1
|
Hirano Y, Sato T, Miura A, Kubota Y, Shindo T, Fukase K, Fukagawa T, Kabayama K, Haraguchi T, Hiraoka Y. Disordered region of nuclear membrane protein Bqt4 recruits phosphatidic acid to the nuclear envelope to maintain its structural integrity. J Biol Chem 2024; 300:107430. [PMID: 38825008 PMCID: PMC11253665 DOI: 10.1016/j.jbc.2024.107430] [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: 01/16/2024] [Revised: 05/09/2024] [Accepted: 05/18/2024] [Indexed: 06/04/2024] Open
Abstract
The nuclear envelope (NE) is a permeable barrier that maintains nuclear-cytoplasmic compartmentalization and ensures nuclear function; however, it ruptures in various situations such as mechanical stress and mitosis. Although the protein components for sealing a ruptured NE have been identified, the mechanism by which lipid components are involved in this process remains to be elucidated. Here, we found that an inner nuclear membrane (INM) protein Bqt4 directly interacts with phosphatidic acid (PA) and serves as a platform for NE maintenance in the fission yeast Schizosaccharomyces pombe. The intrinsically disordered region (IDR) of Bqt4, proximal to the transmembrane domain, binds to PA and forms a solid aggregate in vitro. Excessive accumulation of Bqt4 IDR in INM results in membrane overproliferation and lipid droplet formation in the nucleus, leading to centromere dissociation from the NE and chromosome missegregation. Our findings suggest that Bqt4 IDR controls nuclear membrane homeostasis by recruiting PA to the INM, thereby maintaining the structural integrity of the NE.
Collapse
Affiliation(s)
- Yasuhiro Hirano
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan.
| | - Tsukino Sato
- Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Japan
| | - Ayane Miura
- Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Japan
| | - Yoshino Kubota
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | | | - Koichi Fukase
- Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Japan
| | - Tatsuo Fukagawa
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | - Kazuya Kabayama
- Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Japan
| | - Tokuko Haraguchi
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | - Yasushi Hiraoka
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan.
| |
Collapse
|
2
|
Wang K, Ito H, Kanoh J, Ueno M. Bqt4 affects relative movement between SPB and nucleolus in fission yeast. Biochem Biophys Res Commun 2024; 714:149970. [PMID: 38663097 DOI: 10.1016/j.bbrc.2024.149970] [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: 04/17/2024] [Accepted: 04/17/2024] [Indexed: 05/07/2024]
Abstract
Movement dynamics in the nucleus involve various biological processes, including DNA repair, which is crucial for cancer prevention. Changes in the movement of the components of the nucleus indicate the changes in movement dynamics in the nucleus. In Schizosaccharomyces pombe, the inner nuclear membrane protein Bqt4 plays an essential role in attaching telomeres to the nuclear envelope. We observed that the deletion of bqt4+ caused a significant decrease in the mean square displacement (MSD) calculated from the distance between the nucleolar center and spindle pole body (SPB), hereafter referred to as MSD(SPB-Nucleolus). The MSD(SPB-Nucleolus) decrease in bqt4Δ was microtubule-dependent. The Rap1-binding ability loss mutant, bqt4F46A, and nonspecific DNA-binding ability mutants, bqt43E-A, did not exhibit an MSD(SPB-Nucleolus) decrease compared to the WT. Moreover, the bqt43E-Arap1Δ double mutant and 1-262 amino acids truncated mutant bqt4ΔN (263-432), which does not have either Rap1-binding or nonspecific DNA-binding abilities, did not exhibit the MSD(SPB-Nucleolus) decrease to the same extent as bqt4Δ. These results suggest that the unknown function of Bqt4 in the C-terminal domain is essential for the maintenance of the pattern of relative movement between SPB and the nucleolus.
Collapse
Affiliation(s)
- Kaiyu Wang
- Graduate School of Integrated Sciences for Life, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8530, Japan
| | - Hiroaki Ito
- Graduate School of Integrated Sciences for Life, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8530, Japan
| | - Junko Kanoh
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan
| | - Masaru Ueno
- Graduate School of Integrated Sciences for Life, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8530, Japan; Hiroshima Research Center for Healthy Aging (HiHA), Hiroshima University, Higashi-Hiroshima 739-8530, Japan.
| |
Collapse
|
3
|
Strachan J, Leidecker O, Spanos C, Le Coz C, Chapman E, Arsenijevic A, Zhang H, Zhao N, Spoel SH, Bayne EH. SUMOylation regulates Lem2 function in centromere clustering and silencing. J Cell Sci 2023; 136:jcs260868. [PMID: 37970674 PMCID: PMC10730020 DOI: 10.1242/jcs.260868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 11/07/2023] [Indexed: 11/17/2023] Open
Abstract
Regulation by the small modifier SUMO is heavily dependent on spatial control of enzymes that mediate the attachment and removal of SUMO on substrate proteins. Here, we show that in the fission yeast Schizosaccharomyces pombe, delocalisation of the SUMO protease Ulp1 from the nuclear envelope results in centromeric defects that can be attributed to hyper-SUMOylation at the nuclear periphery. Unexpectedly, we find that although this localised hyper-SUMOylation impairs centromeric silencing, it can also enhance centromere clustering. Moreover, both effects are at least partially dependent on SUMOylation of the inner nuclear membrane protein Lem2. Lem2 has previously been implicated in diverse biological processes, including the promotion of both centromere clustering and silencing, but how these distinct activities are coordinated was unclear; our observations suggest a model whereby SUMOylation serves as a regulatory switch, modulating Lem2 interactions with competing partner proteins to balance its roles in alternative pathways. Our findings also reveal a previously unappreciated role for SUMOylation in promoting centromere clustering.
Collapse
Affiliation(s)
- Joanna Strachan
- Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FF, UK
| | - Orsolya Leidecker
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9b, Cologne 50931, Germany
| | - Christos Spanos
- Wellcome Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Clementine Le Coz
- Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FF, UK
| | - Elliott Chapman
- Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FF, UK
| | - Ana Arsenijevic
- Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FF, UK
| | - Haidao Zhang
- Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FF, UK
| | - Ning Zhao
- Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FF, UK
| | - Steven H. Spoel
- Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Elizabeth H. Bayne
- Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FF, UK
| |
Collapse
|
4
|
Le TK, Hirano Y, Asakawa H, Okamoto K, Fukagawa T, Haraguchi T, Hiraoka Y. A ubiquitin-proteasome pathway degrades the inner nuclear membrane protein Bqt4 to maintain nuclear membrane homeostasis. J Cell Sci 2023; 136:jcs260930. [PMID: 37694715 DOI: 10.1242/jcs.260930] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 08/25/2023] [Indexed: 09/12/2023] Open
Abstract
Aberrant accumulation of inner nuclear membrane (INM) proteins is associated with deformed nuclear morphology and mammalian diseases. However, the mechanisms underlying the maintenance of INM homeostasis remain poorly understood. In this study, we explored the degradation mechanisms of the INM protein Bqt4 in the fission yeast Schizosaccharomyces pombe. We have previously shown that Bqt4 interacts with the transmembrane protein Bqt3 at the INM and is degraded in the absence of Bqt3. Here, we reveal that excess Bqt4, unassociated with Bqt3, is targeted for degradation by the ubiquitin-proteasome system localized in the nucleus and Bqt3 antagonizes this process. The degradation process involves the Doa10 E3 ligase complex at the INM. Bqt4 is a tail-anchored protein and the Cdc48 complex is required for its degradation. The C-terminal transmembrane domain of Bqt4 was necessary and sufficient for proteasome-dependent protein degradation. Accumulation of Bqt4 at the INM impaired cell viability with nuclear envelope deformation, suggesting that quantity control of Bqt4 plays an important role in nuclear membrane homeostasis.
Collapse
Affiliation(s)
- Toan Khanh Le
- Nuclear Dynamics Group, Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan
| | - Yasuhiro Hirano
- Nuclear Dynamics Group, Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan
- Laboratory of Chromosome Biology, Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan
| | - Haruhiko Asakawa
- Nuclear Dynamics Group, Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan
- Laboratory of Chromosome Biology, Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan
| | - Koji Okamoto
- Laboratory of Mitochondrial Dynamics, Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan
| | - Tatsuo Fukagawa
- Laboratory of Chromosome Biology, Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan
| | - Tokuko Haraguchi
- Nuclear Dynamics Group, Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan
| | - Yasushi Hiraoka
- Nuclear Dynamics Group, Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan
| |
Collapse
|
5
|
Carreras-Villaseñor N, Martínez-Rodríguez LA, Ibarra-Laclette E, Monribot-Villanueva JL, Rodríguez-Haas B, Guerrero-Analco JA, Sánchez-Rangel D. The biological relevance of the FspTF transcription factor, homologous of Bqt4, in Fusarium sp. associated with the ambrosia beetle Xylosandrus morigerus. Front Microbiol 2023; 14:1224096. [PMID: 37520351 PMCID: PMC10375492 DOI: 10.3389/fmicb.2023.1224096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 06/22/2023] [Indexed: 08/01/2023] Open
Abstract
Transcription factors in phytopathogenic fungi are key players due to their gene expression regulation leading to fungal growth and pathogenicity. The KilA-N family encompasses transcription factors unique to fungi, and the Bqt4 subfamily is included in it and is poorly understood in filamentous fungi. In this study, we evaluated the role in growth and pathogenesis of the homologous of Bqt4, FspTF, in Fusarium sp. isolated from the ambrosia beetle Xylosandrus morigerus through the characterization of a CRISPR/Cas9 edited strain in Fsptf. The phenotypic analysis revealed that TF65-6, the edited strain, modified its mycelia growth and conidia production, exhibited affectation in mycelia and culture pigmentation, and in the response to certain stress conditions. In addition, the plant infection process was compromised. Untargeted metabolomic and transcriptomic analysis, clearly showed that FspTF may regulate secondary metabolism, transmembrane transport, virulence, and diverse metabolic pathways such as lipid metabolism, and signal transduction. These data highlight for the first time the biological relevance of an orthologue of Bqt4 in Fusarium sp. associated with an ambrosia beetle.
Collapse
Affiliation(s)
- Nohemí Carreras-Villaseñor
- Laboratorios de Biología Molecular y Fitopatología, Instituto de Ecología A.C. (INECOL), Red de Estudios Moleculares Avanzados (REMAv), Xalapa, Mexico
| | - Luis A. Martínez-Rodríguez
- Laboratorios de Biología Molecular y Fitopatología, Instituto de Ecología A.C. (INECOL), Red de Estudios Moleculares Avanzados (REMAv), Xalapa, Mexico
| | - Enrique Ibarra-Laclette
- Laboratorio de Genómica y Transcriptómica, Instituto de Ecología A.C. (INECOL), Red de Estudios Moleculares Avanzados (REMAv), Xalapa, Mexico
| | - Juan L. Monribot-Villanueva
- Laboratorio de Química de Productos Naturales, Instituto de Ecología A.C. (INECOL), Red de Estudios Moleculares Avanzados (REMAv), Xalapa, Mexico
| | - Benjamín Rodríguez-Haas
- Laboratorios de Biología Molecular y Fitopatología, Instituto de Ecología A.C. (INECOL), Red de Estudios Moleculares Avanzados (REMAv), Xalapa, Mexico
| | - José A. Guerrero-Analco
- Laboratorio de Química de Productos Naturales, Instituto de Ecología A.C. (INECOL), Red de Estudios Moleculares Avanzados (REMAv), Xalapa, Mexico
| | - Diana Sánchez-Rangel
- Laboratorios de Biología Molecular y Fitopatología, Instituto de Ecología A.C. (INECOL), Red de Estudios Moleculares Avanzados (REMAv), Xalapa, Mexico
- Investigadora Por Mexico-CONAHCyT, Xalapa, Mexico
| |
Collapse
|
6
|
Schirmer EC, Latonen L, Tollis S. Nuclear size rectification: A potential new therapeutic approach to reduce metastasis in cancer. Front Cell Dev Biol 2022; 10:1022723. [PMID: 36299481 PMCID: PMC9589484 DOI: 10.3389/fcell.2022.1022723] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 09/12/2022] [Indexed: 03/07/2024] Open
Abstract
Research on metastasis has recently regained considerable interest with the hope that single cell technologies might reveal the most critical changes that support tumor spread. However, it is possible that part of the answer has been visible through the microscope for close to 200 years. Changes in nuclear size characteristically occur in many cancer types when the cells metastasize. This was initially discarded as contributing to the metastatic spread because, depending on tumor types, both increases and decreases in nuclear size could correlate with increased metastasis. However, recent work on nuclear mechanics and the connectivity between chromatin, the nucleoskeleton, and the cytoskeleton indicate that changes in this connectivity can have profound impacts on cell mobility and invasiveness. Critically, a recent study found that reversing tumor type-dependent nuclear size changes correlated with reduced cell migration and invasion. Accordingly, it seems appropriate to now revisit possible contributory roles of nuclear size changes to metastasis.
Collapse
Affiliation(s)
- Eric C. Schirmer
- Institute of Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Leena Latonen
- Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
- Foundation for the Finnish Cancer Institute, Helsinki, Finland
| | - Sylvain Tollis
- Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
| |
Collapse
|
7
|
Martín Caballero L, Capella M, Barrales RR, Dobrev N, van Emden T, Hirano Y, Suma Sreechakram VN, Fischer-Burkart S, Kinugasa Y, Nevers A, Rougemaille M, Sinning I, Fischer T, Hiraoka Y, Braun S. The inner nuclear membrane protein Lem2 coordinates RNA degradation at the nuclear periphery. Nat Struct Mol Biol 2022; 29:910-921. [PMID: 36123402 PMCID: PMC9507967 DOI: 10.1038/s41594-022-00831-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 08/02/2022] [Indexed: 11/21/2022]
Abstract
Transcriptionally silent chromatin often localizes to the nuclear periphery. However, whether the nuclear envelope (NE) is a site for post-transcriptional gene repression is not well understood. Here we demonstrate that Schizosaccharomycespombe Lem2, an NE protein, regulates nuclear-exosome-mediated RNA degradation. Lem2 deletion causes accumulation of RNA precursors and meiotic transcripts and de-localization of an engineered exosome substrate from the nuclear periphery. Lem2 does not directly bind RNA but instead interacts with the exosome-targeting MTREC complex and its human homolog PAXT to promote RNA recruitment. This pathway acts largely independently of nuclear bodies where exosome factors assemble. Nutrient availability modulates Lem2 regulation of meiotic transcripts, implying that this pathway is environmentally responsive. Our work reveals that multiple spatially distinct degradation pathways exist. Among these, Lem2 coordinates RNA surveillance of meiotic transcripts and non-coding RNAs by recruiting exosome co-factors to the nuclear periphery. The Braun lab shows that the conserved nuclear membrane protein Lem2 interacts with the MTREC complex of the nuclear-exosome pathway to promote recruitment and degradation of ncRNAs and meiotic transcripts at the nuclear periphery in Schizosaccharomycespombe.
Collapse
Affiliation(s)
- Lucía Martín Caballero
- BioMedical Center (BMC), Division of Physiological Chemistry, Faculty of Medicine, LMU Munich, Planegg-Martinsried, Germany.,International Max Planck Research School for Molecular and Cellular Life Sciences, Planegg-Martinsried, Germany
| | - Matías Capella
- BioMedical Center (BMC), Division of Physiological Chemistry, Faculty of Medicine, LMU Munich, Planegg-Martinsried, Germany.,Instituto de Agrobiotecnología del Litoral, CONICET, Universidad Nacional del Litoral, Santa Fe, Argentina
| | - Ramón Ramos Barrales
- BioMedical Center (BMC), Division of Physiological Chemistry, Faculty of Medicine, LMU Munich, Planegg-Martinsried, Germany.,Centro Andaluz de Biología del Desarrollo (CABD), Universidad Pablo de Olavide-Consejo Superior de Investigaciones Científicas-Junta de Andalucía, Seville, Spain
| | - Nikolay Dobrev
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany.,European Molecular Biology Laboratory, Hamburg Unit, Hamburg, Germany
| | - Thomas van Emden
- BioMedical Center (BMC), Division of Physiological Chemistry, Faculty of Medicine, LMU Munich, Planegg-Martinsried, Germany.,International Max Planck Research School for Molecular and Cellular Life Sciences, Planegg-Martinsried, Germany
| | - Yasuhiro Hirano
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | - Vishnu N Suma Sreechakram
- BioMedical Center (BMC), Division of Physiological Chemistry, Faculty of Medicine, LMU Munich, Planegg-Martinsried, Germany.,Institute for Genetics, Justus-Liebig-University Giessen, Giessen, Germany
| | - Sabine Fischer-Burkart
- BioMedical Center (BMC), Division of Physiological Chemistry, Faculty of Medicine, LMU Munich, Planegg-Martinsried, Germany
| | - Yasuha Kinugasa
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan.,Regulation for intractable Infectious Diseases, National Institutes of Biomedical Innovation, Health and Nutrition, Ibaraki, Japan
| | - Alicia Nevers
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France.,University Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Mathieu Rougemaille
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
| | - Irmgard Sinning
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Tamás Fischer
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany.,The John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Yasushi Hiraoka
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | - Sigurd Braun
- BioMedical Center (BMC), Division of Physiological Chemistry, Faculty of Medicine, LMU Munich, Planegg-Martinsried, Germany. .,International Max Planck Research School for Molecular and Cellular Life Sciences, Planegg-Martinsried, Germany. .,Institute for Genetics, Justus-Liebig-University Giessen, Giessen, Germany.
| |
Collapse
|
8
|
Tollis S, Rizzotto A, Pham NT, Koivukoski S, Sivakumar A, Shave S, Wildenhain J, Zuleger N, Keys JT, Culley J, Zheng Y, Lammerding J, Carragher NO, Brunton VG, Latonen L, Auer M, Tyers M, Schirmer EC. Chemical Interrogation of Nuclear Size Identifies Compounds with Cancer Cell Line-Specific Effects on Migration and Invasion. ACS Chem Biol 2022; 17:680-700. [PMID: 35199530 PMCID: PMC8938924 DOI: 10.1021/acschembio.2c00004] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
![]()
Background: Lower survival rates for many cancer
types correlate with changes in nuclear size/scaling in a tumor-type/tissue-specific
manner. Hypothesizing that such changes might confer an advantage
to tumor cells, we aimed at the identification of commercially available
compounds to guide further mechanistic studies. We therefore screened
for Food and Drug Administration (FDA)/European Medicines Agency (EMA)-approved
compounds that reverse the direction of characteristic tumor nuclear
size changes in PC3, HCT116, and H1299 cell lines reflecting, respectively,
prostate adenocarcinoma, colonic adenocarcinoma, and small-cell squamous
lung cancer. Results: We found distinct, largely
nonoverlapping sets of compounds that rectify nuclear size changes
for each tumor cell line. Several classes of compounds including,
e.g., serotonin uptake inhibitors, cyclo-oxygenase inhibitors, β-adrenergic
receptor agonists, and Na+/K+ ATPase inhibitors,
displayed coherent nuclear size phenotypes focused on a particular
cell line or across cell lines and treatment conditions. Several compounds
from classes far afield from current chemotherapy regimens were also
identified. Seven nuclear size-rectifying compounds selected for further
investigation all inhibited cell migration and/or invasion. Conclusions: Our study provides (a) proof of concept that
nuclear size might be a valuable target to reduce cell migration/invasion
in cancer treatment and (b) the most thorough collection of tool compounds
to date reversing nuclear size changes specific to individual cancer-type
cell lines. Although these compounds still need to be tested in primary
cancer cells, the cell line-specific nuclear size and migration/invasion
responses to particular drug classes suggest that cancer type-specific
nuclear size rectifiers may help reduce metastatic spread.
Collapse
Affiliation(s)
- Sylvain Tollis
- Institute of Biomedicine, University of Eastern Finland, Kuopio 70210, Finland
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Québec H3T 1J4, Canada
| | - Andrea Rizzotto
- The Institute of Cell Biology, University of Edinburgh, Kings Buildings, Michael Swann Buildings, Max Born Crescent, Edinburgh EH9 3BF, U.K
| | - Nhan T. Pham
- Institute of Quantitative Biology, Biochemistry and Biotechnology, University of Edinburgh, Edinburgh EH9 3BF, U.K
| | - Sonja Koivukoski
- Institute of Biomedicine, University of Eastern Finland, Kuopio 70210, Finland
| | - Aishwarya Sivakumar
- The Institute of Cell Biology, University of Edinburgh, Kings Buildings, Michael Swann Buildings, Max Born Crescent, Edinburgh EH9 3BF, U.K
| | - Steven Shave
- Institute of Quantitative Biology, Biochemistry and Biotechnology, University of Edinburgh, Edinburgh EH9 3BF, U.K
| | - Jan Wildenhain
- Institute of Quantitative Biology, Biochemistry and Biotechnology, University of Edinburgh, Edinburgh EH9 3BF, U.K
| | - Nikolaj Zuleger
- The Institute of Cell Biology, University of Edinburgh, Kings Buildings, Michael Swann Buildings, Max Born Crescent, Edinburgh EH9 3BF, U.K
| | - Jeremy T. Keys
- Nancy E. and Peter C. Meinig School of Biomedical Engineering & Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York 14853, United States
| | - Jayne Culley
- Edinburgh Cancer Research UK Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XR, U.K
| | - Yijing Zheng
- Institute of Quantitative Biology, Biochemistry and Biotechnology, University of Edinburgh, Edinburgh EH9 3BF, U.K
| | - Jan Lammerding
- Nancy E. and Peter C. Meinig School of Biomedical Engineering & Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York 14853, United States
| | - Neil O. Carragher
- Edinburgh Cancer Research UK Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XR, U.K
| | - Valerie G. Brunton
- Edinburgh Cancer Research UK Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XR, U.K
| | - Leena Latonen
- Institute of Biomedicine, University of Eastern Finland, Kuopio 70210, Finland
| | - Manfred Auer
- Institute of Quantitative Biology, Biochemistry and Biotechnology, University of Edinburgh, Edinburgh EH9 3BF, U.K
| | - Mike Tyers
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Québec H3T 1J4, Canada
| | - Eric C. Schirmer
- The Institute of Cell Biology, University of Edinburgh, Kings Buildings, Michael Swann Buildings, Max Born Crescent, Edinburgh EH9 3BF, U.K
| |
Collapse
|
9
|
Bestul AJ, Yu Z, Unruh JR, Jaspersen SL. Redistribution of centrosomal proteins by centromeres and Polo kinase controls partial nuclear envelope breakdown in fission yeast. Mol Biol Cell 2021; 32:1487-1500. [PMID: 34133218 PMCID: PMC8351742 DOI: 10.1091/mbc.e21-05-0239] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Proper mitotic progression in Schizosaccharomyces pombe requires partial nuclear envelope breakdown (NEBD) and insertion of the spindle pole body (SPB—yeast centrosome) to build the mitotic spindle. Linkage of the centromere to the SPB is vital to this process, but why that linkage is important is not well understood. Utilizing high-resolution structured illumination microscopy, we show that the conserved Sad1-UNC-84 homology-domain protein Sad1 and other SPB proteins redistribute during mitosis to form a ring complex around SPBs, which is a precursor for localized NEBD and spindle formation. Although the Polo kinase Plo1 is not necessary for Sad1 redistribution, it localizes to the SPB region connected to the centromere, and its activity is vital for redistribution of other SPB ring proteins and for complete NEBD at the SPB to allow for SPB insertion. Our results lead to a model in which centromere linkage to the SPB drives redistribution of Sad1 and Plo1 activation that in turn facilitate partial NEBD and spindle formation through building of a SPB ring structure.
Collapse
Affiliation(s)
- Andrew J Bestul
- Stowers Institute for Medical Research, Kansas City, MO 64110
| | - Zulin Yu
- Stowers Institute for Medical Research, Kansas City, MO 64110
| | - Jay R Unruh
- Stowers Institute for Medical Research, Kansas City, MO 64110
| | - Sue L Jaspersen
- Stowers Institute for Medical Research, Kansas City, MO 64110.,Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS 66160
| |
Collapse
|
10
|
Borah S, Thaller DJ, Hakhverdyan Z, Rodriguez EC, Isenhour AW, Rout MP, King MC, Lusk CP. Heh2/Man1 may be an evolutionarily conserved sensor of NPC assembly state. Mol Biol Cell 2021; 32:1359-1373. [PMID: 34010011 PMCID: PMC8694041 DOI: 10.1091/mbc.e20-09-0584] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Integral membrane proteins of the Lap2-emerin-MAN1 (LEM) family have emerged as important components of the inner nuclear membrane (INM) required for the functional and physical integrity of the nuclear envelope. However, like many INM proteins, there is limited understanding of the biochemical interaction networks that enable LEM protein function. Here, we show that Heh2/Man1 can interact with major scaffold components of the nuclear pore complex (NPC), specifically the inner ring complex (IRC), in evolutionarily distant yeasts. Although an N-terminal domain is required for Heh2 targeting to the INM, we demonstrate that more stable interactions with the NPC are mediated by a C-terminal winged helix (WH) domain, thus decoupling INM targeting and NPC binding. Inhibiting Heh2's interactions with the NPC by deletion of the Heh2 WH domain leads to NPC clustering. Interestingly, Heh2's association with NPCs can also be disrupted by knocking out several outer ring nucleoporins. Thus, Heh2's interaction with NPCs depends on the structural integrity of both major NPC scaffold complexes. We propose a model in which Heh2 acts as a sensor of NPC assembly state, which may be important for NPC quality control mechanisms and the segregation of NPCs during cell division.
Collapse
Affiliation(s)
- Sapan Borah
- Department of Cell Biology, Yale School of Medicine, New Haven, CT 06520
| | - David J Thaller
- Department of Cell Biology, Yale School of Medicine, New Haven, CT 06520
| | | | - Elisa C Rodriguez
- Department of Cell Biology, Yale School of Medicine, New Haven, CT 06520
| | - Anthony W Isenhour
- Department of Cell Biology, Yale School of Medicine, New Haven, CT 06520
| | | | - Megan C King
- Department of Cell Biology, Yale School of Medicine, New Haven, CT 06520
| | - C Patrick Lusk
- Department of Cell Biology, Yale School of Medicine, New Haven, CT 06520
| |
Collapse
|
11
|
Capella M, Martín Caballero L, Pfander B, Braun S, Jentsch S. ESCRT recruitment by the S. cerevisiae inner nuclear membrane protein Heh1 is regulated by Hub1-mediated alternative splicing. J Cell Sci 2020; 133:jcs250688. [PMID: 33262311 DOI: 10.1242/jcs.250688] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 11/17/2020] [Indexed: 12/28/2022] Open
Abstract
Misassembled nuclear pore complexes (NPCs) are removed by sealing off the surrounding nuclear envelope (NE), which is conducted by the endosomal sorting complexes required for transport (ESCRT) machinery. Recruitment of ESCRT proteins to the NE is mediated by the interaction between the ESCRT member Chm7 and the inner nuclear membrane protein Heh1, which belongs to the conserved LEM family. Increased ESCRT recruitment results in excessive membrane scission at damage sites but its regulation remains poorly understood. Here, we show that Hub1-mediated alternative splicing of HEH1 pre-mRNA, resulting in production of its shorter form Heh1-S, is critical for the integrity of the NE in Saccharomyces cerevisiae ESCRT-III mutants lacking Hub1 or Heh1-S display severe growth defects and accumulate improperly assembled NPCs. This depends on the interaction of Chm7 with the conserved MSC domain, which is only present in the longer variant Heh1-L. Heh1 variants assemble into heterodimers, and we demonstrate that a unique splice segment in Heh1-S suppresses growth defects associated with the uncontrolled interaction between Heh1-L and Chm7. Together, our findings reveal that Hub1-mediated splicing generates Heh1-S to regulate ESCRT recruitment to the NE.This article has an associated First Person interview with the first author of the paper.
Collapse
Affiliation(s)
- Matías Capella
- Molecular Cell Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
- Department of Physiological Chemistry, Biomedical Center (BMC), Ludwig Maximilians University of Munich, 82152 Martinsried, Germany
| | - Lucía Martín Caballero
- Department of Physiological Chemistry, Biomedical Center (BMC), Ludwig Maximilians University of Munich, 82152 Martinsried, Germany
- International Max Planck Research School for Molecular and Cellular Life Sciences, 82152 Martinsried, Germany
| | - Boris Pfander
- International Max Planck Research School for Molecular and Cellular Life Sciences, 82152 Martinsried, Germany
- DNA Replication and Genome Integrity, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Sigurd Braun
- Department of Physiological Chemistry, Biomedical Center (BMC), Ludwig Maximilians University of Munich, 82152 Martinsried, Germany
- International Max Planck Research School for Molecular and Cellular Life Sciences, 82152 Martinsried, Germany
| | - Stefan Jentsch
- Molecular Cell Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| |
Collapse
|
12
|
High-Throughput Identification of Nuclear Envelope Protein Interactions in Schizosaccharomyces pombe Using an Arrayed Membrane Yeast-Two Hybrid Library. G3-GENES GENOMES GENETICS 2020; 10:4649-4663. [PMID: 33109728 PMCID: PMC7718735 DOI: 10.1534/g3.120.401880] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The nuclear envelope (NE) contains a specialized set of integral membrane proteins that maintain nuclear shape and integrity and influence chromatin organization and gene expression. Advances in proteomics techniques and studies in model organisms have identified hundreds of proteins that localize to the NE. However, the function of many of these proteins at the NE remains unclear, in part due to a lack of understanding of the interactions that these proteins participate in at the NE membrane. To assist in the characterization of NE transmembrane protein interactions we developed an arrayed library of integral and peripheral membrane proteins from the fission yeast Schizosaccharomyces pombe for high-throughput screening using the split-ubiquitin based membrane yeast two -hybrid system. We used this approach to characterize protein interactions for three conserved proteins that localize to the inner nuclear membrane: Cut11/Ndc1, Lem2 and Ima1/Samp1/Net5. Additionally, we determined how the interaction network for Cut11 is altered in canonical temperature-sensitive cut11-ts mutants. This library and screening approach is readily applicable to characterizing the interactomes of integral membrane proteins localizing to various subcellular compartments.
Collapse
|
13
|
Mirza AN, Gonzalez F, Ha SK, Oro AE. The Sky's the LEMit: New insights into nuclear structure regulation of transcription factor activity. Curr Opin Cell Biol 2020; 68:173-180. [PMID: 33227657 DOI: 10.1016/j.ceb.2020.10.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 09/24/2020] [Accepted: 10/08/2020] [Indexed: 12/31/2022]
Abstract
The nucleoskeleton has been associated with partitioning the genome into active and inactive compartments that dictate local transcription factor (TF) activity. However, recent data indicate that the nucleoskeleton and TFs reciprocally influence each other in dynamic TF trafficking pathways through the functions of LEM proteins. While the conserved peripheral recruitment of TFs by LEM proteins has been viewed as a mechanism of repressing transcription, a diversity of release mechanisms from the lamina suggest this compartment serves as a refuge for nuclear TF accumulation for rapid mobilization and signal stability. Detailed mechanisms suggest that TFs toggle between nuclear lamina refuge and nuclear matrix lamin-LEM protein complexes at sites of active transcription. In this review we will highlight emerging LEM functions acting at the interface of chromatin and nucleoskeleton to create TF trafficking networks.
Collapse
Affiliation(s)
- Amar N Mirza
- Program in Epithelial Biology, Stanford University School of Medicine Stanford, CA, 94305, USA
| | - Fernanda Gonzalez
- Program in Epithelial Biology, Stanford University School of Medicine Stanford, CA, 94305, USA
| | - Sierra K Ha
- Program in Epithelial Biology, Stanford University School of Medicine Stanford, CA, 94305, USA
| | - Anthony E Oro
- Program in Epithelial Biology, Stanford University School of Medicine Stanford, CA, 94305, USA.
| |
Collapse
|
14
|
Capella M, Braun S. ESCRTing Heterochromatin Out of the Nuclear Periphery. Dev Cell 2020; 53:3-5. [PMID: 32259492 DOI: 10.1016/j.devcel.2020.03.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
ESCRT proteins fulfill an important function in membrane remodeling and scission. In this issue of Developmental Cell, Pieper et al. reveal that the ESCRT machinery releases the inner nuclear membrane protein Lem2 from heterochromatin, thus ensuring its function in nuclear envelope resealing after mitosis.
Collapse
Affiliation(s)
- Matías Capella
- Department of Physiological Chemistry, Biomedical Center, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Sigurd Braun
- Department of Physiological Chemistry, Biomedical Center, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany.
| |
Collapse
|
15
|
Nuclear Envelope Proteins Modulating the Heterochromatin Formation and Functions in Fission Yeast. Cells 2020; 9:cells9081908. [PMID: 32824370 PMCID: PMC7464478 DOI: 10.3390/cells9081908] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 08/14/2020] [Accepted: 08/15/2020] [Indexed: 12/16/2022] Open
Abstract
The nuclear envelope (NE) consists of the inner and outer nuclear membranes (INM and ONM), and the nuclear pore complex (NPC), which penetrates the double membrane. ONM continues with the endoplasmic reticulum (ER). INM and NPC can interact with chromatin to regulate the genetic activities of the chromosome. Studies in the fission yeast Schizosaccharomyces pombe have contributed to understanding the molecular mechanisms underlying heterochromatin formation by the RNAi-mediated and histone deacetylase machineries. Recent studies have demonstrated that NE proteins modulate heterochromatin formation and functions through interactions with heterochromatic regions, including the pericentromeric and the sub-telomeric regions. In this review, we first introduce the molecular mechanisms underlying the heterochromatin formation and functions in fission yeast, and then summarize the NE proteins that play a role in anchoring heterochromatic regions and in modulating heterochromatin formation and functions, highlighting roles for a conserved INM protein, Lem2.
Collapse
|
16
|
Hirano Y, Kinugasa Y, Osakada H, Shindo T, Kubota Y, Shibata S, Haraguchi T, Hiraoka Y. Lem2 and Lnp1 maintain the membrane boundary between the nuclear envelope and endoplasmic reticulum. Commun Biol 2020; 3:276. [PMID: 32483293 PMCID: PMC7264229 DOI: 10.1038/s42003-020-0999-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Accepted: 05/11/2020] [Indexed: 01/09/2023] Open
Abstract
The nuclear envelope (NE) continues to the endoplasmic reticulum (ER). Proper partitioning of NE and ER is crucial for cellular activity, but the key factors maintaining the boundary between NE and ER remain to be elucidated. Here we show that the conserved membrane proteins Lem2 and Lnp1 cooperatively play a crucial role in maintaining the NE-ER membrane boundary in fission yeast Schizosaccharomyces pombe. Cells lacking both Lem2 and Lnp1 caused severe growth defects associated with aberrant expansion of the NE/ER membranes, abnormal leakage of nuclear proteins, and abnormal formation of vacuolar-like structures in the nucleus. Overexpression of the ER membrane protein Apq12 rescued the growth defect associated with membrane disorder caused by the loss of Lem2 and Lnp1. Genetic analysis showed that Apq12 had overlapping functions with Lnp1. We propose that a membrane protein network with Lem2 and Lnp1 acts as a critical factor to maintain the NE-ER boundary.
Collapse
Affiliation(s)
- Yasuhiro Hirano
- Graduate School of Frontier Biosciences, Osaka University, Suita, 565-0871, Japan.
| | - Yasuha Kinugasa
- Graduate School of Frontier Biosciences, Osaka University, Suita, 565-0871, Japan
- Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, 734-8553, Japan
| | - Hiroko Osakada
- Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology, Kobe, 651-2492, Japan
| | - Tomoko Shindo
- Electron Microscope Laboratory, Keio University School of Medicine, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Yoshino Kubota
- Graduate School of Frontier Biosciences, Osaka University, Suita, 565-0871, Japan
| | - Shinsuke Shibata
- Electron Microscope Laboratory, Keio University School of Medicine, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Tokuko Haraguchi
- Graduate School of Frontier Biosciences, Osaka University, Suita, 565-0871, Japan
- Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology, Kobe, 651-2492, Japan
| | - Yasushi Hiraoka
- Graduate School of Frontier Biosciences, Osaka University, Suita, 565-0871, Japan.
- Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology, Kobe, 651-2492, Japan.
| |
Collapse
|
17
|
Pieper GH, Sprenger S, Teis D, Oliferenko S. ESCRT-III/Vps4 Controls Heterochromatin-Nuclear Envelope Attachments. Dev Cell 2020; 53:27-41.e6. [PMID: 32109380 PMCID: PMC7139201 DOI: 10.1016/j.devcel.2020.01.028] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 12/05/2019] [Accepted: 01/27/2020] [Indexed: 12/21/2022]
Abstract
Eukaryotic genomes are organized within the nucleus through interactions with inner nuclear membrane (INM) proteins. How chromatin tethering to the INM is controlled in interphase and how this process contributes to subsequent mitotic nuclear envelope (NE) remodeling remains unclear. We have probed these fundamental questions using the fission yeast Schizosaccharomyces japonicus, which breaks and reforms the NE during mitosis. We show that attachments between heterochromatin and the transmembrane Lem2-Nur1 complex at the INM are remodeled in interphase by the ESCRT-III/Vps4 machinery. Failure of ESCRT-III/Vps4 to release Lem2-Nur1 from heterochromatin leads to persistent association of chromosomes with the INM throughout mitosis. At mitotic exit, such trapping of Lem2-Nur1 on heterochromatin prevents it from re-establishing nucleocytoplasmic compartmentalization. Our work identifies the Lem2-Nur1 complex as a substrate for the nuclear ESCRT machinery and explains how the dynamic tethering of chromosomes to the INM is linked to the establishment of nuclear compartmentalization.
Collapse
Affiliation(s)
- Gerard H Pieper
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK; Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences, King's College London, London SE1 1UL, UK
| | - Simon Sprenger
- Institute for Cell Biology, Biocenter, Medical University of Innsbruck, Innrain 80/82, A-6020, Innsbruck, Austria
| | - David Teis
- Institute for Cell Biology, Biocenter, Medical University of Innsbruck, Innrain 80/82, A-6020, Innsbruck, Austria.
| | - Snezhana Oliferenko
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK; Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences, King's College London, London SE1 1UL, UK.
| |
Collapse
|
18
|
Gallardo P, Barrales RR, Daga RR, Salas-Pino S. Nuclear Mechanics in the Fission Yeast. Cells 2019; 8:cells8101285. [PMID: 31635174 PMCID: PMC6829894 DOI: 10.3390/cells8101285] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 10/14/2019] [Accepted: 10/17/2019] [Indexed: 12/13/2022] Open
Abstract
In eukaryotic cells, the organization of the genome within the nucleus requires the nuclear envelope (NE) and its associated proteins. The nucleus is subjected to mechanical forces produced by the cytoskeleton. The physical properties of the NE and the linkage of chromatin in compacted conformation at sites of cytoskeleton contacts seem to be key for withstanding nuclear mechanical stress. Mechanical perturbations of the nucleus normally occur during nuclear positioning and migration. In addition, cell contraction or expansion occurring for instance during cell migration or upon changes in osmotic conditions also result innuclear mechanical stress. Recent studies in Schizosaccharomyces pombe (fission yeast) have revealed unexpected functions of cytoplasmic microtubules in nuclear architecture and chromosome behavior, and have pointed to NE-chromatin tethers as protective elements during nuclear mechanics. Here, we review and discuss how fission yeast cells can be used to understand principles underlying the dynamic interplay between genome organization and function and the effect of forces applied to the nucleus by the microtubule cytoskeleton.
Collapse
Affiliation(s)
- Paola Gallardo
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-Consejo Superior de Investigaciones Científicas, Junta de Andalucia, 41010 Seville, Spain.
| | - Ramón R Barrales
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-Consejo Superior de Investigaciones Científicas, Junta de Andalucia, 41010 Seville, Spain.
| | - Rafael R Daga
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-Consejo Superior de Investigaciones Científicas, Junta de Andalucia, 41010 Seville, Spain.
| | - Silvia Salas-Pino
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-Consejo Superior de Investigaciones Científicas, Junta de Andalucia, 41010 Seville, Spain.
| |
Collapse
|
19
|
Hu C, Inoue H, Sun W, Takeshita Y, Huang Y, Xu Y, Kanoh J, Chen Y. Structural insights into chromosome attachment to the nuclear envelope by an inner nuclear membrane protein Bqt4 in fission yeast. Nucleic Acids Res 2019; 47:1573-1584. [PMID: 30462301 PMCID: PMC6379675 DOI: 10.1093/nar/gky1186] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 10/23/2018] [Accepted: 11/07/2018] [Indexed: 12/13/2022] Open
Abstract
The dynamic association of chromosomes with the nuclear envelope (NE) is essential for chromosome maintenance. Schizosaccharomyces pombe inner nuclear membrane protein Bqt4 plays a critical role in connecting telomeres to the NE, mainly through a direct interaction with the telomeric protein Rap1. Bqt4 also interacts with Lem2 for pericentric heterochromatin maintenance. How Bqt4 coordinates the interactions with different proteins to exert their functions is unclear. Here, we report the crystal structures of the N-terminal domain of Bqt4 in complexes with Bqt4-binding motifs from Rap1, Lem2, and Sad1. The structural, biochemical and cellular analyses reveal that the N-terminal domain of Bqt4 is a protein-interaction module that recognizes a consensus motif and plays essential roles in telomere-NE association and meiosis progression. Phosphorylation of Bqt4-interacting proteins may act as a switch to regulate these interactions during cell cycles. Our studies provide structural insights into the identification and regulation of Bqt4-mediated interactions.
Collapse
Affiliation(s)
- Chunyi Hu
- State Key Laboratory of Molecular Biology, National Center for Protein Science Shanghai, Shanghai Science Research Center, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences; University of Chinese Academy of Sciences, 333 Haike Road, Shanghai 201210, China
| | - Haruna Inoue
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Wenqi Sun
- School of Life Science and Technology, Shanghai Tech University, 100 Haike Road, Shanghai 201210, P.R. China
| | - Yumiko Takeshita
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Yaoguang Huang
- State Key Laboratory of Molecular Biology, National Center for Protein Science Shanghai, Shanghai Science Research Center, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences; University of Chinese Academy of Sciences, 333 Haike Road, Shanghai 201210, China
| | - Ying Xu
- State Key Laboratory of Molecular Biology, National Center for Protein Science Shanghai, Shanghai Science Research Center, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences; University of Chinese Academy of Sciences, 333 Haike Road, Shanghai 201210, China
| | - Junko Kanoh
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Yong Chen
- State Key Laboratory of Molecular Biology, National Center for Protein Science Shanghai, Shanghai Science Research Center, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences; University of Chinese Academy of Sciences, 333 Haike Road, Shanghai 201210, China.,School of Life Science and Technology, Shanghai Tech University, 100 Haike Road, Shanghai 201210, P.R. China
| |
Collapse
|
20
|
Kinugasa Y, Hirano Y, Sawai M, Ohno Y, Shindo T, Asakawa H, Chikashige Y, Shibata S, Kihara A, Haraguchi T, Hiraoka Y. The very-long-chain fatty acid elongase Elo2 rescues lethal defects associated with loss of the nuclear barrier function in fission yeast cells. J Cell Sci 2019; 132:jcs.229021. [PMID: 30975915 DOI: 10.1242/jcs.229021] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 04/03/2019] [Indexed: 12/21/2022] Open
Abstract
In eukaryotic cells, chromosomes are confined to the nucleus, which is compartmentalized by the nuclear membranes; these are continuous with the endoplasmic reticulum membranes. Maintaining the homeostasis of these membranes is an important cellular activity performed by lipid metabolic enzymes. However, how lipid metabolic enzymes affect nuclear membrane functions remains to be elucidated. We found that the very-long-chain fatty acid elongase Elo2 is located in the nuclear membrane and prevents lethal defects associated with nuclear membrane ruptures in mutants of the nuclear membrane proteins Lem2 and Bqt4 in the fission yeast Schizosaccharomyces pombe. Lipid composition analysis shows that t20:0/24:0 phytoceramide (a conjugate of C20:0 phytosphingosine and C24:0 fatty acid) is a major ceramide species in S. pombe The quantity of this ceramide is reduced in the absence of Lem2, and restored by increased expression of Elo2. Furthermore, loss of S. pombe Elo2 can be rescued by its human orthologs. These results suggest that the conserved very-long-chain fatty acid elongase producing the ceramide component is essential for nuclear membrane integrity and cell viability in eukaryotes.This article has an associated First Person interview with the first author of the paper.
Collapse
Affiliation(s)
- Yasuha Kinugasa
- Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan
| | - Yasuhiro Hirano
- Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan
| | - Megumi Sawai
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan
| | - Yusuke Ohno
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan
| | - Tomoko Shindo
- Electron Microscope Laboratory, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Haruhiko Asakawa
- Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan
| | - Yuji Chikashige
- Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology, Kobe 651-2492, Japan
| | - Shinsuke Shibata
- Electron Microscope Laboratory, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Akio Kihara
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan
| | - Tokuko Haraguchi
- Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan.,Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology, Kobe 651-2492, Japan
| | - Yasushi Hiraoka
- Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan .,Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology, Kobe 651-2492, Japan
| |
Collapse
|
21
|
Iwamoto M, Fukuda Y, Osakada H, Mori C, Hiraoka Y, Haraguchi T. Identification of the evolutionarily conserved nuclear envelope proteins Lem2 and MicLem2 in Tetrahymena thermophila. Gene 2019; 721S:100006. [PMID: 32550543 PMCID: PMC7285967 DOI: 10.1016/j.gene.2019.100006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 12/18/2018] [Accepted: 01/11/2019] [Indexed: 11/26/2022]
Abstract
Lem2 family proteins, i.e. the LAP2-Emerin-MAN1 (LEM) domain-containing nuclear envelope proteins, are well-conserved from yeasts to humans, both of which belong to the Opisthokonta supergroup. However, whether their homologs are present in other eukaryotic phylogenies remains unclear. In this study, we identified two Lem2 homolog proteins, which we named as Lem2 and MicLem2, in a ciliate Tetrahymena thermophila belonging to the SAR supergroup. Lem2 was localized to the nuclear envelope of the macronucleus (MAC) and micronucleus (MIC), while MicLem2 was exclusively localized to the nuclear envelope of the MIC. Immunoelectron microscopy revealed that Lem2 in T. thermophila was localized to both the inner and outer nuclear envelopes of the MAC and MIC, while MicLem2 was mostly localized to the nuclear pores of the MIC. Molecular domain analysis using GFP-fused protein showed that the N-terminal and luminal domains, including the transmembrane segments, are responsible for nuclear envelope localization. During sexual reproduction, enrichment of Lem2 occurred in the nuclear envelopes of the MAC and MIC to be degraded, while MicLem2 was enriched in the nuclear envelope of the MIC that escaped degradation. These findings suggest the unique characteristics of Tetrahymena Lem2 proteins. Our findings provide insight into the evolutionary divergence of nuclear envelope proteins. Conserved nuclear envelope proteins Lem2 and MicLem2 are identified in Tetrahymena. Lem2 is localized to the nuclear envelope of the macronucleus and the micronucleus. MicLem2 is localized to the nuclear pore complex of the micronucleus. In sexual reproduction, Lem2 is enriched to the nuclei assigned to degradation. MicLem2 is enriched to the micronuclei that are escaped from degradation.
Collapse
Key Words
- BAF, barrier-to-autointegration factor
- DAPI, 4′,6‑diamidino‑2‑phenylindole
- DDW, double distilled water
- EDTA, ethylenediaminetetraacetic acid
- ER, endoplasmic reticulum
- GA, glutaraldehyde
- HeH domain
- HeH, helix-extension-helix
- LAP2, lamina associated polypeptide 2
- LEM domain
- LEM, LAP2-Emerin-MAN1
- MAC, macronucleus
- MIC, micronucleus
- MSC domain
- MSC, Man1-Src1p-C-terminal
- Man1
- Man1-Src1p-C-terminal domain
- NE, nuclear envelope
- NLS, nuclear localization signal
- NPC, nuclear pore complex
- Nuclear dimorphism
- Nuclear envelope
- ONM and INM, outer and inner nuclear membranes
- PB, phosphate buffer
- PBS, phosphate buffered saline
- Protist
- RRM, RNA recognition motif
- TM, transmembrane
Collapse
Affiliation(s)
- Masaaki Iwamoto
- Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology, Kobe 651-2492, Japan
| | - Yasuhiro Fukuda
- Graduate School of Agricultural Science, Tohoku University, Osaki, 989-6711, Japan
| | - Hiroko Osakada
- Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology, Kobe 651-2492, Japan
| | - Chie Mori
- Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology, Kobe 651-2492, Japan
| | - Yasushi Hiraoka
- Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology, Kobe 651-2492, Japan.,Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan
| | - Tokuko Haraguchi
- Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology, Kobe 651-2492, Japan.,Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan
| |
Collapse
|
22
|
Hu C, Inoue H, Sun W, Takeshita Y, Huang Y, Xu Y, Kanoh J, Chen Y. The Inner Nuclear Membrane Protein Bqt4 in Fission Yeast Contains a DNA-Binding Domain Essential for Telomere Association with the Nuclear Envelope. Structure 2018; 27:335-343.e3. [PMID: 30503780 DOI: 10.1016/j.str.2018.10.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 08/30/2018] [Accepted: 10/15/2018] [Indexed: 01/07/2023]
Abstract
Telomeres, the protective caps at the end of the chromosomes, are often associated with the nuclear envelope (NE). Telomere positioning to the NE is dynamically regulated during mitosis and meiosis. One inner nuclear membrane protein, Bqt4, in Schizosaccharomyces pombe plays essential roles in connecting telomeres to the NE. However, the structural basis of Bqt4 in mediating telomere-NE association is not clear. Here, we report the crystal structure of the N-terminal domain of Bqt4. The N-terminal domain of Bqt4 structurally resembles the APSES-family DNA-binding domain and has a moderate double-stranded DNA-binding activity. Disruption of Bqt4-DNA interaction results in telomere detachment from the NE. These data suggest that the DNA-binding activity of Bqt4 may function to prime the chromosome onto the NE and promote telomere-NE association.
Collapse
Affiliation(s)
- Chunyi Hu
- State Key Laboratory of Molecular Biology, National Center for Protein Science Shanghai, Shanghai Science Research Center, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences; University of Chinese Academy of Sciences, 333 Haike Road, Shanghai 201210, China
| | - Haruna Inoue
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Wenqi Sun
- School of Life Science and Technology, Shanghai Tech University, 100 Haike Road, Shanghai 201210, P. R. China
| | - Yumiko Takeshita
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Yaoguang Huang
- State Key Laboratory of Molecular Biology, National Center for Protein Science Shanghai, Shanghai Science Research Center, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences; University of Chinese Academy of Sciences, 333 Haike Road, Shanghai 201210, China
| | - Ying Xu
- State Key Laboratory of Molecular Biology, National Center for Protein Science Shanghai, Shanghai Science Research Center, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences; University of Chinese Academy of Sciences, 333 Haike Road, Shanghai 201210, China
| | - Junko Kanoh
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Yong Chen
- State Key Laboratory of Molecular Biology, National Center for Protein Science Shanghai, Shanghai Science Research Center, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences; University of Chinese Academy of Sciences, 333 Haike Road, Shanghai 201210, China; School of Life Science and Technology, Shanghai Tech University, 100 Haike Road, Shanghai 201210, P. R. China.
| |
Collapse
|