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Scholey JM. Mitotic spindle membranes. Mol Biol Cell 2025; 36:re1. [PMID: 40067152 PMCID: PMC12005112 DOI: 10.1091/mbc.e24-10-0475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2024] [Revised: 01/31/2025] [Accepted: 02/05/2025] [Indexed: 04/19/2025] Open
Abstract
The mitotic spindle, which uses microtubules (MTs) and MT-based motor proteins to separate sister chromosomes prior to cell division, contains abundant membranes, organelles, and protein assemblies derived from the familiar interphase intracellular membrane network. In this essay, mainly with reference to selected animal and fungal cells, I summarize current ideas about the reciprocal functional relationship between these mitotic spindle-associated membranes and the spindle MT cytoskeleton, in which; 1) spindle membranes control the composition, Ca++ ion concentration and mechanical performance of the spindle MT cytoskeleton; and conversely 2) the spindle MT cytoskeleton contributes to membrane/organelle partitioning and inheritance during cell division and serves as a reservoir of membranes, organelles, and vesicles for delivery to the interphase cytoplasm, plasma membrane, and cleavage furrow.
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Affiliation(s)
- Jonathan M. Scholey
- Department of Molecular and Cell Biology, University of California at Davis, Davis, CA 95616
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2
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Kors S, Schlaitz AL. Dynamic remodelling of the endoplasmic reticulum for mitosis. J Cell Sci 2024; 137:jcs261444. [PMID: 39584405 DOI: 10.1242/jcs.261444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2024] Open
Abstract
The endoplasmic reticulum (ER) is a dynamic and continuous membrane network with roles in many cellular processes. The importance and maintenance of ER structure and function have been extensively studied in interphase cells, yet recent findings also indicate crucial roles of the ER in mitosis. During mitosis, the ER is remodelled significantly with respect to composition and morphology but persists as a continuous network. The ER interacts with microtubules, actin and intermediate filaments, and concomitant with the mitotic restructuring of all cytoskeletal systems, ER dynamics and distribution change. The ER is a metabolic hub and several examples of altered ER functions during mitosis have been described. However, we lack an overall understanding of the ER metabolic pathways and functions that are active during mitosis. In this Review, we will discuss mitotic changes to the ER at different organizational levels to explore how the mitotic ER, with its distinct properties, might support cell division.
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Affiliation(s)
- Suzan Kors
- Heidelberg University Biochemistry Center (BZH), 69120 Heidelberg, Germany
| | - Anne-Lore Schlaitz
- Heidelberg University Biochemistry Center (BZH), 69120 Heidelberg, Germany
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3
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Chuang CH, Schlientz AJ, Yang J, Bowerman B. Microtubule assembly and pole coalescence: early steps in Caenorhabditiselegans oocyte meiosis I spindle assembly. Biol Open 2020; 9:bio052308. [PMID: 32493729 PMCID: PMC7328010 DOI: 10.1242/bio.052308] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 05/11/2020] [Indexed: 12/17/2022] Open
Abstract
How oocytes assemble bipolar meiotic spindles in the absence of centrosomes as microtubule organizing centers remains poorly understood. We have used live cell imaging in Caenorhabditis elegans to investigate requirements for the nuclear lamina and for conserved regulators of microtubule dynamics during oocyte meiosis I spindle assembly, assessing these requirements with respect to recently identified spindle assembly steps. We show that the nuclear lamina is required for microtubule bundles to form a peripheral cage-like structure that appears shortly after oocyte nuclear envelope breakdown and surrounds the oocyte chromosomes, although bipolar spindles still assembled in its absence. Although two conserved regulators of microtubule nucleation, RAN-1 and γ-tubulin, are not required for bipolar spindle assembly, both contribute to normal levels of spindle-associated microtubules and spindle assembly dynamics. Finally, the XMAP215 ortholog ZYG-9 and the nearly identical minus-end directed kinesins KLP-15/16 are required for proper assembly of the early cage-like structure of microtubule bundles, and for early spindle pole foci to coalesce into a bipolar structure. Our results provide a framework for assigning molecular mechanisms to recently described steps in C. elegans oocyte meiosis I spindle assembly.
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Affiliation(s)
- Chien-Hui Chuang
- Institute of Molecular Biology and Department of Biology, 1229 University of Oregon, Eugene, Oregon 97403, USA
| | - Aleesa J Schlientz
- Institute of Molecular Biology and Department of Biology, 1229 University of Oregon, Eugene, Oregon 97403, USA
| | - Jie Yang
- Institute of Molecular Biology and Department of Biology, 1229 University of Oregon, Eugene, Oregon 97403, USA
| | - Bruce Bowerman
- Institute of Molecular Biology and Department of Biology, 1229 University of Oregon, Eugene, Oregon 97403, USA
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4
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Tiwary AK, Zheng Y. Protein phase separation in mitosis. Curr Opin Cell Biol 2019; 60:92-98. [PMID: 31176175 PMCID: PMC6756948 DOI: 10.1016/j.ceb.2019.04.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 04/26/2019] [Indexed: 01/11/2023]
Abstract
Through phase separation, some proteins form liquid-like condensates or droplets which can flow, fuse, and even deform when pressure is applied. In some cases, the condensates 'mature' to form gel or solid-like structure. Recent studies suggest that the liquid-like condensates form the structural basis for several membrane-less subcellular organelles such as stress granules and other subcellular structures. Here, we review and discuss studies that implicate protein phase separation in the function of the spindle apparatus and centrosomes.
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Affiliation(s)
- Ashish Kumar Tiwary
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218, United States
| | - Yixian Zheng
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218, United States.
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5
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Huang Y, Li T, Ems-McClung SC, Walczak CE, Prigent C, Zhu X, Zhang X, Zheng Y. Aurora A activation in mitosis promoted by BuGZ. J Cell Biol 2017; 217:107-116. [PMID: 29074706 PMCID: PMC5748987 DOI: 10.1083/jcb.201706103] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2017] [Revised: 09/22/2017] [Accepted: 09/27/2017] [Indexed: 12/25/2022] Open
Abstract
Mitotic spindle component BuGZ is known to undergo phase separation. Huang et al. show that BuGZ promotes Aurora A phosphorylation and activation and that this is inhibited when BuGZ phase separation is disrupted. Protein phase separation or coacervation has emerged as a potential mechanism to regulate biological functions. We have shown that coacervation of a mostly unstructured protein, BuGZ, promotes assembly of spindle and its matrix. BuGZ in the spindle matrix binds and concentrates tubulin to promote microtubule (MT) assembly. It remains unclear, however, whether BuGZ could regulate additional proteins to promote spindle assembly. In this study, we report that BuGZ promotes Aurora A (AurA) activation in vitro. Depletion of BuGZ in cells reduces the amount of phosphorylated AurA on spindle MTs. BuGZ also enhances MCAK phosphorylation. The two zinc fingers in BuGZ directly bind to the kinase domain of AurA, which allows AurA to incorporate into the coacervates formed by BuGZ in vitro. Importantly, mutant BuGZ that disrupts the coacervation activity in vitro fails to promote AurA phosphorylation in Xenopus laevis egg extracts. These results suggest that BuGZ coacervation promotes AurA activation in mitosis.
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Affiliation(s)
- Yuejia Huang
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD
| | - Teng Li
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD.,Institute of Basic Medical Sciences, National Center of Biomedical Analysis, Beijing, China
| | | | | | - Claude Prigent
- Institut de Génétique et Développement de Rennes, Equipe laboratoryélisée Ligue Nationale Contre la Cancer 2014-2017, Centre National de la Recherche Scientifique, Université Rennes 1, Rennes, France
| | - Xueliang Zhu
- State Key Laboratory of Cell Biology, Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Xuemin Zhang
- Institute of Basic Medical Sciences, National Center of Biomedical Analysis, Beijing, China
| | - Yixian Zheng
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD
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6
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Ranade D, Koul S, Thompson J, Prasad KB, Sengupta K. Chromosomal aneuploidies induced upon Lamin B2 depletion are mislocalized in the interphase nucleus. Chromosoma 2017; 126:223-244. [PMID: 26921073 PMCID: PMC5371638 DOI: 10.1007/s00412-016-0580-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Revised: 01/28/2016] [Accepted: 02/09/2016] [Indexed: 12/31/2022]
Abstract
Chromosome territories assume non-random positions in the interphase nucleus with gene-rich chromosomes localized toward the nuclear interior and gene-poor chromosome territories toward the nuclear periphery. Lamins are intermediate filament proteins of the inner nuclear membrane required for the maintenance of nuclear structure and function. Here, we show using whole-genome expression profiling that Lamin A/C or Lamin B2 depletion in an otherwise diploid colorectal cancer cell line (DLD1) deregulates transcript levels from specific chromosomes. Further, three-dimensional fluorescence in situ hybridization (3D-FISH) analyses of a subset of these transcriptionally deregulated chromosome territories revealed that the diploid chromosome territories in Lamin-depleted cells largely maintain conserved positions in the interphase nucleus in a gene-density-dependent manner. In addition, chromosomal aneuploidies were induced in ~25 % of Lamin A/C or Lamin B2-depleted cells. Sub-populations of these aneuploid cells consistently showed a mislocalization of the gene-rich aneuploid chromosome 19 territory toward the nuclear periphery, while gene-poor aneuploid chromosome 18 territory was mislocalized toward the nuclear interior predominantly upon Lamin B2 than Lamin A/C depletion. In addition, a candidate gene locus ZNF570 (Chr.19q13.12) significantly overexpressed upon Lamin B2 depletion was remarkably repositioned away from the nuclear lamina. Taken together, our studies strongly implicate an overarching role for Lamin B2 in the maintenance of nuclear architecture since loss of Lamin B2 relieves the spatial positional constraints required for maintaining conserved localization of aneuploid chromosome territories in the interphase nucleus.
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Affiliation(s)
- Devika Ranade
- Biology, Indian Institute of Science Education and Research, Pune, Main Building, Homi Bhabha Road, Pashan, Pune, Maharashtra, 411008, India
| | - Shivsmriti Koul
- Biology, Indian Institute of Science Education and Research, Pune, Main Building, Homi Bhabha Road, Pashan, Pune, Maharashtra, 411008, India
| | - Joyce Thompson
- Biology, Indian Institute of Science Education and Research, Pune, Main Building, Homi Bhabha Road, Pashan, Pune, Maharashtra, 411008, India
| | - Kumar Brajesh Prasad
- Biology, Indian Institute of Science Education and Research, Pune, Main Building, Homi Bhabha Road, Pashan, Pune, Maharashtra, 411008, India
| | - Kundan Sengupta
- Biology, Indian Institute of Science Education and Research, Pune, Main Building, Homi Bhabha Road, Pashan, Pune, Maharashtra, 411008, India.
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7
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Abstract
Fully grown oocytes arrest meiosis at prophase I and deposit maternal RNAs. A subset of maternal transcripts is stored in a dormant state in the oocyte, and the timely driven translation of specific mRNAs guides meiotic progression, the oocyte-embryo transition, and early embryo development. In the absence of transcription, the regulation of gene expression in oocytes is controlled almost exclusively at the level of transcriptome and proteome stabilization and at the level of protein synthesis.This chapter focuses on the recent findings on RNA distribution related to the temporal and spatial translational control of the meiotic cycle progression in mammalian oocytes. We discuss the most relevant mechanisms involved in the organization of the oocyte's maternal transcriptome storage and localization, and the regulation of translation, in correlation with the regulation of oocyte meiotic progression.
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8
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Machowska M, Piekarowicz K, Rzepecki R. Regulation of lamin properties and functions: does phosphorylation do it all? Open Biol 2016; 5:rsob.150094. [PMID: 26581574 PMCID: PMC4680568 DOI: 10.1098/rsob.150094] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The main functions of lamins are their mechanical and structural roles as major building blocks of the karyoskeleton. They are also involved in chromatin structure regulation, gene expression, intracellular signalling pathway modulation and development. All essential lamin functions seem to depend on their capacity for assembly or disassembly after the receipt of specific signals, and after specific, selective and precisely regulated interactions through their various domains. Reversible phosphorylation of lamins is crucial for their functions, so it is important to understand how lamin polymerization and interactions are modulated, and which sequences may undergo such modifications. This review combines experimental data with results of our in silico analyses focused on lamin phosphorylation in model organisms to show the presence of evolutionarily conserved sequences and to indicate specific in vivo phosphorylations that affect particular functions.
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Affiliation(s)
- Magdalena Machowska
- Laboratory of Nuclear Proteins, Faculty of Biotechnology, University of Wrocław, ul. Fryderyka Joliot-Curie 14a, Wrocław 50-383, Poland
| | - Katarzyna Piekarowicz
- Laboratory of Nuclear Proteins, Faculty of Biotechnology, University of Wrocław, ul. Fryderyka Joliot-Curie 14a, Wrocław 50-383, Poland
| | - Ryszard Rzepecki
- Laboratory of Nuclear Proteins, Faculty of Biotechnology, University of Wrocław, ul. Fryderyka Joliot-Curie 14a, Wrocław 50-383, Poland
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9
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Burla R, Carcuro M, Torre ML, Fratini F, Crescenzi M, D'Apice MR, Spitalieri P, Raffa GD, Astrologo L, Lattanzi G, Cundari E, Raimondo D, Biroccio A, Gatti M, Saggio I. The telomeric protein AKTIP interacts with A- and B-type lamins and is involved in regulation of cellular senescence. Open Biol 2016; 6:160103. [PMID: 27512140 PMCID: PMC5008010 DOI: 10.1098/rsob.160103] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 07/08/2016] [Indexed: 01/07/2023] Open
Abstract
AKTIP is a shelterin-interacting protein required for replication of telomeric DNA. Here, we show that AKTIP biochemically interacts with A- and B-type lamins and affects lamin A, but not lamin C or B, expression. In interphase cells, AKTIP localizes at the nuclear rim and in discrete regions of the nucleoplasm just like lamins. Double immunostaining revealed that AKTIP partially co-localizes with lamin B1 and lamin A/C in interphase cells, and that proper AKTIP localization requires functional lamin A. In mitotic cells, AKTIP is enriched at the spindle poles and at the midbody of late telophase cells similar to lamin B1. AKTIP-depleted cells show senescence-associated markers and recapitulate several aspects of the progeroid phenotype. Collectively, our results indicate that AKTIP is a new player in lamin-related processes, including those that govern nuclear architecture, telomere homeostasis and cellular senescence.
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Affiliation(s)
- Romina Burla
- Dipartimento di Biologia e Biotecnologie "C. Darwin", Sapienza Università di Roma, 00185, Italy Istituto Pasteur Fondazione Cenci Bolognetti, Rome 00185, Italy Istituto di Biologia e Patologia Molecolari CNR Roma, 00185, Italy
| | - Mariateresa Carcuro
- Dipartimento di Biologia e Biotecnologie "C. Darwin", Sapienza Università di Roma, 00185, Italy
| | - Mattia La Torre
- Dipartimento di Biologia e Biotecnologie "C. Darwin", Sapienza Università di Roma, 00185, Italy
| | | | | | | | - Paola Spitalieri
- Dipartimento di Biomedicina e Prevenzione, Università di Roma Tor Vergata, Roma 00133, Italy
| | - Grazia Daniela Raffa
- Dipartimento di Biologia e Biotecnologie "C. Darwin", Sapienza Università di Roma, 00185, Italy
| | - Letizia Astrologo
- Dipartimento di Biologia e Biotecnologie "C. Darwin", Sapienza Università di Roma, 00185, Italy
| | | | - Enrico Cundari
- Istituto di Biologia e Patologia Molecolari CNR Roma, 00185, Italy
| | - Domenico Raimondo
- Dipartimento di Medicina Molecolare, Sapienza, Università di Roma, Rome 00185, Italy
| | - Annamaria Biroccio
- Unità di Oncogenomica ed Epigenetica, Istituto Nazionale Tumori Regina Elena, Roma 00144, Italy
| | - Maurizio Gatti
- Dipartimento di Biologia e Biotecnologie "C. Darwin", Sapienza Università di Roma, 00185, Italy Istituto di Biologia e Patologia Molecolari CNR Roma, 00185, Italy
| | - Isabella Saggio
- Dipartimento di Biologia e Biotecnologie "C. Darwin", Sapienza Università di Roma, 00185, Italy Istituto di Biologia e Patologia Molecolari CNR Roma, 00185, Italy
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10
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Jiang H, He X, Feng D, Zhu X, Zheng Y. RanGTP aids anaphase entry through Ubr5-mediated protein turnover. J Cell Biol 2015; 211:7-18. [PMID: 26438829 PMCID: PMC4602037 DOI: 10.1083/jcb.201503122] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 08/25/2015] [Indexed: 01/14/2023] Open
Abstract
Cells sense the overall chromosome congression state in metaphase to promote anaphase entry using RanGTP, which induces the reduction of two spindle assembly checkpoint proteins, BuGZ and Bub3, via the E3 ligase Ubr5. RanGTP is known to regulate the spindle assembly checkpoint (SAC), but the underlying molecular mechanism is unclear. BuGZ stabilizes SAC protein Bub3 through direct interaction and facilitates its mitotic function. Here we show that RanGTP promotes the turnover of BuGZ and Bub3 in metaphase, which in turn facilitates metaphase-to-anaphase transition. BuGZ and Bub3 interact with either importin-β or an E3 ubiquitin ligase, Ubr5. RanGTP promotes the dissociation of importin-β from BuGZ and Bub3 in metaphase. This results in increased binding of BuGZ and Bub3 to Ubr5, leading to ubiquitination and subsequent turnover of both proteins. We propose that elevated metaphase RanGTP levels use Ubr5 to couple overall chromosome congression to SAC silencing.
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Affiliation(s)
- Hao Jiang
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218
| | - Xiaonan He
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Di Feng
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Xueliang Zhu
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Yixian Zheng
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218
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11
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Jiang H, Wang S, Huang Y, He X, Cui H, Zhu X, Zheng Y. Phase transition of spindle-associated protein regulate spindle apparatus assembly. Cell 2015; 163:108-22. [PMID: 26388440 DOI: 10.1016/j.cell.2015.08.010] [Citation(s) in RCA: 219] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Revised: 06/09/2015] [Accepted: 07/31/2015] [Indexed: 11/24/2022]
Abstract
Spindle assembly required during mitosis depends on microtubule polymerization. We demonstrate that the evolutionarily conserved low-complexity protein, BuGZ, undergoes phase transition or coacervation to promote assembly of both spindles and their associated components. BuGZ forms temperature-dependent liquid droplets alone or on microtubules in physiological buffers. Coacervation in vitro or in spindle and spindle matrix depends on hydrophobic residues in BuGZ. BuGZ coacervation and its binding to microtubules and tubulin are required to promote assembly of spindle and spindle matrix in Xenopus egg extract and in mammalian cells. Since several previously identified spindle-associated components also contain low-complexity regions, we propose that coacervating proteins may be a hallmark of proteins that comprise a spindle matrix that functions to promote assembly of spindles by concentrating its building blocks.
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Affiliation(s)
- Hao Jiang
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China; Department of Embryology, Carnegie Institution for Science, 3520 San Martin Drive, Baltimore, MD 21218, USA
| | - Shusheng Wang
- Department of Embryology, Carnegie Institution for Science, 3520 San Martin Drive, Baltimore, MD 21218, USA
| | - Yuejia Huang
- Department of Embryology, Carnegie Institution for Science, 3520 San Martin Drive, Baltimore, MD 21218, USA
| | - Xiaonan He
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Honggang Cui
- Department of Chemical and Biomolecular Engineering and Institute for NanoBioTechnology, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA
| | - Xueliang Zhu
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China.
| | - Yixian Zheng
- Department of Embryology, Carnegie Institution for Science, 3520 San Martin Drive, Baltimore, MD 21218, USA.
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12
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Schweizer N, Pawar N, Weiss M, Maiato H. An organelle-exclusion envelope assists mitosis and underlies distinct molecular crowding in the spindle region. J Cell Biol 2015; 210:695-704. [PMID: 26304726 PMCID: PMC4555823 DOI: 10.1083/jcb.201506107] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 07/28/2015] [Indexed: 01/30/2023] Open
Abstract
A microtubule-independent membranous “spindle envelope” confines spindle assembly and accounts for faithful chromosome segregation. The mitotic spindle is a microtubular assembly required for chromosome segregation during mitosis. Additionally, a spindle matrix has long been proposed to assist this process, but its nature has remained elusive. By combining live-cell imaging with laser microsurgery, fluorescence recovery after photobleaching, and fluorescence correlation spectroscopy in Drosophila melanogaster S2 cells, we uncovered a microtubule-independent mechanism that underlies the accumulation of molecules in the spindle region. This mechanism relies on a membranous system surrounding the mitotic spindle that defines an organelle-exclusion zone that is conserved in human cells. Supported by mathematical modeling, we demonstrate that organelle exclusion by a membrane system causes spatio-temporal differences in molecular crowding states that are sufficient to drive accumulation of mitotic regulators, such as Mad2 and Megator/Tpr, as well as soluble tubulin, in the spindle region. This membranous “spindle envelope” confined spindle assembly, and its mechanical disruption compromised faithful chromosome segregation. Thus, cytoplasmic compartmentalization persists during early mitosis to promote spindle assembly and function.
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Affiliation(s)
- Nina Schweizer
- Chromosome Instability & Dynamics Laboratory, Instituto de Biologia Molecular e Celular, Universidade do Porto, 4150-180 Porto, Portugal Cell Division Unit, Department of Experimental Biology, Faculdade de Medicina, Universidade do Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal
| | - Nisha Pawar
- Experimental Physics I, University of Bayreuth, D-95440 Bayreuth, Germany
| | - Matthias Weiss
- Experimental Physics I, University of Bayreuth, D-95440 Bayreuth, Germany
| | - Helder Maiato
- Chromosome Instability & Dynamics Laboratory, Instituto de Biologia Molecular e Celular, Universidade do Porto, 4150-180 Porto, Portugal Cell Division Unit, Department of Experimental Biology, Faculdade de Medicina, Universidade do Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal
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13
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Guo Y, Zheng Y. Lamins position the nuclear pores and centrosomes by modulating dynein. Mol Biol Cell 2015; 26:3379-89. [PMID: 26246603 PMCID: PMC4591684 DOI: 10.1091/mbc.e15-07-0482] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 07/29/2015] [Indexed: 12/30/2022] Open
Abstract
Nuclear lamins counterbalance dynein forces on nuclear pore complexes through BICD2 and ensure even nuclear pore complex distribution and proper centrosome separation at prophase. Lamins, the type V nuclear intermediate filament proteins, are reported to function in both interphase and mitosis. For example, lamin deletion in various cell types can lead to an uneven distribution of the nuclear pore complexes (NPCs) in the interphase nuclear envelope, whereas deletion of B-type lamins results in spindle orientation defects in mitotic neural progenitor cells. How lamins regulate these functions is unknown. Using mouse cells deleted of different combinations or all lamins, we show that lamins are required to prevent the aggregation of NPCs in the nuclear envelope near centrosomes in late G2 and prophase. This asymmetric NPC distribution in the absence of lamins is caused by dynein forces acting on NPCs via the dynein adaptor BICD2. We further show that asymmetric NPC distribution upon lamin depletion disrupts the distribution of BICD2 and p150 dynactin on the nuclear envelope at prophase, which results in inefficient dynein-driven centrosome separation during prophase. Therefore lamins regulate microtubule-based motor forces in vivo to ensure proper NPC distribution in interphase and centrosome separation in the mitotic prophase.
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Affiliation(s)
- Yuxuan Guo
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218; Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218
| | - Yixian Zheng
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218; Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218
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14
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Carvalhal S, Ribeiro SA, Arocena M, Kasciukovic T, Temme A, Koehler K, Huebner A, Griffis ER. The nucleoporin ALADIN regulates Aurora A localization to ensure robust mitotic spindle formation. Mol Biol Cell 2015; 26:3424-38. [PMID: 26246606 PMCID: PMC4591688 DOI: 10.1091/mbc.e15-02-0113] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 07/24/2015] [Indexed: 12/17/2022] Open
Abstract
The nucleoporin ALADIN, which is mutated in patients with triple A syndrome, is necessary for proper spindle formation. Without ALADIN, active Aurora A moves away from centrosomes. The relocalization of active Aurora A leads to a redistribution of specific spindle assembly factors that make spindles less stable and slows their formation. The formation of the mitotic spindle is a complex process that requires massive cellular reorganization. Regulation by mitotic kinases controls this entire process. One of these mitotic controllers is Aurora A kinase, which is itself highly regulated. In this study, we show that the nuclear pore protein ALADIN is a novel spatial regulator of Aurora A. Without ALADIN, Aurora A spreads from centrosomes onto spindle microtubules, which affects the distribution of a subset of microtubule regulators and slows spindle assembly and chromosome alignment. ALADIN interacts with inactive Aurora A and is recruited to the spindle pole after Aurora A inhibition. Of interest, mutations in ALADIN cause triple A syndrome. We find that some of the mitotic phenotypes that we observe after ALADIN depletion also occur in cells from triple A syndrome patients, which raises the possibility that mitotic errors may underlie part of the etiology of this syndrome.
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Affiliation(s)
- Sara Carvalhal
- Centre for Gene Regulation and Expression, University of Dundee, College of Life Sciences, Dundee DD1 5EH, United Kingdom
| | - Susana Abreu Ribeiro
- Physiology Course, Marine Biological Laboratory, Woods Hole, MA 02543 Wellcome Trust Centre for Cell Biology, Institute of Cell and Molecular Biology, University of Edinburgh, Edinburgh EH9 3JR, United Kingdom
| | - Miguel Arocena
- Centre for Gene Regulation and Expression, University of Dundee, College of Life Sciences, Dundee DD1 5EH, United Kingdom
| | - Taciana Kasciukovic
- Centre for Gene Regulation and Expression, University of Dundee, College of Life Sciences, Dundee DD1 5EH, United Kingdom
| | - Achim Temme
- Department of Neurosurgery, University Hospital Carl Gustav Carus, Technische Universität Dresden, D-01307 Dresden, Germany
| | - Katrin Koehler
- Department of Paediatrics, University Hospital Carl Gustav Carus, Technische Universität Dresden, D-01307 Dresden, Germany
| | - Angela Huebner
- Department of Paediatrics, University Hospital Carl Gustav Carus, Technische Universität Dresden, D-01307 Dresden, Germany
| | - Eric R Griffis
- Centre for Gene Regulation and Expression, University of Dundee, College of Life Sciences, Dundee DD1 5EH, United Kingdom Physiology Course, Marine Biological Laboratory, Woods Hole, MA 02543
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15
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Shi C, Channels WE, Zheng Y, Iglesias PA. A computational model for the formation of lamin-B mitotic spindle envelope and matrix. Interface Focus 2014; 4:20130063. [PMID: 24904732 DOI: 10.1098/rsfs.2013.0063] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Recent reports show that, after nuclear envelope breakdown, lamin-B, a component of the nuclear lamina in interphase, localizes around the mitotic spindle as a membranous network. How this process occurs, however, and how it influences mitotic spindle morphogenesis is unclear. Here, we develop a computational model based on a continuum description to represent the abundance and location of various molecular species involved during mitosis, and use the model to test a number of hypotheses regarding the formation of the mitotic matrix. Our model illustrates that freely diffusible nuclear proteins can be captured and transported to the spindle poles by minus-end-directed microtubule (MT) motors. Moreover, simulations show that these proteins can be used to build a shell-like region that envelopes the mitotic spindle, which helps to improve the focusing of the mitotic spindle by spatially restricting MT polymerization and limiting the effective diffusion of the free MTs. Simulations also confirm that spatially dependent regulation of the spindle network through the Ran system improves spindle focusing and morphology. Our results agree with experimental observations that lamin-B reorganizes around the spindle and helps to maintain spindle morphology.
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Affiliation(s)
- Changji Shi
- Department of Electrical and Computer Engineering , The Johns Hopkins University , 3400 North Charles Street, Baltimore, MD 21218 , USA
| | - Wilbur E Channels
- Department of Electrical and Computer Engineering , The Johns Hopkins University , 3400 North Charles Street, Baltimore, MD 21218 , USA
| | - Yixian Zheng
- Department of Embryology , Carnegie Institution of Washington , 3520 San Martin Drive, Baltimore, MD 21218 , USA
| | - Pablo A Iglesias
- Department of Electrical and Computer Engineering , The Johns Hopkins University , 3400 North Charles Street, Baltimore, MD 21218 , USA
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16
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Schweizer N, Weiss M, Maiato H. The dynamic spindle matrix. Curr Opin Cell Biol 2014; 28:1-7. [DOI: 10.1016/j.ceb.2014.01.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 01/09/2014] [Accepted: 01/11/2014] [Indexed: 10/25/2022]
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17
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Abstract
For over two decades, B-type lamins were thought to have roles in fundamental processes including correct assembly of nuclear envelopes, DNA replication, transcription and cell survival. Recent studies have questioned these roles and have instead emphasised the role of these proteins in tissue building and tissue integrity, particularly in tissues devoid of A-type lamins. Other studies have suggested that the expression of B-type lamins in somatic cells influences the rate of entry into states of cellular senescence. In humans duplication of the LMNB1 gene (encoding lamin B1) causes an adult onset neurodegenerative disorder, termed autosomal dominant leukodystrophy, whilst very recently, LMNB1 has been implicated as a susceptibility gene in neural tube defects. This is consistent with studies in mice that reveal a critical role for B-type lamins in neuronal migration and brain development. In this review, I will consider how different model systems have contributed to our understanding of the functions of B-type lamins and which of those functions are critical for human health and disease.
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Affiliation(s)
- C J Hutchison
- School of Biological and Biomedical Sciences, Durham University, Durham DH1 3LE, United Kingdom.
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18
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Guo Y, Kim Y, Shimi T, Goldman RD, Zheng Y. Concentration-dependent lamin assembly and its roles in the localization of other nuclear proteins. Mol Biol Cell 2014; 25:1287-97. [PMID: 24523288 PMCID: PMC3982994 DOI: 10.1091/mbc.e13-11-0644] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 02/05/2014] [Accepted: 02/06/2014] [Indexed: 11/11/2022] Open
Abstract
The nuclear lamina (NL) consists of lamin polymers and proteins that bind to the polymers. Disruption of NL proteins such as lamin and emerin leads to developmental defects and human diseases. However, the expression of multiple lamins, including lamin-A/C, lamin-B1, and lamin-B2, in mammals has made it difficult to study the assembly and function of the NL. Consequently, it has been unclear whether different lamins depend on one another for proper NL assembly and which NL functions are shared by all lamins or are specific to one lamin. Using mouse cells deleted of all or different combinations of lamins, we demonstrate that the assembly of each lamin into the NL depends primarily on the lamin concentration present in the nucleus. When expressed at sufficiently high levels, each lamin alone can assemble into an evenly organized NL, which is in turn sufficient to ensure the even distribution of the nuclear pore complexes. By contrast, only lamin-A can ensure the localization of emerin within the NL. Thus, when investigating the role of the NL in development and disease, it is critical to determine the protein levels of relevant lamins and the intricate shared or specific lamin functions in the tissue of interest.
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Affiliation(s)
- Yuxuan Guo
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218
| | - Youngjo Kim
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218
| | - Takeshi Shimi
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Robert D. Goldman
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Yixian Zheng
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218
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19
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Cau P, Navarro C, Harhouri K, Roll P, Sigaudy S, Kaspi E, Perrin S, De Sandre-Giovannoli A, Lévy N. WITHDRAWN: Nuclear matrix, nuclear envelope and premature aging syndromes in a translational research perspective. Semin Cell Dev Biol 2014:S1084-9521(14)00058-5. [PMID: 24685615 DOI: 10.1016/j.semcdb.2014.03.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Revised: 03/03/2014] [Accepted: 03/09/2014] [Indexed: 10/25/2022]
Abstract
The Publisher regrets that this article is an accidental duplication of an article that has already been published, http://dx.doi.org/10.1016/j.semcdb.2014.03.022. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.
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Affiliation(s)
- Pierre Cau
- Aix-Marseille Université, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France(1); INSERM, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France(1); AP-HM, Service de Biologie Cellulaire, Hôpital La Timone, 264 Rue Saint Pierre, 13385 Marseille Cedex 5, France(2).
| | - Claire Navarro
- Aix-Marseille Université, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France(1); INSERM, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France(1)
| | - Karim Harhouri
- Aix-Marseille Université, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France(1); INSERM, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France(1)
| | - Patrice Roll
- Aix-Marseille Université, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France(1); INSERM, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France(1); AP-HM, Service de Biologie Cellulaire, Hôpital La Timone, 264 Rue Saint Pierre, 13385 Marseille Cedex 5, France(2)
| | - Sabine Sigaudy
- Aix-Marseille Université, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France(1); INSERM, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France(1); AP-HM, Département de Génétique Médicale, Hôpital d'enfants Timone, 264 Rue Saint Pierre, 13385 Marseille Cedex 5, France(3)
| | - Elise Kaspi
- Aix-Marseille Université, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France(1); INSERM, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France(1); AP-HM, Service de Biologie Cellulaire, Hôpital La Timone, 264 Rue Saint Pierre, 13385 Marseille Cedex 5, France(2)
| | - Sophie Perrin
- Aix-Marseille Université, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France(1); INSERM, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France(1)
| | - Annachiara De Sandre-Giovannoli
- Aix-Marseille Université, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France(1); INSERM, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France(1); AP-HM, Département de Génétique Médicale, Hôpital d'enfants Timone, 264 Rue Saint Pierre, 13385 Marseille Cedex 5, France(3)
| | - Nicolas Lévy
- Aix-Marseille Université, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France(1); INSERM, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France(1); AP-HM, Département de Génétique Médicale, Hôpital d'enfants Timone, 264 Rue Saint Pierre, 13385 Marseille Cedex 5, France(3).
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20
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Cau P, Navarro C, Harhouri K, Roll P, Sigaudy S, Kaspi E, Perrin S, De Sandre-Giovannoli A, Lévy N. Nuclear matrix, nuclear envelope and premature aging syndromes in a translational research perspective. Semin Cell Dev Biol 2014; 29:125-47. [PMID: 24662892 DOI: 10.1016/j.semcdb.2014.03.021] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Lamin A-related progeroid syndromes are genetically determined, extremely rare and severe. In the past ten years, our knowledge and perspectives for these diseases has widely progressed, through the progressive dissection of their pathophysiological mechanisms leading to precocious and accelerated aging, from the genes mutations discovery until therapeutic trials in affected children. A-type lamins are major actors in several structural and functional activities at the nuclear periphery, as they are major components of the nuclear lamina. However, while this is usually poorly considered, they also play a key role within the rest of the nucleoplasm, whose defects are related to cell senescence. Although nuclear shape and nuclear envelope deformities are obvious and visible events, nuclear matrix disorganization and abnormal composition certainly represent the most important causes of cell defects with dramatic pathological consequences. Therefore, lamin-associated diseases should be better referred as laminopathies instead of envelopathies, this later being too restrictive, considering neither the key structural and functional roles of soluble lamins in the entire nucleoplasm, nor the nuclear matrix contribution to the pathophysiology of lamin-associated disorders and in particular in defective lamin A processing-associated aging diseases. Based on both our understanding of pathophysiological mechanisms and the biological and clinical consequences of progeria and related diseases, therapeutic trials have been conducted in patients and were terminated less than 10 years after the gene discovery, a quite fast issue for a genetic disease. Pharmacological drugs have been repurposed and used to decrease the toxicity of the accumulated, unprocessed and truncated prelaminA in progeria. To date, none of them may be considered as a cure for progeria and these clinical strategies were essentially designed toward reducing a subset of the most dramatic and morbid features associated to progeria. New therapeutic strategies under study, in particular targeting the protein expression pathway at the mRNA level, have shown a remarkable efficacy both in vitro in cells and in vivo in mice models. Strategies intending to clear the toxic accumulated proteins from the nucleus are also under evaluation. However, although exceedingly rare, improving our knowledge of genetic progeroid syndromes and searching for innovative and efficient therapies in these syndromes is of paramount importance as, even before they can be used to save lives, they may significantly (i) expand the affected childrens' lifespan and preserve their quality of life; (ii) improve our understanding of aging-related disorders and other more common diseases; and (iii) expand our fundamental knowledge of physiological aging and its links with major physiological processes such as those involved in oncogenesis.
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Affiliation(s)
- Pierre Cau
- Aix-Marseille Université, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France; INSERM, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France; AP-HM, Service de Biologie Cellulaire, Hôpital La Timone, 264 Rue Saint Pierre, 13385 Marseille Cedex 5, France.
| | - Claire Navarro
- Aix-Marseille Université, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France; INSERM, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France
| | - Karim Harhouri
- Aix-Marseille Université, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France; INSERM, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France
| | - Patrice Roll
- Aix-Marseille Université, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France; INSERM, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France; AP-HM, Service de Biologie Cellulaire, Hôpital La Timone, 264 Rue Saint Pierre, 13385 Marseille Cedex 5, France
| | - Sabine Sigaudy
- Aix-Marseille Université, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France; INSERM, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France; AP-HM, Département de Génétique Médicale, Hôpital d'enfants Timone, 264 Rue Saint Pierre, 13385 Marseille Cedex 5, France
| | - Elise Kaspi
- Aix-Marseille Université, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France; INSERM, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France; AP-HM, Service de Biologie Cellulaire, Hôpital La Timone, 264 Rue Saint Pierre, 13385 Marseille Cedex 5, France
| | - Sophie Perrin
- Aix-Marseille Université, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France; INSERM, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France
| | - Annachiara De Sandre-Giovannoli
- Aix-Marseille Université, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France; INSERM, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France; AP-HM, Département de Génétique Médicale, Hôpital d'enfants Timone, 264 Rue Saint Pierre, 13385 Marseille Cedex 5, France
| | - Nicolas Lévy
- Aix-Marseille Université, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France; INSERM, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France; AP-HM, Département de Génétique Médicale, Hôpital d'enfants Timone, 264 Rue Saint Pierre, 13385 Marseille Cedex 5, France.
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21
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The nuclear lamina regulates germline stem cell niche organization via modulation of EGFR signaling. Cell Stem Cell 2014; 13:73-86. [PMID: 23827710 DOI: 10.1016/j.stem.2013.05.003] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 03/24/2013] [Accepted: 05/06/2013] [Indexed: 02/08/2023]
Abstract
Stem cell niche interactions have been studied extensively with regard to cell polarity and extracellular signaling. Less is known about the way in which signals and polarity cues integrate with intracellular structures to ensure appropriate niche organization and function. Here, we report that nuclear lamins function in the cyst stem cells (CySCs) of Drosophila testes to control the interaction of CySCs with the hub. This interaction is important for regulation of CySC differentiation and organization of the niche that supports the germline stem cells (GSCs). Lamin promotes nuclear retention of phosphorylated ERK in the CySC lineage by regulating the distribution of specific nucleoporins within the nuclear pores. Lamin-regulated nuclear epidermal growth factor (EGF) receptor signaling in the CySC lineage is essential for proliferation and differentiation of the GSCs and the transient amplifying germ cells. Thus, we have uncovered a role for the nuclear lamina in the integration of EGF signaling to regulate stem cell niche function.
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22
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Jiang H, He X, Wang S, Jia J, Wan Y, Wang Y, Zeng R, Yates J, Zhu X, Zheng Y. A microtubule-associated zinc finger protein, BuGZ, regulates mitotic chromosome alignment by ensuring Bub3 stability and kinetochore targeting. Dev Cell 2014; 28:268-81. [PMID: 24462186 DOI: 10.1016/j.devcel.2013.12.013] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 12/09/2013] [Accepted: 12/20/2013] [Indexed: 11/28/2022]
Abstract
Equal chromosome segregation requires proper assembly of many proteins, including Bub3, onto kinetochores to promote kinetochore-microtubule interactions. By screening for mitotic regulators in the spindle envelope and matrix (Spemix), we identify a conserved Bub3 interacting and GLE-2-binding sequence (GLEBS) containing ZNF207 (BuGZ) that associates with spindle microtubules and regulates chromosome alignment. Using its conserved GLEBS, BuGZ directly binds and stabilizes Bub3. BuGZ also uses its microtubule-binding domain to enhance the loading of Bub3 to kinetochores that have assumed initial interactions with microtubules in prometaphase. This enhanced Bub3 loading is required for proper chromosome alignment and metaphase to anaphase progression. Interestingly, we show that microtubules are required for the highest kinetochore loading of Bub3, BubR1, and CENP-E during prometaphase. These findings suggest that BuGZ not only serves as a molecular chaperone for Bub3 but also enhances its loading onto kinetochores during prometaphase in a microtubule-dependent manner to promote chromosome alignment.
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Affiliation(s)
- Hao Jiang
- State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China; Department of Embryology, Carnegie Institution for Science, 3520 San Martin Dr., Baltimore, MD 21218, USA
| | - Xiaonan He
- State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Shusheng Wang
- Department of Embryology, Carnegie Institution for Science, 3520 San Martin Dr., Baltimore, MD 21218, USA
| | - Junling Jia
- Department of Embryology, Carnegie Institution for Science, 3520 San Martin Dr., Baltimore, MD 21218, USA
| | - Yihan Wan
- State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China; Department of Embryology, Carnegie Institution for Science, 3520 San Martin Dr., Baltimore, MD 21218, USA
| | - Yueju Wang
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Rong Zeng
- State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - John Yates
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Xueliang Zhu
- State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.
| | - Yixian Zheng
- Department of Embryology, Carnegie Institution for Science, 3520 San Martin Dr., Baltimore, MD 21218, USA.
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23
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Hofmann JC, Tegha-Dunghu J, Dräger S, Will CL, Lührmann R, Gruss OJ. The Prp19 complex directly functions in mitotic spindle assembly. PLoS One 2013; 8:e74851. [PMID: 24069358 PMCID: PMC3777999 DOI: 10.1371/journal.pone.0074851] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Accepted: 08/06/2013] [Indexed: 01/10/2023] Open
Abstract
The conserved Prp19 (pre-RNA processing 19) complex is required for pre-mRNA splicing in eukaryotic nuclei. Recent RNAi screens indicated that knockdown of Prp19 complex subunits strongly delays cell proliferation. Here we show that knockdown of the smallest subunit, BCAS2/Spf27, destabilizes the entire complex and leads to specific mitotic defects in human cells. These could result from splicing failures in interphase or reflect a direct function of the complex in open mitosis. Using Xenopus extracts, in which cell cycle progression and spindle formation can be reconstituted in vitro, we tested Prp19 complex functions during a complete cell cycle and directly in open mitosis. Strikingly, immunodepletion of the complex either before or after interphase significantly reduces the number of intact spindles, and increases the percentage of spindles with lower microtubule density and impaired metaphase alignment of chromosomes. Our data identify the Prp19 complex as the first spliceosome subcomplex that directly contributes to mitosis in vertebrates independently of its function in interphase.
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Affiliation(s)
- Jennifer C. Hofmann
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Justus Tegha-Dunghu
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Stefanie Dräger
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Cindy L. Will
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Reinhard Lührmann
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Oliver J. Gruss
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
- * E-mail:
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24
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Wang S, Ketcham SA, Schön A, Goodman B, Wang Y, Yates J, Freire E, Schroer TA, Zheng Y. Nudel/NudE and Lis1 promote dynein and dynactin interaction in the context of spindle morphogenesis. Mol Biol Cell 2013; 24:3522-33. [PMID: 24025714 PMCID: PMC3826990 DOI: 10.1091/mbc.e13-05-0283] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Nudel/NudE facilitates the binding of Lis1 to dynein, which subsequently enhances the recruitment of dynactin to dynein, and dynactin antagonizes Lis1 to relieve Lis1-induced dynein stall on microtubules. Lis1, Nudel/NudE, and dynactin are regulators of cytoplasmic dynein, a minus end–directed, microtubule (MT)-based motor required for proper spindle assembly and orientation. In vitro studies have shown that dynactin promotes processive movement of dynein on MTs, whereas Lis1 causes dynein to enter a persistent force-generating state (referred to here as dynein stall). Yet how the activities of Lis1, Nudel/NudE, and dynactin are coordinated to regulate dynein remains poorly understood in vivo. Working in Xenopus egg extracts, we show that Nudel/NudE facilitates the binding of Lis1 to dynein, which enhances the recruitment of dynactin to dynein. We further report a novel Lis1-dependent dynein–dynactin interaction that is essential for the organization of mitotic spindle poles. Finally, using assays for MT gliding and spindle assembly, we demonstrate an antagonistic relationship between Lis1 and dynactin that allows dynactin to relieve Lis1-induced dynein stall on MTs. Our findings suggest the interesting possibility that Lis1 and dynactin could alternately engage with dynein to allow the motor to promote spindle assembly.
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Affiliation(s)
- Shusheng Wang
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218 Department of Biology, Johns Hopkins University, Baltimore, MD 21218 Department of Chemical Physiology, Scripps Research Institute, La Jolla, California 92037
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Interplay Between Spindle Architecture and Function. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2013; 306:83-125. [DOI: 10.1016/b978-0-12-407694-5.00003-1] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Kim Y, McDole K, Zheng Y. The function of lamins in the context of tissue building and maintenance. Nucleus 2012; 3:256-62. [PMID: 22614537 PMCID: PMC3414402 DOI: 10.4161/nucl.20392] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Lamins are the major structural components of the nuclear lamina found in metazoan organisms. Extensive studies using tissue culture cells have shown that lamins are involved in a wide range of basic cell functions. This has led to the prevailing idea that a given animal cell needs at least one lamin protein for its basic proliferation and survival. However, recent studies have shown that lamins are dispensable for the proliferation and survival of mouse embryonic stem cells (ESC). In contrast to a lack of essential functions in ESCs, certain differentiated cells lacking B-type lamins exhibit increased cell cycle exit rates and enhanced senescence. In this Extra View, we discuss how studies using animal models and cell cultures have begun to reveal cell-type specific functions of lamins in tissue building and homeostasis.
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Affiliation(s)
- Youngjo Kim
- Department of Embryology, Carnegie Institution for Science and Howard Hughes Medical Institute, Baltimore, MD, USA
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Interpolar microtubules are dispensable in fission yeast meiosis II. Nat Commun 2012; 3:695. [PMID: 22426216 DOI: 10.1038/ncomms1725] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Accepted: 02/03/2012] [Indexed: 11/08/2022] Open
Abstract
The mitotic spindle consists of two types of microtubules. Dynamic kinetochore microtubules capture kinetochores, whereas stable interpolar microtubules serve as the structural backbone that connects the two spindle poles. Both have been believed to be indispensable for cell division in eukaryotes. Here we demonstrate that interpolar microtubules are dispensable for the second division of meiosis in fission yeast. Even when interpolar microtubules are disrupted by a microtubule-depolymerizing drug, spindle poles separate and chromosomes segregate poleward in second division of meiosis in most zygotes, producing viable spores. The forespore membrane, which encapsulates the nucleus in second division of meiosis and is guided by septins and the leading-edge proteins, is responsible for carrying out meiotic events in the absence of interpolar microtubules. Furthermore, during physiological second division of meiosis without microtubule perturbation, the forespore membrane assembly contributes structurally to spindle pole separation and nuclear division, generating sufficient force for spindle pole separation and subsequent events independently of interpolar microtubules.
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Choi SH, McCollum D. A role for metaphase spindle elongation forces in correction of merotelic kinetochore attachments. Curr Biol 2012; 22:225-30. [PMID: 22264609 DOI: 10.1016/j.cub.2011.12.022] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Revised: 11/07/2011] [Accepted: 12/06/2011] [Indexed: 11/28/2022]
Abstract
During mitosis, equal segregation of chromosomes depends on proper kinetochore-microtubule attachments. Merotelic kinetochore orientation, in which a single kinetochore binds microtubules from both spindle poles [1], is a major cause of chromosome instability [2], which is commonly observed in solid tumors [3, 4]. Using the fission yeast Schizosaccharomyces pombe, we show that a proper force balance between kinesin motors on interpolar spindle microtubules is critical for correcting merotelic attachments. Inhibition of the plus-end-directed spindle elongation motors kinesin-5 (Cut7) and kinesin-6 (Klp9) reduces spindle length, tension at kinetochores, and the frequency of merotelic attachments. In contrast, merotely is increased by deletion of the minus-end-directed kinesin-14 (Klp2) or overexpression of Klp9. Also, Cdk1 regulates spindle elongation forces to promote merotelic correction by phosphorylating and inhibiting Klp9. The role of spindle elongation motors in merotelic correction is conserved, because partial inhibition of the human kinesin-5 homolog Eg5 using the drug monastrol reduces spindle length and lagging chromosome frequency in both normal (RPE-1) and tumor (CaCo-2) cells. These findings reveal unexpected links between spindle forces and correction of merotelic attachments and show that pharmacological manipulation of spindle elongation forces might be used to reduce chromosome instability in cancer cells.
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Affiliation(s)
- Sung Hugh Choi
- Department of Microbiology and Physiological Systems and Program in Cell Dynamics, University of Massachusetts Medical School, Worcester, MA 01605, USA
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Kim Y, Sharov AA, McDole K, Cheng M, Hao H, Fan CM, Gaiano N, Ko MSH, Zheng Y. Mouse B-type lamins are required for proper organogenesis but not by embryonic stem cells. Science 2011; 334:1706-10. [PMID: 22116031 PMCID: PMC3306219 DOI: 10.1126/science.1211222] [Citation(s) in RCA: 202] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
B-type lamins, the major components of the nuclear lamina, are believed to be essential for cell proliferation and survival. We found that mouse embryonic stem cells (ESCs) do not need any lamins for self-renewal and pluripotency. Although genome-wide lamin-B binding profiles correlate with reduced gene expression, such binding is not directly required for gene silencing in ESCs or trophectoderm cells. However, B-type lamins are required for proper organogenesis. Defects in spindle orientation in neural progenitor cells and migration of neurons probably cause brain disorganizations found in lamin-B null mice. Thus, our studies not only disprove several prevailing views of lamin-Bs but also establish a foundation for redefining the function of the nuclear lamina in the context of tissue building and homeostasis.
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Affiliation(s)
- Youngjo Kim
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218, USA
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - Alexei A. Sharov
- Developmental Genomics and Aging Section, Laboratory of Genetics, National Institute on Aging, NIH, Baltimore, MD 21224, USA
| | - Katie McDole
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218, USA
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Melody Cheng
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Haiping Hao
- Microarray Core Facility, Johns Hopkins University School of Medicine, Baltimore, MD 21209, USA
| | - Chen-Ming Fan
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218, USA
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Nicholas Gaiano
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Minoru S. H. Ko
- Developmental Genomics and Aging Section, Laboratory of Genetics, National Institute on Aging, NIH, Baltimore, MD 21224, USA
| | - Yixian Zheng
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218, USA
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
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Kang J, Goodman B, Zheng Y, Tantin D. Dynamic regulation of Oct1 during mitosis by phosphorylation and ubiquitination. PLoS One 2011; 6:e23872. [PMID: 21897860 PMCID: PMC3163677 DOI: 10.1371/journal.pone.0023872] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Accepted: 07/27/2011] [Indexed: 01/03/2023] Open
Abstract
Background Transcription factor Oct1 regulates multiple cellular processes. It is known to be phosphorylated during the cell cycle and by stress, however the upstream kinases and downstream consequences are not well understood. One of these modified forms, phosphorylated at S335, lacks the ability to bind DNA. Other modification states besides phosphorylation have not been described. Methodology/Principal Findings We show that Oct1 is phosphorylated at S335 in the Oct1 DNA binding domain during M-phase by the NIMA-related kinase Nek6. Phospho-Oct1 is also ubiquitinated. Phosphorylation excludes Oct1 from mitotic chromatin. Instead, Oct1pS335 concentrates at centrosomes, mitotic spindle poles, kinetochores and the midbody. Oct1 siRNA knockdown diminishes the signal at these locations. Both Oct1 ablation and overexpression result in abnormal mitoses. S335 is important for the overexpression phenotype, implicating this residue in mitotic regulation. Oct1 depletion causes defects in spindle morphogenesis in Xenopus egg extracts, establishing a mitosis-specific function of Oct1. Oct1 colocalizes with lamin B1 at the spindle poles and midbody. At the midbody, both proteins are mutually required to correctly localize the other. We show that phospho-Oct1 is modified late in mitosis by non-canonical K11-linked polyubiquitin chains. Ubiquitination requires the anaphase-promoting complex, and we further show that the anaphase-promoting complex large subunit APC1 and Oct1pS335 interact. Conclusions/Significance These findings reveal mechanistic coupling between Oct1 phosphorylation and ubquitination during mitotic progression, and a role for Oct1 in mitosis.
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Affiliation(s)
- Jinsuk Kang
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Ben Goodman
- Department of Embryology, Carnegie Institution of Washington/HHMI, Baltimore, Maryland, United States of America
| | - Yixian Zheng
- Department of Embryology, Carnegie Institution of Washington/HHMI, Baltimore, Maryland, United States of America
| | - Dean Tantin
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
- * E-mail:
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Verstraeten VLRM, Peckham LA, Olive M, Capell BC, Collins FS, Nabel EG, Young SG, Fong LG, Lammerding J. Protein farnesylation inhibitors cause donut-shaped cell nuclei attributable to a centrosome separation defect. Proc Natl Acad Sci U S A 2011; 108:4997-5002. [PMID: 21383178 PMCID: PMC3064351 DOI: 10.1073/pnas.1019532108] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Despite the success of protein farnesyltransferase inhibitors (FTIs) in the treatment of certain malignancies, their mode of action is incompletely understood. Dissecting the molecular pathways affected by FTIs is important, particularly because this group of drugs is now being tested for the treatment of Hutchinson-Gilford progeria syndrome. In the current study, we show that FTI treatment causes a centrosome separation defect, leading to the formation of donut-shaped nuclei in nontransformed cell lines, tumor cell lines, and tissues of FTI-treated mice. Donut-shaped nuclei arise during chromatin decondensation in late mitosis; subsequently, cells with donut-shaped nuclei exhibit defects in karyokinesis, develop aneuploidy, and are often binucleated. Binucleated cells proliferate slowly. We identified lamin B1 and proteasome-mediated degradation of pericentrin as critical components in FTI-induced "donut formation" and binucleation. Reducing pericentrin expression or ectopic expression of nonfarnesylated lamin B1 was sufficient to elicit donut formation and binucleated cells, whereas blocking proteasomal degradation eliminated FTI-induced donut formation. Our studies have uncovered an important role of FTIs on centrosome separation and define pericentrin as a (indirect) target of FTIs affecting centrosome position and bipolar spindle formation, likely explaining some of the anticancer effects of these drugs.
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Affiliation(s)
- Valerie L. R. M. Verstraeten
- Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Cambridge, MA 02139
- Department of Dermatology, Maastricht University Medical Center, 6202 AZ, Maastricht, The Netherlands
- GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center, 6200 MD, Maastricht, The Netherlands
| | - Lana A. Peckham
- Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Cambridge, MA 02139
| | | | - Brian C. Capell
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892; and
| | - Francis S. Collins
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892; and
| | - Elizabeth G. Nabel
- National Heart, Lung, and Blood Institute and
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892; and
| | - Stephen G. Young
- Department of Medicine, University of California, Los Angeles, CA 90095
| | - Loren G. Fong
- Department of Medicine, University of California, Los Angeles, CA 90095
| | - Jan Lammerding
- Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Cambridge, MA 02139
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Oocyte-targeted deletion reveals that hsp90b1 is needed for the completion of first mitosis in mouse zygotes. PLoS One 2011; 6:e17109. [PMID: 21358806 PMCID: PMC3039677 DOI: 10.1371/journal.pone.0017109] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Accepted: 01/20/2011] [Indexed: 11/19/2022] Open
Abstract
Background Hsp90b1 is an endoplasmic reticulum (ER) chaperone (also named Grp94, ERp99, gp96,Targ2, Tra-1, Tra1, Hspc4) (MGI:98817) contributing with Hspa5 (also named Grp78, BIP) (MGI:95835) to protein folding in ER compartment. Besides its high protein expression in mouse oocytes, little is known about Hsp90b1 during the transition from oocyte-to-embryo. Because the constitutive knockout of Hsp90b1 is responsible for peri-implantation embryonic lethality, it was not yet known whether Hsp90b1 is a functionally important maternal factor. Methodology/Findings To circumvent embryonic lethality, we established an oocyte-specific conditional knockout line taking advantage of the more recently created floxed Hsp90b1 line (Hsp90b1flox, MGI:3700023) in combination with the transgenic mouse line expressing the cre recombinase under the control of zona pellucida 3 (ZP3) promoter (Zp3-cre, MGI:2176187). Altered expression of Hsp90b1 in growing oocytes provoked a limited, albeit significant reduction of the zona pellucida thickness but no obvious anomalies in follicular growth, meiotic maturation or fertilization. Interestingly, mutant zygotes obtained from oocytes lacking Hsp90b1 were unable to reach the 2-cell stage. They exhibited either a G2/M block or, more frequently an abnormal mitotic spindle leading to developmental arrest. Despite the fact that Hspa5 displayed a similar profile of expression as Hsp90b1, we found that HSPA5 and HSP90B1 did not fully colocalize in zygotes suggesting distinct function for the two chaperones. Consequently, even if HSPA5 was overexpressed in Hsp90b1 mutant embryos, it did not compensate for HSP90B1 deficiency. Finally, further characterization of ER compartment and cytoskeleton revealed a defective organization of the cytoplasmic region surrounding the mutant zygotic spindle. Conclusions Our findings demonstrate that the maternal contribution of Hsp90b1 is critical for the development of murine zygotes. All together our data indicate that Hsp90b1 is involved in unique and specific aspects of the first mitosis, which brings together the maternal and paternal genomes on a single spindle.
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Johansen KM, Forer A, Yao C, Girton J, Johansen J. Do nuclear envelope and intranuclear proteins reorganize during mitosis to form an elastic, hydrogel-like spindle matrix? Chromosome Res 2011; 19:345-65. [DOI: 10.1007/s10577-011-9187-6] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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