1
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Kono Y, Shimi T. Crosstalk between mitotic reassembly and repair of the nuclear envelope. Nucleus 2024; 15:2352203. [PMID: 38780365 PMCID: PMC11123513 DOI: 10.1080/19491034.2024.2352203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 05/01/2024] [Indexed: 05/25/2024] Open
Abstract
In eukaryotic cells, the nuclear envelope (NE) is a membrane partition between the nucleus and the cytoplasm to compartmentalize nuclear contents. It plays an important role in facilitating nuclear functions including transcription, DNA replication and repair. In mammalian cells, the NE breaks down and then reforms during cell division, and in interphase it is restored shortly after the NE rupture induced by mechanical force. In this way, the partitioning effect is regulated through dynamic processes throughout the cell cycle. A failure in rebuilding the NE structure triggers the mixing of nuclear and cytoplasmic contents, leading to catastrophic consequences for the nuclear functions. Whereas the precise details of molecular mechanisms for NE reformation during cell division and NE restoration in interphase are still being investigated, here, we mostly focus on mammalian cells to describe key aspects that have been identified and to discuss the crosstalk between them.
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Affiliation(s)
- Yohei Kono
- Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kanazawa, Japan
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | - Takeshi Shimi
- Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kanazawa, Japan
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2
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El Dika M, Dudka D, Kloc M, Kubiak JZ. CDC6 as a Key Inhibitory Regulator of CDK1 Activation Dynamics and the Timing of Mitotic Entry and Progression. BIOLOGY 2023; 12:855. [PMID: 37372141 DOI: 10.3390/biology12060855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 06/08/2023] [Accepted: 06/09/2023] [Indexed: 06/29/2023]
Abstract
Timely mitosis is critically important for early embryo development. It is regulated by the activity of the conserved protein kinase CDK1. The dynamics of CDK1 activation must be precisely controlled to assure physiologic and timely entry into mitosis. Recently, a known S-phase regulator CDC6 emerged as a key player in mitotic CDK1 activation cascade in early embryonic divisions, operating together with Xic1 as a CDK1 inhibitor upstream of the Aurora A and PLK1, both CDK1 activators. Herein, we review the molecular mechanisms that underlie the control of mitotic timing, with special emphasis on how CDC6/Xic1 function impacts CDK1 regulatory network in the Xenopus system. We focus on the presence of two independent mechanisms inhibiting the dynamics of CDK1 activation, namely Wee1/Myt1- and CDC6/Xic1-dependent, and how they cooperate with CDK1-activating mechanisms. As a result, we propose a comprehensive model integrating CDC6/Xic1-dependent inhibition into the CDK1-activation cascade. The physiological dynamics of CDK1 activation appear to be controlled by the system of multiple inhibitors and activators, and their integrated modulation ensures concomitantly both the robustness and certain flexibility of the control of this process. Identification of multiple activators and inhibitors of CDK1 upon M-phase entry allows for a better understanding of why cells divide at a specific time and how the pathways involved in the timely regulation of cell division are all integrated to precisely tune the control of mitotic events.
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Affiliation(s)
- Mohammed El Dika
- Department of Biochemistry, Larner College of Medicine, UVM Cancer Center, University of Vermont, Burlington, VT 05405, USA
| | - Damian Dudka
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Malgorzata Kloc
- The Houston Methodist Research Institute, Transplant Immunology, Houston, TX 77030, USA
- Department of Surgery, The Houston Methodist Hospital, Houston, TX 77030, USA
- Department of Genetics, MD Anderson Cancer Center, The University of Texas, Houston, TX 77030, USA
| | - Jacek Z Kubiak
- Laboratory of Molecular Oncology and Innovative Therapies, Military Institute of Medicine-National Research Institute (WIM-PIB), Szaserow 128, 04-141 Warsaw, Poland
- Dynamics and Mechanics of Epithelia Group, Faculty of Medicine, Institute of Genetics and Development of Rennes, University of Rennes, CNRS, UMR 6290, 35043 Rennes, France
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3
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Archambault V, Li J, Emond-Fraser V, Larouche M. Dephosphorylation in nuclear reassembly after mitosis. Front Cell Dev Biol 2022; 10:1012768. [PMID: 36268509 PMCID: PMC9576876 DOI: 10.3389/fcell.2022.1012768] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 08/31/2022] [Indexed: 11/13/2022] Open
Abstract
In most animal cell types, the interphase nucleus is largely disassembled during mitotic entry. The nuclear envelope breaks down and chromosomes are compacted into separated masses. Chromatin organization is also mostly lost and kinetochores assemble on centromeres. Mitotic protein kinases play several roles in inducing these transformations by phosphorylating multiple effector proteins. In many of these events, the mechanistic consequences of phosphorylation have been characterized. In comparison, how the nucleus reassembles at the end of mitosis is less well understood in mechanistic terms. In recent years, much progress has been made in deciphering how dephosphorylation of several effector proteins promotes nuclear envelope reassembly, chromosome decondensation, kinetochore disassembly and interphase chromatin organization. The precise roles of protein phosphatases in this process, in particular of the PP1 and PP2A groups, are emerging. Moreover, how these enzymes are temporally and spatially regulated to ensure that nuclear reassembly progresses in a coordinated manner has been partly uncovered. This review provides a global view of nuclear reassembly with a focus on the roles of dephosphorylation events. It also identifies important open questions and proposes hypotheses.
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Affiliation(s)
- Vincent Archambault
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC, Canada
- Département de Biochimie et Médecine Moléculaire, Université de Montréal, Montréal, QC, Canada
- *Correspondence: Vincent Archambault,
| | - Jingjing Li
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC, Canada
- Département de Biochimie et Médecine Moléculaire, Université de Montréal, Montréal, QC, Canada
| | - Virginie Emond-Fraser
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC, Canada
- Département de Biochimie et Médecine Moléculaire, Université de Montréal, Montréal, QC, Canada
| | - Myreille Larouche
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC, Canada
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4
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Samejima I, Spanos C, Samejima K, Rappsilber J, Kustatscher G, Earnshaw WC. Mapping the invisible chromatin transactions of prophase chromosome remodeling. Mol Cell 2022; 82:696-708.e4. [PMID: 35090599 PMCID: PMC8823707 DOI: 10.1016/j.molcel.2021.12.039] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 11/03/2021] [Accepted: 12/28/2021] [Indexed: 02/07/2023]
Abstract
We have used a combination of chemical genetics, chromatin proteomics, and imaging to map the earliest chromatin transactions during vertebrate cell entry into mitosis. Chicken DT40 CDK1as cells undergo synchronous mitotic entry within 15 min following release from a 1NM-PP1-induced arrest in late G2. In addition to changes in chromatin association with nuclear pores and the nuclear envelope, earliest prophase is dominated by changes in the association of ribonucleoproteins with chromatin, particularly in the nucleolus, where pre-rRNA processing factors leave chromatin significantly before RNA polymerase I. Nuclear envelope barrier function is lost early in prophase, and cytoplasmic proteins begin to accumulate on the chromatin. As a result, outer kinetochore assembly appears complete by nuclear envelope breakdown (NEBD). Most interphase chromatin proteins remain associated with chromatin until NEBD, after which their levels drop sharply. An interactive proteomic map of chromatin transactions during mitotic entry is available as a resource at https://mitoChEP.bio.ed.ac.uk.
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Affiliation(s)
- Itaru Samejima
- Wellcome Centre for Cell Biology, University of Edinburgh, Max Born Crescent, Edinburgh EH9 3BF, Scotland, UK
| | - Christos Spanos
- Wellcome Centre for Cell Biology, University of Edinburgh, Max Born Crescent, Edinburgh EH9 3BF, Scotland, UK
| | - Kumiko Samejima
- Wellcome Centre for Cell Biology, University of Edinburgh, Max Born Crescent, Edinburgh EH9 3BF, Scotland, UK
| | - Juri Rappsilber
- Wellcome Centre for Cell Biology, University of Edinburgh, Max Born Crescent, Edinburgh EH9 3BF, Scotland, UK; Technische Universität Berlin, Chair of Bioanalytics, 10623 Berlin, Germany
| | - Georg Kustatscher
- Institute of Quantitative Biology, Biochemistry and Biotechnology, University of Edinburgh, Max Born Crescent, Edinburgh EH9 3BF, Scotland, UK.
| | - William C Earnshaw
- Wellcome Centre for Cell Biology, University of Edinburgh, Max Born Crescent, Edinburgh EH9 3BF, Scotland, UK.
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5
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El Dika M, Fritz AJ, Toor RH, Rodriguez PD, Foley SJ, Ullah R, Nie D, Banerjee B, Lohese D, Glass KC, Frietze S, Ghule PN, Heath JL, Imbalzano AN, van Wijnen A, Gordon J, Lian JB, Stein JL, Stein GS, Stein GS. Epigenetic-Mediated Regulation of Gene Expression for Biological Control and Cancer: Fidelity of Mechanisms Governing the Cell Cycle. Results Probl Cell Differ 2022; 70:375-396. [PMID: 36348115 PMCID: PMC9703624 DOI: 10.1007/978-3-031-06573-6_13] [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: 11/09/2022]
Abstract
The cell cycle is governed by stringent epigenetic mechanisms that, in response to intrinsic and extrinsic regulatory cues, support fidelity of DNA replication and cell division. We will focus on (1) the complex and interdependent processes that are obligatory for control of proliferation and compromised in cancer, (2) epigenetic and topological domains that are associated with distinct phases of the cell cycle that may be altered in cancer initiation and progression, and (3) the requirement for mitotic bookmarking to maintain intranuclear localization of transcriptional regulatory machinery to reinforce cell identity throughout the cell cycle to prevent malignant transformation.
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Affiliation(s)
- Mohammed El Dika
- University of Vermont, UVM Cancer Center, Larner College of Medicine, Department of Biochemistry, Burlington, VT 05405
| | - Andrew J. Fritz
- University of Vermont, UVM Cancer Center, Larner College of Medicine, Department of Biochemistry, Burlington, VT 05405
| | - Rabail H. Toor
- University of Vermont, UVM Cancer Center, Larner College of Medicine, Department of Biochemistry, Burlington, VT 05405
| | | | - Stephen J. Foley
- University of Vermont, UVM Cancer Center, Larner College of Medicine, Department of Biochemistry, Burlington, VT 05405
| | - Rahim Ullah
- University of Vermont, UVM Cancer Center, Larner College of Medicine, Department of Biochemistry, Burlington, VT 05405
| | - Daijing Nie
- University of Vermont, UVM Cancer Center, Larner College of Medicine, Department of Biochemistry, Burlington, VT 05405
| | - Bodhisattwa Banerjee
- University of Vermont, UVM Cancer Center, Larner College of Medicine, Department of Biochemistry, Burlington, VT 05405
| | - Dorcas Lohese
- University of Vermont, UVM Cancer Center, Larner College of Medicine, Department of Biochemistry, Burlington, VT 05405
| | - Karen C. Glass
- University of Vermont, UVM Cancer Center, Larner College of Medicine, Department of Pharmacology, Burlington, VT 05405
| | - Seth Frietze
- University of Vermont, College of Nursing and Health Sciences, Burlington, VT 05405
| | - Prachi N. Ghule
- University of Vermont, UVM Cancer Center, Larner College of Medicine, Department of Biochemistry, Burlington, VT 05405
| | - Jessica L. Heath
- University of Vermont, UVM Cancer Center, Larner College of Medicine, Department of Biochemistry, Burlington, VT 05405,University of Vermont, Larner College of Medicine, Department of Pediatrics, Burlington, VT 05405
| | - Anthony N. Imbalzano
- UMass Chan Medical School, Department of Biochemistry and Molecular Biotechnology, Worcester, MA 01605
| | - Andre van Wijnen
- University of Vermont, UVM Cancer Center, Larner College of Medicine, Department of Biochemistry, Burlington, VT 05405
| | - Jonathan Gordon
- University of Vermont, UVM Cancer Center, Larner College of Medicine, Department of Biochemistry, Burlington, VT 05405
| | - Jane B. Lian
- University of Vermont, UVM Cancer Center, Larner College of Medicine, Department of Biochemistry, Burlington, VT 05405
| | - Janet L. Stein
- University of Vermont, UVM Cancer Center, Larner College of Medicine, Department of Biochemistry, Burlington, VT 05405
| | - Gary S. Stein
- University of Vermont, UVM Cancer Center, Larner College of Medicine, Department of Biochemistry, Burlington, VT 05405
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6
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Alvarado-Kristensson M, Rosselló CA. The Biology of the Nuclear Envelope and Its Implications in Cancer Biology. Int J Mol Sci 2019; 20:E2586. [PMID: 31137762 PMCID: PMC6566445 DOI: 10.3390/ijms20102586] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2019] [Revised: 05/07/2019] [Accepted: 05/25/2019] [Indexed: 12/18/2022] Open
Abstract
The formation of the nuclear envelope and the subsequent compartmentalization of the genome is a defining feature of eukaryotes. Traditionally, the nuclear envelope was purely viewed as a physical barrier to preserve genetic material in eukaryotic cells. However, in the last few decades, it has been revealed to be a critical cellular component in controlling gene expression and has been implicated in several human diseases. In cancer, the relevance of the cell nucleus was first reported in the mid-1800s when an altered nuclear morphology was observed in tumor cells. This review aims to give a current and comprehensive view of the role of the nuclear envelope on cancer first by recapitulating the changes of the nuclear envelope during cell division, second, by reviewing the role of the nuclear envelope in cell cycle regulation, signaling, and the regulation of the genome, and finally, by addressing the nuclear envelope link to cell migration and metastasis and its use in cancer prognosis.
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Affiliation(s)
- Maria Alvarado-Kristensson
- Molecular Pathology, Department of Translational Medicine, Lund University, Skåne University Hospital, 20502 Malmö, Sweden.
| | - Catalina Ana Rosselló
- Laboratory of Molecular Cell Biomedicine, University of the Balearic Islands, 07121 Palma de Mallorca, Spain.
- Lipopharma Therapeutics, Isaac Newton, 07121 Palma de Mallorca, Spain.
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7
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Champion L, Pawar S, Luithle N, Ungricht R, Kutay U. Dissociation of membrane-chromatin contacts is required for proper chromosome segregation in mitosis. Mol Biol Cell 2018; 30:427-440. [PMID: 30586323 PMCID: PMC6594442 DOI: 10.1091/mbc.e18-10-0609] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The nuclear envelope (NE) aids in organizing the interphase genome by tethering chromatin to the nuclear periphery. During mitotic entry, NE–chromatin contacts are broken. Here, we report on the consequences of impaired NE removal from chromatin for cell division of human cells. Using a membrane–chromatin tether that cannot be dissociated when cells enter mitosis, we show that a failure in breaking membrane–chromatin interactions impairs mitotic chromatin organization, chromosome segregation and cytokinesis, and induces an aberrant NE morphology in postmitotic cells. In contrast, chromosome segregation and cell division proceed successfully when membrane attachment to chromatin is induced during metaphase, after chromosomes have been singularized and aligned at the metaphase plate. These results indicate that the separation of membranes and chromatin is critical during prometaphase to allow for proper chromosome compaction and segregation. We propose that one cause of these defects is the multivalency of membrane–chromatin interactions.
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Affiliation(s)
- Lysie Champion
- Department of Biology, Institute of Biochemistry, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Sumit Pawar
- Department of Biology, Institute of Biochemistry, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Naemi Luithle
- Department of Biology, Institute of Biochemistry, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Rosemarie Ungricht
- Department of Biology, Institute of Biochemistry, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Ulrike Kutay
- Department of Biology, Institute of Biochemistry, ETH Zurich, CH-8093 Zurich, Switzerland
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8
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Paci M, Elkhatib R, Longepied G, Bourgeois P, Ray PF, Levy N, Mitchell MJ, Metzler-Guillemain C. The involvement of the nuclear lamina in human and rodent spermiogenesis: a systematic review. Basic Clin Androl 2018; 28:7. [PMID: 29946470 PMCID: PMC6008938 DOI: 10.1186/s12610-018-0072-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 04/19/2018] [Indexed: 12/11/2022] Open
Abstract
The nuclear lamina (NL) is a filamentous protein meshwork, composed essentially of lamins, situated between the inner nuclear membrane and the chromatin. The NL is a component of the nuclear envelope, interacts with a wide range of proteins and is required for normal nuclear structure and physiological development. During spermiogenesis the spermatid nucleus is elongated, and dramatically reduced in size with protamines replacing histones to produce a highly compacted chromatin. There is mounting evidence from studies in human and rodent, that the NL plays an important role in mammalian spermatid differentiation during spermiogenesis. In this review, we summarize and discuss the data available in the literature regarding the involvement of lamins and their direct or indirect partners in normal and abnormal human spermiogenesis.
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Affiliation(s)
- Marine Paci
- 1Aix Marseille Univ, Inserm, MMG, U1251, Marseille Medical Genetics, 13385 Marseille, France.,APHM Hôpital La Conception, Pôle femmes-Parents-enfants, Centre Clinico-Biologique d'Assistance Médicale à la Procréation-CECOS, 13385 Marseille Cedex 5, France
| | - Razan Elkhatib
- 1Aix Marseille Univ, Inserm, MMG, U1251, Marseille Medical Genetics, 13385 Marseille, France
| | - Guy Longepied
- 1Aix Marseille Univ, Inserm, MMG, U1251, Marseille Medical Genetics, 13385 Marseille, France
| | - Patrice Bourgeois
- 1Aix Marseille Univ, Inserm, MMG, U1251, Marseille Medical Genetics, 13385 Marseille, France
| | - Pierre F Ray
- 3Genetic Epigenetic and Therapies of Infertility, Institute for Advanced Biosciences, Inserm U1209, CNRS UMR 5309, Université Grenoble Alpes, CHU Grenoble Alpes, F-38000 Grenoble, France
| | - Nicolas Levy
- 1Aix Marseille Univ, Inserm, MMG, U1251, Marseille Medical Genetics, 13385 Marseille, France
| | - Michael J Mitchell
- 1Aix Marseille Univ, Inserm, MMG, U1251, Marseille Medical Genetics, 13385 Marseille, France
| | - Catherine Metzler-Guillemain
- 1Aix Marseille Univ, Inserm, MMG, U1251, Marseille Medical Genetics, 13385 Marseille, France.,APHM Hôpital La Conception, Pôle femmes-Parents-enfants, Centre Clinico-Biologique d'Assistance Médicale à la Procréation-CECOS, 13385 Marseille Cedex 5, France
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9
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Abstract
The eukaryotic nucleus is enclosed by the nuclear envelope, which is perforated by the nuclear pores, the gateways of macromolecular exchange between the nucleoplasm and cytoplasm. The nucleoplasm is organized in a complex three-dimensional fashion that changes over time and in response to stimuli. Within the cell, the nucleus must be viewed as an organelle (albeit a gigantic one) that is a recipient of cytoplasmic forces and capable of morphological and positional dynamics. The most dramatic reorganization of this organelle occurs during mitosis and meiosis. Although many of these aspects are less well understood for the nuclei of plants than for those of animals or fungi, several recent discoveries have begun to place our understanding of plant nuclei firmly into this broader cell-biological context.
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Affiliation(s)
- Iris Meier
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio 43210;
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford OX3 0BP, United Kingdom;
| | | | - David E Evans
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford OX3 0BP, United Kingdom;
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10
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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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11
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Patel JT, Bottrill A, Prosser SL, Jayaraman S, Straatman K, Fry AM, Shackleton S. Mitotic phosphorylation of SUN1 loosens its connection with the nuclear lamina while the LINC complex remains intact. Nucleus 2015; 5:462-73. [PMID: 25482198 PMCID: PMC4164488 DOI: 10.4161/nucl.36232] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
At the onset mitosis in higher eukaryotes, the nuclear envelope (NE) undergoes dramatic deconstruction to allow separation of duplicated chromosomes. Studies have shown that during this process of nuclear envelope breakdown (NEBD), the extensive protein networks of the nuclear lamina are disassembled through phosphorylation of lamins and several inner nuclear membrane (INM) proteins. The LINC complex, composed of SUN and nesprin proteins, is involved in multiple interactions at the NE and plays vital roles in nuclear and cellular mechanics by connecting the nucleus to the cytoskeleton. Here, we show that SUN1, located in the INM, undergoes mitosis-specific phosphorylation on at least 3 sites within its nucleoplasmic N-terminus. We further identify Cdk1 as the kinase responsible for serine 48 and 333 phosphorylation, while serine 138 is phosphorylated by Plk1. In mitotic cells, SUN1 loses its interaction with N-terminal domain binding partners lamin A/C, emerin, and short nesprin-2 isoforms. Furthermore, a triple phosphomimetic SUN1 mutant displays increased solubility and reduced retention at the NE. In contrast, the central LINC complex interaction between the SUN1 C-terminus and the KASH domain of nesprin-2 is maintained during mitosis. Together, these data support a model whereby mitotic phosphorylation of SUN1 disrupts interactions with nucleoplasmic binding partners, promoting disassembly of the nuclear lamina and, potentially, its chromatin interactions. At the same time, our data add to an emerging picture that the core LINC complex plays an active role in NEBD.
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Affiliation(s)
- Jennifer T Patel
- a Department of Biochemistry; University of Leicester; Leicester, UK
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12
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Gay S, Foiani M. Nuclear envelope and chromatin, lock and key of genome integrity. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2015; 317:267-330. [PMID: 26008788 DOI: 10.1016/bs.ircmb.2015.03.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
More than as an inert separation between the inside and outside of the nucleus, the nuclear envelope (NE) constitutes an active toll, which controls the import and export of molecules, and also a hub for a diversity of genomic processes, such as transcription, DNA repair, and chromatin dynamics. Proteins localized at the inner surface of the NE (such as lamins, nuclear pore proteins, lamin-associated proteins) interact with chromatin in a dynamic manner, contributing to the establishment of topological domains. In this review, we address the complex interplay between chromatin and NE. We discuss the divergence of this cross talk during evolution and comment both on the current established models and the most recent findings. In particular, we focus our attention on how the NE cooperates with chromatin in protecting the genome integrity.
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Affiliation(s)
- Sophie Gay
- IFOM, the FIRC Institute of Molecular Oncology, Milan, Italy
| | - Marco Foiani
- IFOM, the FIRC Institute of Molecular Oncology, Milan, Italy; Dipartimento di Scienze Biomolecolari e Biotecnologie, Università degli Studi di Milano, Milan, Italy
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13
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Abstract
There are many ways that the nuclear envelope can influence the cell cycle. In addition to roles of lamins in regulating the master cell cycle regulator pRb and nuclear envelope breakdown in mitosis, many other nuclear envelope proteins influence the cell cycle through regulatory or structural functions. Of particular note among these are the nuclear envelope transmembrane proteins (NETs) that appear to influence cell cycle regulation through multiple separate mechanisms. Some NETs and other nuclear envelope proteins accumulate on the mitotic spindle, suggesting functional or structural roles in the cell cycle. In interphase exogenous overexpression of some NETs promotes an increase in G1 populations, while others promote an increase in G2/M populations, sometimes associated with the induction of senescence. Intriguingly, most of the NETs linked to the cell cycle are highly restricted in their tissue expression; thus, their misregulation in cancer could contribute to the many tissue-specific types of cancer.
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14
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Building a nuclear envelope at the end of mitosis: coordinating membrane reorganization, nuclear pore complex assembly, and chromatin de-condensation. Chromosoma 2012; 121:539-54. [PMID: 23104094 PMCID: PMC3501164 DOI: 10.1007/s00412-012-0388-3] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Revised: 10/04/2012] [Accepted: 10/04/2012] [Indexed: 12/01/2022]
Abstract
The metazoan nucleus is disassembled and re-built at every mitotic cell division. The nuclear envelope, including nuclear pore complexes, breaks down at the beginning of mitosis to accommodate the capture of massively condensed chromosomes by the spindle apparatus. At the end of mitosis, a nuclear envelope is newly formed around each set of segregating and de-condensing chromatin. We review the current understanding of the membrane restructuring events involved in the formation of the nuclear membrane sheets of the envelope, the mechanisms governing nuclear pore complex assembly and integration in the nascent nuclear membranes, and the regulated coordination of these events with chromatin de-condensation.
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15
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Clever M, Funakoshi T, Mimura Y, Takagi M, Imamoto N. The nucleoporin ELYS/Mel28 regulates nuclear envelope subdomain formation in HeLa cells. Nucleus 2012; 3:187-99. [PMID: 22555603 PMCID: PMC3383574 DOI: 10.4161/nucl.19595] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
In open mitosis the nuclear envelope (NE) reassembles at the end of each mitosis. This process involves the reformation of the nuclear pore complex (NPC), the inner and outer nuclear membranes, and the nuclear lamina. In human cells cell cycle-dependent NE subdomains exist, characterized as A-type lamin-rich/NPC-free or B-type lamin-rich/NPC-rich, which are initially formed as core or noncore regions on mitotic chromosomes, respectively. Although postmitotic NE formation has been extensively studied, little is known about the coordination of NPC and NE assembly. Here, we report that the nucleoporin ELYS/Mel28, which is crucial for postmitotic NPC formation, is essential for recruiting the lamin B receptor (LBR) to the chromosomal noncore region. Furthermore, ELYS/Mel28 is responsible for focusing of A-type lamin-binding proteins like emerin, Lap2α and the barrier-to-autointegration factor (BAF) at the chromosomal core region. ELYS/Mel28 biochemically interacts with the LBR in a phosphorylation-dependent manner. Recruitment of the LBR depends on the nucleoporin Nup107, which interacts with ELYS/Mel28 but not on nucleoporin Pom121, suggesting that the specific molecular interactions with ELYS/Mel28 are involved in the NE assembly at the noncore region. The depletion of the LBR affected neither the behavior of emerin nor Lap2α indicating that the recruitment of the LBR to mitotic chromosomes is not involved in formation of the core region. The depletion of ELYS/Mel28 also accelerates the entry into cytokinesis after recruitment of emerin to chromosomes. Our data show that ELYS/Mel28 plays a role in NE subdomain formation in late mitosis.
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Affiliation(s)
- Michaela Clever
- Cellular Dynamics Laboratory; Riken Advanced Science Institute; Saitama, Japan
| | - Tomoko Funakoshi
- Cellular Dynamics Laboratory; Riken Advanced Science Institute; Saitama, Japan
- Live-Cell Molecular Imaging Research Team; Riken Advanced Science Institute; Saitama, Japan
| | - Yasuhiro Mimura
- Cellular Dynamics Laboratory; Riken Advanced Science Institute; Saitama, Japan
| | - Masatoshi Takagi
- Cellular Dynamics Laboratory; Riken Advanced Science Institute; Saitama, Japan
| | - Naoko Imamoto
- Cellular Dynamics Laboratory; Riken Advanced Science Institute; Saitama, Japan
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16
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Cohen S, Etingov I, Panté N. Effect of viral infection on the nuclear envelope and nuclear pore complex. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2012; 299:117-59. [PMID: 22959302 DOI: 10.1016/b978-0-12-394310-1.00003-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The nuclear envelope (NE) is a vital structure that separates the nucleus from the cytoplasm. Because the NE is such a critical cellular barrier, many viral pathogens have evolved to modulate its permeability. They do this either by breaching the NE or by disrupting the integrity and functionality of the nuclear pore complex (NPC). Viruses modulate NE permeability for different reasons. Some viruses disrupt NE to deliver the viral genome into the nucleus for replication, while others cause NE disruption during nuclear egress of newly assembled capsids. Yet, other viruses modulate NE permeability and affect the compartmentalization of host proteins or block the nuclear transport of host proteins involved in the host antiviral response. Recent scientific advances demonstrated that other viruses use proteins of the NPC for viral assembly or disassembly. Here we review the ways in which various viruses affect NE and NPC during infection.
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Affiliation(s)
- Sarah Cohen
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
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17
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Domart MC, Larijani B. Lipid-dependent and -independent regulation of nuclear envelope disassembly. J Chem Biol 2012; 6:3-5. [PMID: 24348875 DOI: 10.1007/s12154-012-0088-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Accepted: 11/22/2012] [Indexed: 11/29/2022] Open
Affiliation(s)
- Marie-Charlotte Domart
- Cell Biophysics Laboratory, Cancer Research UK, London Research Institute, 44 Lincoln's Inn Fields, London, WC2A 3LY UK
| | - Banafshé Larijani
- Cell Biophysics Laboratory, Cancer Research UK, London Research Institute, 44 Lincoln's Inn Fields, London, WC2A 3LY UK
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18
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Tseng LC, Chen RH. Temporal control of nuclear envelope assembly by phosphorylation of lamin B receptor. Mol Biol Cell 2011; 22:3306-17. [PMID: 21795390 PMCID: PMC3172257 DOI: 10.1091/mbc.e11-03-0199] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2011] [Revised: 07/06/2011] [Accepted: 07/18/2011] [Indexed: 01/13/2023] Open
Abstract
The nuclear envelope of metazoans disassembles during mitosis and reforms in late anaphase after sister chromatids have well separated. The coordination of these mitotic events is important for genome stability, yet the temporal control of nuclear envelope reassembly is unknown. Although the steps of nuclear formation have been extensively studied in vitro using the reconstitution system from egg extracts, the temporal control can only be studied in vivo. Here, we use time-lapse microscopy to investigate this process in living HeLa cells. We demonstrate that Cdk1 activity prevents premature nuclear envelope assembly and that phosphorylation of the inner nuclear membrane protein lamin B receptor (LBR) by Cdk1 contributes to the temporal control. We further identify a region in the nucleoplasmic domain of LBR that inhibits premature chromatin binding of the protein. We propose that this inhibitory effect is partly mediated by Cdk1 phosphorylation. Furthermore, we show that the reduced chromatin-binding ability of LBR together with Aurora B activity contributes to nuclear envelope breakdown. Our studies reveal for the first time a mechanism that controls the timing of nuclear envelope reassembly through modification of an integral nuclear membrane protein.
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Affiliation(s)
- Li-Chuan Tseng
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei 114, Taiwan
| | - Rey-Huei Chen
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei 114, Taiwan
- Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan
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19
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Lu X, Shi Y, Lu Q, Ma Y, Luo J, Wang Q, Ji J, Jiang Q, Zhang C. Requirement for lamin B receptor and its regulation by importin {beta} and phosphorylation in nuclear envelope assembly during mitotic exit. J Biol Chem 2010; 285:33281-33293. [PMID: 20576617 PMCID: PMC2963407 DOI: 10.1074/jbc.m110.102368] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2010] [Revised: 06/24/2010] [Indexed: 11/06/2022] Open
Abstract
Lamin B receptor (LBR), a chromatin and lamin B-binding protein in the inner nuclear membrane, has been proposed to target the membrane precursor vesicles to chromatin mediated by importin β during the nuclear envelope (NE) assembly. However, the mechanisms for the binding of LBR with importin β and the membrane targeting by LBR in NE assembly remain largely unknown. In this report, we show that the amino acids (aa) 69-90 of LBR sequences are required to bind with importin β at aa 45-462, and the binding is essential for the NE membrane precursor vesicle targeting to the chromatin during the NE assembly at the end of mitosis. We also show that this binding is cell cycle-regulated and dependent on the phosphorylation of LBR Ser-71 by p34(cdc2) kinase. RNAi knockdown of LBR causes the NE assembly failure and abnormal chromatin decondensation of the daughter cell nuclei, leading to the daughter cell death at early G(1) phase by apoptosis. Perturbation of the interaction of LBR with importin β by deleting the LBR N-terminal spanning region or aa 69-73 also induces the NE assembly failure, the abnormal chromatin decondensation, and the daughter cell death. The first transmembrane domain of LBR promotes the NE production and expansion, because overexpressing this domain is sufficient to induce membrane overproduction of the NE. Thus, these results demonstrate that LBR targets the membrane precursor vesicles to chromatin by interacting with importin β in a LBR phosphorylation-dependent manner during the NE assembly at the end of mitosis and that the first transmembrane domain of LBR promotes the LBR-bearing membrane production and the NE expansion in interphase.
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Affiliation(s)
- Xuelong Lu
- From the The Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education and the State Key Laboratory of Bio-membrane and Membrane Bio-engineering, Beijing 100871, China
| | - Yang Shi
- From the The Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education and the State Key Laboratory of Bio-membrane and Membrane Bio-engineering, Beijing 100871, China
| | - Quanlong Lu
- From the The Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education and the State Key Laboratory of Bio-membrane and Membrane Bio-engineering, Beijing 100871, China
| | - Yan Ma
- From the The Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education and the State Key Laboratory of Bio-membrane and Membrane Bio-engineering, Beijing 100871, China
| | - Jia Luo
- From the The Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education and the State Key Laboratory of Bio-membrane and Membrane Bio-engineering, Beijing 100871, China
| | - Qingsong Wang
- State Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Sciences, Peking University, Beijing 100871, China
| | - Jianguo Ji
- State Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Sciences, Peking University, Beijing 100871, China
| | - Qing Jiang
- From the The Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education and the State Key Laboratory of Bio-membrane and Membrane Bio-engineering, Beijing 100871, China
| | - Chuanmao Zhang
- From the The Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education and the State Key Laboratory of Bio-membrane and Membrane Bio-engineering, Beijing 100871, China.
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20
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Clayton P, Fischer B, Mann A, Mansour S, Rossier E, Veen M, Lang C, Baasanjav S, Kieslich M, Brossuleit K, Gravemann S, Schnipper N, Karbasyian M, Demuth I, Zwerger M, Vaya A, Utermann G, Mundlos S, Stricker S, Sperling K, Hoffmann K. Mutations causing Greenberg dysplasia but not Pelger anomaly uncouple enzymatic from structural functions of a nuclear membrane protein. Nucleus 2010; 1:354-66. [PMID: 21327084 PMCID: PMC3027044 DOI: 10.4161/nucl.1.4.12435] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2010] [Revised: 05/21/2010] [Accepted: 05/21/2010] [Indexed: 01/31/2023] Open
Abstract
The lamin B receptor (LBR) is an inner nuclear membrane protein with a structural function interacting with chromatin and lamins, and an enzymatic function as a sterol reductase. Heterozygous LBR mutations cause nuclear hyposegmentation in neutrophils (Pelger anomaly), while homozygous mutations cause prenatal death with skeletal defects and abnormal sterol metabolism (Greenberg dysplasia). It has remained unclear whether the lethality in Greenberg dysplasia is due to cholesterol defects or altered nuclear morphology.To answer this question we characterized two LBR missense mutations and showed that they cause Greenberg dysplasia. Both mutations affect residues that are evolutionary conserved among sterol reductases. In contrast to wildtype LBR, both mutations failed to rescue C14 sterol reductase deficient yeast, indicating an enzymatic defect. We found no Pelger anomaly in the carrier parent excluding marked effects on nuclear structure. We studied Lbr in mouse embryos and demonstrate expression in skin and the developing skeletal system consistent with sites of histological changes in Greenberg dysplasia. Unexpectedly we found in disease-relevant cell types not only nuclear but also cytoplasmatic LBR localization. The cytoplasmatic LBR staining co-localized with ER-markers and is thus consistent with the sites of endogeneous sterol synthesis. We conclude that LBR missense mutations can abolish sterol reductase activity, causing lethal Greenberg dysplasia but not Pelger anomaly. The findings separate the metabolic from the structural function and indicate that the sterol reductase activity is essential for human intrauterine development.
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Affiliation(s)
- Peter Clayton
- UCL Institute of Child Health with Great Ormond Street Hospital for ChildrenNHS Trust; London, UK
| | - Björn Fischer
- Institute for Medical Genetics; Charité University Medicine; Berlin, Germany
| | - Anuska Mann
- UCL Institute of Child Health with Great Ormond Street Hospital for ChildrenNHS Trust; London, UK
| | - Sahar Mansour
- SW Thames Regional Genetics Service; St. George's Hospital Medical School; University of London; London, UK
| | - Eva Rossier
- Humangenetik; Universitätsklinikum Tuebingen; Tuebingen, Germany
| | | | | | - Sevjidmaa Baasanjav
- Division of Nephrology; Department of Medicine, Neurology and Dermatology; University Hospital Leipzig; Leipzig, Germany
- Institute for Human Genetics; Charité University Medicine; Berlin, Germany
| | - Moritz Kieslich
- Institute for Human Genetics; Charité University Medicine; Berlin, Germany
| | - Katja Brossuleit
- Institute for Human Genetics; Charité University Medicine; Berlin, Germany
| | - Sophia Gravemann
- Institute for Human Genetics; Charité University Medicine; Berlin, Germany
| | - Nele Schnipper
- Institute for Human Genetics; Charité University Medicine; Berlin, Germany
| | - Mohsen Karbasyian
- Institute for Human Genetics; Charité University Medicine; Berlin, Germany
| | - Ilja Demuth
- Institute for Human Genetics; Charité University Medicine; Berlin, Germany
| | - Monika Zwerger
- B065 Functional Architecture of the Cell; German Cancer Research Center (DKFZ); Heidelberg, Germany
| | - Amparo Vaya
- Department of Clinical Pathology; La Fe University Hospital; Valencia, Spain
| | - Gerd Utermann
- Human Genetics; Department of Medical Genetics, Molecular and Clinical Pharmacology; Innsbruck, Austria
| | - Stefan Mundlos
- Institute for Medical Genetics; Charité University Medicine; Berlin, Germany
- Max Planck Institute for Molecular Genetics; Berlin, Germany
| | - Sigmar Stricker
- Max Planck Institute for Molecular Genetics; Berlin, Germany
| | - Karl Sperling
- Institute for Human Genetics; Charité University Medicine; Berlin, Germany
| | - Katrin Hoffmann
- Institute for Medical Genetics; Charité University Medicine; Berlin, Germany
- Institute for Human Genetics; Charité University Medicine; Berlin, Germany
- Max Planck Institute for Human Development; Berlin, Germany
- The Berlin Aging Study II; Research Group on Geriatrics; Charité University Medicine; Berlin, Germany
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21
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Errico A, Deshmukh K, Tanaka Y, Pozniakovsky A, Hunt T. Identification of substrates for cyclin dependent kinases. ACTA ACUST UNITED AC 2010; 50:375-99. [DOI: 10.1016/j.advenzreg.2009.12.001] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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22
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Olins AL, Rhodes G, Welch DBM, Zwerger M, Olins DE. Lamin B receptor: multi-tasking at the nuclear envelope. Nucleus 2010; 1:53-70. [PMID: 21327105 PMCID: PMC3035127 DOI: 10.4161/nucl.1.1.10515] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Revised: 11/01/2009] [Accepted: 11/04/2009] [Indexed: 12/11/2022] Open
Abstract
Lamin B receptor (LBR) is an integral membrane protein of the interphase nuclear envelope (NE). The N-terminal end resides in the nucleoplasm, binding to lamin B and heterochromatin, with the interactions disrupted during mitosis. The C-terminal end resides within the inner nuclear membrane, retreating with the ER away from condensing chromosomes during mitotic NE breakdown. Some of these properties are interpretable in terms of our current structural knowledge of LBR, but many of the structural features remain unknown. LBR apparently has an evolutionary history which brought together at least two ancient conserved structural domains (i.e., Tudor and sterol reductase). This convergence may have occurred with the emergence of the chordates and echinoderms. It is not clear what survival values have maintained LBR structure during evolution. But it seems likely that roles in post-mitotic nuclear reformation, interphase NE growth and compartmentalization of nuclear architecture might have provided some evolutionary advantage to preservation of the LBR gene.
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Affiliation(s)
- Ada L Olins
- Department of Biology, Bowdoin College, Brunswick, ME, USA
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23
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Orchestrating nuclear envelope disassembly and reassembly during mitosis. Nat Rev Mol Cell Biol 2009; 10:178-91. [PMID: 19234477 DOI: 10.1038/nrm2641] [Citation(s) in RCA: 340] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Cell division in eukaryotes requires extensive architectural changes of the nuclear envelope (NE) to ensure that segregated DNA is finally enclosed in a single cell nucleus in each daughter cell. Higher eukaryotic cells have evolved 'open' mitosis, the most extreme mechanism to solve the problem of nuclear division, in which the NE is initially completely disassembled and then reassembled in coordination with DNA segregation. Recent progress in the field has now started to uncover mechanistic and molecular details that underlie the changes in NE reorganization during open mitosis. These studies reveal a tight interplay between NE components and the mitotic machinery.
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24
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25
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Kutay U, Hetzer MW. Reorganization of the nuclear envelope during open mitosis. Curr Opin Cell Biol 2008; 20:669-77. [PMID: 18938243 DOI: 10.1016/j.ceb.2008.09.010] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2008] [Revised: 09/18/2008] [Accepted: 09/23/2008] [Indexed: 01/08/2023]
Abstract
The nuclear envelope (NE) provides a selective barrier between the nuclear interior and the cytoplasm and constitutes a central component of intracellular architecture. During mitosis in metazoa, the NE breaks down leading to the complete mixing of the nuclear content with the cytosol. Interestingly, many NE components actively participate in mitotic progression. After chromosome segregation, the NE is reassembled around decondensing chromatin and the nuclear compartment is reestablished in the daughter cells. Here, we summarize recent progress in deciphering the molecular mechanisms underlying NE dynamics during cell division.
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Affiliation(s)
- Ulrike Kutay
- Institute of Biochemistry, ETH Zurich, HPM F11.1, Schafmattstr.18, 8093 Zurich, Switzerland.
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26
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Salpingidou G, Rzepecki R, Kiseleva E, Lyon C, Lane B, Fusiek K, Golebiewska A, Drummond S, Allen T, Ellis JA, Smythe C, Goldberg MW, Hutchison CJ. NEP-A and NEP-B both contribute to nuclear pore formation in Xenopus eggs and oocytes. J Cell Sci 2008; 121:706-16. [PMID: 18270266 DOI: 10.1242/jcs.019968] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
In vertebrates, the nuclear envelope (NE) assembles and disassembles during mitosis. As the NE is a complex structure consisting of inner and outer membranes, nuclear pore complexes (NPCs) and the nuclear lamina, NE assembly must be a controlled and systematic process. In Xenopus egg extracts, NE assembly is mediated by two distinct membrane vesicle populations, termed NEP-A and NEP-B. Here, we re-investigate how these two membrane populations contribute to NPC assembly. In growing stage III Xenopus oocytes, NPC assembly intermediates are frequently observed. High concentrations of NPC assembly intermediates always correlate with fusion of vesicles into preformed membranes. In Xenopus egg extracts, two integral membrane proteins essential for NPC assembly, POM121 and NDC1, are exclusively associated with NEP-B membranes. By contrast, a third integral membrane protein associated with the NPCs, gp210, associates only with NEP-A membranes. During NE assembly, fusion between NEP-A and NEP-B led to the formation of fusion junctions at which >65% of assembling NPCs were located. To investigate how each membrane type contributes to NPC assembly, we preferentially limited NEP-A in NE assembly assays. We found that, by limiting the NEP-A contribution to the NE, partially formed NPCs were assembled in which protein components of the nucleoplasmic face were depleted or absent. Our data suggest that fusion between NEP-A and NEP-B membranes is essential for NPC assembly and that, in contrast to previous reports, both membranes contribute to NPC assembly.
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Affiliation(s)
- Georgia Salpingidou
- Integrative Cell Biology Laboratories, School of Biological and Biomedical Sciences, The University of Durham, South Road, Durham DH1 3LE, UK
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27
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Mühlhäusser P, Kutay U. An in vitro nuclear disassembly system reveals a role for the RanGTPase system and microtubule-dependent steps in nuclear envelope breakdown. ACTA ACUST UNITED AC 2007; 178:595-610. [PMID: 17698605 PMCID: PMC2064467 DOI: 10.1083/jcb.200703002] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
During prophase, vertebrate cells disassemble their nuclear envelope (NE) in the process of NE breakdown (NEBD). We have established an in vitro assay that uses mitotic Xenopus laevis egg extracts and semipermeabilized somatic cells bearing a green fluorescent protein–tagged NE marker to study the molecular requirements underlying the dynamic changes of the NE during NEBD by live microscopy. We applied our in vitro system to analyze the role of the Ran guanosine triphosphatase (GTPase) system in NEBD. Our study shows that high levels of RanGTP affect the dynamics of late steps of NEBD in vitro. Also, inhibition of RanGTP production by RanT24N blocks the dynamic rupture of nuclei, suggesting that the local generation of RanGTP around chromatin may serve as a spatial cue in NEBD. Furthermore, the microtubule-depolymerizing drug nocodazole interferes with late steps of nuclear disassembly in vitro. High resolution live cell imaging reveals that microtubules are involved in the completion of NEBD in vivo by facilitating the efficient removal of membranes from chromatin.
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28
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Cox LS, Faragher RGA. From old organisms to new molecules: integrative biology and therapeutic targets in accelerated human ageing. Cell Mol Life Sci 2007; 64:2620-41. [PMID: 17660942 PMCID: PMC2773833 DOI: 10.1007/s00018-007-7123-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Understanding the basic biology of human ageing is a key milestone in attempting to ameliorate the deleterious consequences of old age. This is an urgent research priority given the global demographic shift towards an ageing population. Although some molecular pathways that have been proposed to contribute to ageing have been discovered using classical biochemistry and genetics, the complex, polygenic and stochastic nature of ageing is such that the process as a whole is not immediately amenable to biochemical analysis. Thus, attempts have been made to elucidate the causes of monogenic progeroid disorders that recapitulate some, if not all, features of normal ageing in the hope that this may contribute to our understanding of normal human ageing. Two canonical progeroid disorders are Werner's syndrome and Hutchinson-Gilford progeroid syndrome (also known as progeria). Because such disorders are essentially phenocopies of ageing, rather than ageing itself, advances made in understanding their pathogenesis must always be contextualised within theories proposed to help explain how the normal process operates. One such possible ageing mechanism is described by the cell senescence hypothesis of ageing. Here, we discuss this hypothesis and demonstrate that it provides a plausible explanation for many of the ageing phenotypes seen in Werner's syndrome and Hutchinson-Gilford progeriod syndrome. The recent exciting advances made in potential therapies for these two syndromes are also reviewed.
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Affiliation(s)
- L. S. Cox
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU UK
| | - R. G. A. Faragher
- School of Pharmacy and Biomolecular Science, University of Brighton, Cockcroft Building, Moulescoomb, Brighton, BN2 4GJ UK
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29
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Graumann K, Irons SL, Runions J, Evans DE. Retention and mobility of the mammalian lamin B receptor in the plant nuclear envelope. Biol Cell 2007; 99:553-62. [PMID: 17868028 DOI: 10.1042/bc20070033] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND INFORMATION In a previous study, we showed that GFP (green fluorescent protein) fused to the N-terminal 238 amino acids of the mammalian LBR (lamin B receptor) localized to the NE (nuclear envelope) when expressed in the plant Nicotiana tabacum. The protein was located in the NE during interphase and migrated with nuclear membranes during cell division. Targeting and retention of inner NE proteins requires several mechanisms: signals that direct movement through the nuclear pore complex, presence of a transmembrane domain or domains and retention by interaction with nuclear or nuclear-membrane constituents. RESULTS Binding mutants of LBR-GFP were produced to investigate the mechanisms for the retention of LBR in the NE. FRAP (fluorescence recovery after photobleaching) analysis of mutant and wild-type constructs was employed to examine the retention of LBR-GFP in the plant NE. wtLBR-GFP (wild-type LBR-GFP) was shown to have significantly lower mobility in the NE than the lamin-binding domain deletion mutant, which showed increased mobility in the NE and was also localized to the endoplasmic reticulum and punctate structures in some cells. Modification of the chromatin-binding domain resulted in the localization of the protein in nuclear inclusions, in which it was immobile. CONCLUSIONS As expression of truncated LBR-GFP in plant cells results in altered targeting and retention compared with wtLBR-GFP, we conclude that plant cells can recognize the INE (inner NE)-targeting motif of LBR. The altered mobility of the truncated protein suggests that not only do plant cells recognize this signal, but also have nuclear proteins that interact weakly with LBR.
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Affiliation(s)
- Katja Graumann
- Research School of Life Sciences, Oxford Brookes University, Gipsy Lane, Oxford OX3 0BP, UK
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30
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Leach N, Bjerke SL, Christensen DK, Bouchard JM, Mou F, Park R, Baines J, Haraguchi T, Roller RJ. Emerin is hyperphosphorylated and redistributed in herpes simplex virus type 1-infected cells in a manner dependent on both UL34 and US3. J Virol 2007; 81:10792-803. [PMID: 17652388 PMCID: PMC2045475 DOI: 10.1128/jvi.00196-07] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Cells infected with wild-type herpes simplex virus type 1 (HSV-1) show disruption of the organization of the nuclear lamina that underlies the nuclear envelope. This disruption is reflected in changes in the localization and phosphorylation of lamin proteins. Here, we show that HSV-1 infection causes relocalization of the LEM domain protein emerin. In cells infected with wild-type virus, emerin becomes more mobile in the nuclear membrane, and in cells infected with viruses that fail to express UL34 protein (pUL34) and US3 protein (pUS3), emerin no longer colocalizes with lamins, suggesting that infection causes a loss of connection between emerin and the lamina. Infection causes hyperphosphorylation of emerin in a manner dependent upon both pUL34 and pUS3. Some emerin hyperphosphorylation can be inhibited by the protein kinase Cdelta (PKCdelta) inhibitor rottlerin. Emerin and pUL34 interact physically, as shown by pull-down and coimmunoprecipitation assays. Emerin expression is not, however, necessary for infection, since virus growth is not impaired in cells derived from emerin-null transgenic mice. The results suggest a model in which pUS3 and PKCdelta that has been recruited by pUL34 hyperphosphorylate emerin, leading to disruption of its connections with lamin proteins and contributing to the disruption of the nuclear lamina. Changes in emerin localization, nuclear shape, and lamin organization characteristic of cells infected with wild-type HSV-1 also occur in cells infected with recombinant virus that does not make viral capsids, suggesting that these changes occur independently of capsid envelopment.
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Affiliation(s)
- Natalie Leach
- Department of Microbiology, The University of Iowa, 3-432 Bowen Science Building, Iowa City, IA 52242, USA
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31
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Curry CL, Reed LL, Broude E, Golde TE, Miele L, Foreman KE. Notch inhibition in Kaposi's sarcoma tumor cells leads to mitotic catastrophe through nuclear factor-κB signaling. Mol Cancer Ther 2007; 6:1983-92. [PMID: 17604336 DOI: 10.1158/1535-7163.mct-07-0093] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Kaposi's sarcoma (KS) is the most common neoplasm in untreated AIDS patients and accounts for significant morbidity and mortality worldwide. We have recently reported that Notch signaling (which plays an important role in cell proliferation, apoptosis, and oncogenesis) is constitutively activated in KS tumor cells. Blockade of this activity using γ-secretase inhibitors resulted in apoptosis of SLK cells, a KS tumor cell line; however, this apoptosis was preceded by a prolonged G2-M cell cycle arrest. This result led us to hypothesize that the cells were undergoing mitotic catastrophe, an abnormal mitosis that leads to eventual cell death. Here, we show that Notch inhibition in KS tumor cells using γ-secretase inhibitors or Notch-1 small interfering RNA resulted in G2-M cell cycle arrest and mitotic catastrophe characterized by the presence of micronucleated cells and an increased mitotic index. Interestingly, Notch inhibition led to a sustained increase in nuclear cyclin B1, a novel observation suggesting that Notch signaling can modulate expression of this critical cell cycle protein. Further analysis showed the induction of cyclin B1 was due, at least in part, to increased nuclear factor-κB (NF-κB) activity, which was also required for the G2-M growth arrest after Notch inhibition. Taken together, these studies suggest that Notch inhibition can initiate aberrant mitosis by inducing NF-κB activity that inappropriately increases cyclin B1 resulting in cell death via mitotic catastrophe. [Mol Cancer Ther 2007;6(7):1983–92]
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Affiliation(s)
- Christine L Curry
- Department of Pathology, Cardinal Bernardin Cancer Center, Loyola University Chicago, 2160 South First Avenue, Maywood, IL 60153, USA
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Kato A, Yamamoto M, Ohno T, Tanaka M, Sata T, Nishiyama Y, Kawaguchi Y. Herpes simplex virus 1-encoded protein kinase UL13 phosphorylates viral Us3 protein kinase and regulates nuclear localization of viral envelopment factors UL34 and UL31. J Virol 2006; 80:1476-86. [PMID: 16415024 PMCID: PMC1346963 DOI: 10.1128/jvi.80.3.1476-1486.2006] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UL13 and Us3 are protein kinases encoded by herpes simplex virus 1. We report here that Us3 is a physiological substrate for UL13 in infected cells, based on the following observations. (i) The electrophoretic mobility, in denaturing gels, of Us3 isoforms from Vero cells infected with wild-type virus was slower than that of isoforms from cells infected with a UL13 deletion mutant virus (DeltaUL13). After treatment with phosphatase, the electrophoretic mobility of the Us3 isoforms from cells infected with wild-type virus changed, with one isoform migrating as fast as one of the Us3 isoforms from DeltaUL13-infected cells. (ii) A recombinant protein containing a domain of Us3 was phosphorylated by UL13 in vitro. (iii) The phenotype of DeltaUL13 resembles that of a recombinant virus lacking the Us3 gene (DeltaUs3) with respect to localization of the viral envelopment factors UL34 and UL31, whose localization has been shown to be regulated by Us3. UL34 and UL31 are localized in a smooth pattern throughout the nuclei of cells infected with wild-type virus, whereas their localization in DeltaUL13- and DeltaUs3-infected cells appeared as nuclear punctate patterns. These results indicate that UL13 phosphorylates Us3 in infected cells and regulates UL34 and UL31 localization, either by phosphorylating Us3 or by a Us3-independent mechanism.
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Affiliation(s)
- Akihisa Kato
- Department of Infectious Disease Control, International Research Center for Infectious Diseases, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
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Hetzer MW, Walther TC, Mattaj IW. PUSHING THE ENVELOPE: Structure, Function, and Dynamics of the Nuclear Periphery. Annu Rev Cell Dev Biol 2005; 21:347-80. [PMID: 16212499 DOI: 10.1146/annurev.cellbio.21.090704.151152] [Citation(s) in RCA: 253] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The nuclear envelope (NE) is a highly specialized membrane that delineates the eukaryotic cell nucleus. It is composed of the inner and outer nuclear membranes, nuclear pore complexes (NPCs) and, in metazoa, the lamina. The NE not only regulates the trafficking of macromolecules between nucleoplasm and cytosol but also provides anchoring sites for chromatin and the cytoskeleton. Through these interactions, the NE helps position the nucleus within the cell and chromosomes within the nucleus, thereby regulating the expression of certain genes. The NE is not static, rather it is continuously remodeled during cell division. The most dramatic example of NE reorganization occurs during mitosis in metazoa when the NE undergoes a complete cycle of disassembly and reformation. Despite the importance of the NE for eukaryotic cell life, relatively little is known about its biogenesis or many of its functions. We thus are far from understanding the molecular etiology of a diverse group of NE-associated diseases.
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Affiliation(s)
- Martin W Hetzer
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, California 92037, USA.
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Worman HJ, Courvalin JC. Nuclear envelope, nuclear lamina, and inherited disease. INTERNATIONAL REVIEW OF CYTOLOGY 2005; 246:231-79. [PMID: 16164970 DOI: 10.1016/s0074-7696(05)46006-4] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The nuclear envelope is composed of the nuclear membranes, nuclear lamina, and nuclear pore complexes. In recent years, mutations in nuclear-envelope proteins have been shown to cause a surprisingly wide array of inherited diseases. While the mutant proteins are generally expressed in most or all differentiated somatic cells, many mutations cause fairly tissue-specific disorders. Perhaps the most dramatic case is that of mutations in A-type lamins, intermediate filament proteins associated with the inner nuclear membrane. Different mutations in the same lamin proteins have been shown to cause striated muscle diseases, partial lipodystrophy syndromes, a peripheral neuropathy, and disorders with features of severe premature aging. In this review, we summarize fundamental aspects of nuclear envelope structure and function, the inherited diseases caused by mutations in lamins and other nuclear envelope proteins, and possible pathogenic mechanisms.
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Affiliation(s)
- Howard J Worman
- Department of Medicine and Department of Anatomy and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, New York 10032, USA
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Olsson M, English MA, Mason J, Licht JD, Ekblom P. Despite WT1 binding sites in the promoter region of human and mouse nucleoporin glycoprotein 210, WT1 does not influence expression of GP210. J Negat Results Biomed 2004; 3:7. [PMID: 15613247 PMCID: PMC544869 DOI: 10.1186/1477-5751-3-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2004] [Accepted: 12/21/2004] [Indexed: 11/10/2022] Open
Abstract
Background Glycoprotein 210 (GP210) is a transmembrane component of the nuclear pore complex of metazoans, with a short carboxyterminus protruding towards the cytoplasm. Its function is unknown, but it is considered to be a major structural component of metazoan nuclear pores. Yet, our previous findings showed pronounced differences in expression levels in embryonic mouse tissues and cell lines. In order to identify factors regulating GP210, the genomic organization of human GP210 was analyzed in silico. Results The human gene was mapped to chromosome 3 and consists of 40 exons spread over 102 kb. The deduced 1887 amino acid showed a high degree of alignment homology to previously reported orthologues. Experimentally we defined two transcription initiation sites, 18 and 29 bp upstream of the ATG start codon. The promoter region is characterized by a CpG island and several consensus binding motifs for gene regulatory transcription factors, including clustered sites associated with Sp1 and the Wilms' tumor suppressor gene zinc finger protein (WT1). In addition, distal to the translation start we found a (GT)n repetitive sequence, an element known for its ability to bind WT1. Homologies for these motifs could be identified in the corresponding mouse genomic region. However, experimental tetracycline dependent induction of WT1 in SAOS osteosarcoma cells did not influence GP210 transcription. Conclusion Although mouse GP210 was identified as an early response gene during induced metanephric kidney development, and WT1 binding sites were identified in the promoter region of the human GP210 gene, experimental modulation of WT1 expression did not influence expression of GP210. Therefore, WT1 is probably not regulating GP210 expression. Instead, we suggest that the identified Sp binding sites are involved.
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Affiliation(s)
- Magnus Olsson
- Department of Cell and Molecular Biology, Section for Cell and Developmental Biology, Lund University, Sweden
| | - Milton A English
- Mount Sinai School of Medicine, 1425 Madison Avenue, New York, NY 10029, USA
| | - Jacqueline Mason
- Mount Sinai School of Medicine, 1425 Madison Avenue, New York, NY 10029, USA
| | - Jonathan D Licht
- Mount Sinai School of Medicine, 1425 Madison Avenue, New York, NY 10029, USA
| | - Peter Ekblom
- Department of Cell and Molecular Biology, Section for Cell and Developmental Biology, Lund University, Sweden
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36
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Gerace L, Foisner R. Integral membrane proteins and dynamic organization of the nuclear envelope. Trends Cell Biol 2004; 4:127-31. [PMID: 14731735 DOI: 10.1016/0962-8924(94)90067-1] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The nuclear envelope is a complex structure consisting of nuclear membranes, nuclear pore complexes and lamina. Several integral membrane proteins specific to the nuclear pore membrane and the inner nuclear membrane are known. Pore membrane proteins are probably important for organization and assembly of the nuclear pore complex, while proteins of the inner nuclear membrane are likely to play major roles in the structure and dynamics of the nuclear lamina and chromatin. Biochemical studies are now identifying potential binding partners for some of these integral membrane proteins, and analysis of nuclear envelope assembly at the end of mitosis is providing important insights into their functions.
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Affiliation(s)
- L Gerace
- Department of Cell Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
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37
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Ryckman BJ, Roller RJ. Herpes simplex virus type 1 primary envelopment: UL34 protein modification and the US3-UL34 catalytic relationship. J Virol 2004; 78:399-412. [PMID: 14671121 PMCID: PMC303423 DOI: 10.1128/jvi.78.1.399-412.2004] [Citation(s) in RCA: 135] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The herpes simplex virus type 1 (HSV-1) US3 kinase is likely important for primary envelopment of progeny nucleocapsids since it localizes to the nuclear envelope of infected cells and largely determines the phosphorylation state and localization of the necessary primary envelopment factor, the UL34 protein. In HEp-2 cells, the production of infectious US3 null progeny is delayed and decreased relative to that of the parental strain, HSV-1(F). Furthermore, the US3 kinase affects the morphology of primary envelopment such that in its absence, UL34 protein-containing enveloped virions accumulate within membrane-bound vesicles. These vesicles are most often found along the interior periphery of the nucleus and may be derived from the inner nuclear membrane. Since the US3 and UL34 proteins comprise a kinase-substrate pair, a reasonable hypothesis is that the US3 kinase influences these replication parameters by direct phosphorylation of the UL34 protein. For this report, recombinant viruses were constructed to determine the significance of UL34 protein phosphorylation and US3 catalytic activity on UL34 protein localization, single-step growth, and envelopment morphology in both HEp-2 and Vero cells. The data presented suggest that the significance of UL34 phosphorylation is cell type dependent and that efficient viral morphogenesis requires US3-mediated phosphorylation of an infected cell protein other than UL34.
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Affiliation(s)
- Brent J Ryckman
- Department of Microbiology, University of Iowa, Iowa City, Iowa 52246, USA
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38
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Steen RL, Beullens M, Landsverk HB, Bollen M, Collas P. AKAP149 is a novel PP1 specifier required to maintain nuclear envelope integrity in G1 phase. J Cell Sci 2003; 116:2237-46. [PMID: 12697839 DOI: 10.1242/jcs.00432] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Reassembly of the nuclear envelope (NE) at the end of mitosis requires targeting of the B-type lamin protein phosphatase, PP1, to the envelope by A-kinase anchoring protein AKAP149. We show here that NE-associated AKAP149 is a novel PP1-specifying subunit involved in maintaining nuclear architecture through G1 phase. PP1 remains associated with NE-bound AKAP149 during G1 but is released from AKAP149 upon S phase entry, as AKAP149 becomes serine-phosphorylated. NE-associated AKAP149 inhibits PP1 activity towards glycogen phosphorylase but enhances PP1 phosphatase activity towards B-type lamins, indicating that AKAP149 is a B-type lamin specifying subunit of PP1. In vivo dissociation of PP1 from NE-bound AKAP149 in G1-phase nuclei triggers phosphorylation and depolymerization of A- and B-type lamins. The lamins solubilize intranuclearly without affecting the inner nuclear membrane or pore complex distribution. This correlates with the induction of a G1 arrest and, ultimately, apoptosis. We propose that AKAP149-regulated PP1 activity at the NE during G1 is required to maintain nuclear integrity and cell survival.
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Affiliation(s)
- Rikke L Steen
- Institute of Medical Biochemistry, University of Oslo, PO Box 1112 Blindern, 0317 Oslo, Norway
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39
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Vermeulen K, Van Bockstaele DR, Berneman ZN. The cell cycle: a review of regulation, deregulation and therapeutic targets in cancer. Cell Prolif 2003; 36:131-49. [PMID: 12814430 PMCID: PMC6496723 DOI: 10.1046/j.1365-2184.2003.00266.x] [Citation(s) in RCA: 1130] [Impact Index Per Article: 53.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2003] [Accepted: 06/02/2003] [Indexed: 12/15/2022] Open
Abstract
The cell cycle is controlled by numerous mechanisms ensuring correct cell division. This review will focus on these mechanisms, i.e. regulation of cyclin-dependent kinases (CDK) by cyclins, CDK inhibitors and phosphorylating events. The quality checkpoints activated after DNA damage are also discussed. The complexity of the regulation of the cell cycle is also reflected in the different alterations leading to aberrant cell proliferation and development of cancer. Consequently, targeting the cell cycle in general and CDK in particular presents unique opportunities for drug discovery. This review provides an overview of deregulation of the cell cycle in cancer. Different families of known CDK inhibitors acting by ATP competition are also discussed. Currently, at least three compounds with CDK inhibitory activity (flavopiridol, UCN-01, roscovitine) have entered clinical trials.
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Affiliation(s)
- Katrien Vermeulen
- Faculty of Medicine, Laboratory of Experimental Hematology, University of Antwerp, Antwerp University Hospital, Edegem, Belgium
| | - Dirk R. Van Bockstaele
- Faculty of Medicine, Laboratory of Experimental Hematology, University of Antwerp, Antwerp University Hospital, Edegem, Belgium
| | - Zwi N. Berneman
- Faculty of Medicine, Laboratory of Experimental Hematology, University of Antwerp, Antwerp University Hospital, Edegem, Belgium
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40
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Courvalin JC, Rabouille C. Réorganisation des compartiments intracellulaires membranaires pendant la mitose. Med Sci (Paris) 2002. [DOI: 10.1051/medsci/200218101017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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41
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Hetzer M, Gruss OJ, Mattaj IW. The Ran GTPase as a marker of chromosome position in spindle formation and nuclear envelope assembly. Nat Cell Biol 2002; 4:E177-84. [PMID: 12105431 DOI: 10.1038/ncb0702-e177] [Citation(s) in RCA: 179] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The small GTPase Ran is a key regulator of nucleocytoplasmic transport during interphase. The asymmetric distribution of the GTP-bound form of Ran across the nuclear envelope--that is, large quantities in the nucleus compared with small quantities in the cytoplasm--determines the directionality of many nuclear transport processes. Recent findings that Ran also functions in spindle formation and nuclear envelope assembly during mitosis suggest that Ran has a general role in chromatin-centred processes. Ran functions in these events as a signal for chromosome position.
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Affiliation(s)
- Martin Hetzer
- European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany
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42
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Beaudouin J, Gerlich D, Daigle N, Eils R, Ellenberg J. Nuclear envelope breakdown proceeds by microtubule-induced tearing of the lamina. Cell 2002; 108:83-96. [PMID: 11792323 DOI: 10.1016/s0092-8674(01)00627-4] [Citation(s) in RCA: 338] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The mechanism of nuclear envelope breakdown (NEBD) was investigated in live cells. Early spindle microtubules caused folds and invaginations in the NE up to one hour prior to NEBD, creating mechanical tension in the nuclear lamina. The first gap in the NE appeared before lamin B depolymerization, at the site of maximal tension, by a tearing mechanism. Gap formation relaxed this tension and dramatically accelerated the rate of chromosome condensation. The hole produced in the NE then rapidly expanded over the nuclear surface. NE fragments remaining on chromosomes were removed toward the centrosomes in a microtubule-dependent manner, suggesting a mechanism mediated by a minus-end-directed motor.
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Affiliation(s)
- Joël Beaudouin
- Gene Expression and Cell Biology/Biophysics Programmes, European Molecular Biology Laboratory, D-69117. Heidelberg, Germany
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43
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Otto H, Dreger M, Bengtsson L, Hucho F. Identification of tyrosine-phosphorylated proteins associated with the nuclear envelope. EUROPEAN JOURNAL OF BIOCHEMISTRY 2001; 268:420-8. [PMID: 11168378 DOI: 10.1046/j.1432-1033.2001.01901.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The nuclear envelope separates the nucleoplasm from the rest of the cell. Throughout the cell cycle, its structural integrity is controlled by reversible protein phosphorylation. Whereas its phosphorylation-dependent disassembly during mitosis is well characterized, little is known about phosphorylation events at this structure during interphase. The few characterized examples cover protein phosphorylation at serine and threonine residues, but not tyrosine phosphorylation at the nuclear envelope. Here, we demonstrate that tyrosine phosphorylation and dephosphorylation occur at the nuclear envelope of intact Neuro2a mouse neuroblastoma cells. Tyrosine kinase and phosphatase activities remain associated with purified nuclear envelopes. A similar pattern of tyrosine-phosphorylated nuclear envelope proteins suggests that the same tyrosine kinases act at the nuclear envelope of intact cells and at the purified nuclear envelope. We have also identified eight tyrosine-phosphorylated nuclear envelope proteins by 2D BAC/SDS/PAGE, immunoblotting with phosphotyrosine-specific antibodies, tryptic in-gel digestion, and MS analysis of tryptic peptides. These proteins are the lamina proteins lamin A, lamin B1, and lamin B2, the inner nuclear membrane protein LAP2beta, the heat shock protein hsc70, and the DNA/RNA-binding proteins PSF, hypothetical 16-kDa protein, and NonO, which copurify with the nuclear envelope.
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Affiliation(s)
- H Otto
- Freie Universität Berlin, Institut für Chemie-Biochemie, Berlin, Germany
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44
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Martins SB, Eide T, Steen RL, Jahnsen T, Skålhegg B S, Collas P. HA95 is a protein of the chromatin and nuclear matrix regulating nuclear envelope dynamics. J Cell Sci 2000; 113 Pt 21:3703-13. [PMID: 11034899 DOI: 10.1242/jcs.113.21.3703] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We report a role for HA95, a nuclear protein with high homology to the nuclear A-kinase anchoring protein AKAP95, in the regulation of nuclear envelope-chromatin interactions. Biochemical and photobleaching data indicate that HA95 is tightly associated with chromatin and the nuclear matrix/lamina network in interphase, and bound to chromatin at mitosis. HA95 resides in a complex together with lamin B receptor (LBR), lamina-associated polypeptide (LAP)2 and emerin, integral proteins of the inner nuclear membrane. Cross-linking experiments, however, illustrate a tight association of HA95 with LBR and LAP2 only. Intra-nuclear blocking of HA95 with anti-HA95 antibodies abolishes nuclear breakdown in a mitotic HeLa cell extract. The antibodies inhibit nuclear membrane breakdown and chromatin condensation - the latter independently of nuclear membranes. However, lamina disassembly is not affected, as judged by immunological analyses of A/C- and B-type lamins. In contrast, immunoblocking of HA95 bound to condensed chromosomes does not impair chromatin decondensation, nuclear membrane reassembly or lamina reformation. Our results argue for a role for HA95 in anchoring nuclear membranes and lamins to chromatin in interphase, and in releasing membranes from chromatin at mitosis. The data also suggest that HA95 is not involved in initial binding of membranes to chromatin upon nuclear reassembly. We propose that HA95 is a central platform at the chromatin/nuclear matrix interface implicated in regulating nuclear envelope-chromatin interactions during the cell cycle.
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Affiliation(s)
- S B Martins
- Institute of Medical Biochemistry, University of Oslo, PO Box 1112 Blindern, Norway
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45
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Affiliation(s)
- P Collas
- Institute of Medical Biochemistry, University of Oslo, Norway
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46
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Abstract
The nuclear envelope (NE) breaks down reversibly and reassembles at mitosis. Two models of mitotic nuclear membrane disassembly and reformation have emerged from studies of NE dynamics in somatic cells and egg extracts. One model suggests that nuclear membranes fragment reversibly by vesiculation, producing NE-derived vesicles separate from the endoplasmic reticulum. The second model proposes that nuclear membranes vanish by diffusion of their integral proteins through a continuous endoplasmic reticulum. Here, we discuss critically the grounds for the elaboration of these apparently mutually exclusive views. Our conclusions favour a model in which nuclear membranes do not vesiculate during mitosis.
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Affiliation(s)
- P Collas
- Institute of Medical Biochemistry, University of Oslo, Oslo, Norway.
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47
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Ellenberg J, Lippincott-Schwartz J. Dynamics and mobility of nuclear envelope proteins in interphase and mitotic cells revealed by green fluorescent protein chimeras. Methods 1999; 19:362-72. [PMID: 10579931 DOI: 10.1006/meth.1999.0872] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Understanding how membrane proteins are targeted to and retained within the nuclear envelope (NE) and the fate of these proteins during NE disassembly/reassembly in mitosis is central for insight into the function of the NE in nuclear organization and dynamics. To address these issues we have attached green fluorescent protein (GFP) to a well-characterized protein of the inner nuclear membrane, lamin B receptor, believed to be one of the major chromatin docking protein in the NE. We have used this construct in a variety of applications, including dual-color GFP time-lapse imaging, to investigate the mechanisms underlying protein targeting to the NE and NE breakdown and reassembly during mitosis. In this review, we present a summary of the results from such studies and discuss the photobleaching and imaging methodology on which they were derived.
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Affiliation(s)
- J Ellenberg
- Gene Expression and Cell Biology/Biophysics Programmes, EMBL, Menehofstrasse 1, Heidelberg, D-69117, Germany.
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48
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49
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Collas P. Sequential PKC- and Cdc2-mediated phosphorylation events elicit zebrafish nuclear envelope disassembly. J Cell Sci 1999; 112 ( Pt 6):977-87. [PMID: 10036247 DOI: 10.1242/jcs.112.6.977] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Molecular markers of the zebrafish inner nuclear membrane (NEP55) and nuclear lamina (L68) were identified, partially characterized and used to demonstrate that disassembly of the zebrafish nuclear envelope requires sequential phosphorylation events by first PKC, then Cdc2 kinase. NEP55 and L68 are immunologically and functionally related to human LAP2beta and lamin B, respectively. Exposure of zebrafish nuclei to meiotic cytosol elicits rapid phosphorylation of NEP55 and L68, and disassembly of both proteins. L68 phosphorylation is completely inhibited by simultaneous inhibition of Cdc2 and PKC and only partially blocked by inhibition of either kinase. NEP55 phosphorylation is completely prevented by inhibition or immunodepletion of cytosolic Cdc2. Inhibition of cAMP-dependent kinase, MEK or CaM kinase II does not affect NEP55 or L68 phosphorylation. In vitro, nuclear envelope disassembly requires phosphorylation of NEP55 and L68 by both mammalian PKC and Cdc2. Inhibition of either kinase is sufficient to abolish NE disassembly. Furthermore, novel two-step phosphorylation assays in cytosol and in vitro indicate that PKC-mediated phosphorylation of L68 prior to Cdc2-mediated phosphorylation of L68 and NEP55 is essential to elicit nuclear envelope breakdown. Phosphorylation elicited by Cdc2 prior to PKC prevents nuclear envelope disassembly even though NEP55 is phosphorylated. The results indicate that sequential phosphorylation events elicited by PKC, followed by Cdc2, are required for zebrafish nuclear disassembly. They also argue that phosphorylation of inner nuclear membrane integral proteins is not sufficient to promote nuclear envelope breakdown, and suggest a multiple-level regulation of disassembly of nuclear envelope components during meiosis and at mitosis.
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Affiliation(s)
- P Collas
- Department of Biochemistry, Norwegian College of Veterinary Medicine, and Institute of Medical Biochemistry, University of Oslo, PO Box 1112, Blindern, Norway.
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50
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Manilal S, Nguyen TM, Morris GE. Colocalization of emerin and lamins in interphase nuclei and changes during mitosis. Biochem Biophys Res Commun 1998; 249:643-7. [PMID: 9731189 DOI: 10.1006/bbrc.1998.9209] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Emerin is a nuclear membrane protein which is affected by mutation in X-linked Emery-Dreifuss muscular dystrophy. We have previously suggested that emerin is a member of a family of type II integral membrane proteins which associate with the nuclear lamina and which include lamina-associated proteins and the lamin B receptor. We now show that emerin in COS cells is not restricted to the nuclear rim but is also found at intranuclear sites, where it colocalizes with nuclear lamins B1, B2 and A/C. During mitosis, emerin is dispersed throughout the cell and then participates in the reconstitution of membranes around the daughter nuclei. Although emerin and lamins do not remain colocalized during mitosis, they all show some association with the midbody of the mitotic spindle.
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Affiliation(s)
- S Manilal
- MRIC Biochemistry Group, N.E. Wales Institute, Wrexham, United Kingdom
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