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Lima JT, Ferreira JG. Mechanobiology of the nucleus during the G2-M transition. Nucleus 2024; 15:2330947. [PMID: 38533923 DOI: 10.1080/19491034.2024.2330947] [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: 11/30/2023] [Accepted: 03/09/2024] [Indexed: 03/28/2024] Open
Abstract
Cellular behavior is continuously influenced by mechanical forces. These forces span the cytoskeleton and reach the nucleus, where they trigger mechanotransduction pathways that regulate downstream biochemical events. Therefore, the nucleus has emerged as a regulator of cellular response to mechanical stimuli. Cell cycle progression is regulated by cyclin-CDK complexes. Recent studies demonstrated these biochemical pathways are influenced by mechanical signals, highlighting the interdependence of cellular mechanics and cell cycle regulation. In particular, the transition from G2 to mitosis (G2-M) shows significant changes in nuclear structure and organization, ranging from nuclear pore complex (NPC) and nuclear lamina disassembly to chromosome condensation. The remodeling of these mechanically active nuclear components indicates that mitotic entry is particularly sensitive to forces. Here, we address how mechanical forces crosstalk with the nucleus to determine the timing and efficiency of the G2-M transition. Finally, we discuss how the deregulation of nuclear mechanics has consequences for mitosis.
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Affiliation(s)
- Joana T Lima
- Epithelial Polarity and Cell Division Laboratory, Instituto de Investigação e Inovação em Saúde (i3S), Porto, Portugal
- Departamento de Biomedicina, Unidade de Biologia Experimental, Faculdade de Medicina do Porto, Porto, Portugal
- Programa Doutoral em Biomedicina, Faculdade de Medicina, Universidade do Porto, Porto, Portugal
| | - Jorge G Ferreira
- Epithelial Polarity and Cell Division Laboratory, Instituto de Investigação e Inovação em Saúde (i3S), Porto, Portugal
- Departamento de Biomedicina, Unidade de Biologia Experimental, Faculdade de Medicina do Porto, Porto, Portugal
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2
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Shah H, Olivetta M, Bhickta C, Ronchi P, Trupinić M, Tromer EC, Tolić IM, Schwab Y, Dudin O, Dey G. Life-cycle-coupled evolution of mitosis in close relatives of animals. Nature 2024; 630:116-122. [PMID: 38778110 PMCID: PMC11153136 DOI: 10.1038/s41586-024-07430-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Accepted: 04/16/2024] [Indexed: 05/25/2024]
Abstract
Eukaryotes have evolved towards one of two extremes along a spectrum of strategies for remodelling the nuclear envelope during cell division: disassembling the nuclear envelope in an open mitosis or constructing an intranuclear spindle in a closed mitosis1,2. Both classes of mitotic remodelling involve key differences in the core division machinery but the evolutionary reasons for adopting a specific mechanism are unclear. Here we use an integrated comparative genomics and ultrastructural imaging approach to investigate mitotic strategies in Ichthyosporea, close relatives of animals and fungi. We show that species in this clade have diverged towards either a fungal-like closed mitosis or an animal-like open mitosis, probably to support distinct multinucleated or uninucleated states. Our results indicate that multinucleated life cycles favour the evolution of closed mitosis.
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Affiliation(s)
- Hiral Shah
- Cell Biology and Biophysics, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany.
| | - Marine Olivetta
- Swiss Institute for Experimental Cancer Research, School of Life Sciences, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland
| | - Chandni Bhickta
- Cell Biology and Biophysics, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Paolo Ronchi
- Electron Microscopy Core Facility, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Monika Trupinić
- Division of Molecular Biology, Ruđer Bošković Institute (RBI), Zagreb, Croatia
| | - Eelco C Tromer
- Cell Biochemistry, Groningen Biomolecular Sciences & Biotechnology Institute, University of Groningen, Groningen, The Netherlands
| | - Iva M Tolić
- Division of Molecular Biology, Ruđer Bošković Institute (RBI), Zagreb, Croatia
| | - Yannick Schwab
- Cell Biology and Biophysics, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
- Electron Microscopy Core Facility, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Omaya Dudin
- Swiss Institute for Experimental Cancer Research, School of Life Sciences, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland.
| | - Gautam Dey
- Cell Biology and Biophysics, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany.
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3
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Collins PP, Broad RC, Yogeeswaran K, Varsani A, Poole AM, Collings DA. Characterisation of the trans-membrane nucleoporins GP210 and NDC1 in Arabidopsis thaliana. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2023; 332:111719. [PMID: 37116717 DOI: 10.1016/j.plantsci.2023.111719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 03/28/2023] [Accepted: 04/23/2023] [Indexed: 05/05/2023]
Abstract
The nuclear pore is structurally conserved across eukaryotes as are many of the pore's constituent proteins. The transmembrane nuclear pore proteins GP210 and NDC1 span the nuclear envelope holding the nuclear pore in place. Orthologues of GP210 and NDC1 in Arabidopsis were investigated through characterisation of T-DNA insertional mutants. While the T-DNA insert into GP210 reduced expression of the gene, the insert in the NDC1 gene resulted in increased expression in both the ndc1 mutant as well as the ndc1/gp210 double mutant. The ndc1 and gp210 individual mutants showed little phenotypic difference from wild-type plants, but the ndc1/gp210 mutant showed a range of phenotypic effects. As with many plant nuclear pore protein mutants, these effects included non-nuclear phenotypes such as reduced pollen viability, reduced growth and glabrous leaves in mature plants. Importantly, however, ndc1/gp210 exhibited nuclear-specific effects including modifications to nuclear shape in different cell types. We also observed functional changes to nuclear transport in ndc1/gp210 plants, with low levels of cytoplasmic fluorescence observed in cells expressing nuclear-targeted GFP. The lack of phenotypes in individual insertional lines, and the relatively mild phenotype suggests that additional transmembrane nucleoporins, such as the recently-discovered CPR5, likely compensate for their loss.
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Affiliation(s)
- Patrick P Collins
- Biomolecular Interaction Centre, School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand
| | - Ronan C Broad
- Biomolecular Interaction Centre, School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand
| | - Krithika Yogeeswaran
- Biomolecular Interaction Centre, School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand
| | - Arvind Varsani
- Biomolecular Interaction Centre, School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand; The Biodesign Center for Fundamental and Applied Microbiomics, Center for Evolution and Medicine, School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | - Anthony M Poole
- Biomolecular Interaction Centre, School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand; School of Biological Sciences, University of Auckland, Auckland 1010, New Zealand
| | - David A Collings
- Biomolecular Interaction Centre, School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand; School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW 2308, Australia; Research School of Biology, Australian National University, Canberra, ACT 2601, Australia.
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4
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Nong JS, Zhou X, Liu JQ, Luo JZ, Huang JM, Xie HX, Yang KJ, Wang J, Ye XP, Peng T. Nucleoporin 107 is a prognostic biomarker in hepatocellular carcinoma associated with immune infiltration. Cancer Med 2023; 12:10990-11009. [PMID: 36952458 DOI: 10.1002/cam4.5807] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 02/16/2023] [Accepted: 02/22/2023] [Indexed: 03/25/2023] Open
Abstract
OBJECTIVE To assess the diagnostic value and clinical significance of nucleoporin 107 (NUP107) in hepatocellular carcinoma (HCC), and explore the possible mechanisms. METHODS The transcriptomic and clinical data of HCC patients were retrieved from The Cancer Genome Atlas (TCGA) and GEO databases. Tissue specimens were collected from HCC patients in the Guangxi area. According to the expression levels and prognostic characteristics of NUP107, ROC curves and nomogram models were constructed using the R package. RESULTS NUP107 was highly expressed in 26 human cancers including HCC, and was associated with advanced HCC staging and worse prognosis. NUP107 showed satisfactory ability to predict the prognosis of HCC patients (AUC >0.8). Results of gene set enrichment analysis (GSEA) further showed that NUP107 was mainly associated with cell cycle-related pathways such as the cell cycle, DNA replication, G2M checkpoint, E2F target, and mitotic spindle. In addition, NUP107 was also associated with immune infiltration in HCC and showed significant positive correlation with immune checkpoints (PD-L1 and TIM-3).
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Affiliation(s)
- Ju-Sen Nong
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of Guangxi Medical University, Nanning, People's Republic of China
- Key Laboratory of Early Prevention & Treatment for Regional High Frequency Tumor, Ministry of Education, Guangxi Medical University, Nanning, People's Republic of China
| | - Xin Zhou
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of Guangxi Medical University, Nanning, People's Republic of China
- Key Laboratory of Early Prevention & Treatment for Regional High Frequency Tumor, Ministry of Education, Guangxi Medical University, Nanning, People's Republic of China
| | - Jun-Qi Liu
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of Guangxi Medical University, Nanning, People's Republic of China
- Key Laboratory of Early Prevention & Treatment for Regional High Frequency Tumor, Ministry of Education, Guangxi Medical University, Nanning, People's Republic of China
| | - Jian-Zhu Luo
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of Guangxi Medical University, Nanning, People's Republic of China
- Key Laboratory of Early Prevention & Treatment for Regional High Frequency Tumor, Ministry of Education, Guangxi Medical University, Nanning, People's Republic of China
| | - Jia-Mi Huang
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of Guangxi Medical University, Nanning, People's Republic of China
- Key Laboratory of Early Prevention & Treatment for Regional High Frequency Tumor, Ministry of Education, Guangxi Medical University, Nanning, People's Republic of China
| | - Hai-Xiang Xie
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of Guangxi Medical University, Nanning, People's Republic of China
- Key Laboratory of Early Prevention & Treatment for Regional High Frequency Tumor, Ministry of Education, Guangxi Medical University, Nanning, People's Republic of China
| | - Ke-Jian Yang
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of Guangxi Medical University, Nanning, People's Republic of China
- Key Laboratory of Early Prevention & Treatment for Regional High Frequency Tumor, Ministry of Education, Guangxi Medical University, Nanning, People's Republic of China
| | - Jing Wang
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of Guangxi Medical University, Nanning, People's Republic of China
- Key Laboratory of Early Prevention & Treatment for Regional High Frequency Tumor, Ministry of Education, Guangxi Medical University, Nanning, People's Republic of China
| | - Xin-Ping Ye
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of Guangxi Medical University, Nanning, People's Republic of China
- Key Laboratory of Early Prevention & Treatment for Regional High Frequency Tumor, Ministry of Education, Guangxi Medical University, Nanning, People's Republic of China
| | - Tao Peng
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of Guangxi Medical University, Nanning, People's Republic of China
- Key Laboratory of Early Prevention & Treatment for Regional High Frequency Tumor, Ministry of Education, Guangxi Medical University, Nanning, People's Republic of China
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5
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Serjanov D, Hyde DR. Extracellular Matrix: The Unexplored Aspects of Retinal Pathologies and Regeneration. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1415:309-317. [PMID: 37440050 DOI: 10.1007/978-3-031-27681-1_45] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/14/2023]
Abstract
Nearly a billion people worldwide are affected by vision-impairing conditions, with retinal degenerative diseases being a major cause of blindness. Unfortunately, such diseases are often permanent and progressive, resulting in further degeneration and loss of sight, due to the human retina possessing little, if any, regenerative capacity. Despite numerous efforts and great progress being made to understand the molecular mechanisms of these diseases and possible therapies, the majority of investigations focused on cell-intrinsic factors. However, the microenvironment surrounding retinal cells throughout these processes also plays an important role, though our current understanding of its involvement remains limited. Here we present a brief overview of the current state of the field of extracellular matrix studies within the retina and its potential roles in retinal diseases and potential therapeutic approaches.
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Affiliation(s)
- Dmitri Serjanov
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
| | - David R Hyde
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA.
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Selezneva A, Gibb AJ, Willis D. The Nuclear Envelope as a Regulator of Immune Cell Function. Front Immunol 2022; 13:840069. [PMID: 35757775 PMCID: PMC9226455 DOI: 10.3389/fimmu.2022.840069] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 05/10/2022] [Indexed: 01/07/2023] Open
Abstract
The traditional view of the nuclear envelope (NE) was that it represented a relatively inert physical barrier within the cell, whose main purpose was to separate the nucleoplasm from the cytoplasm. However, recent research suggests that this is far from the case, with new and important cellular functions being attributed to this organelle. In this review we describe research suggesting an important contribution of the NE and its constituents in regulating the functions of cells of the innate and adaptive immune system. One of the standout properties of immune cells is their ability to migrate around the body, allowing them to carry out their physiological/pathophysiology cellular role at the appropriate location. This together with the physiological role of the tissue, changes in tissue matrix composition due to disease and aging, and the activation status of the immune cell, all result in immune cells being subjected to different mechanical forces. We report research which suggests that the NE may be an important sensor/transducer of these mechanical signals and propose that the NE is an integrator of both mechanical and chemical signals, allowing the cells of the innate immune system to precisely regulate gene transcription and functionality. By presenting this overview we hope to stimulate the interests of researchers into this often-overlooked organelle and propose it should join the ranks of mitochondria and phagosome, which are important organelles contributing to immune cell function.
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Affiliation(s)
- Anna Selezneva
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, United Kingdom
| | - Alasdair J Gibb
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, United Kingdom
| | - Dean Willis
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, United Kingdom
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Natesan R, Gowrishankar K, Kuttippurathu L, Kumar PBS, Rao M. Active Remodeling of Chromatin and Implications for In Vivo Folding. J Phys Chem B 2021; 126:100-109. [DOI: 10.1021/acs.jpcb.1c08655] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ramakrishnan Natesan
- Department of Cancer Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India
| | | | - Lakshmi Kuttippurathu
- Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India
- Daniel Baugh Institute for Functional Genomics and Computational Biology, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, United States
| | - P. B. Sunil Kumar
- Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India
- Department of Physics, Indian Institute of Technology Palakkad, Palakkad 668557, Kerala, India
| | - Madan Rao
- Simons Centre for the Study of Living Machines, National Centre for Biological Sciences (TIFR), Bengaluru 560065, India
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8
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Zhang W, Khan A, Vitale J, Neuner A, Rink K, Lüchtenborg C, Brügger B, Söllner TH, Schiebel E. A short perinuclear amphipathic α-helix in Apq12 promotes nuclear pore complex biogenesis. Open Biol 2021; 11:210250. [PMID: 34814743 PMCID: PMC8611336 DOI: 10.1098/rsob.210250] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The integral membrane protein Apq12 is an important nuclear envelope (NE)/endoplasmic reticulum (ER) modulator that cooperates with the nuclear pore complex (NPC) biogenesis factors Brl1 and Brr6. How Apq12 executes these functions is unknown. Here, we identified a short amphipathic α-helix (AαH) in Apq12 that links the two transmembrane domains in the perinuclear space and has liposome-binding properties. Cells expressing an APQ12 (apq12-ah) version in which AαH is disrupted show NPC biogenesis and NE integrity defects, without impacting Apq12-ah topology or NE/ER localization. Overexpression of APQ12 but not apq12-ah triggers striking over-proliferation of the outer nuclear membrane (ONM)/ER and promotes accumulation of phosphatidic acid (PA) at the NE. Apq12 and Apq12-ah both associate with NPC biogenesis intermediates and removal of AαH increases both Brl1 levels and the interaction between Brl1 and Brr6. We conclude that the short amphipathic α-helix of Apq12 regulates the function of Brl1 and Brr6 and promotes PA accumulation at the NE possibly during NPC biogenesis.
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Affiliation(s)
- Wanlu Zhang
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Allianz, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany
| | - Azqa Khan
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Allianz, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany
| | - Jlenia Vitale
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Allianz, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany
| | - Annett Neuner
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Allianz, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany
| | - Kerstin Rink
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Christian Lüchtenborg
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Britta Brügger
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Thomas H. Söllner
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Elmar Schiebel
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Allianz, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany
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Groth A, Schmitt K, Valerius O, Herzog B, Pöggeler S. Analysis of the Putative Nucleoporin POM33 in the Filamentous Fungus Sordaria macrospora. J Fungi (Basel) 2021; 7:jof7090682. [PMID: 34575720 PMCID: PMC8468769 DOI: 10.3390/jof7090682] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 08/09/2021] [Accepted: 08/17/2021] [Indexed: 02/07/2023] Open
Abstract
In the filamentous fungus Sordaria macrospora (Sm), the STRIPAK complex is required for vegetative growth, fruiting-body development and hyphal fusion. The SmSTRIPAK core consists of the striatin homolog PRO11, the scaffolding subunit of phosphatase PP2A, SmPP2AA, and its catalytic subunit SmPP2Ac1. Among other STRIPAK proteins, the recently identified coiled-coil protein SCI1 was demonstrated to co-localize around the nucleus. Pulldown experiments with SCI identified the transmembrane nucleoporin (TM Nup) SmPOM33 as a potential nuclear-anchor of SmSTRIPAK. Localization studies revealed that SmPOM33 partially localizes to the nuclear envelope (NE), but mainly to the endoplasmic reticulum (ER). We succeeded to generate a Δpom33 deletion mutant by homologous recombination in a new S. macrospora Δku80 recipient strain, which is defective in non-homologous end joining. Deletion of Smpom33 did neither impair vegetative growth nor sexual development. In pulldown experiments of SmPOM33 followed by LC/MS analysis, ER-membrane proteins involved in ER morphology, protein translocation, glycosylation, sterol biosynthesis and Ca2+-transport were significantly enriched. Data are available via ProteomeXchange with identifier PXD026253. Although no SmSTRIPAK components were identified as putative interaction partners, it cannot be excluded that SmPOM33 is involved in temporarily anchoring the SmSTRIPAK to the NE or other sites in the cell.
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Affiliation(s)
- Anika Groth
- Department of Genetics of Eukaryotic Microorganisms, Institute of Microbiology and Genetics, Georg-August-University of Göttingen, Grisebachstr. 8, 37077 Göttingen, Germany; (A.G.); (B.H.)
| | - Kerstin Schmitt
- Department of Molecular Microbiology and Genetics, Service Unit LCMS Protein Analytics, Institute of Microbiology and Genetics, Georg-August-University of Göttingen, Grisebachstr. 8, 37077 Göttingen, Germany; (K.S.); (O.V.)
| | - Oliver Valerius
- Department of Molecular Microbiology and Genetics, Service Unit LCMS Protein Analytics, Institute of Microbiology and Genetics, Georg-August-University of Göttingen, Grisebachstr. 8, 37077 Göttingen, Germany; (K.S.); (O.V.)
| | - Britta Herzog
- Department of Genetics of Eukaryotic Microorganisms, Institute of Microbiology and Genetics, Georg-August-University of Göttingen, Grisebachstr. 8, 37077 Göttingen, Germany; (A.G.); (B.H.)
| | - Stefanie Pöggeler
- Department of Genetics of Eukaryotic Microorganisms, Institute of Microbiology and Genetics, Georg-August-University of Göttingen, Grisebachstr. 8, 37077 Göttingen, Germany; (A.G.); (B.H.)
- Correspondence: ; Tel.: +49-551-391-3930
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Ko YH, Chun J, Kim DH. Functional Analysis of an Essential GSP1/Ran Ortholog Gene, CpRan1, from the Chestnut Blight Fungus Cryphonectria parasitica Using a Heterokaryon. J Fungi (Basel) 2021; 7:jof7050332. [PMID: 33923059 PMCID: PMC8146580 DOI: 10.3390/jof7050332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 04/17/2021] [Accepted: 04/22/2021] [Indexed: 11/16/2022] Open
Abstract
Functional analysis of a GSP1/Ran ortholog, CpRan1, from Cryphonectria parasitica was conducted. Genotype analysis revealed that the putative CpRan1-null mutant was a heterokaryotic transformant harboring two different types of nuclei, one with the wild-type CpRan1 allele and the other with the CpRan1-null mutant allele. The mycelial growth and colony morphology of the heterokaryotic transformant was normal. Microscopic analysis of the resulting conidia (aseptate and monokaryotic asexual spores) demonstrated that although normal germinating spores were observed from conidia harboring a nucleus with the wild-type CpRan1 allele, a number of residual conidia that did not germinate existed. Complementation analysis using protoplasts from the heterokaryon with the wild-type CpRan1 allele confirmed that the CpRan1 gene is essential to C. parasitica. Complementation analysis using the various CpRan1 chimera constructs allowed us to perform a functional analysis of essential amino acids of the CpRan1. Among the four suggested essential amino acids, Lys-97 for ubiquitination was determined to not be an essential residue. Moreover, the CpRan1-null mutant allele was successfully complemented with mouse Ran gene, which suggested that the biological function of Ran gene is evolutionary conserved and that our heterokaryon rescue can be applied for the functional analysis of heterologous genes.
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Affiliation(s)
| | | | - Dae-Hyuk Kim
- Correspondence: ; Tel.: +82-63-270-3440; Fax: +82-63-270-4312
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11
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What Are the Potential Roles of Nuclear Perlecan and Other Heparan Sulphate Proteoglycans in the Normal and Malignant Phenotype. Int J Mol Sci 2021; 22:ijms22094415. [PMID: 33922532 PMCID: PMC8122901 DOI: 10.3390/ijms22094415] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 04/19/2021] [Accepted: 04/19/2021] [Indexed: 12/27/2022] Open
Abstract
The recent discovery of nuclear and perinuclear perlecan in annulus fibrosus and nucleus pulposus cells and its known matrix stabilizing properties in tissues introduces the possibility that perlecan may also have intracellular stabilizing or regulatory roles through interactions with nuclear envelope or cytoskeletal proteins or roles in nucleosomal-chromatin organization that may regulate transcriptional factors and modulate gene expression. The nucleus is a mechano-sensor organelle, and sophisticated dynamic mechanoresponsive cytoskeletal and nuclear envelope components support and protect the nucleus, allowing it to perceive and respond to mechano-stimulation. This review speculates on the potential roles of perlecan in the nucleus based on what is already known about nuclear heparan sulphate proteoglycans. Perlecan is frequently found in the nuclei of tumour cells; however, its specific role in these diseased tissues is largely unknown. The aim of this review is to highlight probable roles for this intriguing interactive regulatory proteoglycan in the nucleus of normal and malignant cell types.
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12
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Yang CW, Hsieh MH, Sun HJ, Teng SC. Nuclear envelope tethering inhibits the formation of ALT-associated PML bodies in ALT cells. Aging (Albany NY) 2021; 13:10490-10516. [PMID: 33820871 PMCID: PMC8064153 DOI: 10.18632/aging.202810] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Accepted: 02/16/2021] [Indexed: 12/12/2022]
Abstract
Telomere length homeostasis is essential for maintaining genomic stability and cancer proliferation. Telomerase-negative cancer cells undergo recombination-mediated alternative lengthening of telomeres. Telomeres associate with the nuclear envelope through the shelterin RAP1 and nuclear envelope SUN1 proteins. However, how the associations between telomeres and the nuclear envelope affect the progression of telomere recombination is not understood. Here, we show that telomere anchorage might inhibit telomere-telomere recombination. SUN1 depletion stimulates the formation of alternative lengthening of telomeres-associated promyelocytic leukemia bodies in ALT cells. In contrast, overexpression of a telomere-nuclear envelope-tethering chimera protein, RAP1-SUN1, suppresses APB formation. Moreover, inhibition of this nuclear envelope attachment alleviates the requirement of TOP3α for resolving the supercoiling pressure during telomere recombination. A coimmunoprecipitation assay revealed that the SUN1 N-terminal nucleoplasmic domain interacts with the RAP1 middle coil domain, and phosphorylation-mimetic mutations in RAP1 inhibit this interaction. However, abolishing the RAP1-SUN1 interaction does not hinder APB formation, which hints at the existence of another SUN1-dependent telomere anchorage pathway. In summary, our results reveal an inhibitory role of telomere-nuclear envelope association in telomere-telomere recombination and imply the presence of redundant pathways for the telomere-nuclear envelope association in ALT cells.
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Affiliation(s)
- Chia-Wei Yang
- Department of Microbiology, College of Medicine, National Taiwan University, Taipei 10051, Taiwan
| | - Meng-Hsun Hsieh
- Department of Microbiology, College of Medicine, National Taiwan University, Taipei 10051, Taiwan
| | - Hao-Jhe Sun
- Department of Microbiology, College of Medicine, National Taiwan University, Taipei 10051, Taiwan
| | - Shu-Chun Teng
- Department of Microbiology, College of Medicine, National Taiwan University, Taipei 10051, Taiwan.,Center of Precision Medicine, National Taiwan University, Taipei 10051, Taiwan
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Shang R, Zhu F, Li Y, He P, Qi J, Chen Y, Sun F, Zhang Y, Wang Q, Shen Z. Identification and localization of Nup170 in the microsporidian Nosema bombycis. Parasitol Res 2021; 120:2125-2134. [PMID: 33768334 DOI: 10.1007/s00436-021-07129-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 03/17/2021] [Indexed: 11/25/2022]
Abstract
As one of the core framework proteins of nuclear pore complex (NPC), nucleoporin Nupl70 acts as a structural adapter between the nucleolus and nuclear pore membrane and maintains the stability of NPC structure through interaction with other proteins. In this study, we identified a Nup170 protein in the microsporidian Nosema bombycis for the first time and named it as NbNup170. Secondary structure prediction showed that the NbNup170 contains α-helices and random coils. The three-dimensional structure of NbNup170 is elliptical in shape. Phylogenetic analysis based on the Nup170 and homologous sequences showed that N. bombycis clustered together with Vairimorpha ceranae and Vairimorpha apis. The immunofluorescence localization results showed that the NbNup170 was located on the plasma membrane of the dormant spore and transferred to the surface of sporoplasm in a punctate pattern when the dormant spore has finished germination, and that NbNup170 was distributed on the nuclear membrane and both sides of the nuclei of early proliferative phase, and only on the nuclear membrane during sporogonic phase in the N. bombycis. qPCR analysis showed that the relative expression level of NbNup170 maintained at a low level from 30 to 78 h post-infection with N. bombycis, then reached the highest at 102 h, while that of NbNup170 was repressed at a very low level throughout its life cycle by RNA interference. These results suggested that NbNup170 protein is involved in the proliferative phase and active during the sporogonic phase of N. bombycis.
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Affiliation(s)
- Ruisha Shang
- Jiangsu University of Science and Technology, Zhenjiang, 212018, Jiangsu Province, China
| | - Feng Zhu
- College of Life Sciences, Zaozhuang University, Zaozhuang, 277160, Shandong Province, China
- Institute of Sericulture and Apiculture, Yunnan Academy of Agricultural Sciences, Mengzi, 661101, Yunnan Province, China
| | - Yu Li
- Jiangsu University of Science and Technology, Zhenjiang, 212018, Jiangsu Province, China
| | - Ping He
- Jiangsu University of Science and Technology, Zhenjiang, 212018, Jiangsu Province, China
| | - Jingru Qi
- Jiangsu University of Science and Technology, Zhenjiang, 212018, Jiangsu Province, China
| | - Yong Chen
- Jiangsu University of Science and Technology, Zhenjiang, 212018, Jiangsu Province, China
| | - Fuzhen Sun
- Jiangsu University of Science and Technology, Zhenjiang, 212018, Jiangsu Province, China
| | - Yiling Zhang
- Jiangsu University of Science and Technology, Zhenjiang, 212018, Jiangsu Province, China
- Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, 212018, Jiangsu Province, China
| | - Qiang Wang
- Jiangsu University of Science and Technology, Zhenjiang, 212018, Jiangsu Province, China
- Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, 212018, Jiangsu Province, China
| | - Zhongyuan Shen
- Jiangsu University of Science and Technology, Zhenjiang, 212018, Jiangsu Province, China.
- Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, 212018, Jiangsu Province, China.
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14
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Hachiya N, Sochocka M, Brzecka A, Shimizu T, Gąsiorowski K, Szczechowiak K, Leszek J. Nuclear Envelope and Nuclear Pore Complexes in Neurodegenerative Diseases-New Perspectives for Therapeutic Interventions. Mol Neurobiol 2021; 58:983-995. [PMID: 33067781 PMCID: PMC7878205 DOI: 10.1007/s12035-020-02168-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 10/12/2020] [Indexed: 12/11/2022]
Abstract
Transport of proteins, transcription factors, and other signaling molecules between the nucleus and cytoplasm is necessary for signal transduction. The study of these transport phenomena is particularly challenging in neurons because of their highly polarized structure. The bidirectional exchange of molecular cargoes across the nuclear envelope (NE) occurs through nuclear pore complexes (NPCs), which are aqueous channels embedded in the nuclear envelope. The NE and NPCs regulate nuclear transport but are also emerging as relevant regulators of chromatin organization and gene expression. The alterations in nuclear transport are regularly identified in affected neurons associated with human neurodegenerative diseases. This review presents insights into the roles played by nuclear transport defects in neurodegenerative disease, focusing primarily on NE proteins and NPCs. The subcellular mislocalization of proteins might be a very desirable means of therapeutic intervention in neurodegenerative disorders.
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Affiliation(s)
- Naomi Hachiya
- Tokyo Metropolitan Industrial Technology Research Institute, Tokyo, Japan
| | - Marta Sochocka
- Laboratory of Virology, Department of Immunology of Infectious Diseases, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wroclaw, Poland
| | - Anna Brzecka
- Department of Pulmonology and Lung Cancer, Wroclaw Medical University, Wroclaw, Poland
| | - Takuto Shimizu
- Tokyo Metropolitan Industrial Technology Research Institute, Tokyo, Japan
- Laboratory of Biochemistry, School of Veterinary Medicine, Azabu University, Sagamihara, Japan
| | | | | | - Jerzy Leszek
- Department of Psychiatry, Wroclaw Medical University, Wybrzeże L. Pasteura 10, 50-367, Wroclaw, Poland.
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15
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Bruno SR, Anathy V. Lung epithelial endoplasmic reticulum and mitochondrial 3D ultrastructure: a new frontier in lung diseases. Histochem Cell Biol 2021; 155:291-300. [PMID: 33598824 PMCID: PMC7889473 DOI: 10.1007/s00418-020-01950-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/24/2020] [Indexed: 12/15/2022]
Abstract
It has long been appreciated that the endoplasmic reticulum (ER) and mitochondria, organelles important for regular cell function and survival, also play key roles in pathogenesis of various lung diseases, including asthma, fibrosis, and infections. Alterations in processes regulated within these organelles, including but not limited to protein folding in the ER and oxidative phosphorylation in the mitochondria, are important in disease pathogenesis. In recent years it has also become increasingly apparent that organelle structure dictates function. It is now clear that organelles must maintain precise organization and localization for proper function. Newer microscopy capabilities have allowed the scientific community to reveal, via 3D imaging, that the structure of these organelles and their interactions with each other are a main component of regulating function and, therefore, effects on the disease state. In this review, we will examine how 3D imaging through techniques could allow advancements in knowledge of how the ER and mitochondria function and the roles they may play in lung epithelia in progression of lung disease.
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Affiliation(s)
- Sierra R Bruno
- Department of Pathology and Laboratory Medicine, University of Vermont, Larner College of Medicine, 149 Beaumont Ave, Burlington, VT, 05405, USA
| | - Vikas Anathy
- Department of Pathology and Laboratory Medicine, University of Vermont, Larner College of Medicine, 149 Beaumont Ave, Burlington, VT, 05405, USA.
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16
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Molenberghs F, Bogers JJ, De Vos WH. Confined no more: Viral mechanisms of nuclear entry and egress. Int J Biochem Cell Biol 2020; 129:105875. [PMID: 33157236 DOI: 10.1016/j.biocel.2020.105875] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 10/27/2020] [Accepted: 10/29/2020] [Indexed: 12/14/2022]
Abstract
Viruses are obligatory intracellular parasites. For their efficient replication, many require access to the nuclear interior. Yet, only few viral particles are small enough to passively diffuse through the nuclear pore complexes, calling for alternative strategies to bypass the nuclear envelope barrier. Some viruses will await mitotic nuclear envelope breakdown to gain access, whereas others will exploit more active means, for instance by hijacking nuclear pore transport or by directly targeting constituents of the nuclear envelope so as to remodel and temporarily perturb its integrity. After replication, newly produced viral DNA complexes need to cross the same barrier to exit the nucleus and enter the cytoplasm, where the final stages of virion maturation take place. There are also different flavours to the feat of nuclear egress that vary in delicacy and intensity. In this review, we define the major entry and egress strategies that are exploited by different viruses and describe the molecular details thereof. Ultimately, a deeper understanding of these pathways may help identifying molecular targets for blocking viral reproduction or spreading.
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Affiliation(s)
- Freya Molenberghs
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences/Medicine and Health Sciences, University of Antwerp, Belgium
| | - Johannes J Bogers
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences/Medicine and Health Sciences, University of Antwerp, Belgium
| | - Winnok H De Vos
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences/Medicine and Health Sciences, University of Antwerp, Belgium.
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17
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Functional analysis of an essential Ran-binding protein gene, CpRbp1, from the chestnut blight fungus Cryphonectria parasitica using heterokaryon rescue. Sci Rep 2020; 10:8111. [PMID: 32415177 PMCID: PMC7229160 DOI: 10.1038/s41598-020-65036-7] [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] [Received: 07/19/2019] [Accepted: 04/24/2020] [Indexed: 12/11/2022] Open
Abstract
A Ran binding protein (RanBP) homolog, CpRbp1, from Cryphonectria parasitica, has been identified as a protein that is affected by hypovirus infection or tannic acid supplementation. In this study, functional analyses of CpRbp1 were performed by constructing a knockout mutant and analyzing the resulting heterokaryon. Transformation-mediated gene replacement resulted in two putative CpRbp1-null mutants and genotype analyses identified these two mutants as heterokaryotic transformants consisting of two types of nuclei, one with the wild-type CpRbp1 allele and another with the CpRbp1-null mutant allele. Although stable mycelial growth of the heterokaryotic transformant was observed on selective medium containing hygromycin B, neither germination nor growth of the resulting conidia, which were single-cell monokaryotic progeny, was observed on the medium. In trans complementation of heterokaryons using a full-length wild-type allele of the CpRbp1 gene resulted in complemented transformants. These transformants sporulated single-cell monokaryotic conidia that were able to grow on media selective for replacing and/or complementing markers. These results clearly indicate that CpRbp1 is an essential gene, and heterokaryons allowed the fungus to maintain lethal CpRbp1-null mutant nuclei. Moreover, in trans complementation of heterokaryons using chimeric structures of the CpRbp1 gene allowed for analysis of its functional domains, which was previously hampered due to the lethality of the gene. In addition, in trans complementation using heterologous RanBP genes from Aspergillus nidulans was successful, suggesting that the function of RanBP is conserved during evolution. Furthermore, in trans complementation allowed for functional analyses of lethal orthologs. This study demonstrates that our fungal heterokaryon system can be applied effectively to determine whether a gene of interest is essential, perform functional analyses of a lethal gene, and analyze corresponding heterologous genes.
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18
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Measurement of Arabidopsis thaliana Nuclear Size and Shape. Methods Mol Biol 2020. [PMID: 32088892 DOI: 10.1007/978-1-0716-0179-2_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Gene expression is tightly linked to the position of genes in the nucleus. Genomic regions associated with the nuclear envelope are usually repressed, including the heterochromatin carrying chromocenters. The shape and size of nuclei varies within tissues in plants and is dependent on proteins associated with the nuclear envelope. Here, we describe a protocol to isolate Arabidopsis thaliana nuclei and measure their size and morphology. Using this method, novel components regulating the nuclear envelope and chromatin association can be identified and analyzed.
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19
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Bergqvist C, Niss F, Figueroa RA, Beckman M, Maksel D, Jafferali MH, Kulyté A, Ström AL, Hallberg E. Monitoring of chromatin organization in live cells by FRIC. Effects of the inner nuclear membrane protein Samp1. Nucleic Acids Res 2019; 47:e49. [PMID: 30793190 PMCID: PMC6511872 DOI: 10.1093/nar/gkz123] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 01/17/2019] [Accepted: 02/19/2019] [Indexed: 12/24/2022] Open
Abstract
In most cells, transcriptionally inactive heterochromatin is preferentially localized in the nuclear periphery and transcriptionally active euchromatin is localized in the nuclear interior. Different cell types display characteristic chromatin distribution patterns, which change dramatically during cell differentiation, proliferation, senescence and different pathological conditions. Chromatin organization has been extensively studied on a cell population level, but there is a need to understand dynamic reorganization of chromatin at the single cell level, especially in live cells. We have developed a novel image analysis tool that we term Fluorescence Ratiometric Imaging of Chromatin (FRIC) to quantitatively monitor dynamic spatiotemporal distribution of euchromatin and total chromatin in live cells. A vector (pTandemH) assures stoichiometrically constant expression of the histone variants Histone 3.3 and Histone 2B, fused to EGFP and mCherry, respectively. Quantitative ratiometric (H3.3/H2B) imaging displayed a concentrated distribution of heterochromatin in the periphery of U2OS cell nuclei. As proof of concept, peripheral heterochromatin responded to experimental manipulation of histone acetylation. We also found that peripheral heterochromatin depended on the levels of the inner nuclear membrane protein Samp1, suggesting an important role in promoting peripheral heterochromatin. Taken together, FRIC is a powerful and robust new tool to study dynamic chromatin redistribution in live cells.
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Affiliation(s)
- Cecilia Bergqvist
- Department of Biochemistry and Biophysics, Stockholm University, Svante Arrhenius väg 16B, SE-106 91 Stockholm, Sweden
| | - Frida Niss
- Department of Biochemistry and Biophysics, Stockholm University, Svante Arrhenius väg 16B, SE-106 91 Stockholm, Sweden
| | - Ricardo A Figueroa
- Department of Biochemistry and Biophysics, Stockholm University, Svante Arrhenius väg 16B, SE-106 91 Stockholm, Sweden
| | - Marie Beckman
- Department of Biochemistry and Biophysics, Stockholm University, Svante Arrhenius väg 16B, SE-106 91 Stockholm, Sweden.,Institute of Environmental Medicine, Karolinska Institutet SE-171 77 Sweden
| | - Danuta Maksel
- Monash Molecular Crystallisation Facility (MMCF), Monash University, VIC 3800, Australia
| | - Mohammed H Jafferali
- Department of Biochemistry and Biophysics, Stockholm University, Svante Arrhenius väg 16B, SE-106 91 Stockholm, Sweden
| | - Agné Kulyté
- Lipid laboratory, Department of Medicine, Karolinska Institutet, SE-141 57 Huddinge, Sweden
| | - Anna-Lena Ström
- Department of Biochemistry and Biophysics, Stockholm University, Svante Arrhenius väg 16B, SE-106 91 Stockholm, Sweden
| | - Einar Hallberg
- Department of Biochemistry and Biophysics, Stockholm University, Svante Arrhenius väg 16B, SE-106 91 Stockholm, Sweden
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20
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Wada E, Kato M, Yamashita K, Kokuba H, Liang WC, Bonne G, Hayashi YK. Deficiency of emerin contributes differently to the pathogenesis of skeletal and cardiac muscles in LmnaH222P/H222P mutant mice. PLoS One 2019; 14:e0221512. [PMID: 31430335 PMCID: PMC6701770 DOI: 10.1371/journal.pone.0221512] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 08/08/2019] [Indexed: 11/18/2022] Open
Abstract
Laminopathies are tissue-selective diseases that affect differently in organ systems. Mutations in nuclear envelopes, emerin (Emd) and lamin A/C (Lmna) genes, cause clinically indistinguishable myopathy called Emery-Dreifuss muscular dystrophy (EDMD) and limb-girdle muscular dystrophy. Several murine models for EDMD have been generated; however, emerin-null (Emd) mice do not show obvious skeletal and cardiac muscle phenotypes, and Lmna H222P/H222P mutant (H222P) mice show only a mild phenotype in skeletal muscle when they already have severe cardiomyopathy. Thus, the underlying molecular mechanism of muscle involvement due to nuclear abnormalities is still unclarified. We generated double mutant (Emd-/-/LmnaH222P/H222P; EH) mice to characterize dystrophic changes and to elucidate interactions between emerin and lamin A/C in skeletal and cardiac muscles. As H222P mice, EH mice grow normally and have breeding productivity. EH mice showed severer muscle involvement compared with that of H222P mice which was an independent of cardiac abnormality at 12 weeks of age. Nuclear abnormalities, reduced muscle fiber size and increased fibrosis were prominent in EH mice. Roles of emerin and lamin A/C in satellite cells function and regeneration of muscle fiber were also evaluated by cardiotoxin-induced muscle injury. Delayed increases in myog and myh3 expression were seen in both H222P and EH mice; however, the expression levels of those genes were similar with control and regenerated muscle fiber size was not different at day 7 after injury. These results indicate that EH mouse is a suitable model for studying skeletal muscle involvement, independent of cardiac function, in laminopathies and an interaction between emerin and lamin A/C in different tissues.
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Affiliation(s)
- Eiji Wada
- Department of Pathophysiology, Tokyo Medical University, Tokyo, Japan
| | - Megumi Kato
- Department of Pathophysiology, Tokyo Medical University, Tokyo, Japan
| | - Kaori Yamashita
- Department of Pathophysiology, Tokyo Medical University, Tokyo, Japan
| | - Hiroko Kokuba
- Institute of Medical Science, Tokyo Medical University, Tokyo, Japan
| | - Wen-Chen Liang
- Department of Pediatrics, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
- Department of Pediatrics, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Gisèle Bonne
- Sorbonne Université, Inserm UMRS 974, Center of Research in Myology, Paris, France
| | - Yukiko K. Hayashi
- Department of Pathophysiology, Tokyo Medical University, Tokyo, Japan
- * E-mail:
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21
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Ahn JH, Cho MG, Sohn S, Lee JH. Inhibition of PP2A activity by H 2O 2 during mitosis disrupts nuclear envelope reassembly and alters nuclear shape. Exp Mol Med 2019; 51:1-18. [PMID: 31164634 PMCID: PMC6548778 DOI: 10.1038/s12276-019-0260-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 11/02/2018] [Accepted: 11/14/2018] [Indexed: 01/01/2023] Open
Abstract
Many types of cancer cells exhibit abnormal nuclear shapes induced by various molecular changes. However, whether reactive oxygen species (ROS) induce nuclear deformation has not been fully addressed. Here, we show that hydrogen peroxide (H2O2) treatment induced concentration-dependent alterations in nuclear shape that were abolished by pretreatment with the antioxidant N-acetyl-L-cysteine or by catalase overexpression. Interestingly, treatment with H2O2 induced nuclear shape alterations significantly more frequently in mitotic cells than in asynchronous cells, suggesting that H2O2 mainly affects nuclear envelope disassembly and/or reassembly processes. Because protein phosphatase 2 A (PP2A) activity is reported to be involved in nuclear envelope reassembly during mitosis, we investigated the possible involvement of PP2A. Indeed, H2O2 reduced the activity of PP2A, an effect that was mimicked by the PP1 and PP2A inhibitor okadaic acid. Moreover, overexpression of PP2A but not PP1 or PP4 partially rescued H2O2-induced alterations in nuclear shape, indicating that the decrease in PP2A activity induced by H2O2 is specifically involved in the observed nuclear shape alterations. We further show that treatment of mitotic cells with H2O2 induced the mislocalization of BAF (barrier-to-autointegration factor), a substrate of PP2A, during telophase. This effect was associated with Lamin A/C mislocalization and was rescued by PP2A overexpression. Collectively, our findings suggest that H2O2 preferentially affects mitotic cells through PP2A inhibition, which induces the subsequent mislocalization of BAF and Lamin A/C during nuclear envelope reassembly, leading to the formation of an abnormal nuclear shape. A class of harmful chemical compounds produces morphological abnormalities in the nucleus that may help promote tumor growth. Reactive oxygen species (ROS) are DNA- and protein-damaging molecules that originate both from environmental contaminants and as a byproduct of cellular metabolism or stress. Jae-Ho Lee and colleagues at Ajou University, Suwon, South Korea have now identified a mechanism by which ROS can disrupt the shape and structure of the nucleus. They show that ROS exposure reduces the ativity of an enzyme called PP2A, which is required for the targeted recruitment of proteins that rebuild the membrane envelope surrounding the nucleus after cell division. Perturbations in this envelope can potentially contribute to damage to the chromosomal DNA within the nucleus, creating conditions that can trigger or accelerate the process of tumorigenesis.
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Affiliation(s)
- Ju-Hyun Ahn
- Department of Biochemistry and Molecular Biology, Ajou University School of Medicine, Suwon, 443-721, South Korea.,Genomic Instability Research Center, Ajou University School of Medicine, Suwon, 443-721, South Korea.,Department of Biomedical Sciences, The Graduate School of Ajou University, Suwon, 443-721, South Korea
| | - Min-Guk Cho
- Department of Biochemistry and Molecular Biology, Ajou University School of Medicine, Suwon, 443-721, South Korea.,Genomic Instability Research Center, Ajou University School of Medicine, Suwon, 443-721, South Korea.,Department of Biomedical Sciences, The Graduate School of Ajou University, Suwon, 443-721, South Korea
| | - Seonghyang Sohn
- Department of Biomedical Sciences, The Graduate School of Ajou University, Suwon, 443-721, South Korea.,Department of Microbiology, Ajou University School of Medicine, Suwon, 443-721, South Korea
| | - Jae-Ho Lee
- Department of Biochemistry and Molecular Biology, Ajou University School of Medicine, Suwon, 443-721, South Korea. .,Genomic Instability Research Center, Ajou University School of Medicine, Suwon, 443-721, South Korea. .,Department of Biomedical Sciences, The Graduate School of Ajou University, Suwon, 443-721, South Korea.
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22
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Kobayashi W, Takizawa Y, Aihara M, Negishi L, Ishii H, Kurumizaka H. Structural and biochemical analyses of the nuclear pore complex component ELYS identify residues responsible for nucleosome binding. Commun Biol 2019; 2:163. [PMID: 31069272 PMCID: PMC6499780 DOI: 10.1038/s42003-019-0385-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 03/08/2019] [Indexed: 12/20/2022] Open
Abstract
The nuclear pore complex embedded within the nuclear envelope is the essential architecture for trafficking macromolecules, such as proteins and RNAs, between the cytoplasm and nucleus. The nuclear pore complex assembly occurs on chromatin in the post-mitotic phase of the cell cycle. ELYS (MEL-28/AHCTF1) binds to the nucleosome, which is the basic chromatin unit, and promotes assembly of the complex around the chromosomes in cells. Here we show that the Arg-Arg-Lys (RRK) stretch of the C-terminal ELYS region plays an essential role in the nucleosome binding. The cryo-EM structure and the crosslinking mass spectrometry reveal that the ELYS C-terminal region directly binds to the acidic patch of the nucleosome. These results provide mechanistic insight into the ELYS-nucleosome interaction, which promotes the post-mitotic nuclear pore complex formation around chromosomes in cells.
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Affiliation(s)
- Wataru Kobayashi
- 1Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-0032 Japan
- 2Graduate School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo, 162-8480 Japan
| | - Yoshimasa Takizawa
- 1Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-0032 Japan
| | - Maya Aihara
- 2Graduate School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo, 162-8480 Japan
| | - Lumi Negishi
- 1Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-0032 Japan
| | - Hajime Ishii
- 2Graduate School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo, 162-8480 Japan
| | - Hitoshi Kurumizaka
- 1Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-0032 Japan
- 2Graduate School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo, 162-8480 Japan
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23
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Shamseldin HE, Makhseed N, Ibrahim N, Al-Sheddi T, Alobeid E, Abdulwahab F, Alkuraya FS. NUP214 deficiency causes severe encephalopathy and microcephaly in humans. Hum Genet 2019; 138:221-229. [PMID: 30758658 DOI: 10.1007/s00439-019-01979-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Accepted: 02/07/2019] [Indexed: 10/27/2022]
Abstract
Nuclear pore complex (NPC) is a fundamental component of the nuclear envelope and is key to the nucleocytoplasmic transport. Mutations in several NUP genes that encode individual components of NPC known as nucleoporins have been identified in recent years among patients with static encephalopathies characterized by developmental delay and microcephaly. We describe a multiplex consanguineous family in which four affected members presented with severe neonatal hypotonia, profound global developmental delay, progressive microcephaly and early death. Autozygome and linkage analysis revealed that this phenotype is linked to a founder disease haplotype (chr9:127,113,732-135,288,807) in which whole exome sequencing revealed the presence of a novel homozygous missense variant in NUP214. Functional analysis of patient-derived fibroblasts recapitulated the dysmorphic phenotype of nuclei that was previously described in NUP214 knockdown cells. In addition, the typical rim staining of NUP214 is largely displaced, further supporting the deleterious effect of the variant. Our data expand the list of NUP genes that are mutated in encephalopathy disorders in humans.
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Affiliation(s)
- Hanan E Shamseldin
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Nawal Makhseed
- Department of Pediatrics, Al-Jahra Hospital, Kuwait City, Kuwait
| | - Niema Ibrahim
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Tarfa Al-Sheddi
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Eman Alobeid
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Firdous Abdulwahab
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Fowzan S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia. .,Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia.
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24
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Garapati HS, Mishra K. Comparative genomics of nuclear envelope proteins. BMC Genomics 2018; 19:823. [PMID: 30445911 PMCID: PMC6240307 DOI: 10.1186/s12864-018-5218-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 10/31/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The nuclear envelope (NE) that encapsulates the nuclear genome is a double lipid bilayer with several integral and peripherally associated proteins. It is a characteristic feature of the eukaryotes and acts as a hub for a number of important nuclear events including transcription, repair, and regulated gene expression. The proteins associated with the nuclear envelope mediate the NE functions and maintain its structural integrity, which is crucial for survival. In spite of the importance of this structure, knowledge of the protein composition of the nuclear envelope and their function, are limited to very few organisms belonging to Opisthokonta and Archaeplastida supergroups. The NE composition is largely unknown in organisms outside these two supergroups. RESULTS In this study, we have taken a comparative sequence analysis approach to identify the NE proteome that is present across all five eukaryotic supergroups. We identified 22 proteins involved in various nuclear functions to be part of the core NE proteome. The presence of these proteins across eukaryotes, suggests that they are traceable to the Last Eukaryotic Common Ancestor (LECA). Additionally, we also identified the NE proteins that have evolved in a lineage specific manner and those that have been preserved only in a subset of organisms. CONCLUSIONS Our study identifies the conserved features of the nuclear envelope across eukaryotes and provides insights into the potential composition and the functionalities that were constituents of the LECA NE.
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Affiliation(s)
- Hita Sony Garapati
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, 500046, India
| | - Krishnaveni Mishra
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, 500046, India.
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Lamin A/C might be involved in the EMT signalling pathway. Gene 2018; 663:51-64. [PMID: 29665450 DOI: 10.1016/j.gene.2018.04.040] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 04/13/2018] [Indexed: 12/13/2022]
Abstract
We have previously reported a heterogeneous expression pattern of the nuclear membrane protein lamin A/C in low- and high-Gleason score (GS) prostate cancer (PC) tissues, and we have now found that this change is not associated with LMNA mutations. This expression pattern appears to be similar to the process of epithelial to mesenchymal transition (EMT) or to that of mesenchymal to epithelial transition (MET). The role of lamin A/C in EMT or MET in PC remains unclear. Therefore, we first investigated the expression levels of and the associations between lamin A/C and several common EMT markers, such as E-cadherin, N-cadherin, β-catenin, snail, slug and vimentin in PC tissues with different GS values and in different cell lines with varying invasion abilities. Our results suggest that lamin A/C might constitute a type of epithelial marker that better signifies EMT and MET in PC tissue, since a decrease in lamin A/C expression in GS 4 + 5 cases is likely associated with the EMT process, while the re-expression of lamin A/C in GS 5 + 4 cases is likely linked with MET. The detailed GS better exhibited the changes in lamin A/C and the EMT markers examined. Lamin A/C overexpression or knockdown had an impact on EMT biomarkers in a cell model by direct regulation of β-catenin. Hence, we suggest that lamin A/C might serve as a reliable epithelial biomarker for the distinction of PC cell differentiation and might also be a fundamental factor in the occurrence of EMT or MET in PC.
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Lu L, Madugula V. Mechanisms of ciliary targeting: entering importins and Rabs. Cell Mol Life Sci 2018; 75:597-606. [PMID: 28852774 PMCID: PMC11105572 DOI: 10.1007/s00018-017-2629-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 08/11/2017] [Accepted: 08/16/2017] [Indexed: 12/29/2022]
Abstract
Primary cilium is a rod-like plasma membrane protrusion that plays important roles in sensing the cellular environment and initiating corresponding signaling pathways. The sensory functions of the cilium critically depend on the unique enrichment of ciliary residents, which is maintained by the ciliary diffusion barrier. It is still unclear how ciliary cargoes specifically enter the diffusion barrier and accumulate within the cilium. In this review, the organization and trafficking mechanism of the cilium are compared to those of the nucleus, which are much better understood at the moment. Though the cilium differs significantly from the nucleus in terms of molecular and cellular functions, analogous themes and principles in the membrane organization and cargo trafficking are notable between them. Therefore, knowledge in the nuclear trafficking can likely shed light on our understanding of the ciliary trafficking. Here, with a focus on membrane cargoes in mammalian cells, we briefly review various ciliary trafficking pathways from the Golgi to the periciliary membrane. Models for the subsequent import translocation across the diffusion barrier and the enrichment of cargoes within the ciliary membrane are discussed in detail. Based on recent discoveries, we propose a Rab-importin-based model in an attempt to accommodate various observations on ciliary targeting.
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Affiliation(s)
- Lei Lu
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 637551, Singapore.
| | - Viswanadh Madugula
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 637551, Singapore
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Houthaeve G, Robijns J, Braeckmans K, De Vos WH. Bypassing Border Control: Nuclear Envelope Rupture in Disease. Physiology (Bethesda) 2018; 33:39-49. [DOI: 10.1152/physiol.00029.2017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 10/31/2017] [Accepted: 10/31/2017] [Indexed: 11/22/2022] Open
Abstract
Recent observations in laminopathy patient cells and cancer cells have revealed that the nuclear envelope (NE) can transiently rupture during interphase. NE rupture leads to an uncoordinated exchange of nuclear and cytoplasmic material, thereby deregulating cellular homeostasis. Moreover, concurrently inflicted DNA damage could prime rupture-prone cells for genome instability. Thus, NE rupture may represent a novel pathogenic mechanism that has far-reaching consequences for cell and organism physiology.
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Affiliation(s)
- Gaëlle Houthaeve
- Department of Veterinary Sciences, Laboratory of Cell Biology and Histology, University of Antwerp, Antwerp, Belgium
- Laboratory of General Biochemistry and Physical Pharmacy, Ghent University, Ghent, Belgium
| | - Joke Robijns
- Department of Veterinary Sciences, Laboratory of Cell Biology and Histology, University of Antwerp, Antwerp, Belgium
| | - Kevin Braeckmans
- Laboratory of General Biochemistry and Physical Pharmacy, Ghent University, Ghent, Belgium
- Centre for Nano- and Biophotonics, Ghent University, Ghent, Belgium
| | - Winnok H. De Vos
- Department of Veterinary Sciences, Laboratory of Cell Biology and Histology, University of Antwerp, Antwerp, Belgium
- Department of Molecular Biotechnology, Cell Systems and Imaging Research Group (CSI), Ghent University, Ghent, Belgium
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Guo T, Mao X, Zhang H, Zhang Y, Fu M, Sun Z, Kuai P, Lou Y, Fang Y. Lamin-like Proteins Negatively Regulate Plant Immunity through NAC WITH TRANSMEMBRANE MOTIF1-LIKE9 and NONEXPRESSOR OF PR GENES1 in Arabidopsis thaliana. MOLECULAR PLANT 2017; 10:1334-1348. [PMID: 28943325 DOI: 10.1016/j.molp.2017.09.008] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 09/17/2017] [Accepted: 09/18/2017] [Indexed: 05/22/2023]
Abstract
Nuclear lamins are involved in multiple biological processes in metazoan cells. The proteins of the CROWDED NUCLEI (CRWN) family are considered lamin-like candidates in Arabidopsis, although the functions of these proteins are largely unknown. In this article we show that crwn1 crwn2 double mutant displays an enhanced resistance against virulent bacterial pathogens, and both virulent bacteria and salicylic acid (SA) induce transcription of CRWN1 gene as well as proteasome-mediated degradation of CRWN1 protein. We also show that CRWN1 interacts with NAC WITH TRANSMEMBRANE MOTIF1-LIKE9 (NTL9), a NAC transcription factor involved in plant immunity. The interaction between CRWN1 and NTL9 enhances the binding of NTL9 to the promoter of the PATHOGENESIS-RELATED1 (PR1) gene, and inhibits PR1 expression. Further genetic experiments indicated that the defense-related phenotypes of crwn1 crwn2 double mutant are dependent on NONEXPRESSOR OF PR GENES1 (NPR1), a transcriptional cofactor of PR1. These findings revealed a regulatory network composed of lamin-like protein CRWN1, NTL9, and NPR1 for the regulation of PR1 expression.
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Affiliation(s)
- Tongtong Guo
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China; University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Xuegao Mao
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China; University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Hui Zhang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China; University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Yu Zhang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China; University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Mengdi Fu
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China; University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Zhenfei Sun
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China; University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Peng Kuai
- State Key Laboratory of Rice Biology, Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China
| | - Yonggen Lou
- State Key Laboratory of Rice Biology, Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China
| | - Yuda Fang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China; University of the Chinese Academy of Sciences, Beijing 100049, China.
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Parisis N, Krasinska L, Harker B, Urbach S, Rossignol M, Camasses A, Dewar J, Morin N, Fisher D. Initiation of DNA replication requires actin dynamics and formin activity. EMBO J 2017; 36:3212-3231. [PMID: 28982779 DOI: 10.15252/embj.201796585] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 08/28/2017] [Accepted: 09/07/2017] [Indexed: 12/19/2022] Open
Abstract
Nuclear actin regulates transcriptional programmes in a manner dependent on its levels and polymerisation state. This dynamics is determined by the balance of nucleocytoplasmic shuttling, formin- and redox-dependent filament polymerisation. Here, using Xenopus egg extracts and human somatic cells, we show that actin dynamics and formins are essential for DNA replication. In proliferating cells, formin inhibition abolishes nuclear transport and initiation of DNA replication, as well as general transcription. In replicating nuclei from transcriptionally silent Xenopus egg extracts, we identified numerous actin regulators, and disruption of actin dynamics abrogates nuclear transport, preventing NLS (nuclear localisation signal)-cargo release from RanGTP-importin complexes. Nuclear formin activity is further required to promote loading of cyclin-dependent kinase (CDK) and proliferating cell nuclear antigen (PCNA) onto chromatin, as well as initiation and elongation of DNA replication. Therefore, actin dynamics and formins control DNA replication by multiple direct and indirect mechanisms.
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Affiliation(s)
- Nikolaos Parisis
- IGMM, CNRS Univ. Montpellier, Montpellier, France.,Laboratory of Functional Proteomics, INRA, Montpellier, France
| | | | | | - Serge Urbach
- Functional Proteomics Platform (FPP), Institute of Functional Genomics (IGF), CNRS UMR 5203 INSERM U661, Montpellier, France
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Yin X, Komatsu S. Comprehensive analysis of response and tolerant mechanisms in early-stage soybean at initial-flooding stress. J Proteomics 2017; 169:225-232. [PMID: 28137666 DOI: 10.1016/j.jprot.2017.01.014] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 01/17/2017] [Accepted: 01/23/2017] [Indexed: 12/31/2022]
Abstract
Soybean is one of the most cultivated crops in the world; however, it is very sensitive to flooding stress, which markedly reduces its growth and yield. Morphological and biochemical changes such as an increase of fresh weight and a decrease of ATP content happen in early-stage soybean at initial-flooding stress, indicating that soybean responses to flooding stress are keys for its survival and seedling growth. Phosphoproteomics and nuclear proteomics are useful tools to detect protein-phosphorylation status and to identify transcriptional factors. In the review, the effect of flooding on soybean response to initial flooding stress is discussed based on recent results of proteomic, phosphoproteomic, nuclear proteomic, and nuclear phosphoproteomic studies. In addition, soybean survival under flooding stress, which is defined as tolerance mechanism, is discussed with the results of comprehensive analysis in flooding-tolerant mutant line and abscisic acid-treated soybean. BIOLOGICAL SIGNIFICANCE Soybean is one of the most cultivated crops in the world; however, it is very sensitive to flooding stress, especially soybean responses to initial flooding stress is key for its survival and seedling growth. Recently, proteomic techniques are applied to investigate the response and tolerant mechanisms of soybean at initial flooding condition. In this review, the progress in proteomic, phosphoproteomic, nuclear proteomic, and nuclear phosphoproteomic studies about the initial-flooding response mechanism in early-stage soybean is presented. In addition, the tolerant mechanism in soybean is discussed with the results of comprehensive analysis in flooding-tolerant mutant line and abscisic acid-treated soybean. Through this review, the key proteins and genes involved in initial flooding response and tolerance at early stage soybean are summarized and they contribute greatly to uncover response and tolerance mechanism at early stage under stressful environmental conditions in soybean.
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Affiliation(s)
- Xiaojian Yin
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba 305-8572, Japan; National Institute of Crop Science, National Agriculture and Food Research Organization, Tsukuba 305-8518, Japan
| | - Setsuko Komatsu
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba 305-8572, Japan; National Institute of Crop Science, National Agriculture and Food Research Organization, Tsukuba 305-8518, Japan.
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31
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The functional versatility of the nuclear pore complex proteins. Semin Cell Dev Biol 2017; 68:2-9. [DOI: 10.1016/j.semcdb.2017.05.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 05/11/2017] [Indexed: 12/28/2022]
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32
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Mimura Y, Takagi M, Clever M, Imamoto N. ELYS regulates the localization of LBR by modulating its phosphorylation state. J Cell Sci 2016; 129:4200-4212. [PMID: 27802161 PMCID: PMC5117198 DOI: 10.1242/jcs.190678] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 09/27/2016] [Indexed: 01/12/2023] Open
Abstract
Lamin B receptor (LBR), an inner nuclear membrane (INM) protein, contributes to the functional integrity of the nucleus by tethering heterochromatin to the nuclear envelope. We have previously reported that the depletion of embryonic large molecule derived from yolk sac (ELYS; also known as AHCTF1), a component of the nuclear pore complex, from cells perturbs the localization of LBR to the INM, but little is known about the underlying molecular mechanism. In this study, we found that the depletion of ELYS promoted LBR phosphorylation at the residues known to be phosphorylated by cyclin-dependent kinase (CDK) and serine/arginine protein kinases 1 and 2 (SRPK1 and SRPK2, respectively). These phosphorylation events were most likely to be counter-balanced by protein phosphatase 1 (PP1), and the depletion of PP1 from cells consistently caused the mislocalization of LBR. These observations point to a new mechanism regulating the localization of LBR, which is governed by an ELYS-mediated phosphorylation network. This phosphorylation-dependent coordination between INM proteins and the nuclear pore complex might be important for the integrity of the nucleus.
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Affiliation(s)
- Yasuhiro Mimura
- Cellular Dynamics Laboratory, Riken, Saitama 351-0198, Japan
| | | | - Michaela Clever
- Cellular Dynamics Laboratory, Riken, Saitama 351-0198, Japan
| | - Naoko Imamoto
- Cellular Dynamics Laboratory, Riken, Saitama 351-0198, Japan
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Madugula V, Lu L. A ternary complex comprising transportin1, Rab8 and the ciliary targeting signal directs proteins to ciliary membranes. J Cell Sci 2016; 129:3922-3934. [PMID: 27633000 PMCID: PMC5087665 DOI: 10.1242/jcs.194019] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 08/31/2016] [Indexed: 12/13/2022] Open
Abstract
The sensory functions of cilia are dependent on the enrichment of cilium-resident proteins. Although it is known that ciliary targeting signals (CTSs) specifically target ciliary proteins to cilia, it is still unclear how CTSs facilitate the entry and retention of cilium-resident proteins at the molecular level. We found that non-ciliary membrane reporters can passively diffuse into cilia through the lateral transport pathway, and the translocation of membrane reporters through the ciliary diffusion barrier is facilitated by importin binding motifs and domains. Screening known CTSs of ciliary membrane residents uncovered that fibrocystin, photoreceptor retinol dehydrogenase, rhodopsin and retinitis pigmentosa 2 interact with transportin1 (TNPO1) through previously identified CTSs. We further discovered that a new ternary complex, comprising TNPO1, Rab8 and a CTS, can assemble or disassemble under the guanine nucleotide exchange activity of Rab8. Our study suggests a new mechanism in which the TNPO1-Rab8-CTS complex mediates selective entry into and retention of cargos within cilia.
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Affiliation(s)
- Viswanadh Madugula
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551 Singapore
| | - Lei Lu
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551 Singapore
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Hayashi D, Tanabe K, Katsube H, Inoue YH. B-type nuclear lamin and the nuclear pore complex Nup107-160 influences maintenance of the spindle envelope required for cytokinesis in Drosophila male meiosis. Biol Open 2016; 5:1011-21. [PMID: 27402967 PMCID: PMC5004606 DOI: 10.1242/bio.017566] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In higher eukaryotes, nuclear envelope (NE) disassembly allows chromatin to condense and spindle microtubules to access kinetochores. The nuclear lamina, which strengthens the NE, is composed of a polymer meshwork made of A- and B-type lamins. We found that the B-type lamin (Lam) is not fully disassembled and continues to localize along the spindle envelope structure during Drosophila male meiosis I, while the A-type lamin (LamC) is completely dispersed throughout the cytoplasm. Among the nuclear pore complex proteins, Nup107 co-localized with Lam during this meiotic division. Surprisingly, Lam depletion resulted in a higher frequency of cytokinesis failure in male meiosis. We also observed the similar meiotic phenotype in Nup107-depleted cells. Abnormal localization of Lam was found in the Nup-depleted cells at premeiotic and meiotic stages. The central spindle microtubules became abnormal and recruitment of a contractile ring component to the cleavage sites was disrupted in Lam-depleted cells and Nup107-depleted cells. Therefore, we speculate that both proteins are required for a reinforcement of the spindle envelope, which supports the formation of central spindle microtubules essential for cytokinesis in Drosophila male meiosis.
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Affiliation(s)
- Daisuke Hayashi
- Insect Biomedical Research Center, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-0962, Japan
| | - Karin Tanabe
- Insect Biomedical Research Center, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-0962, Japan
| | - Hiroka Katsube
- Insect Biomedical Research Center, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-0962, Japan
| | - Yoshihiro H Inoue
- Insect Biomedical Research Center, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-0962, Japan
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Endoplasmic Reticulum: The Favorite Intracellular Niche for Viral Replication and Assembly. Viruses 2016; 8:v8060160. [PMID: 27338443 PMCID: PMC4926180 DOI: 10.3390/v8060160] [Citation(s) in RCA: 122] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Revised: 05/23/2016] [Accepted: 05/26/2016] [Indexed: 02/07/2023] Open
Abstract
The endoplasmic reticulum (ER) is the largest intracellular organelle. It forms a complex network of continuous sheets and tubules, extending from the nuclear envelope (NE) to the plasma membrane. This network is frequently perturbed by positive-strand RNA viruses utilizing the ER to create membranous replication factories (RFs), where amplification of their genomes occurs. In addition, many enveloped viruses assemble progeny virions in association with ER membranes, and viruses replicating in the nucleus need to overcome the NE barrier, requiring transient changes of the NE morphology. This review first summarizes some key aspects of ER morphology and then focuses on the exploitation of the ER by viruses for the sake of promoting the different steps of their replication cycles.
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Abstract
The nuclear envelope segregates the nucleoplasm from the cytoplasm and is a key feature of eukaryotic cells. Nuclear envelope architecture is comprised of two concentric membrane shells which fuse at multiple sites and yet maintain a uniform separation of 30-50 nm over the rest of the membrane. Studies have revealed the roles for numerous nuclear proteins in forming and maintaining the architecture of the nuclear envelope. However, there is a lack of consensus on the fundamental forces and physical mechanisms that establish the geometry. The objective of this review is to discuss recent findings in the context of membrane mechanics in an effort to define open questions and possible answers.
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Affiliation(s)
- Mehdi Torbati
- Department of Mechanical Engineering, University of Houston, Houston, TX
| | - Tanmay P Lele
- Department of Chemical Engineering, University of Florida, Gainesville, FL
| | - Ashutosh Agrawal
- Department of Mechanical Engineering, University of Houston, Houston, TX
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Meng F, Na I, Kurgan L, Uversky VN. Compartmentalization and Functionality of Nuclear Disorder: Intrinsic Disorder and Protein-Protein Interactions in Intra-Nuclear Compartments. Int J Mol Sci 2015; 17:ijms17010024. [PMID: 26712748 PMCID: PMC4730271 DOI: 10.3390/ijms17010024] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2015] [Revised: 11/23/2015] [Accepted: 12/18/2015] [Indexed: 01/12/2023] Open
Abstract
The cell nucleus contains a number of membrane-less organelles or intra-nuclear compartments. These compartments are dynamic structures representing liquid-droplet phases which are only slightly denser than the bulk intra-nuclear fluid. They possess different functions, have diverse morphologies, and are typically composed of RNA (or, in some cases, DNA) and proteins. We analyzed 3005 mouse proteins localized in specific intra-nuclear organelles, such as nucleolus, chromatin, Cajal bodies, nuclear speckles, promyelocytic leukemia (PML) nuclear bodies, nuclear lamina, nuclear pores, and perinuclear compartment and compared them with ~29,863 non-nuclear proteins from mouse proteome. Our analysis revealed that intrinsic disorder is enriched in the majority of intra-nuclear compartments, except for the nuclear pore and lamina. These compartments are depleted in proteins that lack disordered domains and enriched in proteins that have multiple disordered domains. Moonlighting proteins found in multiple intra-nuclear compartments are more likely to have multiple disordered domains. Protein-protein interaction networks in the intra-nuclear compartments are denser and include more hubs compared to the non-nuclear proteins. Hubs in the intra-nuclear compartments (except for the nuclear pore) are enriched in disorder compared with non-nuclear hubs and non-nuclear proteins. Therefore, our work provides support to the idea of the functional importance of intrinsic disorder in the cell nucleus and shows that many proteins associated with sub-nuclear organelles in nuclei of mouse cells are enriched in disorder. This high level of disorder in the mouse nuclear proteins defines their ability to serve as very promiscuous binders, possessing both large quantities of potential disorder-based interaction sites and the ability of a single such site to be involved in a large number of interactions.
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Affiliation(s)
- Fanchi Meng
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, AB T6G 2V4, Canada.
| | - Insung Na
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA.
| | - Lukasz Kurgan
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, AB T6G 2V4, Canada.
- Department of Computer Science, Virginia Commonwealth University, Richmond, VA 23219, USA.
| | - Vladimir N Uversky
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA.
- University of South Florida Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA.
- Institute for Biological Instrumentation, Russian Academy of Sciences, Pushchino, Moscow Region 142292, Russian.
- Biology Department, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21589, Saudi Arabia.
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, Saint Petersburg 194064, Russian.
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Baum DA. A comparison of autogenous theories for the origin of eukaryotic cells. AMERICAN JOURNAL OF BOTANY 2015; 102:1954-1965. [PMID: 26643887 DOI: 10.3732/ajb.1500196] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Accepted: 10/21/2015] [Indexed: 06/05/2023]
Abstract
PREMISE Eukaryotic cells have many unique features that all evolved on the stem lineage of living eukaryotes, making it difficult to reconstruct the order in which they accumulated. Nuclear endosymbiotic theories hold that three prokaryotes (nucleus, cytoplasm, and mitochondrion) came together to form a eukaryotic cell, whereas autogenous models hold that the nucleus and cytoplasm formed through evolutionary changes in a single prokaryotic lineage. Given several problems with nuclear endosymbiotic theories, this review focuses on autogenous models. KEY INSIGHTS Until recently all autogenous models assumed an outside-in (OI) topology, proposing that the nuclear envelope was formed from membrane-bound vesicles within the original cell body. Buzz Baum and I recently proposed an inside-out (IO) alternative, suggesting that the nucleus corresponds to the original cell body, with the cytoplasmic compartment deriving from extracellular protrusions. In this review, I show that OI and IO models are compatible with both mitochondria early (ME) or mitochondria late (ML) formulations. Whereas ME models allow that the relationship between mitochondria and host was mutualistic from the outset, ML models imply that the association began with predation or parasitism, becoming mutualistic later. In either case, the mutualistic interaction that eventually formed was probably syntrophic. CONCLUSIONS Diverse features of eukaryotic cell biology align well with the IOME model, but it would be premature to rule out the OIME model. ML models require that phagocytosis, a complex and energy expensive process, evolved before mitochondria, which seems unlikely. Nonetheless, further research is needed, especially resolution of the phylogenetic affinities of mitochondria.
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Affiliation(s)
- David A Baum
- Department of Botany and Wisconsin Institute for Discovery, University of Wisconsin, 430 Lincoln Drive, Madison, Wisconsin 53706 USA
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Casey AK, Chen S, Novick P, Ferro-Novick S, Wente SR. Nuclear pore complex integrity requires Lnp1, a regulator of cortical endoplasmic reticulum. Mol Biol Cell 2015; 26:2833-44. [PMID: 26041935 PMCID: PMC4571342 DOI: 10.1091/mbc.e15-01-0053] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Revised: 04/21/2015] [Accepted: 05/27/2015] [Indexed: 12/31/2022] Open
Abstract
The nuclear envelope (NE) and endoplasmic reticulum (ER) are components of the same contiguous membrane system and yet have distinct cellular functions. Mounting evidence suggests roles for some ER proteins in the NE for proper nuclear pore complex (NPC) structure and function. In this study, we identify a NE role in Saccharomyces cerevisiae for Lnp1 and Sey1, proteins required for proper cortical ER formation. Both lnp1Δ and sey1Δ mutants exhibit synthetic genetic interactions with mutants in genes encoding key NPC structural components. Both Lnp1 and Sey1 physically associate with other ER components that have established NPC roles, including Rtn1, Yop1, Pom33, and Per33. Of interest, lnp1Δ rtn1Δ mutants but not rtn1Δ sey1Δ mutants exhibit defects in NPC distribution. Furthermore, the essential NPC assembly factor Ndc1 has altered interactions in the absence of Sey1. Lnp1 dimerizes in vitro via its C-terminal zinc finger motif, a property that is required for proper ER structure but not NPC integrity. These findings suggest that Lnp1's role in NPC integrity is separable from functions in the ER and is linked to Ndc1 and Rtn1 interactions.
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Affiliation(s)
- Amanda K Casey
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232
| | - Shuliang Chen
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, CA 92093
| | - Peter Novick
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, CA 92093 Howard Hughes Medical Institute, University of California at San Diego, La Jolla, CA 92093
| | - Susan Ferro-Novick
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, CA 92093
| | - Susan R Wente
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232 )
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40
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Abstract
Mechanistic target of rapamycin (mTOR) is a central component of the essential signaling pathway that regulates cell growth and proliferation by controlling anabolic processes in cells. mTOR exists in two distinct mTOR complexes known as mTORC1 and mTORC2 that reside mostly in cytoplasm. In our study, the biochemical characterization of mTOR led to discovery of its novel localization on nuclear envelope where it associates with a critical regulator of nuclear import Ran Binding Protein 2 (RanBP2). We show that association of mTOR with RanBP2 is dependent on the mTOR kinase activity that regulates the nuclear import of ribosomal proteins. The mTOR kinase inhibitors within thirty minutes caused a substantial decrease of ribosomal proteins in the nuclear but not cytoplasmic fraction. Detection of a nuclear accumulation of the GFP-tagged ribosomal protein rpL7a also indicated its dependence on the mTOR kinase activity. The nuclear abundance of ribosomal proteins was not affected by inhibition of mTOR Complex 1 (mTORC1) by rapamycin or deficiency of mTORC2, suggesting a distinctive role of the nuclear envelope mTOR complex in the nuclear import. Thus, we identified that mTOR in association with RanBP2 mediates the active nuclear import of ribosomal proteins.
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41
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The Inner Nuclear Membrane Protein Src1 Is Required for Stable Post-Mitotic Progression into G1 in Aspergillus nidulans. PLoS One 2015; 10:e0132489. [PMID: 26147902 PMCID: PMC4492595 DOI: 10.1371/journal.pone.0132489] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 06/15/2015] [Indexed: 01/13/2023] Open
Abstract
How membranes and associated proteins of the nuclear envelope (NE) are assembled specifically and inclusively around segregated genomes during exit from mitosis is incompletely understood. Inner nuclear membrane (INM) proteins play key roles by providing links between DNA and the NE. In this study we have investigated the highly conserved INM protein Src1 in Aspergillus nidulans and have uncovered a novel cell cycle response during post mitotic formation of G1 nuclei. Live cell imaging indicates Src1 could have roles during mitotic exit as it preferentially locates to the NE abscission points during nucleokinesis and to the NE surrounding forming daughter G1 nuclei. Deletion analysis further supported this idea revealing that although Src1 is not required for interphase progression or mitosis it is required for stable post-mitotic G1 nuclear formation. This conclusion is based upon the observation that in the absence of Src1 newly formed G1 nuclei are structurally unstable and immediately undergo architectural modifications typical of mitosis. These changes include NPC modifications that stop nuclear transport as well as disassembly of nucleoli. More intriguingly, the newly generated G1 nuclei then cycle between mitotic- and interphase-like states. The findings indicate that defects in post-mitotic G1 nuclear formation caused by lack of Src1 promote repeated failed attempts to generate stable G1 nuclei. To explain this unexpected phenotype we suggest a type of regulation that promotes repetition of defective cell cycle transitions rather than preventing progression past the defective cell cycle transition. We suggest the term “reboot regulation” to define this mode of cell cycle regulation. The findings are discussed in relationship to recent studies showing the Cdk1 master oscillator can entrain subservient oscillators that when uncoupled cause cell cycle transitions to be repeated.
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42
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Thiopurines induce oxidative stress in T-lymphocytes: a proteomic approach. Mediators Inflamm 2015; 2015:434825. [PMID: 25873760 PMCID: PMC4385670 DOI: 10.1155/2015/434825] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 09/06/2014] [Accepted: 09/09/2014] [Indexed: 01/24/2023] Open
Abstract
Thiopurines are extensively used immunosuppressants for the treatment of inflammatory bowel disease (IBD). The polymorphism of thiopurine S-methyltransferase (TPMT) influences thiopurine metabolism and therapy outcome. We used a TPMT knockdown (kd) model of human Jurkat T-lymphocytes cells to study the effects of treatment with 6-mercaptopurine (6-MP) and 6-thioguanine (6-TG) on proteome and phosphoproteome. We identified thirteen proteins with altered expression and nine proteins with altered phosphorylation signals. Three proteins (THIO, TXD17, and GSTM3) with putative functions in cellular oxidative stress responses were altered by 6-TG treatment and another protein PRDX3 was differentially phosphorylated in TPMT kd cells. Furthermore, reactive oxygen species (ROS) assay results were consistent with a significant induction of oxidative stress by both TPMT knockdown and thiopurine treatments. Immunoblot analyses showed treatment altered expression of key antioxidant enzymes (i.e., SOD2 and catalase) in both wt and kd groups, while SOD1 was downregulated by 6-TG treatment and TPMT knockdown. Collectively, increased oxidative stress might be a mechanism involved in thiopurine induced cytotoxicity and adverse effects (i.e., hepatotoxicity) and an antioxidant cotherapy might help to combat this. Results highlight the significance of oxidative stress in thiopurines' actions and could have important implications for the treatment of IBD patients.
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43
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Petrovská B, Šebela M, Doležel J. Inside a plant nucleus: discovering the proteins. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:1627-40. [PMID: 25697798 DOI: 10.1093/jxb/erv041] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Nuclear proteins are a vital component of eukaryotic cell nuclei and have a profound effect on the way in which genetic information is stored, expressed, replicated, repaired, and transmitted to daughter cells and progeny. Because of the plethora of functions, nuclear proteins represent the most abundant components of cell nuclei in all eukaryotes. However, while the plant genome is well understood at the DNA level, information on plant nuclear proteins remains scarce, perhaps with the exception of histones and a few other proteins. This lack of knowledge hampers efforts to understand how the plant genome is organized in the nucleus and how it functions. This review focuses on the current state of the art of the analysis of the plant nuclear proteome. Previous proteome studies have generally been designed to search for proteins involved in plant response to various forms of stress or to identify rather a modest number of proteins. Thus, there is a need for more comprehensive and systematic studies of proteins in the nuclei obtained at individual phases of the cell cycle, or isolated from various tissue types and stages of cell and tissue differentiation. All this in combination with protein structure, predicted function, and physical localization in 3D nuclear space could provide much needed progress in our understanding of the plant nuclear proteome and its role in plant genome organization and function.
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Affiliation(s)
- Beáta Petrovská
- Institute of Experimental Botany, Centre of the Region Haná for Biotechnological and Agricultural Research, Šlechtitelů 31, 783 71 Olomouc, Czech Republic Department of Protein Biochemistry and Proteomics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Šlechtitelů 11, 783 71 Olomouc, Czech Republic
| | - Marek Šebela
- Department of Protein Biochemistry and Proteomics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Šlechtitelů 11, 783 71 Olomouc, Czech Republic
| | - Jaroslav Doležel
- Institute of Experimental Botany, Centre of the Region Haná for Biotechnological and Agricultural Research, Šlechtitelů 31, 783 71 Olomouc, Czech Republic
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44
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Abstract
The proper folding of proteins is continuously challenged by intrinsic and extrinsic stresses, and the accumulation of toxic misfolded proteins is associated with many human diseases. Eukaryotic cells have evolved a complex network of protein quality control pathways to protect the proteome, and these pathways are specialized for each subcellular compartment. While many details have been elucidated for how the cytosol and endoplasmic reticulum counteract proteotoxic stress, relatively little is known about the pathways protecting the nucleus from protein misfolding. Proper maintenance of nuclear proteostasis has important implications in preserving genomic integrity, as well as for aging and disease. Here, we offer a conceptual framework for how proteostasis is maintained in this organelle. We define the particular requirements that must be considered for the nucleus to manage proteotoxic stress, summarize the known and implicated pathways of nuclear protein quality control, and identify the unresolved questions in the field.
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Affiliation(s)
- Yoko Shibata
- Department of Molecular Biosciences, Rice Institute for Biomedical Research, Northwestern University, Evanston, IL 60208, USA
| | - Richard I Morimoto
- Department of Molecular Biosciences, Rice Institute for Biomedical Research, Northwestern University, Evanston, IL 60208, USA.
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45
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Westrate LM, Lee JE, Prinz WA, Voeltz GK. Form follows function: the importance of endoplasmic reticulum shape. Annu Rev Biochem 2015; 84:791-811. [PMID: 25580528 DOI: 10.1146/annurev-biochem-072711-163501] [Citation(s) in RCA: 266] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The endoplasmic reticulum (ER) has a remarkably complex structure, composed of a single bilayer that forms the nuclear envelope, along with a network of sheets and dynamic tubules. Our understanding of the biological significance of the complex architecture of the ER has improved dramatically in the last few years. The identification of proteins and forces required for maintaining ER shape, as well as more advanced imaging techniques, has allowed the relationship between ER shape and function to come into focus. These studies have also revealed unexpected new functions of the ER and novel ER domains regulating alterations in ER dynamics. The importance of ER structure has become evident as recent research has identified diseases linked to mutations in ER-shaping proteins. In this review, we discuss what is known about the maintenance of ER architecture, the relationship between ER structure and function, and diseases associated with defects in ER structure.
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Affiliation(s)
- L M Westrate
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, Colorado 80303;
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46
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Sazer S, Lynch M, Needleman D. Deciphering the evolutionary history of open and closed mitosis. Curr Biol 2014; 24:R1099-103. [PMID: 25458223 DOI: 10.1016/j.cub.2014.10.011] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The origin of the nucleus at the prokaryote-to-eukaryote transition represents one of the most important events in the evolution of cellular organization. The nuclear envelope encircles the chromosomes in interphase and is a selectively permeable barrier between the nucleoplasm and cytoplasm and an organizational scaffold for the nucleus. It remains intact in the 'closed' mitosis of some yeasts, but loses its integrity in the 'open' mitosis of mammals. Instances of both types of mitosis within two evolutionary clades indicate multiple evolutionary transitions between open and closed mitosis, although the underlying genetic changes that influenced these transitions remain unknown. A survey of the diversity of mitotic nuclei that fall between these extremes is the starting point from which to determine the physiologically relevant characteristics distinguishing open from closed mitosis and to understand how they evolved and why they are retained in present-day organisms. The field is now poised to begin addressing these issues by defining and documenting patterns of mitotic nuclear variation within and among species and mapping them onto a phylogenic tree. Deciphering the evolutionary history of open and closed mitosis will complement cell biological and genetic approaches aimed at deciphering the fundamental organizational principles of the nucleus.
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Affiliation(s)
- Shelley Sazer
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, and Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Michael Lynch
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Daniel Needleman
- School of Engineering and Applied Sciences, and Department of Molecular and Cellular Biology, and FAS Center for Systems Biology, Harvard University, Cambridge, MA 02138, USA
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47
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Mijaljica D, Prescott M, Devenish RJ. The intricacy of nuclear membrane dynamics during nucleophagy. Nucleus 2014. [DOI: 10.4161/nucl.11738] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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48
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Figueroa R, Gudise S, Larsson V, Hallberg E. A transmembrane inner nuclear membrane protein in the mitotic spindle. Nucleus 2014. [DOI: 10.4161/nucl.11740] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
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49
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Abstract
Current anti-cancer therapies have a great deal of undesirable side effects; therefore, there is a need to develop efficient and cancer cell-specific new drugs without strong dose-limiting side effects. In my opinion, mechanisms of nuclear assembly and organization represent a novel platform for drug targets, which might fulfill these criteria. The nuclear stiffness and organization of some cancer types are often compromised, making them more vulnerable for further targeting the mechanisms of nuclear integrity than their normal counterparts. Here I will discuss the nuclear organization of normal cells and cancer cells, the molecular mechanisms that govern nuclear assembly with emphasis on those that, in my view, might be considered as targets for future anti-cancer therapies.
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Affiliation(s)
- Mátyás Gorjánácz
- Bayer Pharma AG; Bayer Healthcare Pharmaceuticals; Global Drug Discovery; Therapeutic Research Group Oncology; Berlin, Germany
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50
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Guo T, Fang Y. Functional organization and dynamics of the cell nucleus. FRONTIERS IN PLANT SCIENCE 2014; 5:378. [PMID: 25161658 PMCID: PMC4130368 DOI: 10.3389/fpls.2014.00378] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 07/16/2014] [Indexed: 05/16/2023]
Abstract
The eukaryotic cell nucleus enclosed within the nuclear envelope harbors organized chromatin territories and various nuclear bodies as sub-nuclear compartments. This higher-order nuclear organization provides a unique environment to regulate the genome during replication, transcription, maintenance, and other processes. In this review, we focus on the plant four-dimensional nuclear organization, its dynamics and function in response to signals during development or stress.
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Affiliation(s)
| | - Yuda Fang
- *Correspondence: Yuda Fang, National key Laboratory of Plant Molecular Genetics, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032, China e-mail:
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