. Once assembled, NPCs remain seemingly unexchangeable in post-mitotic cells. There are a number of as yet unresolved questions about how the versatility of NPC assembly and composition is established, how cells monitor the functional state of NPCs or how they could be renewed. Here, we review current progress in our understanding of the key aspects of NPC architecture and lifecycle.
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Affiliation(s)
- Elisa Dultz
- Institute of Biochemistry, Department of Biology, ETHZ Zurich, 8093 Zurich, Switzerland;
| | - Matthias Wojtynek
- Institute of Biochemistry, Department of Biology, ETHZ Zurich, 8093 Zurich, Switzerland;
- Department of Biochemistry, University of Zurich, 8057 Zurich, Switzerland;
| | - Ohad Medalia
- Department of Biochemistry, University of Zurich, 8057 Zurich, Switzerland;
| | - Evgeny Onischenko
- Department of Biological Sciences, University of Bergen, 5020 Bergen, Norway
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18
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Nag N, Sasidharan S, Uversky VN, Saudagar P, Tripathi T. Phase separation of FG-nucleoporins in nuclear pore complexes. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2022; 1869:119205. [PMID: 34995711 DOI: 10.1016/j.bbamcr.2021.119205] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 12/14/2021] [Accepted: 12/23/2021] [Indexed: 12/11/2022]
Abstract
The nuclear envelope (NE) is a bilayer membrane that separates and physically isolates the genetic material from the cytoplasm. Nuclear pore complexes (NPCs) are cylindrical structures embedded in the NE and remain the sole channel of communication between the nucleus and the cytoplasm. The interior of NPCs contains densely packed intrinsically disordered FG-nucleoporins (FG-Nups), consequently forming a permeability barrier. This barrier facilitates the selection and specificity of the cargoes that are imported, exported, or shuttled through the NPCs. Recent studies have revealed that FG-Nups undergo the process of liquid-liquid phase separation into liquid droplets. Moreover, these liquid droplets mimic the permeability barrier observed in the interior of NPCs. This review highlights the phase separation of FG-Nups occurring inside the NPCs rooted in the NE. We discuss the phase separation of FG-Nups and compare the different aspects contributing to their phase separation. Furthermore, several diseases caused by the aberrant phase separation of the proteins are examined with respect to NEs. By understanding the fundamental process of phase separation at the nuclear membrane, the review seeks to explore the parameters influencing this phenomenon as well as its importance, ultimately paving the way for better research on the structure-function relationship of biomolecular condensates.
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Affiliation(s)
- Niharika Nag
- Molecular and Structural Biophysics Laboratory, Department of Biochemistry, North-Eastern Hill University, Shillong 793022, India
| | - Santanu Sasidharan
- Department of Biotechnology, National Institute of Technology Warangal, Warangal 506004, India
| | - Vladimir N Uversky
- Department of Molecular Medicine and Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL 33620, United States; Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Institutskiy pereulok, 9, Dolgoprudny, Moscow Region 141700, Russia
| | - Prakash Saudagar
- Department of Biotechnology, National Institute of Technology Warangal, Warangal 506004, India.
| | - Timir Tripathi
- Molecular and Structural Biophysics Laboratory, Department of Biochemistry, North-Eastern Hill University, Shillong 793022, India.
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19
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Matsuda A, Mofrad MRK. On the nuclear pore complex and its emerging role in cellular mechanotransduction. APL Bioeng 2022; 6:011504. [PMID: 35308827 PMCID: PMC8916845 DOI: 10.1063/5.0080480] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 02/21/2022] [Indexed: 12/13/2022] Open
Abstract
The nuclear pore complex (NPC) is a large protein assembly that perforates the nuclear envelope and provides a sole gateway for traffic between the cytoplasm and the nucleus. The NPC controls the nucleocytoplasmic transport by selectively allowing cargoes such as proteins and mRNA to pass through its central channel, thereby playing a vital role in protecting the nuclear component and regulating gene expression and protein synthesis. The selective transport through the NPC originates from its exquisite molecular structure featuring a large scaffold and the intrinsically disordered central channel domain, but the exact mechanism underlying the selective transport remains elusive and is the subject of various, often conflicting, hypotheses. Moreover, recent studies have suggested a new role for the NPC as a mechanosensor, where the NPC changes its channel diameter depending on the nuclear envelope tension, altering the molecular transportability through this nanopore. In this mini-review, we summarize the current understandings of the selective nature of the NPC and discuss its emerging role in cellular mechanotransduction.
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Affiliation(s)
- Atsushi Matsuda
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California Berkeley, Berkeley, California 94720, USA
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20
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Raices M, D'Angelo MA. Structure, Maintenance, and Regulation of Nuclear Pore Complexes: The Gatekeepers of the Eukaryotic Genome. Cold Spring Harb Perspect Biol 2022; 14:a040691. [PMID: 34312247 PMCID: PMC8789946 DOI: 10.1101/cshperspect.a040691] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
In eukaryotic cells, the genetic material is segregated inside the nucleus. This compartmentalization of the genome requires a transport system that allows cells to move molecules across the nuclear envelope, the membrane-based barrier that surrounds the chromosomes. Nuclear pore complexes (NPCs) are the central component of the nuclear transport machinery. These large protein channels penetrate the nuclear envelope, creating a passage between the nucleus and the cytoplasm through which nucleocytoplasmic molecule exchange occurs. NPCs are one of the largest protein assemblies of eukaryotic cells and, in addition to their critical function in nuclear transport, these structures also play key roles in many cellular processes in a transport-independent manner. Here we will review the current knowledge of the NPC structure, the cellular mechanisms that regulate their formation and maintenance, and we will provide a brief description of a variety of processes that NPCs regulate.
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Affiliation(s)
- Marcela Raices
- Cell and Molecular Biology of Cancer Program, NCI-Designated Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California 92037, USA
| | - Maximiliano A D'Angelo
- Cell and Molecular Biology of Cancer Program, NCI-Designated Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California 92037, USA
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21
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Chowdhury R, Sau A, Musser SM. Super-resolved 3D tracking of cargo transport through nuclear pore complexes. Nat Cell Biol 2022; 24:112-122. [PMID: 35013558 PMCID: PMC8820391 DOI: 10.1038/s41556-021-00815-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 11/12/2021] [Indexed: 12/14/2022]
Abstract
Nuclear pore complexes (NPCs) embedded within the nuclear envelope (NE) mediate rapid, selective, and bidirectional traffic between the cytoplasm and the nucleoplasm. Deciphering the mechanism and dynamics of this process is challenged by the need for high spatial and temporal precision. We report here a multi-color imaging approach that enables direct 3D visualization of cargo transport trajectories relative to a super-resolved octagonal double-ring structure of the NPC scaffold. The success of this approach is enabled by the high positional stability of NPCs within permeabilized cells, as verified by a combined experimental and simulation analysis. Hourglass-shaped translocation conduits for two cargo complexes representing different nuclear transport receptor (NTR) pathways indicates rapid migration through the permeability barrier on or near the NPC scaffold. Binding sites for cargo complexes extend over 100 nm from the pore openings, consistent with a wide distribution of the FG-polypeptides that bind NTRs.
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Affiliation(s)
- Rajdeep Chowdhury
- Department of Molecular and Cellular Medicine, Texas A&M University, College of Medicine, The Texas A&M Health Science Center, College Station, TX, USA
| | - Abhishek Sau
- Department of Molecular and Cellular Medicine, Texas A&M University, College of Medicine, The Texas A&M Health Science Center, College Station, TX, USA
| | - Siegfried M Musser
- Department of Molecular and Cellular Medicine, Texas A&M University, College of Medicine, The Texas A&M Health Science Center, College Station, TX, USA.
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22
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Schnell SJ, Tingey M, Yang W. Speed Microscopy: High-Speed Single Molecule Tracking and Mapping of Nucleocytoplasmic Transport. Methods Mol Biol 2022; 2502:353-371. [PMID: 35412250 PMCID: PMC10131132 DOI: 10.1007/978-1-0716-2337-4_23] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The nuclear pore complex (NPC) functions as a gateway through which molecules translocate into and out of the nucleus. Understanding the transport dynamics of these transiting molecules and how they interact with the NPC has great potentials in the discovery of clinical targets. Single-molecule microscopy techniques are powerful tools to provide sub-diffraction limit information about the dynamic and structural details of nucleocytoplasmic transport. Here we detail single-point edge-excitation subdiffraction (SPEED) microscopy, a high-speed superresolution microscopy technique designed to track and map proteins and RNAs as they cross native NPCs.
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Affiliation(s)
| | - Mark Tingey
- Department of Biology, Temple University, Philadelphia, PA, USA
| | - Weidong Yang
- Department of Biology, Temple University, Philadelphia, PA, USA.
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23
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Zimmerli CE, Allegretti M, Rantos V, Goetz SK, Obarska-Kosinska A, Zagoriy I, Halavatyi A, Hummer G, Mahamid J, Kosinski J, Beck M. Nuclear pores dilate and constrict in cellulo. Science 2021; 374:eabd9776. [PMID: 34762489 DOI: 10.1126/science.abd9776] [Citation(s) in RCA: 151] [Impact Index Per Article: 50.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Christian E Zimmerli
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany.,Collaboration for joint PhD degree between EMBL and Heidelberg University, Faculty of Biosciences, 69120 Heidelberg, Germany.,Department of Molecular Sociology, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
| | - Matteo Allegretti
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany.,Department of Molecular Sociology, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
| | - Vasileios Rantos
- Centre for Structural Systems Biology (CSSB), 22607 Hamburg, Germany.,EMBL Hamburg, 22607 Hamburg, Germany
| | - Sara K Goetz
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany.,Collaboration for joint PhD degree between EMBL and Heidelberg University, Faculty of Biosciences, 69120 Heidelberg, Germany
| | - Agnieszka Obarska-Kosinska
- Department of Molecular Sociology, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany.,EMBL Hamburg, 22607 Hamburg, Germany
| | - Ievgeniia Zagoriy
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
| | | | - Gerhard Hummer
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany.,Institute of Biophysics, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany
| | - Julia Mahamid
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
| | - Jan Kosinski
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany.,Centre for Structural Systems Biology (CSSB), 22607 Hamburg, Germany.,EMBL Hamburg, 22607 Hamburg, Germany
| | - Martin Beck
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany.,Department of Molecular Sociology, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
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24
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Distinct roles of nuclear basket proteins in directing the passage of mRNA through the nuclear pore. Proc Natl Acad Sci U S A 2021; 118:2015621118. [PMID: 34504007 DOI: 10.1073/pnas.2015621118] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/06/2021] [Indexed: 11/18/2022] Open
Abstract
The in vivo characterization of the exact copy number and the specific function of each composite protein within the nuclear pore complex (NPC) remains both desirable and challenging. Through the implementation of live-cell high-speed super-resolution single-molecule microscopy, we first quantified the native copies of nuclear basket (BSK) proteins (Nup153, Nup50, and Tpr) prior to knocking them down in a highly specific manner via an auxin-inducible degron strategy. Second, we determined the specific roles that BSK proteins play in the nuclear export kinetics of model messenger RNA (mRNA) substrates. Finally, the three-dimensional (3D) nuclear export routes of these mRNA substrates through native NPCs in the absence of specific BSK proteins were obtained and further validated via postlocalization computational simulations. We found that these BSK proteins possess the stoichiometric ratio of 1:1:1 and play distinct roles in the nuclear export of mRNAs within live cells. The absence of Tpr from the NPC predominantly reduces the probability of nuclear mRNAs entering the NPC for export. Complete depletion of Nup153 and Nup50 results in an mRNA nuclear export efficiency decrease of approximately four folds. mRNAs can gain their maximum successful export efficiency as the copy number of Nup153 increased from zero to only half the full complement natively within the NPC. Lastly, the absence of Tpr or Nup153 seems to alter the 3D export routes of mRNAs as they pass through the NPC. However, the removal of Nup50 alone has almost no impact upon mRNA export route and kinetics.
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25
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The journey of herpesvirus capsids and genomes to the host cell nucleus. Curr Opin Virol 2021; 50:147-158. [PMID: 34464845 DOI: 10.1016/j.coviro.2021.08.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 08/06/2021] [Accepted: 08/09/2021] [Indexed: 01/04/2023]
Abstract
Starting a herpesviral infection is a steeplechase across membranes, cytosol, and nuclear envelopes and against antiviral defence mechanisms. Here, we highlight recent insights on capsid stabilization at the portals during assembly, early capsid-host interactions ensuring nuclear targeting of incoming capsids, and genome uncoating. After fusion with a host membrane, incoming capsids recruit microtubule motors for traveling to the centrosome, and by unknown mechanisms get forward towards the nucleus. The interaction of capsid-associated tegument proteins with nucleoporins orients the capsid portal towards the nuclear pore, and presumably after removal of the portal caps the genomes that have been packaged under pressure can be injected into the nucleoplasm for transcription and replication. Some cell types disarm the incoming capsids or silence the incoming genomes to reduce the likelihood of infection.
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26
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Blanco-Rodriguez G, Di Nunzio F. The Viral Capsid: A Master Key to Access the Host Nucleus. Viruses 2021; 13:v13061178. [PMID: 34203080 PMCID: PMC8234750 DOI: 10.3390/v13061178] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Revised: 06/02/2021] [Accepted: 06/16/2021] [Indexed: 12/15/2022] Open
Abstract
Viruses are pathogens that have evolved to hijack the cellular machinery to replicate themselves and spread to new cells. During the course of evolution, viruses developed different strategies to overcome the cellular defenses and create new progeny. Among them, some RNA and many DNA viruses require access to the nucleus to replicate their genome. In non-dividing cells, viruses can only access the nucleus through the nuclear pore complex (NPC). Therefore, viruses have developed strategies to usurp the nuclear transport machinery and gain access to the nucleus. The majority of these viruses use the capsid to manipulate the nuclear import machinery. However, the particular tactics employed by each virus to reach the host chromatin compartment are very different. Nevertheless, they all require some degree of capsid remodeling. Recent notions on the interplay between the viral capsid and cellular factors shine new light on the quest for the nuclear entry step and for the fate of these viruses. In this review, we describe the main components and function of nuclear transport machinery. Next, we discuss selected examples of RNA and DNA viruses (HBV, HSV, adenovirus, and HIV) that remodel their capsid as part of their strategies to access the nucleus and to replicate.
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Affiliation(s)
- Guillermo Blanco-Rodriguez
- Advanced Molecular Virology and Retroviral Dynamics Group, Department of Virology, Pasteur Institute, 75015 Paris, France;
- Immunity and Cancer Department, Curie Institute, PSL Research University, INSERM U932, 75005 Paris, France
| | - Francesca Di Nunzio
- Advanced Molecular Virology and Retroviral Dynamics Group, Department of Virology, Pasteur Institute, 75015 Paris, France;
- Correspondence:
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27
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De Jesús-González LA, Palacios-Rápalo S, Reyes-Ruiz JM, Osuna-Ramos JF, Cordero-Rivera CD, Farfan-Morales CN, Gutiérrez-Escolano AL, del Ángel RM. The Nuclear Pore Complex Is a Key Target of Viral Proteases to Promote Viral Replication. Viruses 2021; 13:v13040706. [PMID: 33921849 PMCID: PMC8073804 DOI: 10.3390/v13040706] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 04/13/2021] [Accepted: 04/16/2021] [Indexed: 12/17/2022] Open
Abstract
Various viruses alter nuclear pore complex (NPC) integrity to access the nuclear content favoring their replication. Alteration of the nuclear pore complex has been observed not only in viruses that replicate in the nucleus but also in viruses with a cytoplasmic replicative cycle. In this last case, the alteration of the NPC can reduce the transport of transcription factors involved in the immune response or mRNA maturation, or inhibit the transport of mRNA from the nucleus to the cytoplasm, favoring the translation of viral mRNAs or allowing access to nuclear factors necessary for viral replication. In most cases, the alteration of the NPC is mediated by viral proteins, being the viral proteases, one of the most critical groups of viral proteins that regulate these nucleus–cytoplasmic transport changes. This review focuses on the description and discussion of the role of viral proteases in the modification of nucleus–cytoplasmic transport in viruses with cytoplasmic replicative cycles and its repercussions in viral replication.
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Ding B, Sepehrimanesh M. Nucleocytoplasmic Transport: Regulatory Mechanisms and the Implications in Neurodegeneration. Int J Mol Sci 2021; 22:4165. [PMID: 33920577 PMCID: PMC8072611 DOI: 10.3390/ijms22084165] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Revised: 04/13/2021] [Accepted: 04/15/2021] [Indexed: 12/12/2022] Open
Abstract
Nucleocytoplasmic transport (NCT) across the nuclear envelope is precisely regulated in eukaryotic cells, and it plays critical roles in maintenance of cellular homeostasis. Accumulating evidence has demonstrated that dysregulations of NCT are implicated in aging and age-related neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), Alzheimer's disease (AD), and Huntington disease (HD). This is an emerging research field. The molecular mechanisms underlying impaired NCT and the pathogenesis leading to neurodegeneration are not clear. In this review, we comprehensively described the components of NCT machinery, including nuclear envelope (NE), nuclear pore complex (NPC), importins and exportins, RanGTPase and its regulators, and the regulatory mechanisms of nuclear transport of both protein and transcript cargos. Additionally, we discussed the possible molecular mechanisms of impaired NCT underlying aging and neurodegenerative diseases, such as ALS/FTD, HD, and AD.
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Affiliation(s)
- Baojin Ding
- Department of Biology, University of Louisiana at Lafayette, 410 East Saint Mary Boulevard, Lafayette, LA 70503, USA;
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Mozolewski P, Jeziorek M, Schuster CM, Bading H, Frost B, Dobrowolski R. The role of nuclear Ca2+ in maintaining neuronal homeostasis and brain health. J Cell Sci 2021; 134:jcs254904. [PMID: 33912918 PMCID: PMC8084578 DOI: 10.1242/jcs.254904] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Nuclear Ca2+ has emerged as one of the most potent mediators of the dialogue between neuronal synapses and the nucleus that regulates heterochromatin states, transcription factor activity, nuclear morphology and neuronal gene expression induced by synaptic activity. Recent studies underline the importance of nuclear Ca2+ signaling in long-lasting, activity-induced adaptation and maintenance of proper brain function. Diverse forms of neuroadaptation require transient nuclear Ca2+ signaling and cyclic AMP-responsive element-binding protein (CREB1, referred to here as CREB) as its prime target, which works as a tunable switch to drive and modulate specific gene expression profiles associated with memory, pain, addiction and neuroprotection. Furthermore, a reduction of nuclear Ca2+ levels has been shown to be neurotoxic and a causal factor driving the progression of neurodegenerative disorders, as well as affecting neuronal autophagy. Because of its central role in the brain, deficits in nuclear Ca2+ signaling may underlie a continuous loss of neuroprotection in the aging brain, contributing to the pathophysiology of Alzheimer's disease. In this Review, we discuss the principles of the 'nuclear calcium hypothesis' in the context of human brain function and its role in controlling diverse forms of neuroadaptation and neuroprotection. Furthermore, we present the most relevant and promising perspectives for future studies.
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Affiliation(s)
- Pawel Mozolewski
- Department of Biological Sciences, Rutgers University, Newark, NJ 07102, USA
| | - Maciej Jeziorek
- Department of Biological Sciences, Rutgers University, Newark, NJ 07102, USA
| | - Christoph M. Schuster
- Department of Neurobiology, Interdisciplinary Center for Neurosciences (IZN), Heidelberg University, INF 345 and INF 366, 69120 Heidelberg, Germany
| | - Hilmar Bading
- Department of Neurobiology, Interdisciplinary Center for Neurosciences (IZN), Heidelberg University, INF 345 and INF 366, 69120 Heidelberg, Germany
| | - Bess Frost
- Glenn Biggs Institute for Alzheimer's and Neurodegenerative Diseases, University of Texas Health, San Antonio, San Antonio, TX 78229, USA
- Sam and Ann Barshop Institute for Longevity and Aging Studies, Department of Cell Systems and Anatomy, University of Texas Health, San Antonio, San Antonio, TX 78229, USA
| | - Radek Dobrowolski
- Department of Biological Sciences, Rutgers University, Newark, NJ 07102, USA
- Glenn Biggs Institute for Alzheimer's and Neurodegenerative Diseases, University of Texas Health, San Antonio, San Antonio, TX 78229, USA
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30
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Nuclear Import of Adeno-Associated Viruses Imaged by High-Speed Single-Molecule Microscopy. Viruses 2021; 13:v13020167. [PMID: 33499411 PMCID: PMC7911914 DOI: 10.3390/v13020167] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 01/21/2021] [Accepted: 01/21/2021] [Indexed: 12/15/2022] Open
Abstract
Understanding the detailed nuclear import kinetics of adeno-associated virus (AAV) through the nuclear pore complex (NPC) is essential for the application of AAV capsids as a nuclear delivery instrument as well as a target for drug development. However, a comprehensive understanding of AAV transport through the sub-micrometer NPCs in live cells calls for new techniques that can conquer the limitations of conventional fluorescence microscopy and electron microscopy. With recent technical advances in single-molecule fluorescence microscopy, we are now able to image the entire nuclear import process of AAV particles and also quantify the transport dynamics of viral particles through the NPCs in live human cells. In this review, we initially evaluate the necessity of single-molecule live-cell microscopy in the study of nuclear import for AAV particles. Then, we detail the application of high-speed single-point edge-excitation sub-diffraction (SPEED) microscopy in tracking the entire process of nuclear import for AAV particles. Finally, we summarize the major findings for AAV nuclear import by using SPEED microscopy.
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31
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Schuller AP, Wojtynek M, Mankus D, Tatli M, Kronenberg-Tenga R, Regmi SG, Dip PV, Lytton-Jean AKR, Brignole EJ, Dasso M, Weis K, Medalia O, Schwartz TU. The cellular environment shapes the nuclear pore complex architecture. Nature 2021; 598:667-671. [PMID: 34646014 PMCID: PMC8550940 DOI: 10.1038/s41586-021-03985-3] [Citation(s) in RCA: 123] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 09/01/2021] [Indexed: 12/04/2022]
Abstract
Nuclear pore complexes (NPCs) create large conduits for cargo transport between the nucleus and cytoplasm across the nuclear envelope (NE)1-3. These multi-megadalton structures are composed of about thirty different nucleoporins that are distributed in three main substructures (the inner, cytoplasmic and nucleoplasmic rings) around the central transport channel4-6. Here we use cryo-electron tomography on DLD-1 cells that were prepared using cryo-focused-ion-beam milling to generate a structural model for the human NPC in its native environment. We show that-compared with previous human NPC models obtained from purified NEs-the inner ring in our model is substantially wider; the volume of the central channel is increased by 75% and the nucleoplasmic and cytoplasmic rings are reorganized. Moreover, the NPC membrane exhibits asymmetry around the inner-ring complex. Using targeted degradation of Nup96, a scaffold nucleoporin of the cytoplasmic and nucleoplasmic rings, we observe the interdependence of each ring in modulating the central channel and maintaining membrane asymmetry. Our findings highlight the inherent flexibility of the NPC and suggest that the cellular environment has a considerable influence on NPC dimensions and architecture.
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Affiliation(s)
- Anthony P. Schuller
- grid.116068.80000 0001 2341 2786Department of Biology, Massachusetts Institute of Technology, Cambridge, MA USA
| | - Matthias Wojtynek
- grid.7400.30000 0004 1937 0650Department of Biochemistry, University of Zurich, Zurich, Switzerland ,grid.5801.c0000 0001 2156 2780Department of Biology, Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
| | - David Mankus
- grid.116068.80000 0001 2341 2786Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA USA
| | - Meltem Tatli
- grid.7400.30000 0004 1937 0650Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Rafael Kronenberg-Tenga
- grid.7400.30000 0004 1937 0650Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Saroj G. Regmi
- grid.94365.3d0000 0001 2297 5165Division of Molecular and Cellular Biology, National Institute of Child Health and Human Development, NIH, Bethesda, MD USA
| | - Phat V. Dip
- grid.116068.80000 0001 2341 2786Department of Biology, Massachusetts Institute of Technology, Cambridge, MA USA ,grid.116068.80000 0001 2341 2786MIT.nano, Massachusetts Institute of Technology, Cambridge, MA USA
| | - Abigail K. R. Lytton-Jean
- grid.116068.80000 0001 2341 2786Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA USA
| | - Edward J. Brignole
- grid.116068.80000 0001 2341 2786Department of Biology, Massachusetts Institute of Technology, Cambridge, MA USA ,grid.116068.80000 0001 2341 2786MIT.nano, Massachusetts Institute of Technology, Cambridge, MA USA
| | - Mary Dasso
- grid.94365.3d0000 0001 2297 5165Division of Molecular and Cellular Biology, National Institute of Child Health and Human Development, NIH, Bethesda, MD USA
| | - Karsten Weis
- grid.5801.c0000 0001 2156 2780Department of Biology, Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
| | - Ohad Medalia
- grid.7400.30000 0004 1937 0650Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Thomas U. Schwartz
- grid.116068.80000 0001 2341 2786Department of Biology, Massachusetts Institute of Technology, Cambridge, MA USA
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Madni A, Rehman S, Sultan H, Khan MM, Ahmad F, Raza MR, Rai N, Parveen F. Mechanistic Approaches of Internalization, Subcellular Trafficking, and Cytotoxicity of Nanoparticles for Targeting the Small Intestine. AAPS PharmSciTech 2020; 22:3. [PMID: 33221968 PMCID: PMC7680634 DOI: 10.1208/s12249-020-01873-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 11/05/2020] [Indexed: 12/12/2022] Open
Abstract
Targeting the small intestine employing nanotechnology has proved to be a more effective way for site-specific drug delivery. The drug targeting to the small intestine can be achieved via nanoparticles for its optimum bioavailability within the systemic circulation. The small intestine is a remarkable candidate for localized drug delivery. The intestine has its unique properties. It has a less harsh environment than the stomach, provides comparatively more retention time, and possesses a greater surface area than other parts of the gastrointestinal tract. This review focuses on elaborating the intestinal barriers and approaches to overcome these barriers for internalizing nanoparticles and adopting different cellular trafficking pathways. We have discussed various factors that contribute to nanocarriers' cellular uptake, including their surface chemistry, surface morphology, and functionalization of nanoparticles. Furthermore, the fate of nanoparticles after their uptake at cellular and subcellular levels is also briefly explained. Finally, we have delineated the strategies that are adopted to determine the cytotoxicity of nanoparticles.
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Affiliation(s)
- Asadullah Madni
- Department of Pharmacy, The Islamia University of Bahawalpur, Bahawalpur, Pakistan.
| | - Sadia Rehman
- Department of Pharmacy, The Islamia University of Bahawalpur, Bahawalpur, Pakistan
| | - Humaira Sultan
- Department of Pharmacy, The Islamia University of Bahawalpur, Bahawalpur, Pakistan
| | | | - Faiz Ahmad
- Departments of Mechanical Engineering, Universiti Teknologi PETRONAS, Seri Iskandar, Malaysia
| | - M Rafi Raza
- Department of Mechanical Engineering, COMSATS University Islamabad, Sahiwal Campus, Sahiwal, Pakistan
| | - Nadia Rai
- Department of Pharmacy, The Islamia University of Bahawalpur, Bahawalpur, Pakistan
| | - Farzana Parveen
- Department of Pharmacy, The Islamia University of Bahawalpur, Bahawalpur, Pakistan
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Jérôme V, Synatschke CV, Freitag R. Transient Destabilization of Biological Membranes Contributes to the Superior Performance of Star-Shaped PDMAEMA in Delivering pDNA. ACS OMEGA 2020; 5:26640-26654. [PMID: 33110991 PMCID: PMC7581230 DOI: 10.1021/acsomega.0c03367] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 09/17/2020] [Indexed: 06/11/2023]
Abstract
Nonviral DNA vectors are promising alternatives to viral ones. Their use in DNA medicine is limited by an inability to transfect, for example, nondividing or suspension cells. In recent years, star-shaped synthetic polycationic vectors, so called "Nanostars", have shown some promise in this regard, at least when compared to the "gold standard" in nonviral vectors, namely, linear poly(ethyleneimine) (l-PEI). It has been hypothesized that an ability to transiently destabilize cellular membranes is partially responsible for the phenomenon. This hypothesis is investigated here, taking human leukemia suspension cells (Jurkat cells) as an example. Contrary to l-PEI, the Nanostars promote the cellular uptake of small, normally membrane-impermeant molecules (trypan blue and propidium iodide) as well as that of fluorescent polystyrene beads (average diameter 100 nm). Since Nanostars, but not l-PEI, are apparently able to deliver DNA to nuclei of nondividing cells, nuclear uptake is, in addition, investigated with isolated cell nuclei. Our results provide evidence that Nanostars are more efficient than l-PEI in increasing the nuclear membrane association/permeability, allowing accumulation of their cargo on/in the nucleus.
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Affiliation(s)
- Valérie Jérôme
- Process Biotechnology, University of Bayreuth, 95440 Bayreuth, Germany
| | | | - Ruth Freitag
- Process Biotechnology, University of Bayreuth, 95440 Bayreuth, Germany
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34
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Zhang Y, Li S, Zeng C, Huang G, Zhu X, Wang Q, Wang K, Zhou Q, Yan C, Zhang W, Yang G, Liu M, Tao Q, Lei J, Shi Y. Molecular architecture of the luminal ring of the Xenopus laevis nuclear pore complex. Cell Res 2020; 30:532-540. [PMID: 32367042 PMCID: PMC7264284 DOI: 10.1038/s41422-020-0320-y] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 04/06/2020] [Indexed: 12/23/2022] Open
Abstract
The nuclear pore complex (NPC) mediates the flow of substances between the nucleus and cytoplasm in eukaryotic cells. Here we report the cryo-electron tomography (cryo-ET) structure of the luminal ring (LR) of the NPC from Xenopus laevis oocyte. The observed key structural features of the LR are independently confirmed by single-particle cryo-electron microscopy (cryo-EM) analysis. The LR comprises eight butterfly-shaped subunits, each containing two symmetric wings. Each wing consists of four elongated, tubular protomers. Within the LR subunit, the eight protomers form a Finger domain, which directly contacts the fusion between the inner and outer nuclear membranes and a Grid domain, which serves as a rigid base for the Finger domain. Two neighboring LR subunits interact with each other through the lateral edges of their wings to constitute a Bumper domain, which displays two major conformations and appears to cushion neighboring NPCs. Our study reveals previously unknown features of the LR and potentially explains the elastic property of the NPC.
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Affiliation(s)
- Yanqing Zhang
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, Zhejiang, 310024, China
- Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, Zhejiang, 310024, China
| | - Sai Li
- Beijing Advanced Innovation Center for Structural Biology & Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Tsinghua University-Peking University Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Chao Zeng
- Tsinghua University-Peking University Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Gaoxingyu Huang
- Beijing Advanced Innovation Center for Structural Biology & Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Xuechen Zhu
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, Zhejiang, 310024, China
- Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, Zhejiang, 310024, China
| | - Qifan Wang
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, Zhejiang, 310024, China
- Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, Zhejiang, 310024, China
| | - Kunpeng Wang
- Tsinghua Computing Facility & Department of Computer Science, Tsinghua University, Beijing, 100084, China
| | - Qiang Zhou
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, Zhejiang, 310024, China
- Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, Zhejiang, 310024, China
| | - Chuangye Yan
- Beijing Advanced Innovation Center for Structural Biology & Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Wusheng Zhang
- Tsinghua Computing Facility & Department of Computer Science, Tsinghua University, Beijing, 100084, China
| | - Guangwen Yang
- Tsinghua Computing Facility & Department of Computer Science, Tsinghua University, Beijing, 100084, China
| | - Minhao Liu
- Beijing Advanced Innovation Center for Structural Biology & Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Qinghua Tao
- Beijing Advanced Innovation Center for Structural Biology & Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Jianlin Lei
- Beijing Advanced Innovation Center for Structural Biology & Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Yigong Shi
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, Zhejiang, 310024, China.
- Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, Zhejiang, 310024, China.
- Beijing Advanced Innovation Center for Structural Biology & Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
- Tsinghua University-Peking University Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
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35
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Mudumbi KC, Czapiewski R, Ruba A, Junod SL, Li Y, Luo W, Ngo C, Ospina V, Schirmer EC, Yang W. Nucleoplasmic signals promote directed transmembrane protein import simultaneously via multiple channels of nuclear pores. Nat Commun 2020; 11:2184. [PMID: 32366843 PMCID: PMC7198523 DOI: 10.1038/s41467-020-16033-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 04/09/2020] [Indexed: 02/07/2023] Open
Abstract
Roughly 10% of eukaryotic transmembrane proteins are found on the nuclear membrane, yet how such proteins target and translocate to the nucleus remains in dispute. Most models propose transport through the nuclear pore complexes, but a central outstanding question is whether transit occurs through their central or peripheral channels. Using live-cell high-speed super-resolution single-molecule microscopy we could distinguish protein translocation through the central and peripheral channels, finding that most inner nuclear membrane proteins use only the peripheral channels, but some apparently extend intrinsically disordered domains containing nuclear localization signals into the central channel for directed nuclear transport. These nucleoplasmic signals are critical for central channel transport as their mutation blocks use of the central channels; however, the mutated proteins can still complete their translocation using only the peripheral channels, albeit at a reduced rate. Such proteins can still translocate using only the peripheral channels when central channel is blocked, but blocking the peripheral channels blocks translocation through both channels. This suggests that peripheral channel transport is the default mechanism that was adapted in evolution to include aspects of receptor-mediated central channel transport for directed trafficking of certain membrane proteins.
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Affiliation(s)
- Krishna C Mudumbi
- Department of Biology, Temple University, Philadelphia, PA, 19122, USA.
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT, 06520, USA.
- Yale Cancer Biology Institute, Yale University, West Haven, CT, 06516, USA.
| | - Rafal Czapiewski
- The Institute of Cell Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Andrew Ruba
- Department of Biology, Temple University, Philadelphia, PA, 19122, USA
| | - Samuel L Junod
- Department of Biology, Temple University, Philadelphia, PA, 19122, USA
| | - Yichen Li
- Department of Biology, Temple University, Philadelphia, PA, 19122, USA
| | - Wangxi Luo
- Department of Biology, Temple University, Philadelphia, PA, 19122, USA
| | - Christina Ngo
- Department of Biology, Temple University, Philadelphia, PA, 19122, USA
| | - Valentina Ospina
- Department of Biology, Temple University, Philadelphia, PA, 19122, USA
| | - Eric C Schirmer
- The Institute of Cell Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK.
| | - Weidong Yang
- Department of Biology, Temple University, Philadelphia, PA, 19122, USA.
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36
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Junod SL, Kelich JM, Ma J, Yang W. Nucleocytoplasmic transport of intrinsically disordered proteins studied by high-speed super-resolution microscopy. Protein Sci 2020; 29:1459-1472. [PMID: 32096308 DOI: 10.1002/pro.3845] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 02/18/2020] [Accepted: 02/18/2020] [Indexed: 11/10/2022]
Abstract
Both natively folded and intrinsically disordered proteins (IDPs) destined for the nucleus need to transport through the nuclear pore complexes (NPCs) in eukaryotic cells. NPCs allow for passive diffusion of small folded proteins while barricading large ones, unless they are facilitated by nuclear transport receptors. However, whether nucleocytoplasmic transport of IDPs would follow these rules remains unknown. By using a high-speed super-resolution fluorescence microscopy, we have measured transport kinetics and 3D spatial locations of transport routes through native NPCs for various IDPs. Our data revealed that the rules executed for folded proteins are not well followed by the IDPs. Instead, both large and small IDPs can passively diffuse through the NPCs. Furthermore, their diffusion efficiencies and routes are differentiated by their content ratio of charged (Ch) and hydrophobic (Hy) amino acids. A Ch/Hy-ratio mechanism was finally suggested for nucleocytoplasmic transport of IDPs.
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Affiliation(s)
- Samuel L Junod
- Department of Biology, Temple University, Philadelphia, Pennsylvania
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37
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Moore S, Rabichow BE, Sattler R. The Hitchhiker's Guide to Nucleocytoplasmic Trafficking in Neurodegeneration. Neurochem Res 2020; 45:1306-1327. [PMID: 32086712 DOI: 10.1007/s11064-020-02989-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 02/12/2020] [Accepted: 02/14/2020] [Indexed: 12/12/2022]
Abstract
The widespread nature of nucleocytoplasmic trafficking defects and protein accumulation suggests distinct yet overlapping mechanisms in a variety of neurodegenerative diseases. Detailed understanding of the cellular pathways involved in nucleocytoplasmic transport and its dysregulation are essential for elucidating neurodegenerative pathogenesis and pinpointing potential areas for therapeutic intervention. The transport of cargos from the nucleus to the cytoplasm is generally regulated by the structure and function of the nuclear pore as well as the karyopherin α/β, importin, exportin, and mRNA export mechanisms. The disruption of these crucial transport mechanisms has been extensively described in the context of neurodegenerative diseases. One common theme in neurodegeneration is the cytoplasmic aggregation of proteins, including nuclear RNA binding proteins, repeat expansion associated gene products, and tau. These cytoplasmic aggregations are partly a consequence of failed nucleocytoplasmic transport machinery, but can also further disrupt transport, creating cyclical feed-forward mechanisms that exacerbate neurodegeneration. Here we describe the canonical mechanisms that regulate nucleocytoplasmic trafficking as well as how these mechanisms falter in neurodegenerative diseases.
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Affiliation(s)
- Stephen Moore
- Department of Neurobiology, Barrow Neurological Institute, 350 W Thomas Road, Phoenix, AZ, 85013, USA.,School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | - Benjamin E Rabichow
- Department of Neurobiology, Barrow Neurological Institute, 350 W Thomas Road, Phoenix, AZ, 85013, USA
| | - Rita Sattler
- Department of Neurobiology, Barrow Neurological Institute, 350 W Thomas Road, Phoenix, AZ, 85013, USA.
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38
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Gomar-Alba M, Mendoza M. Modulation of Cell Identity by Modification of Nuclear Pore Complexes. Front Genet 2020; 10:1301. [PMID: 31969901 PMCID: PMC6960265 DOI: 10.3389/fgene.2019.01301] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 11/26/2019] [Indexed: 11/17/2022] Open
Abstract
Nuclear pore complexes (NPCs) are protein assemblies that form channels across the nuclear envelope to mediate communication between the nucleus and the cytoplasm. Additionally, NPCs interact with chromatin and influence the position and expression of multiple genes. Interestingly, the composition of NPCs can vary in different cell-types, tissues, and developmental states. Here, we review recent findings suggesting that modifications of NPC composition, including post-translational modifications, play an instructive role in cell fate establishment. In particular, we focus on the role of cell-specific NPC deacetylation in asymmetrically dividing budding yeast, which modulates transport-dependent and transport-independent NPC functions to determine the time of commitment to a new division cycle in daughter cells. By modulating protein localization and gene expression, NPCs are therefore emerging as central regulators of cell identity.
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Affiliation(s)
- Mercè Gomar-Alba
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France.,Centre National de la Recherche Scientifique, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, Illkirch, France.,Université de Strasbourg, Strasbourg, France
| | - Manuel Mendoza
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France.,Centre National de la Recherche Scientifique, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, Illkirch, France.,Université de Strasbourg, Strasbourg, France
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Singh SP, Raja S, Mahalingam S. Viral protein X unlocks the nuclear pore complex through a human Nup153-dependent pathway to promote nuclear translocation of the lentiviral genome. Mol Biol Cell 2020; 31:304-317. [PMID: 31913756 PMCID: PMC7183765 DOI: 10.1091/mbc.e19-08-0438] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Simian immunodeficiency virus (SIV) and human immunodeficiency virus 2 (HIV-2) display unique ability to infect nondividing target cells. Viral protein X (Vpx) of HIV-2/SIV is known to be involved in the nuclear import of viral genome in nondividing cells, but the mechanism remains poorly understood. In the present investigation for the first time we provide evidence that Vpx of SIVsmPBj1.9 physically interacts with human nucleoporin 153 (Nup153), which is known to provide a docking site for protein-cargo complexes at the nuclear pore complex (NPC). Results from superresolution-structured illumination microscopy studies reveal that Vpx interaction with NPC-associated Nup153 is critical for its efficient nuclear translocation. Virion-associated MAPK/ERK-2-mediated phosphorylation of Vpx plays a critical role in its interaction with human Nup153 and this interaction was found to be evolutionarily conserved in various SIV isolates and HIV-2. Interestingly, MAPK/ERK-2 packaging defective SIV failed to promote the efficient nuclear import of viral genome and suggests that MAPK/ERK-2-mediated Vpx phosphorylation is important for its interaction with Nup153, which is critical for lentiviruses to establish infection in nondividing target cells. Together, our data elucidate the mechanism by which Vpx orchestrates the challenging task of nuclear translocation of HIV-2/SIV genome in nondividing target cells.
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Affiliation(s)
- Satya Prakash Singh
- Laboratory of Molecular Cell Biology, Indian Institute of Technology-Madras, Chennai 600 036, India
| | - Sebastian Raja
- Laboratory of Molecular Cell Biology, Indian Institute of Technology-Madras, Chennai 600 036, India
| | - Sundarasamy Mahalingam
- Laboratory of Molecular Cell Biology, Indian Institute of Technology-Madras, Chennai 600 036, India.,National Cancer Tissue Biobank, Bhupat and Jyoti Mehta School of Biosciences, Department of Biotechnology, Indian Institute of Technology-Madras, Chennai 600 036, India
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40
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Toro-Nahuelpan M, Zagoriy I, Senger F, Blanchoin L, Théry M, Mahamid J. Tailoring cryo-electron microscopy grids by photo-micropatterning for in-cell structural studies. Nat Methods 2020; 17:50-54. [PMID: 31740821 PMCID: PMC6949126 DOI: 10.1038/s41592-019-0630-5] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 10/07/2019] [Indexed: 01/01/2023]
Abstract
Spatially controlled cell adhesion on electron microscopy supports remains a bottleneck in specimen preparation for cellular cryo-electron tomography. Here, we describe contactless and mask-free photo-micropatterning of electron microscopy grids for site-specific deposition of extracellular matrix-related proteins. We attained refined cell positioning for micromachining by cryo-focused ion beam milling. Complex micropatterns generated predictable intracellular organization, allowing direct correlation between cell architecture and in-cell three-dimensional structural characterization of the underlying molecular machinery.
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Affiliation(s)
- Mauricio Toro-Nahuelpan
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Ievgeniia Zagoriy
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Fabrice Senger
- CytomorphoLab, Interdisciplinary Research Institute of Grenoble, Laboratoire de Physiologie Cellulaire et Végétale, Université Grenoble-Alpes/CEA/CNRS/INRA, Grenoble, France
| | - Laurent Blanchoin
- CytomorphoLab, Interdisciplinary Research Institute of Grenoble, Laboratoire de Physiologie Cellulaire et Végétale, Université Grenoble-Alpes/CEA/CNRS/INRA, Grenoble, France
- CytomorphoLab, Hôpital Saint Louis, Institut Universitaire d'Hématologie, Université Paris Diderot, Paris, France
| | - Manuel Théry
- CytomorphoLab, Interdisciplinary Research Institute of Grenoble, Laboratoire de Physiologie Cellulaire et Végétale, Université Grenoble-Alpes/CEA/CNRS/INRA, Grenoble, France
- CytomorphoLab, Hôpital Saint Louis, Institut Universitaire d'Hématologie, Université Paris Diderot, Paris, France
| | - Julia Mahamid
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany.
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41
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Toro-Nahuelpan M, Zagoriy I, Senger F, Blanchoin L, Théry M, Mahamid J. Tailoring cryo-electron microscopy grids by photo-micropatterning for in-cell structural studies. Nat Methods 2020; 17:50-54. [PMID: 31740821 DOI: 10.21203/rs.2.12377/v1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 10/07/2019] [Indexed: 05/22/2023]
Abstract
Spatially controlled cell adhesion on electron microscopy supports remains a bottleneck in specimen preparation for cellular cryo-electron tomography. Here, we describe contactless and mask-free photo-micropatterning of electron microscopy grids for site-specific deposition of extracellular matrix-related proteins. We attained refined cell positioning for micromachining by cryo-focused ion beam milling. Complex micropatterns generated predictable intracellular organization, allowing direct correlation between cell architecture and in-cell three-dimensional structural characterization of the underlying molecular machinery.
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Affiliation(s)
- Mauricio Toro-Nahuelpan
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Ievgeniia Zagoriy
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Fabrice Senger
- CytomorphoLab, Interdisciplinary Research Institute of Grenoble, Laboratoire de Physiologie Cellulaire et Végétale, Université Grenoble-Alpes/CEA/CNRS/INRA, Grenoble, France
| | - Laurent Blanchoin
- CytomorphoLab, Interdisciplinary Research Institute of Grenoble, Laboratoire de Physiologie Cellulaire et Végétale, Université Grenoble-Alpes/CEA/CNRS/INRA, Grenoble, France
- CytomorphoLab, Hôpital Saint Louis, Institut Universitaire d'Hématologie, Université Paris Diderot, Paris, France
| | - Manuel Théry
- CytomorphoLab, Interdisciplinary Research Institute of Grenoble, Laboratoire de Physiologie Cellulaire et Végétale, Université Grenoble-Alpes/CEA/CNRS/INRA, Grenoble, France
- CytomorphoLab, Hôpital Saint Louis, Institut Universitaire d'Hématologie, Université Paris Diderot, Paris, France
| | - Julia Mahamid
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany.
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42
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Frei MS, Hoess P, Lampe M, Nijmeijer B, Kueblbeck M, Ellenberg J, Wadepohl H, Ries J, Pitsch S, Reymond L, Johnsson K. Photoactivation of silicon rhodamines via a light-induced protonation. Nat Commun 2019; 10:4580. [PMID: 31594948 PMCID: PMC6783549 DOI: 10.1038/s41467-019-12480-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 09/13/2019] [Indexed: 12/17/2022] Open
Abstract
Photoactivatable fluorophores are important for single-particle tracking and super-resolution microscopy. Here we present a photoactivatable fluorophore that forms a bright silicon rhodamine derivative through a light-dependent protonation. In contrast to other photoactivatable fluorophores, no caging groups are required, nor are there any undesired side-products released. Using this photoactivatable fluorophore, we create probes for HaloTag and actin for live-cell single-molecule localization microscopy and single-particle tracking experiments. The unusual mechanism of photoactivation and the fluorophore's outstanding spectroscopic properties make it a powerful tool for live-cell super-resolution microscopy.
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Affiliation(s)
- Michelle S Frei
- Department of Chemical Biology, Max Planck Institute for Medical Research, Jahnstrasse 29, 69120, Heidelberg, Germany
- Institute of Chemical Sciences and Engineering (ISIC), École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
| | - Philipp Hoess
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, 69117, Heidelberg, Germany
- Collaboration for joint PhD degree between EMBL and Heidelberg University, Faculty of Biosciences, Heidelberg, Germany
| | - Marko Lampe
- Advanced Light Microscopy Facility (ALMF), European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, 69117, Heidelberg, Germany
| | - Bianca Nijmeijer
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, 69117, Heidelberg, Germany
| | - Moritz Kueblbeck
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, 69117, Heidelberg, Germany
| | - Jan Ellenberg
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, 69117, Heidelberg, Germany
| | - Hubert Wadepohl
- Anorganisch-Chemisches Institut, University of Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Jonas Ries
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, 69117, Heidelberg, Germany
| | - Stefan Pitsch
- Spirochrome AG, Chalberweidstrasse 4, CH-8260, Stein am Rhein, Switzerland
| | - Luc Reymond
- Biomolecular Screening Facility, École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland.
- National Centre of Competence in Research (NCCR) in Chemical Biology, 1015, Lausanne, Switzerland.
| | - Kai Johnsson
- Department of Chemical Biology, Max Planck Institute for Medical Research, Jahnstrasse 29, 69120, Heidelberg, Germany.
- Institute of Chemical Sciences and Engineering (ISIC), École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland.
- National Centre of Competence in Research (NCCR) in Chemical Biology, 1015, Lausanne, Switzerland.
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43
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Infante E, Stannard A, Board SJ, Rico-Lastres P, Panagaki F, Beedle AE, Rajan VS, Rostkova E, Lezamiz A, Wang YJ, Breen SG, Shanahan C, Roca-Cusachs P, Garcia-Manyes S. The mechanical stability of proteins regulates their translocation rate into the cell nucleus. NATURE PHYSICS 2019; 15:973-981. [PMID: 37484710 PMCID: PMC7614795 DOI: 10.1038/s41567-019-0551-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Accepted: 05/10/2019] [Indexed: 07/25/2023]
Abstract
The translocation of mechanosensitive transcription factors (TFs) across the nuclear envelope is a crucial step in cellular mechanotransduction. Yet the molecular mechanisms by which external mechanical cues control the nuclear shuttling dynamics of TFs through the nuclear pore complex (NPC) to activate gene expression are poorly understood. Here, we show that the nuclear import rate of myocardin-related transcription factor A (MRTFA) - a protein that regulates cytoskeletal dynamics via the activation of the TF serum response factor (SRF) - inversely correlates with the protein's nanomechanical stability and does not relate to its thermodynamic stability. Tagging MRTFA with mechanically resistant proteins results in the downregulation of SRF-mediated myosin light-chain 9 (MYL9) gene expression and subsequent slowing down of cell migration. We conclude that the mechanical unfolding of proteins regulates their nuclear translocation rate through the NPC, and highlight the role of the NPC as a selective mechanosensor able to discriminate forces as low as ~10 pN. The modulation of the mechanical stability of TFs may represent a new strategy for the control of gene expression.
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Affiliation(s)
- Elvira Infante
- Department of Physics and Randall Centre for Cell and Molecular Biophysics, King’s College London, WC2R 2LS, London, UK
| | - Andrew Stannard
- Department of Physics and Randall Centre for Cell and Molecular Biophysics, King’s College London, WC2R 2LS, London, UK
| | - Stephanie J. Board
- Department of Physics and Randall Centre for Cell and Molecular Biophysics, King’s College London, WC2R 2LS, London, UK
| | - Palma Rico-Lastres
- Department of Physics and Randall Centre for Cell and Molecular Biophysics, King’s College London, WC2R 2LS, London, UK
| | - Fani Panagaki
- Department of Physics and Randall Centre for Cell and Molecular Biophysics, King’s College London, WC2R 2LS, London, UK
| | - Amy E.M. Beedle
- Department of Physics and Randall Centre for Cell and Molecular Biophysics, King’s College London, WC2R 2LS, London, UK
| | - Vinoth Sundar Rajan
- Department of Physics and Randall Centre for Cell and Molecular Biophysics, King’s College London, WC2R 2LS, London, UK
| | - Elena Rostkova
- Department of Physics and Randall Centre for Cell and Molecular Biophysics, King’s College London, WC2R 2LS, London, UK
| | - Ainhoa Lezamiz
- Department of Physics and Randall Centre for Cell and Molecular Biophysics, King’s College London, WC2R 2LS, London, UK
| | - Yong Jian Wang
- Department of Physics and Randall Centre for Cell and Molecular Biophysics, King’s College London, WC2R 2LS, London, UK
| | - Samuel Gulaidi Breen
- Department of Physics and Randall Centre for Cell and Molecular Biophysics, King’s College London, WC2R 2LS, London, UK
| | - Catherine Shanahan
- Cardiovascular Division, James Black Centre, King’s College London, London SE5 9NU, UK Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and
| | - Pere Roca-Cusachs
- Technology (BIST) and University of Barcelona, 08028 Barcelona, Spain
| | - Sergi Garcia-Manyes
- Department of Physics and Randall Centre for Cell and Molecular Biophysics, King’s College London, WC2R 2LS, London, UK
- The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
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44
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Enhanced Nucleocytoplasmic Transport due to Competition for Elastic Binding Sites. Biophys J 2019; 115:108-116. [PMID: 29972802 DOI: 10.1016/j.bpj.2018.05.034] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 05/21/2018] [Accepted: 05/31/2018] [Indexed: 01/08/2023] Open
Abstract
Nuclear pore complexes (NPCs) control all traffic into and out of the cell nucleus. NPCs are molecular machines that simultaneously achieve high selectivity and high transport rates. The biophysical details of how cargoes rapidly traverse the pore remain unclear but are known to be mediated by interactions between cargo-binding chaperone proteins and natively unstructured nucleoporin proteins containing many phenylalanine-glycine repeats (FG nups) that line the pore's central channel. Here, we propose a specific and detailed physical mechanism for the high speed of nuclear import based on the elasticity of FG nups and on competition between individual chaperone proteins for FG nup binding. We develop a mathematical model to support our proposed mechanism. We suggest that the recycling of nuclear import factors back to the cytoplasm is important for driving high-speed import and predict the existence of an optimal cytoplasmic concentration of cargo for enhancing the rate of import over a purely diffusive rate.
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45
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The NAE Pathway: Autobahn to the Nucleus for Cell Surface Receptors. Cells 2019; 8:cells8080915. [PMID: 31426451 PMCID: PMC6721735 DOI: 10.3390/cells8080915] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 08/13/2019] [Accepted: 08/13/2019] [Indexed: 12/19/2022] Open
Abstract
Various growth factors and full-length cell surface receptors such as EGFR are translocated from the cell surface to the nucleoplasm, baffling cell biologists to the mechanisms and functions of this process. Elevated levels of nuclear EGFR correlate with poor prognosis in various cancers. In recent years, nuclear EGFR has been implicated in regulating gene transcription, cell proliferation and DNA damage repair. Different models have been proposed to explain how the receptors are transported into the nucleus. However, a clear consensus has yet to be reached. Recently, we described the nuclear envelope associated endosomes (NAE) pathway, which delivers EGFR from the cell surface to the nucleus. This pathway involves transport, docking and fusion of NAEs with the outer membrane of the nuclear envelope. EGFR is then presumed to be transported through the nuclear pore complex, extracted from membranes and solubilised. The SUN1/2 nuclear envelope proteins, Importin-beta, nuclear pore complex proteins and the Sec61 translocon have been implicated in the process. While this framework can explain the cell surface to nucleus traffic of EGFR and other cell surface receptors, it raises several questions that we consider in this review, together with implications for health and disease.
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46
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Ben-Yishay R, Mor A, Shraga A, Ashkenazy-Titelman A, Kinor N, Schwed-Gross A, Jacob A, Kozer N, Kumar P, Garini Y, Shav-Tal Y. Imaging within single NPCs reveals NXF1's role in mRNA export on the cytoplasmic side of the pore. J Cell Biol 2019; 218:2962-2981. [PMID: 31375530 PMCID: PMC6719458 DOI: 10.1083/jcb.201901127] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 06/21/2019] [Accepted: 07/03/2019] [Indexed: 12/12/2022] Open
Abstract
Translocation of mRNA through the nuclear pore complex (NPC) requires interactions with different NPC regions. To determine the interactions that are crucial for effective mRNA export in living cells, we examined mRNA export within individual pores by applying various types of mRNA export blocks that stalled mRNPs at different stages of transition. Focusing on the major mRNA export factor NXF1, we found that initial mRNP binding to the NPC did not require NXF1 in the NPC, whereas release into the cytoplasm did. NXF1 localization in the NPC did not require RNA or RNA binding. Superresolution microscopy showed that NXF1 consistently occupied positions on the cytoplasmic side of the NPC. Interactions with specific nucleoporins were pinpointed using FLIM-FRET for measuring protein-protein interactions inside single NPCs, showing that Dbp5 helicase activity of mRNA release is conserved in yeast and humans. Altogether, we find that specific interactions on the cytoplasmic side of the NPC are fundamental for the directional flow of mRNA export.
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Affiliation(s)
- Rakefet Ben-Yishay
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel.,Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat Gan, Israel
| | - Amir Mor
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel.,Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat Gan, Israel
| | - Amit Shraga
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel.,Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat Gan, Israel
| | - Asaf Ashkenazy-Titelman
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel.,Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat Gan, Israel
| | - Noa Kinor
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel.,Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat Gan, Israel
| | - Avital Schwed-Gross
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel.,Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat Gan, Israel
| | - Avi Jacob
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel.,Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat Gan, Israel
| | - Noga Kozer
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel.,Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat Gan, Israel
| | - Pramod Kumar
- Department of Physics, Bar-Ilan University, Ramat Gan, Israel.,Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat Gan, Israel
| | - Yuval Garini
- Department of Physics, Bar-Ilan University, Ramat Gan, Israel.,Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat Gan, Israel
| | - Yaron Shav-Tal
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel .,Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat Gan, Israel
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47
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Vallotton P, Rajoo S, Wojtynek M, Onischenko E, Kralt A, Derrer CP, Weis K. Mapping the native organization of the yeast nuclear pore complex using nuclear radial intensity measurements. Proc Natl Acad Sci U S A 2019; 116:14606-14613. [PMID: 31262825 PMCID: PMC6642398 DOI: 10.1073/pnas.1903764116] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Selective transport across the nuclear envelope (NE) is mediated by the nuclear pore complex (NPC), a massive ∼100-MDa assembly composed of multiple copies of ∼30 nuclear pore proteins (Nups). Recent advances have shed light on the composition and structure of NPCs, but approaches that could map their organization in live cells are still lacking. Here, we introduce an in vivo method to perform nuclear radial intensity measurements (NuRIM) using fluorescence microscopy to determine the average position of NE-localized proteins along the nucleocytoplasmic transport axis. We apply NuRIM to study the organization of the NPC and the mobile transport machinery in budding yeast. This reveals a unique snapshot of the intact yeast NPC and identifies distinct steady-state localizations for various NE-associated proteins and nuclear transport factors. We find that the NPC architecture is robust against compositional changes and could also confirm that in contrast to Chlamydomonas reinhardtii, the scaffold Y complex is arranged symmetrically in the yeast NPC. Furthermore, NuRIM was applied to probe the orientation of intrinsically disordered FG-repeat segments, providing insight into their roles in selective NPC permeability and structure.
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Affiliation(s)
- Pascal Vallotton
- Institute of Biochemistry, Department of Biology, Swiss Federal Institute of Technology Zürich (ETH Zürich), 8093 Zürich, Switzerland;
| | - Sasikumar Rajoo
- Institute of Biochemistry, Department of Biology, Swiss Federal Institute of Technology Zürich (ETH Zürich), 8093 Zürich, Switzerland
| | - Matthias Wojtynek
- Institute of Biochemistry, Department of Biology, Swiss Federal Institute of Technology Zürich (ETH Zürich), 8093 Zürich, Switzerland
- Department of Biochemistry, University of Zürich, 8057 Zürich, Switzerland
| | - Evgeny Onischenko
- Institute of Biochemistry, Department of Biology, Swiss Federal Institute of Technology Zürich (ETH Zürich), 8093 Zürich, Switzerland
| | - Annemarie Kralt
- Institute of Biochemistry, Department of Biology, Swiss Federal Institute of Technology Zürich (ETH Zürich), 8093 Zürich, Switzerland
| | - Carina Patrizia Derrer
- Institute of Biochemistry, Department of Biology, Swiss Federal Institute of Technology Zürich (ETH Zürich), 8093 Zürich, Switzerland
| | - Karsten Weis
- Institute of Biochemistry, Department of Biology, Swiss Federal Institute of Technology Zürich (ETH Zürich), 8093 Zürich, Switzerland;
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48
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Li Y, Luo W, Yang W. Nuclear Transport and Accumulation of Smad Proteins Studied by Single-Molecule Microscopy. Biophys J 2019; 114:2243-2251. [PMID: 29742417 DOI: 10.1016/j.bpj.2018.03.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2018] [Accepted: 03/15/2018] [Indexed: 12/24/2022] Open
Abstract
Nuclear translocation of stimulated Smad heterocomplexes is a critical step in the signal transduction of transforming growth factor β (TGF-β) from transmembrane receptors into the nucleus. Specifically, normal nuclear accumulation of Smad2/Smad4 heterocomplexes induced by TGF-β1 is involved in carcinogenesis. However, the relationship between nuclear accumulation and the nucleocytoplasmic transport kinetics of Smad proteins in the presence of TGF-β1 remains obscure. By combining a high-speed single-molecule tracking microscopy and Förster resonance energy transfer technique, we tracked the entire TGF-β1-induced process of Smad2/Smad4 heterocomplex formation, as well as their transport through nuclear pore complexes in live cells, with a high single-molecule localization precision of 2 ms and <20 nm. Our single-molecule Förster resonance energy transfer data have revealed that in TGF-β1-treated cells, Smad2/Smad4 heterocomplexes formed in the cytoplasm, imported through the nuclear pore complexes as entireties, and finally dissociated in the nucleus. Moreover, we found that basal-state Smad2 or Smad4 cannot accumulate in the nucleus without the presence of TGF-β1, mainly because both of them have an approximately twofold higher nuclear export efficiency compared to their nuclear import. Remarkably and reversely, heterocomplexes of Smad2/Smad4 induced by TGF-β1 can rapidly concentrate in the nucleus because of their almost fourfold higher nuclear import rate in comparison with their nuclear export rate. Thus, we believe that the determined TGF-β1-dependent transport configurations and efficiencies for the basal-state Smad or stimulated Smad heterocomplexes elucidate the basic molecular mechanism to understand their nuclear transport and accumulation.
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Affiliation(s)
- Yichen Li
- Department of Biology, Temple University, Philadelphia, Pennsylvania
| | - Wangxi Luo
- Department of Biology, Temple University, Philadelphia, Pennsylvania
| | - Weidong Yang
- Department of Biology, Temple University, Philadelphia, Pennsylvania.
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49
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Asymmetrical localization of Nup107-160 subcomplex components within the nuclear pore complex in fission yeast. PLoS Genet 2019; 15:e1008061. [PMID: 31170156 PMCID: PMC6553703 DOI: 10.1371/journal.pgen.1008061] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 03/01/2019] [Indexed: 01/05/2023] Open
Abstract
The nuclear pore complex (NPC) forms a gateway for nucleocytoplasmic transport. The outer ring protein complex of the NPC (the Nup107-160 subcomplex in humans) is a key component for building the NPC. Nup107-160 subcomplexes are believed to be symmetrically localized on the nuclear and cytoplasmic sides of the NPC. However, in S. pombe immunoelectron and fluorescence microscopic analyses revealed that the homologous components of the human Nup107-160 subcomplex had an asymmetrical localization: constituent proteins spNup132 and spNup107 were present only on the nuclear side (designated the spNup132 subcomplex), while spNup131, spNup120, spNup85, spNup96, spNup37, spEly5 and spSeh1 were localized only on the cytoplasmic side (designated the spNup120 subcomplex), suggesting the complex was split into two pieces at the interface between spNup96 and spNup107. This contrasts with the symmetrical localization reported in other organisms. Fusion of spNup96 (cytoplasmic localization) with spNup107 (nuclear localization) caused cytoplasmic relocalization of spNup107. In this strain, half of the spNup132 proteins, which interact with spNup107, changed their localization to the cytoplasmic side of the NPC, leading to defects in mitotic and meiotic progression similar to an spNup132 deletion strain. These observations suggest the asymmetrical localization of the outer ring spNup132 and spNup120 subcomplexes of the NPC is necessary for normal cell cycle progression in fission yeast. The nuclear pore complexes (NPCs) form gateways to transport intracellular molecules between the nucleus and the cytoplasm across the nuclear envelope. The Nup107-160 subcomplex, that forms nuclear and cytoplasmic outer rings, is a key complex responsible for building the NPC by symmetrical localization on the nuclear and cytoplasmic sides of the nuclear pore. This structural characteristic was found in various organisms including humans and budding yeasts, and therefore believed to be common among “all” eukaryotes. However, in this paper, we revealed an asymmetrical localization of the homologous components of the human Nup107-160 subcomplex in fission yeast by immunoelectron and fluorescence microscopic analyses: in this organism, the Nup107-160 subcomplex is split into two pieces, and each of the split pieces is differentially distributed to the nuclear and cytoplasmic side of the NPC: one piece is only in the nuclear side while the other piece is only in the cytoplasmic side. This contrasts with the symmetrical localization reported in other organisms. In addition, we confirmed that the asymmetrical configuration of the outer ring structure is necessary for cell cycle progression in fission yeast. This study provides notions of diverse structures and functions of NPCs evolved in eukaryotes.
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Schur FK. Toward high-resolution in situ structural biology with cryo-electron tomography and subtomogram averaging. Curr Opin Struct Biol 2019; 58:1-9. [PMID: 31005754 DOI: 10.1016/j.sbi.2019.03.018] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 03/08/2019] [Accepted: 03/12/2019] [Indexed: 01/03/2023]
Abstract
Cryo-electron tomography (cryo-ET) provides unprecedented insights into the molecular constituents of biological environments. In combination with an image processing method called subtomogram averaging (STA), detailed 3D structures of biological molecules can be obtained in large, irregular macromolecular assemblies or in situ, without the need for purification. The contextual meta-information these methods also provide, such as a protein's location within its native environment, can then be combined with functional data. This allows the derivation of a detailed view on the physiological or pathological roles of proteins from the molecular to cellular level. Despite their tremendous potential in in situ structural biology, cryo-ET and STA have been restricted by methodological limitations, such as the low obtainable resolution. Exciting progress now allows one to reach unprecedented resolutions in situ, ranging in optimal cases beyond the nanometer barrier. Here, I review current frontiers and future challenges in routinely determining high-resolution structures in in situ environments using cryo-ET and STA.
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Affiliation(s)
- Florian Km Schur
- Institute of Science and Technology Austria, Am Campus 1, A-3400 Klosterneuburg, Austria.
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