1
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van der Graaf K, Srivastav S, Nishad R, Stern M, McNew JA. The Drosophila Nesprin-1 homolog MSP300 is required for muscle autophagy and proteostasis. J Cell Sci 2024; 137:jcs262096. [PMID: 38757366 PMCID: PMC11213522 DOI: 10.1242/jcs.262096] [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: 03/06/2024] [Accepted: 05/13/2024] [Indexed: 05/18/2024] Open
Abstract
Nesprin proteins, which are components of the linker of nucleoskeleton and cytoskeleton (LINC) complex, are located within the nuclear envelope and play prominent roles in nuclear architecture. For example, LINC complex proteins interact with both chromatin and the cytoskeleton. Here, we report that the Drosophila Nesprin MSP300 has an additional function in autophagy within larval body wall muscles. RNAi-mediated MSP300 knockdown in larval body wall muscles resulted in defects in the contractile apparatus, muscle degeneration and defective autophagy. In particular, MSP300 knockdown caused accumulation of cytoplasmic aggregates that contained poly-ubiquitylated cargo, as well as the autophagy receptor ref(2)P (the fly homolog of p62 or SQSTM) and Atg8a. Furthermore, MSP300 knockdown larvae expressing an mCherry-GFP-tagged Atg8a transgene exhibited aberrant persistence of the GFP signal within these aggregates, indicating failure of autophagosome maturation. These autophagy deficits were similar to those exhibited by loss of the endoplasmic reticulum (ER) fusion protein Atlastin (Atl), raising the possibility that Atl and MSP300 might function in the same pathway. In support of this possibility, we found that a GFP-tagged MSP300 protein trap exhibited extensive localization to the ER. Alteration of ER-directed MSP300 might abrogate important cytoskeletal contacts necessary for autophagosome completion.
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Affiliation(s)
| | | | - Rajkishor Nishad
- Department of BioSciences, Rice University, Houston, TX 77005, USA
| | - Michael Stern
- Department of BioSciences, Rice University, Houston, TX 77005, USA
| | - James A. McNew
- Department of BioSciences, Rice University, Houston, TX 77005, USA
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2
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van der Graaf K, Srivastav S, Singh P, McNew JA, Stern M. The Drosophila melanogaster attP40 docking site and derivatives are insertion mutations of msp-300. PLoS One 2022; 17:e0278598. [PMID: 36516171 PMCID: PMC9750024 DOI: 10.1371/journal.pone.0278598] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 11/19/2022] [Indexed: 12/15/2022] Open
Abstract
The ɸC31 integrase system is widely used in Drosophila melanogaster to allow transgene targeting to specific loci. Over the years, flies bearing any of more than 100 attP docking sites have been constructed. One popular docking site, termed attP40, is located close to the Nesprin-1 orthologue msp-300 and lies upstream of certain msp-300 isoforms and within the first intron of others. Here we show that attP40 causes larval muscle nuclear clustering, which is a phenotype also conferred by msp-300 mutations. We also show that flies bearing insertions within attP40 can exhibit decreased msp-300 transcript levels in third instar larvae. Finally, chromosomes carrying certain "transgenic RNAi project" (TRiP) insertions into attP40 can confer pupal or adult inviability or infertility, or dominant nuclear clustering effects in certain genetic backgrounds. These phenotypes do not require transcription from the insertions within attP40. These results demonstrate that attP40 and insertion derivatives act as msp-300 insertional mutations. These findings should be considered when interpreting data from attP40-bearing flies.
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Affiliation(s)
- Kevin van der Graaf
- Department of Biosciences, Program in Biochemistry and Cell Biology, Rice University, Houston, Texas, United States of America
| | - Saurabh Srivastav
- Department of Biosciences, Program in Biochemistry and Cell Biology, Rice University, Houston, Texas, United States of America
| | - Pratibha Singh
- Department of Biosciences, Program in Biochemistry and Cell Biology, Rice University, Houston, Texas, United States of America
| | - James A. McNew
- Department of Biosciences, Program in Biochemistry and Cell Biology, Rice University, Houston, Texas, United States of America
| | - Michael Stern
- Department of Biosciences, Program in Biochemistry and Cell Biology, Rice University, Houston, Texas, United States of America
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3
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Shaw NM, Rios-Monterrosa JL, Fedorchak GR, Ketterer MR, Coombs GS, Lammerding J, Wallrath LL. Effects of mutant lamins on nucleo-cytoskeletal coupling in Drosophila models of LMNA muscular dystrophy. Front Cell Dev Biol 2022; 10:934586. [PMID: 36120560 PMCID: PMC9471154 DOI: 10.3389/fcell.2022.934586] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 07/20/2022] [Indexed: 11/13/2022] Open
Abstract
The nuclei of multinucleated skeletal muscles experience substantial external force during development and muscle contraction. Protection from such forces is partly provided by lamins, intermediate filaments that form a scaffold lining the inner nuclear membrane. Lamins play a myriad of roles, including maintenance of nuclear shape and stability, mediation of nuclear mechanoresponses, and nucleo-cytoskeletal coupling. Herein, we investigate how disease-causing mutant lamins alter myonuclear properties in response to mechanical force. This was accomplished via a novel application of a micropipette harpooning assay applied to larval body wall muscles of Drosophila models of lamin-associated muscular dystrophy. The assay enables the measurement of both nuclear deformability and intracellular force transmission between the cytoskeleton and nuclear interior in intact muscle fibers. Our studies revealed that specific mutant lamins increase nuclear deformability while other mutant lamins cause nucleo-cytoskeletal coupling defects, which were associated with loss of microtubular nuclear caging. We found that microtubule caging of the nucleus depended on Msp300, a KASH domain protein that is a component of the linker of nucleoskeleton and cytoskeleton (LINC) complex. Taken together, these findings identified residues in lamins required for connecting the nucleus to the cytoskeleton and suggest that not all muscle disease-causing mutant lamins produce similar defects in subcellular mechanics.
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Affiliation(s)
- Nicholas M. Shaw
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
| | - Jose L. Rios-Monterrosa
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
| | - Gregory R. Fedorchak
- The Nancy E. and Peter C. Meinig School of Biomedical Engineering, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, United States
| | - Margaret R. Ketterer
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
| | - Gary S. Coombs
- Biology Department, Waldorf University, Forest City, IA, United States
| | - Jan Lammerding
- The Nancy E. and Peter C. Meinig School of Biomedical Engineering, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, United States
| | - Lori L. Wallrath
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
- *Correspondence: Lori L. Wallrath,
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4
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Buckley KH, Nestor-Kalinoski AL, Pizza FX. Positional Context of Myonuclear Transcription During Injury-Induced Muscle Regeneration. Front Physiol 2022; 13:845504. [PMID: 35492593 PMCID: PMC9040890 DOI: 10.3389/fphys.2022.845504] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 03/02/2022] [Indexed: 01/31/2023] Open
Abstract
Fundamental aspects underlying downstream processes of skeletal muscle regeneration, such as myonuclear positioning and transcription are poorly understood. This investigation begins to address deficiencies in knowledge by examining the kinetics of myonuclear accretion, positioning, and global transcription during injury-induced muscle regeneration in mice. We demonstrate that myonuclear accretion plateaus within 7 days of an injury and that the majority (∼70%) of myonuclei are centrally aligned in linear arrays (nuclear chains) throughout the course of regeneration. Relatively few myonuclei were found in a peripheral position (∼20%) or clustered (∼10%) together during regeneration. Importantly, transcriptional activity of individual myonuclei in nuclear chains was high, and greater than that of peripheral or clustered myonuclei. Transcription occurring primarily in nuclear chains elevated the collective transcriptional activity of regenerating myofibers during the later stage of regeneration. Importantly, the number of myonuclei in chains and their transcriptional activity were statistically correlated with an increase in myofiber size during regeneration. Our findings demonstrate the positional context of transcription during regeneration and highlight the importance of centralized nuclear chains in facilitating hypertrophy of regenerating myofibers after injury.
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Affiliation(s)
- Kole H. Buckley
- School of Exercise and Rehabilitation Sciences, University of Toledo, Toledo, OH, United States
| | | | - Francis X. Pizza
- School of Exercise and Rehabilitation Sciences, University of Toledo, Toledo, OH, United States
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5
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A 10-day mild treadmill exercise performed before an epileptic seizure alleviates oxidative injury in the skeletal muscle and brain tissues of the rats. MARMARA MEDICAL JOURNAL 2022. [DOI: 10.5472/marumj.1056192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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6
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Costa ML, Jurberg AD, Mermelstein C. The Role of Embryonic Chick Muscle Cell Culture in the Study of Skeletal Myogenesis. Front Physiol 2021; 12:668600. [PMID: 34093232 PMCID: PMC8173222 DOI: 10.3389/fphys.2021.668600] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 04/21/2021] [Indexed: 11/13/2022] Open
Abstract
The mechanisms involved in the development of skeletal muscle fibers have been studied in the last 70 years and yet many aspects of this process are still not completely understood. A myriad of in vivo and in vitro invertebrate and vertebrate animal models has been used for dissecting the molecular and cellular events involved in muscle formation. Among the most used animal models for the study of myogenesis are the rodents rat and mouse, the fruit fly Drosophila, and the birds chicken and quail. Here, we describe the robustness and advantages of the chick primary muscle culture model for the study of skeletal myogenesis. In the myoblast culture obtained from embryonic chick pectoralis muscle it is possible to analyze all the steps involved in skeletal myogenesis, such as myoblast proliferation, withdrawal from cell cycle, cell elongation and migration, myoblast alignment and fusion, the assembly of striated myofibrils, and the formation of multinucleated myotubes. The fact that in vitro chick myotubes can harbor hundreds of nuclei, whereas myotubes from cell lines have only a dozen nuclei demonstrates the high level of differentiation of the autonomous chick myogenic program. This striking differentiation is independent of serum withdrawal, which points to the power of the model. We also review the major pro-myogenic and anti-myogenic molecules and signaling pathways involved in chick myogenesis, in addition to providing a detailed protocol for the preparation of embryonic chick myogenic cultures. Moreover, we performed a bibliometric analysis of the articles that used this model to evaluate which were the main explored topics of interest and their contributors. We expect that by describing the major findings, and their advantages, of the studies using the embryonic chick myogenic model we will foster new studies on the molecular and cellular process involved in muscle proliferation and differentiation that are more similar to the actual in vivo condition than the muscle cell lines.
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Affiliation(s)
- Manoel L Costa
- Laboratório de Diferenciação Muscular, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Arnon D Jurberg
- Laboratório de Diferenciação Muscular, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Faculdade de Medicina-Presidente Vargas, Universidade Estácio de Sá, Rio de Janeiro, Brazil
| | - Claudia Mermelstein
- Laboratório de Diferenciação Muscular, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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7
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Shin D, Nakamura M, Morishita Y, Eiraku M, Yamakawa T, Sasamura T, Akiyama M, Inaki M, Matsuno K. Collective nuclear behavior shapes bilateral nuclear symmetry for subsequent left-right asymmetric morphogenesis in Drosophila. Development 2021; 148:260539. [PMID: 34097729 PMCID: PMC8126412 DOI: 10.1242/dev.198507] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 03/23/2021] [Indexed: 11/20/2022]
Abstract
Proper organ development often requires nuclei to move to a specific position within the cell. To determine how nuclear positioning affects left-right (LR) development in the Drosophila anterior midgut (AMG), we developed a surface-modeling method to measure and describe nuclear behavior at stages 13-14, captured in three-dimensional time-lapse movies. We describe the distinctive positioning and a novel collective nuclear behavior by which nuclei align LR symmetrically along the anterior-posterior axis in the visceral muscles that overlie the midgut and are responsible for the LR-asymmetric development of this organ. Wnt4 signaling is crucial for the collective behavior and proper positioning of the nuclei, as are myosin II and the LINC complex, without which the nuclei fail to align LR symmetrically. The LR-symmetric positioning of the nuclei is important for the subsequent LR-asymmetric development of the AMG. We propose that the bilaterally symmetrical positioning of these nuclei may be mechanically coupled with subsequent LR-asymmetric morphogenesis.
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Affiliation(s)
- Dongsun Shin
- Department of Biological Sciences, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Mitsutoshi Nakamura
- Department of Biological Sciences, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Yoshitaka Morishita
- Department of Biological Sciences, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Mototsugu Eiraku
- Department of Biosystems Science, Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
| | - Tomoko Yamakawa
- Department of Biological Sciences, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Takeshi Sasamura
- Department of Biological Sciences, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Masakazu Akiyama
- Meiji Institute for Advanced Study of Mathematical Sciences, Meiji University, 4-21-1 Nakano, Nakanoku, Tokyo 164-8525, Japan
| | - Mikiko Inaki
- Department of Biological Sciences, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Kenji Matsuno
- Department of Biological Sciences, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
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8
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Unnikannan CP, Reuveny A, Grunberg D, Volk T. Recruitment of BAF to the nuclear envelope couples the LINC complex to endoreplication. Development 2020; 147:dev.191304. [PMID: 33168584 PMCID: PMC7758627 DOI: 10.1242/dev.191304] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 10/29/2020] [Indexed: 12/21/2022]
Abstract
DNA endoreplication has been implicated as a cell strategy for cell growth and in tissue injury. Here, we demonstrate that barrier-to-autointegration factor (BAF) represses endoreplication in Drosophila myofibers. We show that BAF localization at the nuclear envelope is eliminated in flies with mutations of the linker of nucleoskeleton and cytoskeleton (LINC) complex in which the LEM-domain protein Otefin is excluded, or after disruption of the nucleus-sarcomere connections. Furthermore, BAF localization at the nuclear envelope requires the activity of the BAF kinase VRK1/Ball, and, consistently, non-phosphorylatable BAF-GFP is excluded from the nuclear envelope. Importantly, removal of BAF from the nuclear envelope correlates with increased DNA content in the myonuclei. E2F1, a key regulator of endoreplication, overlaps BAF localization at the myonuclear envelope, and BAF removal from the nuclear envelope results in increased E2F1 levels in the nucleoplasm and subsequent elevated DNA content. We suggest that LINC-dependent and phosphosensitive attachment of BAF to the nuclear envelope, through its binding to Otefin, tethers E2F1 to the nuclear envelope thus inhibiting its accumulation in the nucleoplasm. Summary: Localization of BAF at the nuclear envelope of myonuclei depends on a functional LINC complex and on nucleus-sarcomere connections, and is shown to restrict E2F1 levels in the nucleoplasm.
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Affiliation(s)
- C P Unnikannan
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Adriana Reuveny
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Dvorah Grunberg
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Talila Volk
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
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9
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Titlow J, Robertson F, Järvelin A, Ish-Horowicz D, Smith C, Gratton E, Davis I. Syncrip/hnRNP Q is required for activity-induced Msp300/Nesprin-1 expression and new synapse formation. J Cell Biol 2020; 219:133707. [PMID: 32040548 PMCID: PMC7055005 DOI: 10.1083/jcb.201903135] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 08/21/2019] [Accepted: 12/12/2019] [Indexed: 01/09/2023] Open
Abstract
Memory and learning involve activity-driven expression of proteins and cytoskeletal reorganization at new synapses, requiring posttranscriptional regulation of localized mRNA a long distance from corresponding nuclei. A key factor expressed early in synapse formation is Msp300/Nesprin-1, which organizes actin filaments around the new synapse. How Msp300 expression is regulated during synaptic plasticity is poorly understood. Here, we show that activity-dependent accumulation of Msp300 in the postsynaptic compartment of the Drosophila larval neuromuscular junction is regulated by the conserved RNA binding protein Syncrip/hnRNP Q. Syncrip (Syp) binds to msp300 transcripts and is essential for plasticity. Single-molecule imaging shows that msp300 is associated with Syp in vivo and forms ribosome-rich granules that contain the translation factor eIF4E. Elevated neural activity alters the dynamics of Syp and the number of msp300:Syp:eIF4E RNP granules at the synapse, suggesting that these particles facilitate translation. These results introduce Syp as an important early acting activity-dependent regulator of a plasticity gene that is strongly associated with human ataxias.
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Affiliation(s)
- Joshua Titlow
- Department of Biochemistry, University of Oxford, Oxford, UK
| | | | - Aino Järvelin
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - David Ish-Horowicz
- Department of Biochemistry, University of Oxford, Oxford, UK.,Medical Research Council Lab for Molecular Cell Biology, University College London, London, UK
| | - Carlas Smith
- Centre for Neural Circuits and Behaviour, University of Oxford, Oxford, UK
| | - Enrico Gratton
- Laboratory for Fluorescence Dynamics, University of California Irvine, Irvine, CA
| | - Ilan Davis
- Department of Biochemistry, University of Oxford, Oxford, UK
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10
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Bataillé L, Colombié N, Pelletier A, Paululat A, Lebreton G, Carrier Y, Frendo JL, Vincent A. Alary muscles and thoracic alary-related muscles are atypical striated muscles involved in maintaining the position of internal organs. Development 2020; 147:dev.185645. [PMID: 32188630 DOI: 10.1242/dev.185645] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 03/04/2020] [Indexed: 12/11/2022]
Abstract
Alary muscles (AMs) have been described as a component of the cardiac system in various arthropods. Lineage-related thoracic muscles (TARMs), linking the exoskeleton to specific gut regions, have recently been discovered in Drosophila Asymmetrical attachments of AMs and TARMs, to the exoskeleton on one side and internal organs on the other, suggested an architectural function in moving larvae. Here, we analysed the shape and sarcomeric organisation of AMs and TARMs, and imaged their atypical deformability in crawling larvae. We then selectively eliminated AMs and TARMs by targeted apoptosis. Elimination of AMs revealed that AMs are required for suspending the heart in proper intra-haemocelic position and for opening of the heart lumen, and that AMs constrain the curvature of the respiratory tracheal system during crawling; TARMs are required for proper positioning of visceral organs and efficient food transit. AM/TARM cardiac versus visceral attachment depends on Hox control, with visceral attachment being the ground state. TARMs and AMs are the first example of multinucleate striated muscles connecting the skeleton to the cardiac and visceral systems in bilaterians, with multiple physiological functions.
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Affiliation(s)
- Laetitia Bataillé
- Centre de Biologie du Développement (CBD), Centre de Biologie Intégrative (CBI), Université de Toulouse 3, CNRS, UPS, 118 route de Narbonne, 31062 Toulouse, France
| | - Nathalie Colombié
- Centre de Biologie du Développement (CBD), Centre de Biologie Intégrative (CBI), Université de Toulouse 3, CNRS, UPS, 118 route de Narbonne, 31062 Toulouse, France
| | - Aurore Pelletier
- Centre de Biologie du Développement (CBD), Centre de Biologie Intégrative (CBI), Université de Toulouse 3, CNRS, UPS, 118 route de Narbonne, 31062 Toulouse, France
| | - Achim Paululat
- University of Osnabrück, Department of Biology/Chemistry, Zoology and Developmental Biology, Barbarastraße 11, 49076 Osnabrück, Germany
| | - Gaëlle Lebreton
- Centre de Biologie du Développement (CBD), Centre de Biologie Intégrative (CBI), Université de Toulouse 3, CNRS, UPS, 118 route de Narbonne, 31062 Toulouse, France
| | - Yannick Carrier
- Centre de Biologie du Développement (CBD), Centre de Biologie Intégrative (CBI), Université de Toulouse 3, CNRS, UPS, 118 route de Narbonne, 31062 Toulouse, France
| | - Jean-Louis Frendo
- Centre de Biologie du Développement (CBD), Centre de Biologie Intégrative (CBI), Université de Toulouse 3, CNRS, UPS, 118 route de Narbonne, 31062 Toulouse, France
| | - Alain Vincent
- Centre de Biologie du Développement (CBD), Centre de Biologie Intégrative (CBI), Université de Toulouse 3, CNRS, UPS, 118 route de Narbonne, 31062 Toulouse, France
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11
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A Large Scale Systemic RNAi Screen in the Red Flour Beetle Tribolium castaneum Identifies Novel Genes Involved in Insect Muscle Development. G3-GENES GENOMES GENETICS 2019; 9:1009-1026. [PMID: 30733381 PMCID: PMC6469426 DOI: 10.1534/g3.118.200995] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Although muscle development has been widely studied in Drosophila melanogaster there are still many gaps in our knowledge, and it is not known to which extent this knowledge can be transferred to other insects. To help in closing these gaps we participated in a large-scale RNAi screen that used the red flour beetle, Tribolium castaneum, as a screening platform. The effects of systemic RNAi were screened upon double-stranded RNA injections into appropriate muscle-EGFP tester strains. Injections into pupae were followed by the analysis of the late embryonic/early larval muscle patterns, and injections into larvae by the analysis of the adult thoracic muscle patterns. Herein we describe the results of the first-pass screens with pupal and larval injections, which covered ∼8,500 and ∼5,000 genes, respectively, of a total of ∼16,500 genes of the Tribolium genome. Apart from many genes known from Drosophila as regulators of muscle development, a collection of genes previously unconnected to muscle development yielded phenotypes in larval body wall and leg muscles as well as in indirect flight muscles. We then present the main candidates from the pupal injection screen that remained after being processed through a series of verification and selection steps. Further, we discuss why distinct though overlapping sets of genes are revealed by the Drosophila and Tribolium screening approaches.
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12
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Nuclear Scaling Is Coordinated among Individual Nuclei in Multinucleated Muscle Fibers. Dev Cell 2019; 49:48-62.e3. [PMID: 30905770 DOI: 10.1016/j.devcel.2019.02.020] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 11/28/2018] [Accepted: 02/22/2019] [Indexed: 12/22/2022]
Abstract
Optimal cell performance depends on cell size and the appropriate relative size, i.e., scaling, of the nucleus. How nuclear scaling is regulated and contributes to cell function is poorly understood, especially in skeletal muscle fibers, which are among the largest cells, containing hundreds of nuclei. Here, we present a Drosophila in vivo system to analyze nuclear scaling in whole multinucleated muscle fibers, genetically manipulate individual components, and assess muscle function. Despite precise global coordination, we find that individual nuclei within a myofiber establish different local scaling relationships by adjusting their size and synthetic activity in correlation with positional or spatial cues. While myonuclei exhibit compensatory potential, even minor changes in global nuclear size scaling correlate with reduced muscle function. Our study provides the first comprehensive approach to unraveling the intrinsic regulation of size in multinucleated muscle fibers. These insights to muscle cell biology will accelerate the development of interventions for muscle diseases.
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13
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Abstract
Nuclear positioning plays an essential role in defining cell architecture and behaviour in both development and disease, and nuclear location frequently adjusts according to internal and external cues. For instance, during periods of migration in many cell types, the nucleus may be actively repositioned behind the microtubule-organising centre. Nuclear movement, for the most part, is dependent upon coupling of the cytoskeleton to the nuclear periphery. This is accomplished largely through SUN and KASH domain proteins, which together assemble to form LINC (linker of the nucleoskeleton and cytoskeleton) complexes spanning the nuclear envelope. SUN proteins of the inner nuclear membrane provide a connection to nuclear structures while acting as a tether for outer nuclear membrane KASH proteins. The latter contain binding sites for diverse cytoskeletal components. Recent publications highlight new aspects of LINC complex regulation revealing that the interplay between SUN and KASH partners can strongly influence how the nucleus functionally engages with different branches of the cytoskeleton.
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Affiliation(s)
- Brian Burke
- Institute for Medical Biology, 8A Biomedical Grove, #06-06 Immunos , 138648, Singapore
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14
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Levy Y, Ross JA, Niglas M, Snetkov VA, Lynham S, Liao CY, Puckelwartz MJ, Hsu YM, McNally EM, Alsheimer M, Harridge SD, Young SG, Fong LG, Español Y, Lopez-Otin C, Kennedy BK, Lowe DA, Ochala J. Prelamin A causes aberrant myonuclear arrangement and results in muscle fiber weakness. JCI Insight 2018; 3:120920. [PMID: 30282816 PMCID: PMC6237469 DOI: 10.1172/jci.insight.120920] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 08/23/2018] [Indexed: 01/06/2023] Open
Abstract
Physiological and premature aging are frequently associated with an accumulation of prelamin A, a precursor of lamin A, in the nuclear envelope of various cell types. Here, we aimed to underpin the hitherto unknown mechanisms by which prelamin A alters myonuclear organization and muscle fiber function. By experimentally studying membrane-permeabilized myofibers from various transgenic mouse lines, our results indicate that, in the presence of prelamin A, the abundance of nuclei and myosin content is markedly reduced within muscle fibers. This leads to a concept by which the remaining myonuclei are very distant from each other and are pushed to function beyond their maximum cytoplasmic capacity, ultimately inducing muscle fiber weakness.
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Affiliation(s)
- Yotam Levy
- School of Basic and Medical Biosciences, Faculty of Life Sciences & Medicine, and
| | - Jacob A Ross
- School of Basic and Medical Biosciences, Faculty of Life Sciences & Medicine, and
| | - Marili Niglas
- School of Basic and Medical Biosciences, Faculty of Life Sciences & Medicine, and
| | - Vladimir A Snetkov
- School of Basic and Medical Biosciences, Faculty of Life Sciences & Medicine, and
| | - Steven Lynham
- Proteomics Facility, Centre of Excellence for Mass Spectrometry, King's College London, London, United Kingdom
| | - Chen-Yu Liao
- Buck Institute for Research on Aging, Novato, California, USA
| | - Megan J Puckelwartz
- Center for Genetic Medicine, Northwestern University, Chicago, Illinois, USA
| | - Yueh-Mei Hsu
- Buck Institute for Research on Aging, Novato, California, USA
| | - Elizabeth M McNally
- Center for Genetic Medicine, Northwestern University, Chicago, Illinois, USA
| | - Manfred Alsheimer
- Department of Cell and Developmental Biology, University of Würzburg, Würzburg, Germany
| | - Stephen Dr Harridge
- School of Basic and Medical Biosciences, Faculty of Life Sciences & Medicine, and
| | - Stephen G Young
- Department of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Loren G Fong
- Department of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Yaiza Español
- Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Instituto Universitario de Oncología (IUOPA), Universidad de Oviedo, Oviedo, Spain
| | - Carlos Lopez-Otin
- Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Instituto Universitario de Oncología (IUOPA), Universidad de Oviedo, Oviedo, Spain.,Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), Spain
| | - Brian K Kennedy
- Buck Institute for Research on Aging, Novato, California, USA.,Departments of Biochemistry and Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Centre for Healthy Ageing, National University Health System, Singapore.,Singapore Institute for Clinical Sciences, Singapore
| | - Dawn A Lowe
- Divisions of Rehabilitation Science and Physical Therapy, Department of Rehabilitation Medicine, School of Medicine, University of Minnesota, Minneapolis, Minnesota, USA
| | - Julien Ochala
- School of Basic and Medical Biosciences, Faculty of Life Sciences & Medicine, and
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15
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Reuveny A, Shnayder M, Lorber D, Wang S, Volk T. Ma2/d promotes myonuclear positioning and association with the sarcoplasmic reticulum. Development 2018; 145:dev.159558. [PMID: 30093550 DOI: 10.1242/dev.159558] [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: 09/18/2017] [Accepted: 07/24/2018] [Indexed: 12/24/2022]
Abstract
The cytoplasm of striated myofibers contains a large number of membrane organelles, including sarcoplasmic reticulum (SR), T-tubules and the nuclear membrane. These organelles maintain a characteristic juxtaposition that appears to be essential for efficient inter-membranous exchange of RNA, proteins and ions. We found that the membrane-associated Muscle-specific α2/δ (Ma2/d) subunit of the Ca2+ channel complex localizes to the SR and T-tubules, and accumulates at the myonuclear surfaces. Furthermore, Ma2/d mutant larval muscles exhibit nuclear positioning defects, disruption of the nuclear-SR juxtapositioning, as well as impaired larval locomotion. Ma2/d localization at the nuclear membrane depends on the proper function of the nesprin ortholog Msp300 and the BAR domain protein Amphiphysin (Amph). Importantly, live imaging of muscle contraction in intact Drosophila larvae indicated altered distribution of Sarco/Endoplamic Reticulum Ca2+-ATPase (SERCA) around the myonuclei of Ma2/d mutant larvae. Co-immunoprecipitation analysis supports association between Ma2/d and Amph, and indirectly with Msp300. We therefore suggest that Ma2/d, in association with Msp300 and Amph, mediates interactions between the SR and the nuclear membrane.
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Affiliation(s)
- Adriana Reuveny
- Department of Molecular Genetics, Weizmann Institute, Rehovot 76100, Israel
| | - Marina Shnayder
- Department of Molecular Genetics, Weizmann Institute, Rehovot 76100, Israel
| | - Dana Lorber
- Department of Molecular Genetics, Weizmann Institute, Rehovot 76100, Israel
| | - Shuoshuo Wang
- Department of Molecular Genetics, Weizmann Institute, Rehovot 76100, Israel
| | - Talila Volk
- Department of Molecular Genetics, Weizmann Institute, Rehovot 76100, Israel
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16
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Potter C, Razafsky D, Wozniak D, Casey M, Penrose S, Ge X, Mahjoub MR, Hodzic D. The KASH-containing isoform of Nesprin1 giant associates with ciliary rootlets of ependymal cells. Neurobiol Dis 2018; 115:82-91. [PMID: 29630990 DOI: 10.1016/j.nbd.2018.04.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 02/25/2018] [Accepted: 04/04/2018] [Indexed: 12/14/2022] Open
Abstract
Biallelic nonsense mutations of SYNE1 underlie a variable array of cerebellar and non-cerebellar pathologies of unknown molecular etiology. SYNE1 encodes multiple isoforms of Nesprin1 that associate with the nuclear envelope, with large cerebellar synapses and with ciliary rootlets of photoreceptors. Using two novel mouse models, we determined the expression pattern of Nesprin1 isoforms in the cerebellum whose integrity and functions are invariably affected by SYNE1 mutations. We further show that a giant isoform of Nesprin1 associates with the ciliary rootlets of ependymal cells that line brain ventricles and establish that this giant ciliary isoform of Nesprin1 harbors a KASH domain. Whereas cerebellar phenotypes are not recapitulated in Nes1gSTOP/STOP mice, these mice display a significant increase of ventricular volume. Together, these data fuel novel hypotheses about the molecular pathogenesis of SYNE1 mutations and support that KASH proteins may localize beyond the nuclear envelope in vivo.
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Affiliation(s)
- C Potter
- Department of Developmental Biology, Washington University School of Medicine, 660 S. Euclid Ave, St Louis, MO 63110, USA
| | - D Razafsky
- Department of Developmental Biology, Washington University School of Medicine, 660 S. Euclid Ave, St Louis, MO 63110, USA
| | - D Wozniak
- Department of Psychiatry, Washington University School of Medicine, 660 S. Euclid Ave, St Louis, MO 63110, USA
| | - M Casey
- Department of Developmental Biology, Washington University School of Medicine, 660 S. Euclid Ave, St Louis, MO 63110, USA
| | - S Penrose
- Department of Developmental Biology, Washington University School of Medicine, 660 S. Euclid Ave, St Louis, MO 63110, USA
| | - X Ge
- Department of Radiology, Washington University School of Medicine, 660 S. Euclid Ave, St Louis, MO 63110, USA
| | - M R Mahjoub
- Department of Medicine, Washington University School of Medicine, 660 S. Euclid Ave, St Louis, MO 63110, USA
| | - D Hodzic
- Department of Developmental Biology, Washington University School of Medicine, 660 S. Euclid Ave, St Louis, MO 63110, USA.
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17
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Ross JA, Levy Y, Svensson K, Philp A, Schenk S, Ochala J. SIRT1 regulates nuclear number and domain size in skeletal muscle fibers. J Cell Physiol 2018; 233:7157-7163. [PMID: 29574748 PMCID: PMC5993587 DOI: 10.1002/jcp.26542] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 02/12/2018] [Indexed: 12/16/2022]
Abstract
Skeletal muscle fibers are giant multinucleated cells wherein individual nuclei govern the protein synthesis in a finite volume of cytoplasm; this is termed the myonuclear domain (MND). The factors that control MND size remain to be defined. In the present study, we studied the contribution of the NAD+‐dependent deacetylase, sirtuin 1 (SIRT1), to the regulation of nuclear number and MND size. For this, we isolated myofibers from mice with tissue‐specific inactivation (mKO) or inducible overexpression (imOX) of SIRT1 and analyzed the 3D organisation of myonuclei. In imOX mice, the number of nuclei was increased whilst the average MND size was decreased as compared to littermate controls. Our findings were the opposite in mKO mice. Muscle stem cell (satellite cell) numbers were reduced in mKO muscles, a possible explanation for the lower density of myonuclei in these mice; however, no change was observed in imOX mice, suggesting that other factors might also be involved, such as the functional regulation of stem cells/muscle precursors. Interestingly, however, the changes in the MND volume did not impact the force‐generating capacity of muscle fibers. Taken together, our results demonstrate that SIRT1 is a key regulator of MND sizes, although the underlying molecular mechanisms and the cause‐effect relationship between MND and muscle function remain to be fully defined.
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Affiliation(s)
- Jacob A Ross
- School of Basic and Medical Biosciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Yotam Levy
- School of Basic and Medical Biosciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Kristoffer Svensson
- Department of Orthopaedic Surgery, University of California San Diego, La Jolla, California.,Biomedical Sciences Graduate Program, University of California San Diego, La Jolla, California
| | - Andrew Philp
- School of Sport and Exercise Sciences, University of Birmingham, Birmingham, UK
| | - Simon Schenk
- Department of Orthopaedic Surgery, University of California San Diego, La Jolla, California.,Biomedical Sciences Graduate Program, University of California San Diego, La Jolla, California
| | - Julien Ochala
- School of Basic and Medical Biosciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
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18
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Lee YL, Burke B. LINC complexes and nuclear positioning. Semin Cell Dev Biol 2017; 82:67-76. [PMID: 29191370 DOI: 10.1016/j.semcdb.2017.11.008] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 11/06/2017] [Accepted: 11/06/2017] [Indexed: 12/14/2022]
Abstract
One of the characteristics of eukaryotic cells is their structural plasticity associated with the ability to carry out a broad range of complex functions, both autonomously and as components of tissues and organs. Major cellular rearrangements can be observed in various systems from meiosis in fission yeast, through dermal differentiation in nematodes, to muscle and neuronal development in vertebrates. Each of these processes involves oftentimes dramatic relocation of the nucleus within the cell. During the last decade it has become apparent that the nuclear periphery represents a nexus of cytoskeletal interactions that are involved not only in nuclear movement but also in the distribution and dissemination of mechanical forces throughout the cell. Nucleocytoskeletal coupling is mediated in large part by SUN- and KASH-domain proteins of the nuclear membranes, that together assemble to form LINC (Linker of the Nucleoskeleton and Cytoskeleton) complexes. In this review we will describe how the LINC complex repertoire contributes to nuclear positioning and chromosome dynamics in a variety of cellular contexts.
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Affiliation(s)
- Yin Loon Lee
- Laboratory of Nuclear Dynamics and Architecture, Institute of Medical Biology, 8A Biomedical Grove, Immunos, 138648, Singapore
| | - Brian Burke
- Laboratory of Nuclear Dynamics and Architecture, Institute of Medical Biology, 8A Biomedical Grove, Immunos, 138648, Singapore.
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19
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Lamin A/C Is Required for ChAT-Dependent Neuroblastoma Differentiation. Mol Neurobiol 2016; 54:3729-3744. [PMID: 27221609 DOI: 10.1007/s12035-016-9902-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 05/03/2016] [Indexed: 01/21/2023]
Abstract
The mouse neuroblastoma N18TG2 clone is unable to differentiate and is defective for the enzymes of the biosynthesis of neurotransmitters. The forced expression of choline acetyltransferase (ChAT) in these cells results in the synthesis and release of acetylcholine (Ach) and hence in the expression of neurospecific features and markers. To understand how the expression of ChAT triggered neuronal differentiation, we studied the differences in genome-wide transcription profiles between the N18TG2 parental cells and its ChAT-expressing 2/4 derived clone. The engagement of the 2/4 cells in the neuronal developmental program was confirmed by the increase of the expression level of several differentiation-related genes and by the reduction of the amount of transcripts of cell cycle genes. At the same time, we observed a massive reorganization of cytoskeletal proteins in terms of gene expression, with the accumulation of the nucleoskeletal lamina component Lamin A/C in differentiating cells. The increase of the Lmna transcripts induced by ChAT expression in 2/4 cells was mimicked treating the parental N18TG2 cells with the acetylcholine receptor agonist carbachol, thus demonstrating the direct role played by this receptor in neuron nuclei maturation. Conversely, a treatment of 2/4 cells with the muscarinic receptor antagonist atropine resulted in the reduction of the amount of Lmna RNA. Finally, the hypothesis that Lmna gene product might play a crucial role in the ChAT-dependent molecular differentiation cascade was strongly supported by Lmna knockdown in 2/4 cells leading to the downregulation of genes involved in differentiation and cytoskeleton formation and to the upregulation of genes known to regulate self-renewal and stemness.
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20
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Kuleesha Y, Puah WC, Wasser M. A model of muscle atrophy based on live microscopy of muscle remodelling in Drosophila metamorphosis. ROYAL SOCIETY OPEN SCIENCE 2016; 3:150517. [PMID: 26998322 PMCID: PMC4785973 DOI: 10.1098/rsos.150517] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 01/08/2016] [Indexed: 06/05/2023]
Abstract
Genes controlling muscle size and survival play important roles in muscle wasting diseases. In Drosophila melanogaster metamorphosis, larval abdominal muscles undergo two developmental fates. While a doomed population is eliminated by cell death, another persistent group is remodelled and survives into adulthood. To identify and characterize genes involved in the development of remodelled muscles, we devised a workflow consisting of in vivo imaging, targeted gene perturbation and quantitative image analysis. We show that inhibition of TOR signalling and activation of autophagy promote developmental muscle atrophy in early, while TOR and yorkie activation are required for muscle growth in late pupation. We discovered changes in the localization of myonuclei during remodelling that involve anti-polar migration leading to central clustering followed by polar migration resulting in localization along the midline. We demonstrate that the Cathepsin L orthologue Cp1 is required for myonuclear clustering in mid, while autophagy contributes to central positioning of nuclei in late metamorphosis. In conclusion, studying muscle remodelling in metamorphosis can provide new insights into the cell biology of muscle wasting.
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Affiliation(s)
- Yadav Kuleesha
- Imaging Informatics Division, Bioinformatics Institute (BII), Agency for Science, Technology and Research (A*STAR), 30 Biopolis Street, no. 07-01 Matrix, Singapore 138671, Republic of Singapore
- School of Computer Engineering, Nanyang Technological University, N4-2A-05, Nanyang Avenue, Singapore 639798, Republic of Singapore
| | - Wee Choo Puah
- Imaging Informatics Division, Bioinformatics Institute (BII), Agency for Science, Technology and Research (A*STAR), 30 Biopolis Street, no. 07-01 Matrix, Singapore 138671, Republic of Singapore
| | - Martin Wasser
- Imaging Informatics Division, Bioinformatics Institute (BII), Agency for Science, Technology and Research (A*STAR), 30 Biopolis Street, no. 07-01 Matrix, Singapore 138671, Republic of Singapore
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21
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Kim DI, Birendra KC, Roux KJ. Making the LINC: SUN and KASH protein interactions. Biol Chem 2015; 396:295-310. [PMID: 25720065 DOI: 10.1515/hsz-2014-0267] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 01/20/2015] [Indexed: 01/15/2023]
Abstract
Cell nuclei are physically integrated with the cytoskeleton through the linker of nucleoskeleton and cytoskeleton (LINC) complex, a structure that spans the nuclear envelope to link the nucleoskeleton and cytoskeleton. Outer nuclear membrane KASH domain proteins and inner nuclear membrane SUN domain proteins interact to form the core of the LINC complex. In this review, we provide a comprehensive analysis of the reported protein-protein interactions for KASH and SUN domain proteins. This critical structure, directly connecting the genome with the rest of the cell, contributes to a myriad of cellular functions and, when perturbed, is associated with human disease.
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22
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Packard M, Jokhi V, Ding B, Ruiz-Cañada C, Ashley J, Budnik V. Nucleus to Synapse Nesprin1 Railroad Tracks Direct Synapse Maturation through RNA Localization. Neuron 2015; 86:1015-1028. [PMID: 25959729 DOI: 10.1016/j.neuron.2015.04.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 02/11/2015] [Accepted: 03/27/2015] [Indexed: 10/23/2022]
Abstract
An important mechanism underlying synapse development and plasticity is the localization of mRNAs that travel from the nucleus to synaptic sites. Here we demonstrate that the giant nuclear-associated Nesprin1 (dNesp1) forms striated F-actin-based filaments, which we dubbed "railroad tracks," that span from muscle nuclei to postsynaptic sites at the neuromuscular junction in Drosophila. These railroad tracks specifically wrap around immature boutons formed during development and in response to electrical activity. In the absence of dNesp1, mRNAs normally localized at postsynaptic sites are lacking and synaptic maturation is inhibited. This dNesp1 function does not depend on direct association of dNesp1 isoforms with the nuclear envelope. We also show that dNesp1 functions with an unconventional myosin, Myo1D, and that both dNesp1 and Myo1D are mutually required for their localization to immature boutons. These studies unravel a novel pathway directing the transport of mRNAs from the nucleus to postsynaptic sites during synaptic maturation. VIDEO ABSTRACT.
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Affiliation(s)
- Mary Packard
- Department of Neurobiology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01452, USA
| | - Vahbiz Jokhi
- Department of Neurobiology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01452, USA
| | - Baojin Ding
- Department of Neurobiology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01452, USA
| | - Catalina Ruiz-Cañada
- Department of Neurobiology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01452, USA
| | - James Ashley
- Department of Neurobiology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01452, USA
| | - Vivian Budnik
- Department of Neurobiology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01452, USA.
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23
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McDermott SM, Yang L, Halstead JM, Hamilton RS, Meignin C, Davis I. Drosophila Syncrip modulates the expression of mRNAs encoding key synaptic proteins required for morphology at the neuromuscular junction. RNA (NEW YORK, N.Y.) 2014; 20:1593-606. [PMID: 25171822 PMCID: PMC4174441 DOI: 10.1261/rna.045849.114] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2014] [Accepted: 06/09/2014] [Indexed: 05/24/2023]
Abstract
Localized mRNA translation is thought to play a key role in synaptic plasticity, but the identity of the transcripts and the molecular mechanism underlying their function are still poorly understood. Here, we show that Syncrip, a regulator of localized translation in the Drosophila oocyte and a component of mammalian neuronal mRNA granules, is also expressed in the Drosophila larval neuromuscular junction, where it regulates synaptic growth. We use RNA-immunoprecipitation followed by high-throughput sequencing and qRT-PCR to show that Syncrip associates with a number of mRNAs encoding proteins with key synaptic functions, including msp-300, syd-1, neurexin-1, futsch, highwire, discs large, and α-spectrin. The protein levels of MSP-300, Discs large, and a number of others are significantly affected in syncrip null mutants. Furthermore, syncrip mutants show a reduction in MSP-300 protein levels and defects in muscle nuclear distribution characteristic of msp-300 mutants. Our results highlight a number of potential new players in localized translation during synaptic plasticity in the neuromuscular junction. We propose that Syncrip acts as a modulator of synaptic plasticity by regulating the translation of these key mRNAs encoding synaptic scaffolding proteins and other important components involved in synaptic growth and function.
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Affiliation(s)
- Suzanne M McDermott
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Lu Yang
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - James M Halstead
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Russell S Hamilton
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Carine Meignin
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Ilan Davis
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
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24
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Rothballer A, Kutay U. The diverse functional LINCs of the nuclear envelope to the cytoskeleton and chromatin. Chromosoma 2013; 122:415-29. [PMID: 23736899 PMCID: PMC3777164 DOI: 10.1007/s00412-013-0417-x] [Citation(s) in RCA: 101] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Revised: 05/14/2013] [Accepted: 05/15/2013] [Indexed: 11/30/2022]
Abstract
The nuclear envelope (NE) is connected to the different types of cytoskeletal elements by linker of nucleoskeleton and cytoskeleton (LINC) complexes. LINC complexes exist from yeast to humans, and have preserved their general architecture throughout evolution. They are composed of SUN and KASH domain proteins of the inner and the outer nuclear membrane, respectively. These SUN–KASH bridges are used for the transmission of forces across the NE and support diverse biological processes. Here, we review the function of SUN and KASH domain proteins in various unicellular and multicellular species. Specifically, we discuss their influence on nuclear morphology and cytoskeletal organization. Further, emphasis is given on the role of LINC complexes in nuclear anchorage and migration as well as in genome organization.
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Affiliation(s)
- Andrea Rothballer
- Department of Biology, Institute of Biochemistry, ETH Zurich, Schafmattstrasse 18, 8093 Zurich, Switzerland
| | - Ulrike Kutay
- Department of Biology, Institute of Biochemistry, ETH Zurich, Schafmattstrasse 18, 8093 Zurich, Switzerland
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