1
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Pinello JF, Loidl J, Seltzer ES, Cassidy-Hanley D, Kolbin D, Abdelatif A, Rey FA, An R, Newberger NJ, Bisharyan Y, Papoyan H, Byun H, Aguilar HC, Lai AL, Freed JH, Maugel T, Cole ES, Clark TG. Novel requirements for HAP2/GCS1-mediated gamete fusion in Tetrahymena. iScience 2024; 27:110146. [PMID: 38904066 PMCID: PMC11187246 DOI: 10.1016/j.isci.2024.110146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 04/29/2024] [Accepted: 05/27/2024] [Indexed: 06/22/2024] Open
Abstract
The ancestral gamete fusion protein, HAP2/GCS1, plays an essential role in fertilization in a broad range of taxa. To identify factors that may regulate HAP2/GCS1 activity, we screened mutants of the ciliate Tetrahymena thermophila for behaviors that mimic Δhap2/gcs1 knockout phenotypes in this species. Using this approach, we identified two new genes, GFU1 and GFU2, whose products are necessary for membrane pore formation following mating type recognition and adherence. GFU2 is predicted to be a single-pass transmembrane protein, while GFU1, though lacking obvious transmembrane domains, has the potential to interact directly with membrane phospholipids in the cytoplasm. Like Tetrahymena HAP2/GCS1, expression of GFU1 is required in both cells of a mating pair for efficient fusion to occur. To explain these bilateral requirements, we propose a model that invokes cooperativity between the fusion machinery on apposed membranes of mating cells and accounts for successful fertilization in Tetrahymena's multiple mating type system.
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Affiliation(s)
- Jennifer F. Pinello
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Josef Loidl
- Department of Chromosome Biology, Max Perutz Labs, University of Vienna, Vienna, Austria
| | - Ethan S. Seltzer
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Donna Cassidy-Hanley
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Daniel Kolbin
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Anhar Abdelatif
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Félix A. Rey
- Unité de Virologie Structurale, Institut Pasteur, 75724 Paris, France
- CNRS UMR 3569, 75724 Paris, France
| | - Rocky An
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Nicole J. Newberger
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Yelena Bisharyan
- Office of Technology Development, Harvard University, Cambridge, MA 02138, USA
| | - Hayk Papoyan
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Haewon Byun
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Hector C. Aguilar
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Alex L. Lai
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14850, USA
| | - Jack H. Freed
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14850, USA
| | - Timothy Maugel
- Department of Biology, Laboratory for Biological Ultrastructure, University of Maryland, College Park, MD 20742, USA
| | - Eric S. Cole
- Biology Department, St. Olaf College, Northfield, MN 55057, USA
| | - Theodore G. Clark
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
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2
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Picas L, André-Arpin C, Comunale F, Bousquet H, Tsai FC, Rico F, Maiuri P, Pernier J, Bodin S, Nicot AS, Laporte J, Bassereau P, Goud B, Gauthier-Rouvière C, Miserey S. BIN1 regulates actin-membrane interactions during IRSp53-dependent filopodia formation. Commun Biol 2024; 7:549. [PMID: 38724689 PMCID: PMC11082164 DOI: 10.1038/s42003-024-06168-8] [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: 05/02/2023] [Accepted: 04/09/2024] [Indexed: 05/12/2024] Open
Abstract
Amphiphysin 2 (BIN1) is a membrane and actin remodeling protein mutated in congenital and adult centronuclear myopathies. Here, we report an unexpected function of this N-BAR domain protein BIN1 in filopodia formation. We demonstrated that BIN1 expression is necessary and sufficient to induce filopodia formation. BIN1 is present at the base of forming filopodia and all along filopodia, where it colocalizes with F-actin. We identify that BIN1-mediated filopodia formation requires IRSp53, which allows its localization at negatively-curved membrane topologies. Our results show that BIN1 bundles actin in vitro. Finally, we identify that BIN1 regulates the membrane-to-cortex architecture and functions as a molecular platform to recruit actin-binding proteins, dynamin and ezrin, to promote filopodia formation.
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Affiliation(s)
- Laura Picas
- Institut de Recherche en Infectiologie de Montpellier (IRIM), University of Montpellier, CNRS UMR 9004, Montpellier, France.
| | - Charlotte André-Arpin
- Institut de Recherche en Infectiologie de Montpellier (IRIM), University of Montpellier, CNRS UMR 9004, Montpellier, France
| | - Franck Comunale
- CRBM, University of Montpellier, CNRS UMR 5237, Montpellier, France
| | - Hugo Bousquet
- Institut Curie, CNRS UMR 144, PSL Research University, Paris, France
| | - Feng-Ching Tsai
- Institut Curie, CNRS UMR 168, PSL Research University, Paris, France
| | - Félix Rico
- Aix-Marseille Université, U1325 INSERM, DyNaMo, Turing center for living systems, Marseille, France
| | - Paolo Maiuri
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università degli Studi di Napoli Federico II, Naples, Italy
| | - Julien Pernier
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
| | - Stéphane Bodin
- CRBM, University of Montpellier, CNRS UMR 5237, Montpellier, France
| | - Anne-Sophie Nicot
- Grenoble Alpes University, INSERM U1216, Grenoble Institut Neurosciences, Grenoble, France
| | - Jocelyn Laporte
- Department of Translational Medicine, IGBMC, U1258, UMR7104 Strasbourg University, Collège de France, Illkirch, France
| | | | - Bruno Goud
- Institut Curie, CNRS UMR 144, PSL Research University, Paris, France
| | | | - Stéphanie Miserey
- Institut Curie, CNRS UMR 144, PSL Research University, Paris, France.
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3
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Ruan ZR, Yu Z, Xing C, Chen EH. Inter-organ steroid hormone signaling promotes myoblast fusion via direct transcriptional regulation of a single key effector gene. Curr Biol 2024; 34:1438-1452.e6. [PMID: 38513654 PMCID: PMC11003854 DOI: 10.1016/j.cub.2024.02.056] [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: 07/09/2023] [Revised: 12/24/2023] [Accepted: 02/23/2024] [Indexed: 03/23/2024]
Abstract
Steroid hormones regulate tissue development and physiology by modulating the transcription of a broad spectrum of genes. In insects, the principal steroid hormones, ecdysteroids, trigger the expression of thousands of genes through a cascade of transcription factors (TFs) to coordinate developmental transitions such as larval molting and metamorphosis. However, whether ecdysteroid signaling can bypass transcriptional hierarchies to exert its function in individual developmental processes is unclear. Here, we report that a single non-TF effector gene mediates the transcriptional output of ecdysteroid signaling in Drosophila myoblast fusion, a critical step in muscle development and differentiation. Specifically, we show that the 20-hydroxyecdysone (commonly referred to as "ecdysone") secreted from an extraembryonic tissue, amnioserosa, acts on embryonic muscle cells to directly activate the expression of antisocial (ants), which encodes an essential scaffold protein enriched at the fusogenic synapse. Not only is ants transcription directly regulated by the heterodimeric ecdysone receptor complex composed of ecdysone receptor (EcR) and ultraspiracle (USP) via ecdysone-response elements but also more strikingly, expression of ants alone is sufficient to rescue the myoblast fusion defect in ecdysone signaling-deficient mutants. We further show that EcR/USP and a muscle-specific TF Twist synergistically activate ants expression in vitro and in vivo. Taken together, our study provides the first example of a steroid hormone directly activating the expression of a single key non-TF effector gene to regulate a developmental process via inter-organ signaling and provides a new paradigm for understanding steroid hormone signaling in other developmental and physiological processes.
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Affiliation(s)
- Zhi-Rong Ruan
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Ze Yu
- McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Chao Xing
- McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Elizabeth H Chen
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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4
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Luo Z, Shi J, Pandey P, Ruan ZR, Sevdali M, Bu Y, Lu Y, Du S, Chen EH. The cellular architecture and molecular determinants of the zebrafish fusogenic synapse. Dev Cell 2022; 57:1582-1597.e6. [PMID: 35709765 PMCID: PMC10180866 DOI: 10.1016/j.devcel.2022.05.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 04/04/2022] [Accepted: 05/20/2022] [Indexed: 11/03/2022]
Abstract
Myoblast fusion is an indispensable process in skeletal muscle development and regeneration. Studies in Drosophila led to the discovery of the asymmetric fusogenic synapse, in which one cell invades its fusion partner with actin-propelled membrane protrusions to promote fusion. However, the timing and sites of vertebrate myoblast fusion remain elusive. Here, we show that fusion between zebrafish fast muscle cells is mediated by an F-actin-enriched invasive structure. Two cell adhesion molecules, Jam2a and Jam3b, are associated with the actin structure, with Jam2a being the major organizer. The Arp2/3 actin nucleation-promoting factors, WAVE and WASP-but not the bipartite fusogenic proteins, Myomaker or Myomixer-promote the formation of the invasive structure. Moreover, the convergence of fusogen-containing microdomains and the invasive protrusions is a prerequisite for cell membrane fusion. Thus, our study provides unprecedented insights into the cellular architecture and molecular determinants of the asymmetric fusogenic synapse in an intact vertebrate animal.
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Affiliation(s)
- Zhou Luo
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jun Shi
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
| | - Pratima Pandey
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Zhi-Rong Ruan
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Maria Sevdali
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Ye Bu
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Yue Lu
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Shaojun Du
- Institute of Marine and Environmental Technology, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Elizabeth H Chen
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA; Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA; Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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5
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Monocyte-Macrophage Lineage Cell Fusion. Int J Mol Sci 2022; 23:ijms23126553. [PMID: 35742997 PMCID: PMC9223484 DOI: 10.3390/ijms23126553] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 06/07/2022] [Accepted: 06/10/2022] [Indexed: 02/06/2023] Open
Abstract
Cell fusion (fusogenesis) occurs in natural and pathological conditions in prokaryotes and eukaryotes. Cells of monocyte–macrophage lineage are highly fusogenic. They create syncytial multinucleated giant cells (MGCs) such as osteoclasts (OCs), MGCs associated with the areas of infection/inflammation, and foreign body-induced giant cells (FBGCs). The fusion of monocytes/macrophages with tumor cells may promote cancer metastasis. We describe types and examples of monocyte–macrophage lineage cell fusion and the role of actin-based structures in cell fusion.
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6
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Generation of Cancer Stem/Initiating Cells by Cell-Cell Fusion. Int J Mol Sci 2022; 23:ijms23094514. [PMID: 35562905 PMCID: PMC9101717 DOI: 10.3390/ijms23094514] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 04/10/2022] [Accepted: 04/17/2022] [Indexed: 02/04/2023] Open
Abstract
CS/ICs have raised great expectations in cancer research and therapy, as eradication of this key cancer cell type is expected to lead to a complete cure. Unfortunately, the biology of CS/ICs is rather complex, since no common CS/IC marker has yet been identified. Certain surface markers or ALDH1 expression can be used for detection, but some studies indicated that cancer cells exhibit a certain plasticity, so CS/ICs can also arise from non-CS/ICs. Another problem is intratumoral heterogeneity, from which it can be inferred that different CS/IC subclones must be present in the tumor. Cell–cell fusion between cancer cells and normal cells, such as macrophages and stem cells, has been associated with the generation of tumor hybrids that can exhibit novel properties, such as an enhanced metastatic capacity and even CS/IC properties. Moreover, cell–cell fusion is a complex process in which parental chromosomes are mixed and randomly distributed among daughter cells, resulting in multiple, unique tumor hybrids. These, if they have CS/IC properties, may contribute to the heterogeneity of the CS/IC pool. In this review, we will discuss whether cell–cell fusion could also lead to the origin of different CS/ICs that may expand the overall CS/IC pool in a primary tumor.
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7
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Regulation of the myoblast fusion reaction for muscle development, regeneration, and adaptations. Exp Cell Res 2022; 415:113134. [PMID: 35367215 DOI: 10.1016/j.yexcr.2022.113134] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 02/23/2022] [Accepted: 03/28/2022] [Indexed: 12/27/2022]
Abstract
Fusion of plasma membranes is essential for skeletal muscle development, regeneration, exercise-induced adaptations, and results in a cell that contains hundreds to thousands of nuclei within a shared cytoplasm. The differentiation process in myocytes culminates in their fusion to form a new myofiber or fusion to an existing myofiber thereby contributing more synthetic material to the syncytium. The choice for two cells to fuse and become one could be a dangerous event if the two cells are not committed to an allied function. Thus, fusion events are highly regulated with positive and negative factors to fine-tune the process, and requires muscle-specific fusogens (Myomaker and Myomerger) as well as general cellular machinery to achieve the union of membranes. While a unified vertebrate myoblast fusion pathway is not yet established, recent discoveries should make this pursuit attainable. Not only does myocyte fusion impact the normal biology of skeletal muscle, but new evidence indicates dysregulation of the process impacts pathologies of skeletal muscle. Here, I will highlight the molecular players and biochemical mechanisms that drive fusion events in muscle, and discuss how this key myogenic process impacts skeletal muscle diseases.
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8
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Eigler T, Zarfati G, Amzallag E, Sinha S, Segev N, Zabary Y, Zaritsky A, Shakked A, Umansky KB, Schejter ED, Millay DP, Tzahor E, Avinoam O. ERK1/2 inhibition promotes robust myotube growth via CaMKII activation resulting in myoblast-to-myotube fusion. Dev Cell 2021; 56:3349-3363.e6. [PMID: 34932950 PMCID: PMC8693863 DOI: 10.1016/j.devcel.2021.11.022] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 07/28/2021] [Accepted: 11/21/2021] [Indexed: 11/19/2022]
Abstract
Myoblast fusion is essential for muscle development and regeneration. Yet, it remains poorly understood how mononucleated myoblasts fuse with preexisting fibers. We demonstrate that ERK1/2 inhibition (ERKi) induces robust differentiation and fusion of primary mouse myoblasts through a linear pathway involving RXR, ryanodine receptors, and calcium-dependent activation of CaMKII in nascent myotubes. CaMKII activation results in myotube growth via fusion with mononucleated myoblasts at a fusogenic synapse. Mechanistically, CaMKII interacts with and regulates MYMK and Rac1, and CaMKIIδ/γ knockout mice exhibit smaller regenerated myofibers following injury. In addition, the expression of a dominant negative CaMKII inhibits the formation of large multinucleated myotubes. Finally, we demonstrate the evolutionary conservation of the pathway in chicken myoblasts. We conclude that ERK1/2 represses a signaling cascade leading to CaMKII-mediated fusion of myoblasts to myotubes, providing an attractive target for the cultivated meat industry and regenerative medicine.
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Affiliation(s)
- Tamar Eigler
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Giulia Zarfati
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Emmanuel Amzallag
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Sansrity Sinha
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Nadav Segev
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Yishaia Zabary
- Department of Software & Information Systems Engineering, Ben Gurion University, Be'er Sheva, Israel
| | - Assaf Zaritsky
- Department of Software & Information Systems Engineering, Ben Gurion University, Be'er Sheva, Israel
| | - Avraham Shakked
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Kfir-Baruch Umansky
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Eyal D Schejter
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Douglas P Millay
- Division of Molecular Cardiovascular Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Eldad Tzahor
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel.
| | - Ori Avinoam
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel.
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9
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Hammers DW, Hart CC, Matheny MK, Heimsath EG, Lee YI, Hammer JA, Cheney RE, Sweeney HL. Filopodia powered by class x myosin promote fusion of mammalian myoblasts. eLife 2021; 10:e72419. [PMID: 34519272 PMCID: PMC8500716 DOI: 10.7554/elife.72419] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Accepted: 09/13/2021] [Indexed: 12/30/2022] Open
Abstract
Skeletal muscle fibers are multinucleated cellular giants formed by the fusion of mononuclear myoblasts. Several molecules involved in myoblast fusion have been discovered, and finger-like projections coincident with myoblast fusion have also been implicated in the fusion process. The role of these cellular projections in muscle cell fusion was investigated herein. We demonstrate that these projections are filopodia generated by class X myosin (Myo10), an unconventional myosin motor protein specialized for filopodia. We further show that Myo10 is highly expressed by differentiating myoblasts, and Myo10 ablation inhibits both filopodia formation and myoblast fusion in vitro. In vivo, Myo10 labels regenerating muscle fibers associated with Duchenne muscular dystrophy and acute muscle injury. In mice, conditional loss of Myo10 from muscle-resident stem cells, known as satellite cells, severely impairs postnatal muscle regeneration. Furthermore, the muscle fusion proteins Myomaker and Myomixer are detected in myoblast filopodia. These data demonstrate that Myo10-driven filopodia facilitate multinucleated mammalian muscle formation.
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MESH Headings
- Animals
- Cell Differentiation
- Cell Fusion
- Cell Line
- Cell Proliferation
- Disease Models, Animal
- Humans
- Membrane Proteins/genetics
- Membrane Proteins/metabolism
- Mice, Inbred C57BL
- Mice, Inbred mdx
- Mice, Knockout
- Muscle Development
- Muscle Fibers, Skeletal/metabolism
- Muscle Fibers, Skeletal/pathology
- Muscle Proteins/genetics
- Muscle Proteins/metabolism
- Muscular Dystrophy, Duchenne/genetics
- Muscular Dystrophy, Duchenne/metabolism
- Muscular Dystrophy, Duchenne/pathology
- Myoblasts, Skeletal/metabolism
- Myoblasts, Skeletal/pathology
- Myosins/genetics
- Myosins/metabolism
- Pseudopodia/genetics
- Pseudopodia/metabolism
- Regeneration
- Satellite Cells, Skeletal Muscle/metabolism
- Satellite Cells, Skeletal Muscle/pathology
- Time Factors
- Mice
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Affiliation(s)
- David W Hammers
- Department of Pharmacology & Therapeutics, University of Florida College of MedicineGainesvilleUnited States
- University of Florida Myology InstituteGainesvilleUnited States
| | - Cora C Hart
- Department of Pharmacology & Therapeutics, University of Florida College of MedicineGainesvilleUnited States
- University of Florida Myology InstituteGainesvilleUnited States
| | - Michael K Matheny
- Department of Pharmacology & Therapeutics, University of Florida College of MedicineGainesvilleUnited States
- University of Florida Myology InstituteGainesvilleUnited States
| | - Ernest G Heimsath
- Department of Cell Biology & Physiology and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill School of MedicineChapel HillUnited States
| | - Young il Lee
- Department of Pharmacology & Therapeutics, University of Florida College of MedicineGainesvilleUnited States
- University of Florida Myology InstituteGainesvilleUnited States
| | - John A Hammer
- Cell Biology and Physiology Center, National Heart, Lung and Blood InstituteBethesdaUnited States
| | - Richard E Cheney
- Department of Cell Biology & Physiology and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill School of MedicineChapel HillUnited States
| | - H Lee Sweeney
- Department of Pharmacology & Therapeutics, University of Florida College of MedicineGainesvilleUnited States
- University of Florida Myology InstituteGainesvilleUnited States
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10
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An insight on Drosophila myogenesis and its assessment techniques. Mol Biol Rep 2020; 47:9849-9863. [PMID: 33263930 DOI: 10.1007/s11033-020-06006-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 11/16/2020] [Indexed: 10/22/2022]
Abstract
Movement assisted by muscles forms the basis of various behavioural traits seen in Drosophila. Myogenesis involves developmental processes like cellular specification, differentiation, migration, fusion, adherence to tendons and neuronal innervation in a series of coordinated event well defined in body space and time. Gene regulatory networks are switched on-off, fine tuning at the right developmental stage to assist each cellular event. Drosophila is a holometabolous organism that undergoes myogenesis waves at two developmental stages, and is ideal for comparative analysis of the role of genes and genetic pathways conserved across phyla. In this review we have summarized myogenic events from the embryo to adult focussing on the somatic muscle development during the early embryonic stage and then on indirect flight muscles (IFM) formation required for adult life, emphasizing on recent trends of analysing muscle mutants and advances in Drosophila muscle biology.
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11
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Gutiérrez-Guerrero YT, Ibarra-Laclette E, Martínez del Río C, Barrera-Redondo J, Rebollar EA, Ortega J, León-Paniagua L, Urrutia A, Aguirre-Planter E, Eguiarte LE. Genomic consequences of dietary diversification and parallel evolution due to nectarivory in leaf-nosed bats. Gigascience 2020; 9:giaa059. [PMID: 32510151 PMCID: PMC7276932 DOI: 10.1093/gigascience/giaa059] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 05/04/2020] [Accepted: 05/10/2020] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND The New World leaf-nosed bats (Phyllostomids) exhibit a diverse spectrum of feeding habits and innovations in their nutrient acquisition and foraging mechanisms. However, the genomic signatures associated with their distinct diets are unknown. RESULTS We conducted a genomic comparative analysis to study the evolutionary dynamics related to dietary diversification and specialization. We sequenced, assembled, and annotated the genomes of five Phyllostomid species: one insect feeder (Macrotus waterhousii), one fruit feeder (Artibeus jamaicensis), and three nectar feeders from the Glossophaginae subfamily (Leptonycteris yerbabuenae, Leptonycteris nivalis, and Musonycteris harrisoni), also including the previously sequenced vampire Desmodus rotundus. Our phylogenomic analysis based on 22,388 gene families displayed differences in expansion and contraction events across the Phyllostomid lineages. Independently of diet, genes relevant for feeding strategies and food intake experienced multiple expansions and signatures of positive selection. We also found adaptation signatures associated with specialized diets: the vampire exhibited traits associated with a blood diet (i.e., coagulation mechanisms), whereas the nectarivore clade shares a group of positively selected genes involved in sugar, lipid, and iron metabolism. Interestingly, in fruit-nectar-feeding Phyllostomid and Pteropodids bats, we detected positive selection in two genes: AACS and ALKBH7, which are crucial in sugar and fat metabolism. Moreover, in these two proteins we found parallel amino acid substitutions in conserved positions exclusive to the tribe Glossophagini and to Pteropodids. CONCLUSIONS Our findings illuminate the genomic and molecular shifts associated with the evolution of nectarivory and shed light on how nectar-feeding bats can avoid the adverse effects of diets with high glucose content.
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Affiliation(s)
- Yocelyn T Gutiérrez-Guerrero
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria, 04510 Coyoacán, Mexico City, Mexico
| | - Enrique Ibarra-Laclette
- Red de Estudios Moleculares Avanzados, Instituto de Ecología AC, 91070 Xalapa, Veracruz, Mexico
| | | | - Josué Barrera-Redondo
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria, 04510 Coyoacán, Mexico City, Mexico
| | - Eria A Rebollar
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, 62210 Cuernavaca, Morelos, Mexico
| | - Jorge Ortega
- Departamento de Zoología, Laboratorio de Bioconservación y Manejo, Posgrado en Ciencias Quimicobiológicas, Instituto Politécnico Nacional-ENCB, 11340 Mexico City, Mexico
| | - Livia León-Paniagua
- Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510 Coyoacán, Mexico City, Mexico
| | - Araxi Urrutia
- Departamento de Ecología Funcional, Instituto de Ecología, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria, 04510 Coyoacán, Mexico City, Mexico
| | - Erika Aguirre-Planter
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria, 04510 Coyoacán, Mexico City, Mexico
| | - Luis E Eguiarte
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria, 04510 Coyoacán, Mexico City, Mexico
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12
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Dynamin regulates the dynamics and mechanical strength of the actin cytoskeleton as a multifilament actin-bundling protein. Nat Cell Biol 2020; 22:674-688. [PMID: 32451441 PMCID: PMC7953826 DOI: 10.1038/s41556-020-0519-7] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 04/07/2020] [Indexed: 01/28/2023]
Abstract
The dynamin GTPase is known to bundle actin filaments, but the underlying molecular mechanism and physiological relevance remain unclear. Our genetic analyses revealed a function of dynamin in propelling invasive membrane protrusions during myoblast fusion in vivo. Using biochemistry, total internal reflection fluorescence microscopy, electron microscopy and cryo-electron tomography, we show that dynamin bundles actin while forming a helical structure. At its full capacity, each dynamin helix captures 12-16 actin filaments on the outer rim of the helix. GTP hydrolysis by dynamin triggers disassembly of fully assembled dynamin helices, releasing free dynamin dimers/tetramers and facilitating Arp2/3-mediated branched actin polymerization. The assembly/disassembly cycles of dynamin promote continuous actin bundling to generate mechanically stiff actin super-bundles. Super-resolution and immunogold platinum replica electron microscopy revealed dynamin along actin bundles at the fusogenic synapse. These findings implicate dynamin as a unique multifilament actin-bundling protein that regulates the dynamics and mechanical strength of the actin cytoskeletal network.
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13
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Abstract
Cell-cell fusion is indispensable for creating life and building syncytial tissues and organs. Ever since the discovery of cell-cell fusion, how cells join together to form zygotes and multinucleated syncytia has remained a fundamental question in cell and developmental biology. In the past two decades, Drosophila myoblast fusion has been used as a powerful genetic model to unravel mechanisms underlying cell-cell fusion in vivo. Many evolutionarily conserved fusion-promoting factors have been identified and so has a surprising and conserved cellular mechanism. In this review, we revisit key findings in Drosophila myoblast fusion and highlight the critical roles of cellular invasion and resistance in driving cell membrane fusion.
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Affiliation(s)
- Donghoon M Lee
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA;
| | - Elizabeth H Chen
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA;
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
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14
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Abstract
Cell-cell fusion is a fundamental process underlying fertilization, development, regeneration and physiology of metazoans. It is a multi-step process involving cell recognition and adhesion, actin cytoskeletal rearrangements, fusogen engagement, lipid mixing and fusion pore formation, ultimately resulting in the integration of two fusion partners. Here, we focus on the asymmetric actin cytoskeletal rearrangements at the site of fusion, known as the fusogenic synapse, which was first discovered during myoblast fusion in Drosophila embryos and later also found in mammalian muscle and non-muscle cells. At the asymmetric fusogenic synapse, actin-propelled invasive membrane protrusions from an attacking fusion partner trigger actomyosin-based mechanosensory responses in the receiving cell. The interplay between the invasive and resisting forces generated by the two fusion partners puts the fusogenic synapse under high mechanical tension and brings the two cell membranes into close proximity, promoting the engagement of fusogens to initiate fusion pore formation. In this Cell Science at a Glance article and the accompanying poster, we highlight the molecular, cellular and biophysical events at the asymmetric fusogenic synapse using Drosophila myoblast fusion as a model.
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Affiliation(s)
- Ji Hoon Kim
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Elizabeth H Chen
- Department of Molecular Biology, UT Southwestern Medical Center, Dallas, TX 75390, USA .,Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX 75390, USA
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15
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Faust JJ, Balabiyev A, Heddleston JM, Podolnikova NP, Baluch DP, Chew TL, Ugarova TP. An actin-based protrusion originating from a podosome-enriched region initiates macrophage fusion. Mol Biol Cell 2019; 30:2254-2267. [PMID: 31242090 PMCID: PMC6743464 DOI: 10.1091/mbc.e19-01-0009] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Macrophage fusion resulting in the formation of multinucleated giant cells occurs in a variety of chronic inflammatory diseases, yet the mechanism responsible for initiating this process is unknown. Here, we used live cell imaging to show that actin-based protrusions at the leading edge initiate macrophage fusion. Phase-contrast video microscopy demonstrated that in the majority of events, short protrusions (∼3 µm) between two closely apposed cells initiated fusion, but occasionally we observed long protrusions (∼12 µm). Using macrophages isolated from LifeAct mice and imaging with lattice light sheet microscopy, we further found that fusion-competent protrusions formed at sites enriched in podosomes. Inducing fusion in mixed populations of GFP- and mRFP-LifeAct macrophages showed rapid spatial overlap between GFP and RFP signal at the site of fusion. Cytochalasin B strongly reduced fusion and when rare fusion events occurred, protrusions were not observed. Fusion of macrophages deficient in Wiskott-Aldrich syndrome protein and Cdc42, key molecules involved in the formation of actin-based protrusions and podosomes, was also impaired both in vitro and in vivo. Finally, inhibiting the activity of the Arp2/3 complex decreased fusion and podosome formation. Together these data suggest that an actin-based protrusion formed at the leading edge initiates macrophage fusion.
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Affiliation(s)
- James J Faust
- School of Life Sciences, Arizona State University, Tempe, AZ 85287
| | - Arnat Balabiyev
- School of Life Sciences, Arizona State University, Tempe, AZ 85287
| | - John M Heddleston
- Advanced Imaging Center, HHMI Janelia Research Campus, Ashburn, VA 20147
| | | | - D Page Baluch
- School of Life Sciences, Arizona State University, Tempe, AZ 85287
| | - Teng-Leong Chew
- Advanced Imaging Center, HHMI Janelia Research Campus, Ashburn, VA 20147
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16
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Alonso F, Spuul P, Kramer IJ, Génot E. [Variations on the theme of podosomes, context matters]. Med Sci (Paris) 2019; 34:1063-1070. [PMID: 30623771 DOI: 10.1051/medsci/2018296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Podosomes are actin-based microdomains connecting the cell with its extracellular matrix. Contractile actin-myosin cables assemble them into a network that constitutes a versatile cellular superstructure. Discovered and extensively described in in vitro conditions, podosomes now appear as major actors of specific physiological processes. They share common characteristics but their morphology and their effect on cell functioning can only be apprehended in specific cellular contexts. We focus here on three cellular processes involving podosomes and discuss their properties in context.
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Affiliation(s)
- Florian Alonso
- Centre de recherche cardio-thoracique de Bordeaux (Inserm U1045), Université de Bordeaux, Bordeaux Cedex, F-33076 France
| | - Pirjo Spuul
- Department of chemistry and biotechnology, division of gene technology, Tallinn University of Technology, 12618 Tallinn, Estonie
| | - IJsbrand Kramer
- Centre de recherche cardio-thoracique de Bordeaux (Inserm U1045), Université de Bordeaux, Bordeaux Cedex, F-33076 France
| | - Elisabeth Génot
- Centre de recherche cardio-thoracique de Bordeaux (Inserm U1045), Université de Bordeaux, Bordeaux Cedex, F-33076 France
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17
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Alonso F, Spuul P, Daubon T, Kramer IJ, Génot E. Variations on the theme of podosomes: A matter of context. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1866:545-553. [PMID: 30594495 DOI: 10.1016/j.bbamcr.2018.12.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 12/15/2018] [Accepted: 12/18/2018] [Indexed: 12/22/2022]
Abstract
Extensive in vitro studies have described podosomes as actin-based structures at the plasma membrane, connecting the cell with its extracellular matrix and endowed with multiple capabilities. Contractile actin-myosin cables assemble them into a network that constitutes a multifaceted cellular superstructure taking different forms - with common characteristics - but manifesting different properties depending on the context of study. Their morphology and their role in cell functioning and behavior are therefore now apprehended in in vivo or in vitro situations relevant to physiological processes. We focus here on three of them, namely: macrophage migration, antigen presentation by dendritic cells and endothelial cell sprouting during angiogenesis to highlight the characteristics of podosomes and their functioning shaped by the microenvironment.
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Affiliation(s)
- Florian Alonso
- Centre de Recherche Cardio-Thoracique de Bordeaux (INSERM U1045), Université de Bordeaux, Bordeaux F-33076 Cedex, France
| | - Pirjo Spuul
- Department of Chemistry and Biotechnology, Division of Gene Technology, Tallinn University of Technology, 12618 Tallinn, Estonia
| | - Thomas Daubon
- Laboratoire de l'Angiogénèse et du Microenvironnement des Cancers (INSERM U1029), Université de Bordeaux, Bordeaux F-33076 Cedex, France
| | - IJsbrand Kramer
- Centre de Recherche Cardio-Thoracique de Bordeaux (INSERM U1045), Université de Bordeaux, Bordeaux F-33076 Cedex, France
| | - Elisabeth Génot
- Centre de Recherche Cardio-Thoracique de Bordeaux (INSERM U1045), Université de Bordeaux, Bordeaux F-33076 Cedex, France.
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18
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Zhang Y, Yang Y, Zhu Z, Ou G. WASP-Arp2/3-dependent actin polymerization influences fusogen localization during cell-cell fusion in Caenorhabditiselegans embryos. Biol Open 2017; 6:1324-1328. [PMID: 28760733 PMCID: PMC5612239 DOI: 10.1242/bio.026807] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Cell-cell fusion is essential for development and physiology. Actin polymerization was implicated in the Caenorhabditiselegans fusogen EFF-1 engagement in a reconstituted Drosophila cell culture system, and the actin-binding protein spectraplakin links EFF-1 to the actin cytoskeleton and promotes cell-cell fusions in C. elegans larvae. However, it remains unclear whether and how fusogens and the actin cytoskeleton are coordinated in C. elegans embryos. Here, we used live imaging analysis of GFP knock-in and RNAi embryos to study the embryonic cell-cell fusions in C. elegans. Our results show that the inhibition of WASP-Arp2/3-dependent actin polymerization delays cell-cell fusions. EFF-1 is primarily distributed in intracellular vesicles in embryonic fusing cells, and we find that the perturbation of actin polymerization reduces the number of EFF-1-postive vesicles. Thus, the actin cytoskeleton differently promotes cell-cell fusion by regulating fusogen localization to the fusing plasma membrane in larvae or to intracellular vesicles in embryos. Summary: WASP-Arp2/3 regulates fusogen localization to intracellular vesicles in C. elegans embryos. Our results indicate that cell-cell fusions rely on distinct mechanisms at different developmental stages.
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Affiliation(s)
- Yan Zhang
- Tsinghua-Peking Center for Life Sciences, School of Life Sciences and MOE Key Laboratory for Protein Science, Tsinghua University, Beijing 100084, China
| | - Yihong Yang
- Tsinghua-Peking Center for Life Sciences, School of Life Sciences and MOE Key Laboratory for Protein Science, Tsinghua University, Beijing 100084, China
| | - Zhiwen Zhu
- Tsinghua-Peking Center for Life Sciences, School of Life Sciences and MOE Key Laboratory for Protein Science, Tsinghua University, Beijing 100084, China
| | - Guangshuo Ou
- Tsinghua-Peking Center for Life Sciences, School of Life Sciences and MOE Key Laboratory for Protein Science, Tsinghua University, Beijing 100084, China
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19
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Yang Y, Zhang Y, Li WJ, Jiang Y, Zhu Z, Hu H, Li W, Wu JW, Wang ZX, Dong MQ, Huang S, Ou G. Spectraplakin Induces Positive Feedback between Fusogens and the Actin Cytoskeleton to Promote Cell-Cell Fusion. Dev Cell 2017; 41:107-120.e4. [DOI: 10.1016/j.devcel.2017.03.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 01/18/2017] [Accepted: 03/10/2017] [Indexed: 10/25/2022]
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20
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Development of fusogenic glass surfaces that impart spatiotemporal control over macrophage fusion: Direct visualization of multinucleated giant cell formation. Biomaterials 2017; 128:160-171. [PMID: 28340410 DOI: 10.1016/j.biomaterials.2017.02.031] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 02/21/2017] [Accepted: 02/26/2017] [Indexed: 01/07/2023]
Abstract
Implantation of synthetic material, including vascular grafts, pacemakers, etc. results in the foreign body reaction and the formation of multinucleated giant cells (MGCs) at the exterior surface of the implant. Despite the long-standing premise that fusion of mononucleated macrophages results in the formation of MGCs, to date, no published study has shown fusion in context with living specimens. This is due to the fact that optical-quality glass, which is required for the majority of live imaging techniques, does not promote macrophage fusion. Consequently, the morphological changes that macrophages undergo during fusion as well as the mechanisms that govern this process remain ill-defined. In this study, we serendipitously identified a highly fusogenic glass surface and discovered that the capacity to promote fusion was due to oleamide contamination. When adsorbed on glass, oleamide and other molecules that contain long-chain hydrocarbons promoted high levels of macrophage fusion. Adhesion, an essential step for macrophage fusion, was apparently mediated by Mac-1 integrin (CD11b/CD18, αMβ2) as determined by single cell force spectroscopy and adhesion assays. Micropatterned glass further increased fusion and enabled a remarkable degree of spatiotemporal control over MGC formation. Using these surfaces, we reveal the kinetics that govern MGC formation in vitro. We anticipate that the spatiotemporal control afforded by these surfaces will expedite studies designed to identify the mechanism(s) of macrophage fusion and MGC formation with implication for the design of novel biomaterials.
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21
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Schejter ED. Myoblast fusion: Experimental systems and cellular mechanisms. Semin Cell Dev Biol 2016; 60:112-120. [DOI: 10.1016/j.semcdb.2016.07.016] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Revised: 07/11/2016] [Accepted: 07/12/2016] [Indexed: 12/18/2022]
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22
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Ravaux B, Garroum N, Perez E, Willaime H, Gourier C. A specific flagellum beating mode for inducing fusion in mammalian fertilization and kinetics of sperm internalization. Sci Rep 2016; 6:31886. [PMID: 27539564 PMCID: PMC4990900 DOI: 10.1038/srep31886] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 07/26/2016] [Indexed: 12/30/2022] Open
Abstract
The salient phases of fertilization are gamete adhesion, membrane fusion, and internalization of the spermatozoon into the oocyte but the precise timeline and the molecular, membrane and cell mechanisms underlying these highly dynamical events are far from being established. The high motility of the spermatozoa and the unpredictable location of sperm/egg fusion dramatically hinder the use of real time imaging optical techniques that should directly provide the dynamics of cell events. Using an approach based on microfluidics technology, the sperm/egg interaction zone was imaged with the best front view, and the timeline of the fertilization events was established with an unparalleled temporal accuracy from the onset of gamete contact to full sperm DNA decondensation. It reveals that a key element of the adhesion phase to initiate fusion is the oscillatory motion of the sperm head on the oocyte plasma membrane generated by a specific flagellum-beating mode. It also shows that the incorporation of the spermatozoon head is a two steps process that includes simultaneous diving, tilt, and plasma membrane degradation of the sperm head into the oocyte and subsequent DNA decondensation.
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Affiliation(s)
- Benjamin Ravaux
- Laboratoire de Physique Statistique, Ecole Normale Superieure/PSL Research University, UPMC Univ Paris 06, Université Paris Diderot, CNRS, 24 rue Lhomond, 75005 Paris, France
| | - Nabil Garroum
- Laboratoire de Physique Statistique, Ecole Normale Superieure/PSL Research University, UPMC Univ Paris 06, Université Paris Diderot, CNRS, 24 rue Lhomond, 75005 Paris, France
| | - Eric Perez
- Laboratoire de Physique Statistique, Ecole Normale Superieure/PSL Research University, UPMC Univ Paris 06, Université Paris Diderot, CNRS, 24 rue Lhomond, 75005 Paris, France
| | - Hervé Willaime
- Chimie ParisTech, PSL Research University, CNRS, Institut de Recherche de Chimie Paris (IRCP), F-75005 Paris, France
| | - Christine Gourier
- Laboratoire de Physique Statistique, Ecole Normale Superieure/PSL Research University, UPMC Univ Paris 06, Université Paris Diderot, CNRS, 24 rue Lhomond, 75005 Paris, France
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23
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ten Harkel B, Koopsen J, van Putten SM, van Veen H, Picavet DI, de Vries TJ, Bank RA, Everts V. Ultrastructural aspects of foreign body giant cells generated on different substrates. J Struct Biol 2016; 195:31-40. [DOI: 10.1016/j.jsb.2016.04.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 03/31/2016] [Accepted: 04/28/2016] [Indexed: 11/17/2022]
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24
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Dhanyasi N, Segal D, Shimoni E, Shinder V, Shilo BZ, VijayRaghavan K, Schejter ED. Surface apposition and multiple cell contacts promote myoblast fusion in Drosophila flight muscles. J Cell Biol 2016; 211:191-203. [PMID: 26459604 PMCID: PMC4602036 DOI: 10.1083/jcb.201503005] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Transmission EM methods reveal that cell–cell fusion of individual myoblasts with growing Drosophila flight muscles is a stepwise process in which the cell adhesion and branched actin machineries mediate tight apposition and formation of multiple contacts and pores between the surfaces of the fusing cells. Fusion of individual myoblasts to form multinucleated myofibers constitutes a widely conserved program for growth of the somatic musculature. We have used electron microscopy methods to study this key form of cell–cell fusion during development of the indirect flight muscles (IFMs) of Drosophila melanogaster. We find that IFM myoblast–myotube fusion proceeds in a stepwise fashion and is governed by apparent cross talk between transmembrane and cytoskeletal elements. Our analysis suggests that cell adhesion is necessary for bringing myoblasts to within a minimal distance from the myotubes. The branched actin polymerization machinery acts subsequently to promote tight apposition between the surfaces of the two cell types and formation of multiple sites of cell–cell contact, giving rise to nascent fusion pores whose expansion establishes full cytoplasmic continuity. Given the conserved features of IFM myogenesis, this sequence of cell interactions and membrane events and the mechanistic significance of cell adhesion elements and the actin-based cytoskeleton are likely to represent general principles of the myoblast fusion process.
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Affiliation(s)
- Nagaraju Dhanyasi
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, Karnataka 560065, India Manipal University, Manipal, Karnataka 576104, India
| | - Dagan Segal
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Eyal Shimoni
- Department of Chemical Research Support, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Vera Shinder
- Department of Chemical Research Support, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Ben-Zion Shilo
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - K VijayRaghavan
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, Karnataka 560065, India
| | - Eyal D Schejter
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
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25
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Brüser L, Bogdan S. Molecular Control of Actin Dynamics In Vivo: Insights from Drosophila. Handb Exp Pharmacol 2016; 235:285-310. [PMID: 27757759 DOI: 10.1007/164_2016_33] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The actin cytoskeleton provides mechanical support for cells and generates forces to drive cell shape changes and cell migration in morphogenesis. Molecular understanding of actin dynamics requires a genetically traceable model system that allows interdisciplinary experimental approaches to elucidate the regulatory network of cytoskeletal proteins in vivo. Here, we will discuss some examples of how advances in Drosophila genetics and high-resolution imaging techniques contribute to the discovery of new actin functions, signaling pathways, and mechanisms of actin regulation in vivo.
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Affiliation(s)
- Lena Brüser
- Institute for Neurobiology, University of Muenster, Badestrasse 9, 48149, Muenster, Germany
| | - Sven Bogdan
- Institute for Neurobiology, University of Muenster, Badestrasse 9, 48149, Muenster, Germany.
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26
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Kim JH, Jin P, Duan R, Chen EH. Mechanisms of myoblast fusion during muscle development. Curr Opin Genet Dev 2015; 32:162-70. [PMID: 25989064 DOI: 10.1016/j.gde.2015.03.006] [Citation(s) in RCA: 158] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Revised: 03/13/2015] [Accepted: 03/17/2015] [Indexed: 01/24/2023]
Abstract
The development and regeneration of skeletal muscle require the fusion of mononucleated muscle cells to form multinucleated, contractile muscle fibers. Studies using a simple genetic model, Drosophila melanogaster, have discovered many evolutionarily conserved fusion-promoting factors in vivo. Recent work in zebrafish and mouse also identified several vertebrate-specific factors required for myoblast fusion. Here, we integrate progress in multiple in vivo systems and highlight conceptual advance in understanding how muscle cell membranes are brought together for fusion. We focus on the molecular machinery at the fusogenic synapse and present a three-step model to describe the molecular and cellular events leading to fusion pore formation.
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Affiliation(s)
- Ji Hoon Kim
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, United States
| | - Peng Jin
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, United States
| | - Rui Duan
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, United States
| | - Elizabeth H Chen
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, United States.
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27
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Schulman VK, Dobi KC, Baylies MK. Morphogenesis of the somatic musculature in Drosophila melanogaster. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2015; 4:313-34. [PMID: 25758712 DOI: 10.1002/wdev.180] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Revised: 01/28/2015] [Accepted: 01/30/2015] [Indexed: 12/22/2022]
Abstract
In Drosophila melanogaster, the somatic muscle system is first formed during embryogenesis, giving rise to the larval musculature. Later during metamorphosis, this system is destroyed and replaced by an entirely new set of muscles in the adult fly. Proper formation of the larval and adult muscles is critical for basic survival functions such as hatching and crawling (in the larva), walking and flying (in the adult), and feeding (at both larval and adult stages). Myogenesis, from mononucleated muscle precursor cells to multinucleated functional muscles, is driven by a number of cellular processes that have begun to be mechanistically defined. Once the mesodermal cells destined for the myogenic lineage have been specified, individual myoblasts fuse together iteratively to form syncytial myofibers. Combining cytoplasmic contents demands a level of intracellular reorganization that, most notably, leads to redistribution of the myonuclei to maximize internuclear distance. Signaling from extending myofibers induces terminal tendon cell differentiation in the ectoderm, which results in secure muscle-tendon attachments that are critical for muscle contraction. Simultaneously, muscles become innervated and undergo sarcomerogenesis to establish the contractile apparatus that will facilitate movement. The cellular mechanisms governing these morphogenetic events share numerous parallels to mammalian development, and the basic unit of all muscle, the myofiber, is conserved from flies to mammals. Thus, studies of Drosophila myogenesis and comparisons to muscle development in other systems highlight conserved regulatory programs of biomedical relevance to general muscle biology and studies of muscle disease.
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Affiliation(s)
- Victoria K Schulman
- Cell and Developmental Biology, Weill Cornell Graduate School of Medical Sciences, Cornell University, New York, NY, USA.,Program in Developmental Biology, Sloan Kettering Institute, New York, NY, USA
| | - Krista C Dobi
- Program in Developmental Biology, Sloan Kettering Institute, New York, NY, USA
| | - Mary K Baylies
- Cell and Developmental Biology, Weill Cornell Graduate School of Medical Sciences, Cornell University, New York, NY, USA.,Program in Developmental Biology, Sloan Kettering Institute, New York, NY, USA
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28
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Kim JH, Ren Y, Ng WP, Li S, Son S, Kee YS, Zhang S, Zhang G, Fletcher DA, Robinson DN, Chen EH. Mechanical tension drives cell membrane fusion. Dev Cell 2015; 32:561-73. [PMID: 25684354 DOI: 10.1016/j.devcel.2015.01.005] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 11/14/2014] [Accepted: 01/10/2015] [Indexed: 01/05/2023]
Abstract
Membrane fusion is an energy-consuming process that requires tight juxtaposition of two lipid bilayers. Little is known about how cells overcome energy barriers to bring their membranes together for fusion. Previously, we have shown that cell-cell fusion is an asymmetric process in which an "attacking" cell drills finger-like protrusions into the "receiving" cell to promote cell fusion. Here, we show that the receiving cell mounts a Myosin II (MyoII)-mediated mechanosensory response to its invasive fusion partner. MyoII acts as a mechanosensor, which directs its force-induced recruitment to the fusion site, and the mechanosensory response of MyoII is amplified by chemical signaling initiated by cell adhesion molecules. The accumulated MyoII, in turn, increases cortical tension and promotes fusion pore formation. We propose that the protrusive and resisting forces from fusion partners put the fusogenic synapse under high mechanical tension, which helps to overcome energy barriers for membrane apposition and drives cell membrane fusion.
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Affiliation(s)
- Ji Hoon Kim
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Yixin Ren
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Win Pin Ng
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Shuo Li
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Sungmin Son
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Yee-Seir Kee
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Shiliang Zhang
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Guofeng Zhang
- Laboratory of Bioengineering and Physical Science, National Institute of Biomedical Imaging and Bioengineering, NIH, Bethesda, MD 20892, USA
| | - Daniel A Fletcher
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Douglas N Robinson
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Elizabeth H Chen
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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29
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Bothe I, Deng S, Baylies M. PI(4,5)P2 regulates myoblast fusion through Arp2/3 regulator localization at the fusion site. Development 2014; 141:2289-301. [PMID: 24821989 DOI: 10.1242/dev.100743] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Cell-cell fusion is a regulated process that requires merging of the opposing membranes and underlying cytoskeletons. However, the integration between membrane and cytoskeleton signaling during fusion is not known. Using Drosophila, we demonstrate that the membrane phosphoinositide PI(4,5)P2 is a crucial regulator of F-actin dynamics during myoblast fusion. PI(4,5)P2 is locally enriched and colocalizes spatially and temporally with the F-actin focus that defines the fusion site. PI(4,5)P2 enrichment depends on receptor engagement but is upstream or parallel to actin remodeling. Regulators of actin branching via Arp2/3 colocalize with PI(4,5)P2 in vivo and bind PI(4,5)P2 in vitro. Manipulation of PI(4,5)P2 availability leads to impaired fusion, with a reduction in the F-actin focus size and altered focus morphology. Mechanistically, the changes in the actin focus are due to a failure in the enrichment of actin regulators at the fusion site. Moreover, improper localization of these regulators hinders expansion of the fusion interface. Thus, PI(4,5)P2 enrichment at the fusion site encodes spatial and temporal information that regulates fusion progression through the localization of activators of actin polymerization.
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Affiliation(s)
- Ingo Bothe
- Program in Developmental Biology, Sloan Kettering Institute, New York, NY 10065, USA
| | - Su Deng
- Graduate Program in Physiology, Biophysics & Systems Biology, Weill Cornell Graduate School of Medical Sciences, Cornell University, New York, NY 10065, USA
| | - Mary Baylies
- Program in Developmental Biology, Sloan Kettering Institute, New York, NY 10065, USA Graduate Program in Physiology, Biophysics & Systems Biology, Weill Cornell Graduate School of Medical Sciences, Cornell University, New York, NY 10065, USA
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30
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Wang R, Dang YL, Zheng R, Li Y, Li W, Lu X, Wang LJ, Zhu C, Lin HY, Wang H. Live cell imaging of in vitro human trophoblast syncytialization. Biol Reprod 2014; 90:117. [PMID: 24740598 DOI: 10.1095/biolreprod.113.114892] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Human trophoblast syncytialization, a process of cell-cell fusion, is one of the most important yet least understood events during placental development. Investigating the fusion process in a placenta in vivo is very challenging given the complexity of this process. Application of primary cultured cytotrophoblast cells isolated from term placentas and BeWo cells derived from human choriocarcinoma formulates a biphasic strategy to achieve the mechanism of trophoblast cell fusion, as the former can spontaneously fuse to form the multinucleated syncytium and the latter is capable of fusing under the treatment of forskolin (FSK). Live-cell imaging is a powerful tool that is widely used to investigate many physiological or pathological processes in various animal models or humans; however, to our knowledge, the mechanism of trophoblast cell fusion has not been reported using a live- cell imaging manner. In this study, a live-cell imaging system was used to delineate the fusion process of primary term cytotrophoblast cells and BeWo cells. By using live staining with Hoechst 33342 or cytoplasmic dyes or by stably transfecting enhanced green fluorescent protein (EGFP) and DsRed2-Nuc reporter plasmids, we observed finger-like protrusions on the cell membranes of fusion partners before fusion and the exchange of cytoplasmic contents during fusion. In summary, this study provides the first video recording of the process of trophoblast syncytialization. Furthermore, the various live-cell imaging systems used in this study will help to yield molecular insights into the syncytialization process during placental development.
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Affiliation(s)
- Rui Wang
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China Graduate School of Chinese Academy of Sciences, Beijing, China
| | - Yan-Li Dang
- Department of Obstetrics and Gynecology, the 306th Hospital of PLA, Beijing, China
| | - Ru Zheng
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China Graduate School of Chinese Academy of Sciences, Beijing, China
| | - Yue Li
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Weiwei Li
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China College of Life Science, Beijing Normal University, Beijing, China
| | - Xiaoyin Lu
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China Graduate School of Chinese Academy of Sciences, Beijing, China
| | - Li-Juan Wang
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Cheng Zhu
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Hai-Yan Lin
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Hongmei Wang
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
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31
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Shilagardi K, Li S, Luo F, Marikar F, Duan R, Jin P, Kim JH, Murnen K, Chen EH. Actin-propelled invasive membrane protrusions promote fusogenic protein engagement during cell-cell fusion. Science 2013; 340:359-63. [PMID: 23470732 DOI: 10.1126/science.1234781] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Cell-cell fusion is critical for the conception, development, and physiology of multicellular organisms. Although cellular fusogenic proteins and the actin cytoskeleton are implicated in cell-cell fusion, it remains unclear whether and how they coordinate to promote plasma membrane fusion. We reconstituted a high-efficiency, inducible cell fusion culture system in the normally nonfusing Drosophila S2R+ cells. Both fusogenic proteins and actin cytoskeletal rearrangements were necessary for cell fusion, and in combination they were sufficient to impart fusion competence. Localized actin polymerization triggered by specific cell-cell or cell-matrix adhesion molecules propelled invasive cell membrane protrusions, which in turn promoted fusogenic protein engagement and plasma membrane fusion. This de novo cell fusion culture system reveals a general role for actin-propelled invasive membrane protrusions in driving fusogenic protein engagement during cell-cell fusion.
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Affiliation(s)
- Khurts Shilagardi
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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32
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Satouh Y, Inoue N, Ikawa M, Okabe M. Visualization of the moment of mouse sperm-egg fusion and dynamic localization of IZUMO1. J Cell Sci 2012; 125:4985-90. [PMID: 22946049 DOI: 10.1242/jcs.100867] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023] Open
Abstract
Gene disruption experiments have proven that the acrosomal protein IZUMO1 is essential for sperm-egg fusion in the mouse. However, despite its predicted function, it is not expressed on the surface of ejaculated spermatozoa. Here, we report the dynamics of diffusion of IZUMO1 from the acrosomal membrane to the sperm surface at the time of the acrosome reaction, visualized using a fluorescent protein tag. IZUMO1 showed a tendency to localize in the equatorial segment of the sperm surface after the acrosome reaction. This region is considered to initiate fusion with the oolemma. The moment of sperm-egg fusion and the dynamic movements of proteins during fusion were also imaged live. Translocation of IZUMO1 during the fertilization process was clarified, and a fundamental mechanism in mammalian fertilization is postulated.
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Affiliation(s)
- Yuhkoh Satouh
- World Premier International Immunology Frontier Research Center, Osaka University, Yamadaoka 3-1, Suita, Osaka 565-0871, Japan
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33
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Duan R, Jin P, Luo F, Zhang G, Anderson N, Chen EH. Group I PAKs function downstream of Rac to promote podosome invasion during myoblast fusion in vivo. ACTA ACUST UNITED AC 2012; 199:169-85. [PMID: 23007650 PMCID: PMC3461515 DOI: 10.1083/jcb.201204065] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Group I p21-activated kinases organize actin filaments in myoblasts into dense foci, which promote podosome invasion and subsequent myoblast fusion. The p21-activated kinases (PAKs) play essential roles in diverse cellular processes and are required for cell proliferation, apoptosis, polarity establishment, migration, and cell shape changes. Here, we have identified a novel function for the group I PAKs in cell–cell fusion. We show that the two Drosophila group I PAKs, DPak3 and DPak1, have partially redundant functions in myoblast fusion in vivo, with DPak3 playing a major role. DPak3 is enriched at the site of fusion colocalizing with the F-actin focus within a podosome-like structure (PLS), and promotes actin filament assembly during PLS invasion. Although the small GTPase Rac is involved in DPak3 activation and recruitment to the PLS, the kinase activity of DPak3 is required for effective PLS invasion. We propose a model whereby group I PAKs act downstream of Rac to organize the actin filaments within the PLS into a dense focus, which in turn promotes PLS invasion and fusion pore initiation during myoblast fusion.
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Affiliation(s)
- Rui Duan
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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34
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Abstract
The fusion of myoblasts into multinucleate syncytia plays a fundamental role in muscle function, as it supports the formation of extended sarcomeric arrays, or myofibrils, within a large volume of cytoplasm. Principles learned from the study of myoblast fusion not only enhance our understanding of myogenesis, but also contribute to our perspectives on membrane fusion and cell-cell fusion in a wide array of model organisms and experimental systems. Recent studies have advanced our views of the cell biological processes and crucial proteins that drive myoblast fusion. Here, we provide an overview of myoblast fusion in three model systems that have contributed much to our understanding of these events: the Drosophila embryo; developing and regenerating mouse muscle; and cultured rodent muscle cells.
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Affiliation(s)
- Susan M Abmayr
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA.
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