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Antao NV, Lam C, Davydov A, Riggi M, Sall J, Petzold C, Liang FX, Iwasa JH, Ekiert DC, Bhabha G. 3D reconstructions of parasite development and the intracellular niche of the microsporidian pathogen Encephalitozoon intestinalis. Nat Commun 2023; 14:7662. [PMID: 37996434 PMCID: PMC10667486 DOI: 10.1038/s41467-023-43215-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 11/02/2023] [Indexed: 11/25/2023] Open
Abstract
Microsporidia are an early-diverging group of fungal pathogens with a wide host range. Several microsporidian species cause opportunistic infections in humans that can be fatal. As obligate intracellular parasites with highly reduced genomes, microsporidia are dependent on host metabolites for successful replication and development. Our knowledge of microsporidian intracellular development remains rudimentary, and our understanding of the intracellular niche occupied by microsporidia has relied on 2D TEM images and light microscopy. Here, we use serial block-face scanning electron microscopy (SBF-SEM) to capture 3D snapshots of the human-infecting species, Encephalitozoon intestinalis, within host cells. We track E. intestinalis development through its life cycle, which allows us to propose a model for how its infection organelle, the polar tube, is assembled de novo in developing spores. 3D reconstructions of parasite-infected cells provide insights into the physical interactions between host cell organelles and parasitophorous vacuoles, which contain the developing parasites. The host cell mitochondrial network is substantially remodeled during E. intestinalis infection, leading to mitochondrial fragmentation. SBF-SEM analysis shows changes in mitochondrial morphology in infected cells, and live-cell imaging provides insights into mitochondrial dynamics during infection. Our data provide insights into parasite development, polar tube assembly, and microsporidia-induced host mitochondria remodeling.
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Affiliation(s)
- Noelle V Antao
- Department of Cell Biology, New York University School of Medicine, New York, NY, USA
| | - Cherry Lam
- Department of Cell Biology, New York University School of Medicine, New York, NY, USA
| | - Ari Davydov
- Department of Cell Biology, New York University School of Medicine, New York, NY, USA
| | - Margot Riggi
- Department of Biochemistry, University of Utah, Salt Lake City, USA
| | - Joseph Sall
- Office of Science and Research Microscopy Laboratory, New York University School of Medicine, New York, NY, USA
| | - Christopher Petzold
- Office of Science and Research Microscopy Laboratory, New York University School of Medicine, New York, NY, USA
| | - Feng-Xia Liang
- Department of Cell Biology, New York University School of Medicine, New York, NY, USA
- Office of Science and Research Microscopy Laboratory, New York University School of Medicine, New York, NY, USA
| | - Janet H Iwasa
- Department of Biochemistry, University of Utah, Salt Lake City, USA
| | - Damian C Ekiert
- Department of Cell Biology, New York University School of Medicine, New York, NY, USA.
- Department of Microbiology, New York University School of Medicine, New York, NY, USA.
| | - Gira Bhabha
- Department of Cell Biology, New York University School of Medicine, New York, NY, USA.
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2
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Antao NV, Lam C, Davydov A, Riggi M, Sall J, Petzold C, Liang FX, Iwasa J, Ekiert DC, Bhabha G. 3D reconstructions of parasite development and the intracellular niche of the microsporidian pathogen E. intestinalis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.02.547383. [PMID: 37425741 PMCID: PMC10327200 DOI: 10.1101/2023.07.02.547383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Microsporidia are an early-diverging group of fungal pathogens that infect a wide range of hosts. Several microsporidian species infect humans, and infections can lead to fatal disease in immunocompromised individuals. As obligate intracellular parasites with highly reduced genomes, microsporidia are dependent on metabolites from their hosts for successful replication and development. Our knowledge of how microsporidian parasites develop inside the host remains rudimentary, and our understanding of the intracellular niche occupied by microsporidia has thus far relied largely on 2D TEM images and light microscopy. Here, we use serial block face scanning electron microscopy (SBF-SEM) to capture 3D snapshots of the human-infecting microsporidian, Encephalitozoon intestinalis , within host cells. We track the development of E. intestinalis through its life cycle, which allows us to propose a model for how its infection organelle, the polar tube, is assembled de novo in each developing spore. 3D reconstructions of parasite-infected cells provide insights into the physical interactions between host cell organelles and parasitophorous vacuoles, which contain the developing parasites. The host cell mitochondrial network is substantially remodeled during E. intestinalis infection, leading to mitochondrial fragmentation. SBF-SEM analysis shows changes in mitochondrial morphology in infected cells, and live-cell imaging provides insights into mitochondrial dynamics during infection. Together, our data provide insights into parasite development, polar tube assembly, and microsporidia-induced mitochondrial remodeling in the host cell.
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3
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Schibler AC, Jevtic P, Pegoraro G, Levy DL, Misteli T. Identification of epigenetic modulators as determinants of nuclear size and shape. eLife 2023; 12:e80653. [PMID: 37219077 PMCID: PMC10259489 DOI: 10.7554/elife.80653] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Accepted: 05/04/2023] [Indexed: 05/24/2023] Open
Abstract
The shape and size of the human cell nucleus is highly variable among cell types and tissues. Changes in nuclear morphology are associated with disease, including cancer, as well as with premature and normal aging. Despite the very fundamental nature of nuclear morphology, the cellular factors that determine nuclear shape and size are not well understood. To identify regulators of nuclear architecture in a systematic and unbiased fashion, we performed a high-throughput imaging-based siRNA screen targeting 867 nuclear proteins including chromatin-associated proteins, epigenetic regulators, and nuclear envelope components. Using multiple morphometric parameters, and eliminating cell cycle effectors, we identified a set of novel determinants of nuclear size and shape. Interestingly, most identified factors altered nuclear morphology without affecting the levels of lamin proteins, which are known prominent regulators of nuclear shape. In contrast, a major group of nuclear shape regulators were modifiers of repressive heterochromatin. Biochemical and molecular analysis uncovered a direct physical interaction of histone H3 with lamin A mediated via combinatorial histone modifications. Furthermore, disease-causing lamin A mutations that result in disruption of nuclear shape inhibited lamin A-histone H3 interactions. Oncogenic histone H3.3 mutants defective for H3K27 methylation resulted in nuclear morphology abnormalities. Altogether, our results represent a systematic exploration of cellular factors involved in determining nuclear morphology and they identify the interaction of lamin A with histone H3 as an important contributor to nuclear morphology in human cells.
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Affiliation(s)
| | - Predrag Jevtic
- Department of Molecular Biology, University of WyomingLaramieUnited States
| | - Gianluca Pegoraro
- High Throughput Imaging Facility (HiTIF), National Cancer Institute, NIHBethesdaUnited States
| | - Daniel L Levy
- Department of Molecular Biology, University of WyomingLaramieUnited States
| | - Tom Misteli
- National Cancer InstituteBethesdaUnited States
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4
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Schirmer EC, Latonen L, Tollis S. Nuclear size rectification: A potential new therapeutic approach to reduce metastasis in cancer. Front Cell Dev Biol 2022; 10:1022723. [PMID: 36299481 PMCID: PMC9589484 DOI: 10.3389/fcell.2022.1022723] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 09/12/2022] [Indexed: 03/07/2024] Open
Abstract
Research on metastasis has recently regained considerable interest with the hope that single cell technologies might reveal the most critical changes that support tumor spread. However, it is possible that part of the answer has been visible through the microscope for close to 200 years. Changes in nuclear size characteristically occur in many cancer types when the cells metastasize. This was initially discarded as contributing to the metastatic spread because, depending on tumor types, both increases and decreases in nuclear size could correlate with increased metastasis. However, recent work on nuclear mechanics and the connectivity between chromatin, the nucleoskeleton, and the cytoskeleton indicate that changes in this connectivity can have profound impacts on cell mobility and invasiveness. Critically, a recent study found that reversing tumor type-dependent nuclear size changes correlated with reduced cell migration and invasion. Accordingly, it seems appropriate to now revisit possible contributory roles of nuclear size changes to metastasis.
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Affiliation(s)
- Eric C. Schirmer
- Institute of Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Leena Latonen
- Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
- Foundation for the Finnish Cancer Institute, Helsinki, Finland
| | - Sylvain Tollis
- Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
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5
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A quantitative and spatial analysis of cell cycle regulators during the fission yeast cycle. Proc Natl Acad Sci U S A 2022; 119:e2206172119. [PMID: 36037351 PMCID: PMC9457408 DOI: 10.1073/pnas.2206172119] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Across eukaryotes, the increasing level of cyclin-dependent kinase (CDK) activity drives progression through the cell cycle. As most cells divide at specific sizes, information responding to the size of the cell must feed into the regulation of CDK activity. In this study, we use fission yeast to precisely measure how proteins that have been previously identified in genome-wide screens as cell cycle regulators change in their levels with cell cycle progression. We identify the mitotic B-type cyclin Cdc13 and the mitotic inhibitory phosphatase Cdc25 as the only two proteins that change in both whole-cell and nuclear concentration through the cell cycle, making them potential candidates for universal cell size sensors at the onset of mitosis and cell division. We have carried out a systems-level analysis of the spatial and temporal dynamics of cell cycle regulators in the fission yeast Schizosaccharomyces pombe. In a comprehensive single-cell analysis, we have precisely quantified the levels of 38 proteins previously identified as regulators of the G2 to mitosis transition and of 7 proteins acting at the G1- to S-phase transition. Only 2 of the 38 mitotic regulators exhibit changes in concentration at the whole-cell level: the mitotic B-type cyclin Cdc13, which accumulates continually throughout the cell cycle, and the regulatory phosphatase Cdc25, which exhibits a complex cell cycle pattern. Both proteins show similar patterns of change within the nucleus as in the whole cell but at higher concentrations. In addition, the concentrations of the major fission yeast cyclin-dependent kinase (CDK) Cdc2, the CDK regulator Suc1, and the inhibitory kinase Wee1 also increase in the nucleus, peaking at mitotic onset, but are constant in the whole cell. The significant increase in concentration with size for Cdc13 supports the view that mitotic B-type cyclin accumulation could act as a cell size sensor. We propose a two-step process for the control of mitosis. First, Cdc13 accumulates in a size-dependent manner, which drives increasing CDK activity. Second, from mid-G2, the increasing nuclear accumulation of Cdc25 and the counteracting Wee1 introduce a bistability switch that results in a rapid rise of CDK activity at the end of G2 and thus, brings about an orderly progression into mitosis.
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6
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Tollis S, Rizzotto A, Pham NT, Koivukoski S, Sivakumar A, Shave S, Wildenhain J, Zuleger N, Keys JT, Culley J, Zheng Y, Lammerding J, Carragher NO, Brunton VG, Latonen L, Auer M, Tyers M, Schirmer EC. Chemical Interrogation of Nuclear Size Identifies Compounds with Cancer Cell Line-Specific Effects on Migration and Invasion. ACS Chem Biol 2022; 17:680-700. [PMID: 35199530 PMCID: PMC8938924 DOI: 10.1021/acschembio.2c00004] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
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Background: Lower survival rates for many cancer
types correlate with changes in nuclear size/scaling in a tumor-type/tissue-specific
manner. Hypothesizing that such changes might confer an advantage
to tumor cells, we aimed at the identification of commercially available
compounds to guide further mechanistic studies. We therefore screened
for Food and Drug Administration (FDA)/European Medicines Agency (EMA)-approved
compounds that reverse the direction of characteristic tumor nuclear
size changes in PC3, HCT116, and H1299 cell lines reflecting, respectively,
prostate adenocarcinoma, colonic adenocarcinoma, and small-cell squamous
lung cancer. Results: We found distinct, largely
nonoverlapping sets of compounds that rectify nuclear size changes
for each tumor cell line. Several classes of compounds including,
e.g., serotonin uptake inhibitors, cyclo-oxygenase inhibitors, β-adrenergic
receptor agonists, and Na+/K+ ATPase inhibitors,
displayed coherent nuclear size phenotypes focused on a particular
cell line or across cell lines and treatment conditions. Several compounds
from classes far afield from current chemotherapy regimens were also
identified. Seven nuclear size-rectifying compounds selected for further
investigation all inhibited cell migration and/or invasion. Conclusions: Our study provides (a) proof of concept that
nuclear size might be a valuable target to reduce cell migration/invasion
in cancer treatment and (b) the most thorough collection of tool compounds
to date reversing nuclear size changes specific to individual cancer-type
cell lines. Although these compounds still need to be tested in primary
cancer cells, the cell line-specific nuclear size and migration/invasion
responses to particular drug classes suggest that cancer type-specific
nuclear size rectifiers may help reduce metastatic spread.
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Affiliation(s)
- Sylvain Tollis
- Institute of Biomedicine, University of Eastern Finland, Kuopio 70210, Finland
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Québec H3T 1J4, Canada
| | - Andrea Rizzotto
- The Institute of Cell Biology, University of Edinburgh, Kings Buildings, Michael Swann Buildings, Max Born Crescent, Edinburgh EH9 3BF, U.K
| | - Nhan T. Pham
- Institute of Quantitative Biology, Biochemistry and Biotechnology, University of Edinburgh, Edinburgh EH9 3BF, U.K
| | - Sonja Koivukoski
- Institute of Biomedicine, University of Eastern Finland, Kuopio 70210, Finland
| | - Aishwarya Sivakumar
- The Institute of Cell Biology, University of Edinburgh, Kings Buildings, Michael Swann Buildings, Max Born Crescent, Edinburgh EH9 3BF, U.K
| | - Steven Shave
- Institute of Quantitative Biology, Biochemistry and Biotechnology, University of Edinburgh, Edinburgh EH9 3BF, U.K
| | - Jan Wildenhain
- Institute of Quantitative Biology, Biochemistry and Biotechnology, University of Edinburgh, Edinburgh EH9 3BF, U.K
| | - Nikolaj Zuleger
- The Institute of Cell Biology, University of Edinburgh, Kings Buildings, Michael Swann Buildings, Max Born Crescent, Edinburgh EH9 3BF, U.K
| | - Jeremy T. Keys
- Nancy E. and Peter C. Meinig School of Biomedical Engineering & Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York 14853, United States
| | - Jayne Culley
- Edinburgh Cancer Research UK Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XR, U.K
| | - Yijing Zheng
- Institute of Quantitative Biology, Biochemistry and Biotechnology, University of Edinburgh, Edinburgh EH9 3BF, U.K
| | - Jan Lammerding
- Nancy E. and Peter C. Meinig School of Biomedical Engineering & Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York 14853, United States
| | - Neil O. Carragher
- Edinburgh Cancer Research UK Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XR, U.K
| | - Valerie G. Brunton
- Edinburgh Cancer Research UK Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XR, U.K
| | - Leena Latonen
- Institute of Biomedicine, University of Eastern Finland, Kuopio 70210, Finland
| | - Manfred Auer
- Institute of Quantitative Biology, Biochemistry and Biotechnology, University of Edinburgh, Edinburgh EH9 3BF, U.K
| | - Mike Tyers
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Québec H3T 1J4, Canada
| | - Eric C. Schirmer
- The Institute of Cell Biology, University of Edinburgh, Kings Buildings, Michael Swann Buildings, Max Born Crescent, Edinburgh EH9 3BF, U.K
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7
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Lemière J, Real-Calderon P, Holt LJ, Fai TG, Chang F. Control of nuclear size by osmotic forces in Schizosaccharomyces pombe. eLife 2022; 11:76075. [PMID: 35856499 PMCID: PMC9410708 DOI: 10.7554/elife.76075] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 07/19/2022] [Indexed: 11/13/2022] Open
Abstract
The size of the nucleus scales robustly with cell size so that the nuclear-to-cell volume ratio (N/C ratio) is maintained during cell growth in many cell types. The mechanism responsible for this scaling remains mysterious. Previous studies have established that the N/C ratio is not determined by DNA amount but is instead influenced by factors such as nuclear envelope mechanics and nuclear transport. Here, we developed a quantitative model for nuclear size control based upon colloid osmotic pressure and tested key predictions in the fission yeast Schizosaccharomyces pombe. This model posits that the N/C ratio is determined by the numbers of macromolecules in the nucleoplasm and cytoplasm. Osmotic shift experiments showed that the fission yeast nucleus behaves as an ideal osmometer whose volume is primarily dictated by osmotic forces. Inhibition of nuclear export caused accumulation of macromolecules in the nucleoplasm, leading to nuclear swelling. We further demonstrated that the N/C ratio is maintained by a homeostasis mechanism based upon synthesis of macromolecules during growth. These studies demonstrate the functions of colloid osmotic pressure in intracellular organization and size control.
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Affiliation(s)
- Joël Lemière
- Department of Cell and Tissue Biology, University of California, San FranciscoSan FranciscoUnited States
| | - Paula Real-Calderon
- Department of Cell and Tissue Biology, University of California, San FranciscoSan FranciscoUnited States,Centro Andaluz de Biología del DesarrolloSevillaSpain
| | - Liam J Holt
- Institute for Systems Genetics, New York University Langone HealthNew YorkUnited States
| | - Thomas G Fai
- Department of Mathematics and Volen Center for Complex Systems, Brandeis UniversityWalthamUnited States
| | - Fred Chang
- Department of Cell and Tissue Biology, University of California, San FranciscoSan FranciscoUnited States
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8
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Cantwell H, Dey G. Nuclear size and shape control. Semin Cell Dev Biol 2021; 130:90-97. [PMID: 34776332 DOI: 10.1016/j.semcdb.2021.10.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 10/26/2021] [Accepted: 10/29/2021] [Indexed: 11/27/2022]
Abstract
The nucleus displays a wide range of sizes and shapes in different species and cell types, yet its size scaling and many of the key structural constituents that determine its shape are highly conserved. In this review, we discuss the cellular properties and processes that contribute to nuclear size and shape control, drawing examples from across eukaryotes and highlighting conserved themes and pathways. We then outline physiological roles that have been uncovered for specific nuclear morphologies and disease pathologies associated with aberrant nuclear morphology. We argue that a comparative approach, assessing and integrating observations from different systems, will be a powerful way to help us address the open questions surrounding functional roles of nuclear size and shape in cell physiology.
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Affiliation(s)
- Helena Cantwell
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA 94720, USA.
| | - Gautam Dey
- Cell Biology and Biophysics, European Molecular Biology Laboratory, Meyerhofstr.1, 69117 Heidelberg, Germany.
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9
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Malerba ME, Marshall DJ. Larger cells have relatively smaller nuclei across the Tree of Life. Evol Lett 2021; 5:306-314. [PMID: 34367657 PMCID: PMC8327945 DOI: 10.1002/evl3.243] [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] [Received: 01/27/2021] [Revised: 05/13/2021] [Accepted: 06/07/2021] [Indexed: 01/13/2023] Open
Abstract
Larger cells have larger nuclei, but the precise relationship between cell size and nucleus size remains unclear, and the evolutionary forces that shape this relationship are debated. We compiled data for almost 900 species - from yeast to mammals - at three scales of biological organisation: among-species, within-species, and among-lineages of a species that was artificially selected for cell size. At all scales, we showed that the ratio of nucleus size to cell size (the 'N: C' ratio) decreased systematically in larger cells. Size evolution appears more constrained in nuclei than cells: cell size spans across six orders of magnitude, whereas nucleus size varies by only three. The next important challenge is to determine the drivers of this apparently ubiquitous relationship in N:C ratios across such a diverse array of organisms.
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Affiliation(s)
- Martino E. Malerba
- Centre of Geometric Biology, School of Biological SciencesMonash UniversityMelbourneAustralia
- Centre for Integrative Ecology, School of Life and Environmental SciencesDeakin UniversityVictoriaAustralia
| | - Dustin J. Marshall
- Centre of Geometric Biology, School of Biological SciencesMonash UniversityMelbourneAustralia
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10
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VCP maintains nuclear size by regulating the DNA damage-associated MDC1-p53-autophagy axis in Drosophila. Nat Commun 2021; 12:4258. [PMID: 34253734 PMCID: PMC8275807 DOI: 10.1038/s41467-021-24556-0] [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: 07/26/2020] [Accepted: 06/24/2021] [Indexed: 12/20/2022] Open
Abstract
The maintenance of constant karyoplasmic ratios suggests that nuclear size has physiological significance. Nuclear size anomalies have been linked to malignant transformation, although the mechanism remains unclear. By expressing dominant-negative TER94 mutants in Drosophila photoreceptors, here we show disruption of VCP (valosin-containing protein, human TER94 ortholog), a ubiquitin-dependent segregase, causes progressive nuclear size increase. Loss of VCP function leads to accumulations of MDC1 (mediator of DNA damage checkpoint protein 1), connecting DNA damage or associated responses to enlarged nuclei. TER94 can interact with MDC1 and decreases MDC1 levels, suggesting that MDC1 is a VCP substrate. Our evidence indicates that MDC1 accumulation stabilizes p53A, leading to TER94K2A-associated nuclear size increase. Together with a previous report that p53A disrupts autophagic flux, we propose that the stabilization of p53A in TER94K2A-expressing cells likely hinders the removal of nuclear content, resulting in aberrant nuclear size increase. Cells maintain a constant cytoplasm to nucleus volume ratio, although the role of DNA damage is not well explored. Here, the authors use Drosophila to connect TER94, the fly homolog of VCP, to disruption of DNA damage repair, leading to ubiquitinated Mu2 protein accumulation and enlarged nuclei.
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11
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Abstract
Membrane-bound organelles provide physical and functional compartmentalization of biological processes in eukaryotic cells. The characteristic shape and internal organization of these organelles is determined by a combination of multiple internal and external factors. The maintenance of the shape of nucleus, which houses the genetic material within a double membrane bilayer, is crucial for a seamless spatio-temporal control over nuclear and cellular functions. Dynamic morphological changes in the shape of nucleus facilitate various biological processes. Chromatin packaging, nuclear and cytosolic protein organization, and nuclear membrane lipid homeostasis are critical determinants of overall nuclear morphology. As such, a multitude of molecular players and pathways act together to regulate the nuclear shape. Here, we review the known mechanisms governing nuclear shape in various unicellular and multicellular organisms, including the non-spherical nuclei and non-lamin-related structural determinants. The review also touches upon cellular consequences of aberrant nuclear morphologies.
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Affiliation(s)
- Pallavi Deolal
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Krishnaveni Mishra
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, India
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12
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High-Throughput Identification of Nuclear Envelope Protein Interactions in Schizosaccharomyces pombe Using an Arrayed Membrane Yeast-Two Hybrid Library. G3-GENES GENOMES GENETICS 2020; 10:4649-4663. [PMID: 33109728 PMCID: PMC7718735 DOI: 10.1534/g3.120.401880] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The nuclear envelope (NE) contains a specialized set of integral membrane proteins that maintain nuclear shape and integrity and influence chromatin organization and gene expression. Advances in proteomics techniques and studies in model organisms have identified hundreds of proteins that localize to the NE. However, the function of many of these proteins at the NE remains unclear, in part due to a lack of understanding of the interactions that these proteins participate in at the NE membrane. To assist in the characterization of NE transmembrane protein interactions we developed an arrayed library of integral and peripheral membrane proteins from the fission yeast Schizosaccharomyces pombe for high-throughput screening using the split-ubiquitin based membrane yeast two -hybrid system. We used this approach to characterize protein interactions for three conserved proteins that localize to the inner nuclear membrane: Cut11/Ndc1, Lem2 and Ima1/Samp1/Net5. Additionally, we determined how the interaction network for Cut11 is altered in canonical temperature-sensitive cut11-ts mutants. This library and screening approach is readily applicable to characterizing the interactomes of integral membrane proteins localizing to various subcellular compartments.
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13
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Groaz A, Moghimianavval H, Tavella F, Giessen TW, Vecchiarelli AG, Yang Q, Liu AP. Engineering spatiotemporal organization and dynamics in synthetic cells. WILEY INTERDISCIPLINARY REVIEWS-NANOMEDICINE AND NANOBIOTECHNOLOGY 2020; 13:e1685. [PMID: 33219745 DOI: 10.1002/wnan.1685] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 10/13/2020] [Accepted: 10/30/2020] [Indexed: 12/28/2022]
Abstract
Constructing synthetic cells has recently become an appealing area of research. Decades of research in biochemistry and cell biology have amassed detailed part lists of components involved in various cellular processes. Nevertheless, recreating any cellular process in vitro in cell-sized compartments remains ambitious and challenging. Two broad features or principles are key to the development of synthetic cells-compartmentalization and self-organization/spatiotemporal dynamics. In this review article, we discuss the current state of the art and research trends in the engineering of synthetic cell membranes, development of internal compartmentalization, reconstitution of self-organizing dynamics, and integration of activities across scales of space and time. We also identify some research areas that could play a major role in advancing the impact and utility of engineered synthetic cells. This article is categorized under: Biology-Inspired Nanomaterials > Lipid-Based Structures Biology-Inspired Nanomaterials > Protein and Virus-Based Structures.
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Affiliation(s)
| | | | | | | | | | - Qiong Yang
- University of Michigan, Ann Arbor, Michigan, USA
| | - Allen P Liu
- University of Michigan, Ann Arbor, Michigan, USA
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14
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Heijo H, Shimogama S, Nakano S, Miyata A, Iwao Y, Hara Y. DNA content contributes to nuclear size control in Xenopus laevis. Mol Biol Cell 2020; 31:2703-2717. [PMID: 32997613 PMCID: PMC7927187 DOI: 10.1091/mbc.e20-02-0113] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 08/28/2020] [Accepted: 09/25/2020] [Indexed: 12/17/2022] Open
Abstract
Cells adapt to drastic changes in genome quantity during evolution and cell division by adjusting the nuclear size to exert genomic functions. However, the mechanism by which DNA content within the nucleus contributes to controlling the nuclear size remains unclear. Here, we experimentally evaluated the effects of DNA content by utilizing cell-free Xenopus egg extracts and imaging of in vivo embryos. Upon manipulation of DNA content while maintaining cytoplasmic effects constant, both plateau size and expansion speed of the nucleus correlated highly with DNA content. We also found that nuclear expansion dynamics was altered when chromatin interaction with the nuclear envelope or chromatin condensation was manipulated while maintaining DNA content constant. Furthermore, excess membrane accumulated on the nuclear surface when the DNA content was low. These results clearly demonstrate that nuclear expansion is determined not only by cytoplasmic membrane supply but also by the physical properties of chromatin, including DNA quantity and chromatin structure within the nucleus, rather than the coding sequences themselves. In controlling the dynamics of nuclear expansion, we propose that chromatin interaction with the nuclear envelope plays a role in transmitting chromatin repulsion forces to the nuclear membrane.
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Affiliation(s)
- Hiroko Heijo
- Evolutionary Cell Biology Laboratory, Faculty of Science, Yamaguchi University, Yoshida 1677-1, Yamaguchi City, 753-8512, Japan
| | - Sora Shimogama
- Evolutionary Cell Biology Laboratory, Faculty of Science, Yamaguchi University, Yoshida 1677-1, Yamaguchi City, 753-8512, Japan
| | - Shuichi Nakano
- Evolutionary Cell Biology Laboratory, Faculty of Science, Yamaguchi University, Yoshida 1677-1, Yamaguchi City, 753-8512, Japan
| | - Anna Miyata
- Evolutionary Cell Biology Laboratory, Faculty of Science, Yamaguchi University, Yoshida 1677-1, Yamaguchi City, 753-8512, Japan
| | - Yasuhiro Iwao
- Laboratory of Molecular Developmental Biology, Department of Biology, Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yoshida 1677-1, Yamaguchi City, 753-8512, Japan
| | - Yuki Hara
- Evolutionary Cell Biology Laboratory, Faculty of Science, Yamaguchi University, Yoshida 1677-1, Yamaguchi City, 753-8512, Japan
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15
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Male G, Deolal P, Manda NK, Yagnik S, Mazumder A, Mishra K. Nucleolar size regulates nuclear envelope shape in Saccharomyces cerevisiae. J Cell Sci 2020; 133:jcs242172. [PMID: 32973112 DOI: 10.1242/jcs.242172] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 09/17/2020] [Indexed: 12/12/2022] Open
Abstract
Nuclear shape and size are cell-type specific. Change in nuclear shape is seen during cell division, development and pathology. The nucleus of Saccharomycescerevisiae is spherical in interphase and becomes dumbbell shaped during mitotic division to facilitate the transfer of one nucleus to the daughter cell. Because yeast cells undergo closed mitosis, the nuclear envelope remains intact throughout the cell cycle. The pathways that regulate nuclear shape are not well characterized. The nucleus is organized into various subcompartments, with the nucleolus being the most prominent. We have conducted a candidate-based genetic screen for nuclear shape abnormalities in S. cerevisiae to ask whether the nucleolus influences nuclear shape. We find that increasing nucleolar volume triggers a non-isometric nuclear envelope expansion resulting in an abnormal nuclear envelope shape. We further show that the tethering of rDNA to the nuclear envelope is required for the appearance of these extensions.
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Affiliation(s)
- Gurranna Male
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| | - Pallavi Deolal
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| | - Naresh Kumar Manda
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| | - Shantam Yagnik
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research Hyderabad, 36/P, Gopanpally, Serilingampally Manda 500046l, Hyderabad, Telangana, India
| | - Aprotim Mazumder
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research Hyderabad, 36/P, Gopanpally, Serilingampally Manda 500046l, Hyderabad, Telangana, India
| | - Krishnaveni Mishra
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
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16
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Abstract
The size of the intracellular structure that encloses genomic DNA - known as the nucleus in eukaryotes and nucleoid in prokaryotes - is believed to scale according to cell size and genomic content inside them across the tree of life. However, an actual scaling relationship remains largely unexplored across eukaryotic species. Here, I collected a large dataset of nuclear and cell volumes in diverse species across different phyla, including some prokaryotes, from the published literature and assessed the scaling relationship. Although entire inter-species data showed that nuclear volume correlates with cell volume, the quantitative scaling property exhibited differences among prokaryotes, unicellular eukaryotes and multicellular eukaryotes. Additionally, the nuclear volume correlates with genomic content inside the nucleus of multicellular eukaryotes but not of prokaryotes and unicellular eukaryotes. In this Hypothesis, I, thus, propose that the basic concept of nuclear-size scaling is conserved across eukaryotes; however, structural and mechanical properties of nuclear membranes and chromatin can result in different scaling relationships of nuclear volume to cell volume and genomic content among species. In particular, eukaryote-specific properties of the nuclear membrane may contribute to the extreme flexibility of nuclear size with regard to DNA density inside the nucleus.
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Affiliation(s)
- Yuki Hara
- Evolutionary Cell Biology Laboratory, Faculty of Science, Yamaguchi University, Yoshida 1677-1, Yamaguchi city 753-8512, Japan
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17
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Le Goff X, Comelles J, Kervrann C, Riveline D. Ends and middle: Global force balance and septum location in fission yeast. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2020; 43:31. [PMID: 32474823 DOI: 10.1140/epje/i2020-11955-x] [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: 03/09/2020] [Accepted: 05/07/2020] [Indexed: 06/11/2023]
Abstract
The fission yeast cell is shaped as a very regular cylinder ending by hemi-spheres at both cell ends. Its conserved phenotypes are often used as read-outs for classifying interacting genes and protein networks. Using Pascal and Young-Laplace laws, we proposed a framework where scaling arguments predicted shapes. Here we probed quantitatively one of these relations which predicts that the division site would be located closer to the cell end with the larger radius of curvature. By combining genetics and quantitative imaging, we tested experimentally whether altered shapes of cell end correlate with a displaced division site, leading to asymmetric cell division. Our results show that the division site position depends on the radii of curvatures of both ends. This new geometrical mechanism for the proper division plane positioning could be essential to achieve even partitioning of cellular material at each cell division.
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Affiliation(s)
- Xavier Le Goff
- Univ. Rennes, CNRS, IGDR (Institut de génétique et développement de Rennes) - UMR 6290, F-35000, Rennes, France
| | - Jordi Comelles
- Laboratory of Cell Physics ISIS/IGBMC, ISIS & icFRC, Université de Strasbourg & CNRS, 8 allée Gaspard Monge, 67000, Strasbourg, France
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France
- Centre National de la Recherche Scientifique, UMR7104, Illkirch, France
- Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France
- Université de Strasbourg, Illkirch, France
| | - Charles Kervrann
- SERPICO Team, INRIA Rennes, Campus de Beaulieu, 35042, Rennes, France
| | - Daniel Riveline
- Laboratory of Cell Physics ISIS/IGBMC, ISIS & icFRC, Université de Strasbourg & CNRS, 8 allée Gaspard Monge, 67000, Strasbourg, France.
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France.
- Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.
- Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France.
- Université de Strasbourg, Illkirch, France.
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18
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Wesley CC, Mishra S, Levy DL. Organelle size scaling over embryonic development. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2020; 9:e376. [PMID: 32003549 DOI: 10.1002/wdev.376] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 12/19/2019] [Accepted: 01/08/2020] [Indexed: 12/13/2022]
Abstract
Cell division without growth results in progressive cell size reductions during early embryonic development. How do the sizes of intracellular structures and organelles scale with cell size and what are the functional implications of such scaling relationships? Model organisms, in particular Caenorhabditis elegans worms, Drosophila melanogaster flies, Xenopus laevis frogs, and Mus musculus mice, have provided insights into developmental size scaling of the nucleus, mitotic spindle, and chromosomes. Nuclear size is regulated by nucleocytoplasmic transport, nuclear envelope proteins, and the cytoskeleton. Regulators of microtubule dynamics and chromatin compaction modulate spindle and mitotic chromosome size scaling, respectively. Developmental scaling relationships for membrane-bound organelles, like the endoplasmic reticulum, Golgi, mitochondria, and lysosomes, have been less studied, although new imaging approaches promise to rectify this deficiency. While models that invoke limiting components and dynamic regulation of assembly and disassembly can account for some size scaling relationships in early embryos, it will be exciting to investigate the contribution of newer concepts in cell biology such as phase separation and interorganellar contacts. With a growing understanding of the underlying mechanisms of organelle size scaling, future studies promise to uncover the significance of proper scaling for cell function and embryonic development, as well as how aberrant scaling contributes to disease. This article is categorized under: Establishment of Spatial and Temporal Patterns > Regulation of Size, Proportion, and Timing Early Embryonic Development > Fertilization to Gastrulation Comparative Development and Evolution > Model Systems.
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Affiliation(s)
- Chase C Wesley
- Department of Molecular Biology, University of Wyoming, Laramie, Wyoming
| | - Sampada Mishra
- Department of Molecular Biology, University of Wyoming, Laramie, Wyoming
| | - Daniel L Levy
- Department of Molecular Biology, University of Wyoming, Laramie, Wyoming
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19
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Kume K. Control of cellular organization and its coordination with the cell cycle. Biosci Biotechnol Biochem 2020; 84:869-875. [PMID: 31987003 DOI: 10.1080/09168451.2020.1717926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Cells organize themselves to maintain proper shape, structure, and size during growth and division for their cellular functions. However, how these cellular organizations coordinate with the cell cycle is not well understood. This review focuses on cell morphogenesis and size of the membrane-bound nucleus in the fission yeast Schizosaccharomyces pombe. Growth polarity, an important factor for cell morphogenesis, in rod-shaped fission yeast is restricted to the cell tips and dynamically changes depending on the cell cycle stage. Furthermore, nuclear size in fission yeast is proportional to the cell size, resulting in a constant ratio between nuclear volume and cellular volume (N/C ratio). This review summarizes the signaling pathway(s) involved in growth polarity control and key factors involved in N/C ratio control and provides their roles in coordination between cell organization and the cell cycle.
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Affiliation(s)
- Kazunori Kume
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Japan
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20
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Maysinger D, Gran ER, Bertorelle F, Fakhouri H, Antoine R, Kaul ES, Samhadaneh DM, Stochaj U. Gold nanoclusters elicit homeostatic perturbations in glioblastoma cells and adaptive changes of lysosomes. Am J Cancer Res 2020; 10:1633-1648. [PMID: 32042327 PMCID: PMC6993243 DOI: 10.7150/thno.37674] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 10/03/2019] [Indexed: 01/07/2023] Open
Abstract
Unique physicochemical features place gold nanoclusters at the forefront of nanotechnology for biological and biomedical applications. To date, information on the interactions of gold nanoclusters with biological macromolecules is limited and restricts their use in living cells. Methods: Our multidisciplinary study begins to fill the current knowledge gap by focusing on lysosomes and associated biological pathways in U251N human glioblastoma cells. We concentrated on lysosomes, because they are the intracellular destination for many nanoparticles, regulate cellular homeostasis and control cell survival. Results: Quantitative data presented here show that gold nanoclusters (with 15 and 25 gold atoms), surface-modified with glutathione or PEG, did not diminish cell viability at concentrations ≤1 µM. However, even at sublethal concentrations, gold nanoclusters modulated the abundance, positioning, pH and enzymatic activities of lysosomes. Gold nanoclusters also affected other aspects of cellular homeostasis. Specifically, they stimulated the transient nuclear accumulation of TFEB and Nrf2, transcription factors that promote lysosome biogenesis and stress responses. Moreover, gold nanoclusters also altered the formation of protein aggregates in the cytoplasm. The cellular responses elicited by gold nanoclusters were largely reversible within a 24-hour period. Conclusions: Taken together, this study explores the subcellular and molecular effects induced by gold nanoclusters and shows their effectiveness to regulate lysosome biology. Our results indicate that gold nanoclusters cause homeostatic perturbations without marked cell loss. Notably, cells adapt to the challenge inflicted by gold nanoclusters. These new insights provide a framework for the further development of gold nanocluster-based applications in biological sciences.
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21
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Cantwell H, Nurse P. A homeostatic mechanism rapidly corrects aberrant nucleocytoplasmic ratios maintaining nuclear size in fission yeast. J Cell Sci 2019; 132:jcs.235911. [PMID: 31649142 PMCID: PMC6899009 DOI: 10.1242/jcs.235911] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 10/18/2019] [Indexed: 12/21/2022] Open
Abstract
Nuclear size scales with cell size across a wide range of cell types. The mechanism by which this scaling is maintained in growing cells remains unclear. Here, we investigate the mechanism of nuclear size homeostasis in the simple eukaryote fission yeast, by monitoring the recovery of aberrant nuclear volume to cell volume (N/C) ratios following perturbation. We demonstrate that both high and low N/C ratios correct rapidly, maintaining nuclear size homeostasis. We assess the kinetics of nuclear and cellular growth and of N/C ratio correction, and demonstrate that nuclear and cellular growth rates are not directly coupled. We propose that the mechanism underlying nuclear size homeostasis involves multiple limiting factors implicated in processes including nucleocytoplasmic transport, lipid biogenesis and RNA processing. We speculate that these link cellular size increases to changes in nuclear contents, which in turn lead to changes in nuclear membrane surface area. Our study reveals that there is rapid nuclear size homeostasis in cells, informing understanding of nuclear size control and size homeostasis of other membrane-bound organelles. Summary: Nuclear size homeostasis is achieved by a rapid correction mechanism modulating nuclear growth rate in growing fission yeast cells.
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Affiliation(s)
- Helena Cantwell
- Cell Cycle Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Paul Nurse
- Cell Cycle Laboratory, The Francis Crick Institute, London NW1 1AT, UK.,Laboratory of Yeast Genetics and Cell Biology, Rockefeller University, New York, NY 10065, USA
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22
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Abstract
Correlation between nuclear and cell size, the nucleocytoplasmic ratio, is a cellular phenomenon that has been reported throughout eukaryotes for more than a century but the mechanisms that achieve it are not well understood. Here, we review work that has shed light on the cellular processes involved in nuclear size control. These studies have implicated nucleocytoplasmic transport, LINC complexes, RNA processing, regulation of nuclear envelope expansion and partitioning of importin α in nuclear size control, moving us closer to a mechanistic understanding of this phenomenon.
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23
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Jevtić P, Schibler AC, Wesley CC, Pegoraro G, Misteli T, Levy DL. The nucleoporin ELYS regulates nuclear size by controlling NPC number and nuclear import capacity. EMBO Rep 2019; 20:embr.201847283. [PMID: 31085625 DOI: 10.15252/embr.201847283] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 04/09/2019] [Accepted: 04/11/2019] [Indexed: 12/13/2022] Open
Abstract
How intracellular organelles acquire their characteristic sizes is a fundamental question in cell biology. Given stereotypical changes in nuclear size in cancer, it is important to understand the mechanisms that control nuclear size in human cells. Using a high-throughput imaging RNAi screen, we identify and mechanistically characterize ELYS, a nucleoporin required for post-mitotic nuclear pore complex (NPC) assembly, as a determinant of nuclear size in mammalian cells. ELYS knockdown results in small nuclei, reduced nuclear lamin B2 localization, lower NPC density, and decreased nuclear import. Increasing nuclear import by importin α overexpression rescues nuclear size and lamin B2 import, while inhibiting importin α/β-mediated nuclear import decreases nuclear size. Conversely, ELYS overexpression increases nuclear size, enriches nuclear lamin B2 at the nuclear periphery, and elevates NPC density and nuclear import. Consistent with these observations, knockdown or inhibition of exportin 1 increases nuclear size. Thus, we identify ELYS as a novel positive effector of mammalian nuclear size and propose that nuclear size is sensitive to NPC density and nuclear import capacity.
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Affiliation(s)
- Predrag Jevtić
- Department of Molecular Biology, University of Wyoming, Laramie, WY, USA
| | | | - Chase C Wesley
- Department of Molecular Biology, University of Wyoming, Laramie, WY, USA
| | - Gianluca Pegoraro
- High Throughput Imaging Facility (HiTIF), National Cancer Institute, NIH, Bethesda, MD, USA
| | - Tom Misteli
- National Cancer Institute, NIH, Bethesda, MD, USA
| | - Daniel L Levy
- Department of Molecular Biology, University of Wyoming, Laramie, WY, USA
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