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Liu W, Gao T, Li N, Shao S, Liu B. Vesicle fusion and release in neurons under dynamic mechanical equilibrium. iScience 2024; 27:109793. [PMID: 38736547 PMCID: PMC11088343 DOI: 10.1016/j.isci.2024.109793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2024] Open
Abstract
Vesicular fusion plays a pivotal role in cellular processes, involving stages like vesicle trafficking, fusion pore formation, content release, and membrane integration or separation. This dynamic process is regulated by a complex interplay of protein assemblies, osmotic forces, and membrane tension, which together maintain a mechanical equilibrium within the cell. Changes in cellular mechanics or external pressures prompt adjustments in this equilibrium, highlighting the system's adaptability. This review delves into the synergy between intracellular proteins, structural components, and external forces in facilitating vesicular fusion and release. It also explores how cells respond to mechanical stress, maintaining equilibrium and offering insights into vesicle fusion mechanisms and the development of neurological disorders.
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Affiliation(s)
- Wenhao Liu
- Cancer Hospital of Dalian University of Technology, Shenyang 110042, China
| | - Tianyu Gao
- Cancer Hospital of Dalian University of Technology, Shenyang 110042, China
| | - Na Li
- Cancer Hospital of Dalian University of Technology, Shenyang 110042, China
- Faculty of Medicine, Liaoning Key Lab of Integrated Circuit and Biomedical Electronic System, Dalian University of Technology, Dalian 116024, China
| | - Shuai Shao
- Cancer Hospital of Dalian University of Technology, Shenyang 110042, China
- Faculty of Medicine, Liaoning Key Lab of Integrated Circuit and Biomedical Electronic System, Dalian University of Technology, Dalian 116024, China
| | - Bo Liu
- Cancer Hospital of Dalian University of Technology, Shenyang 110042, China
- Faculty of Medicine, Liaoning Key Lab of Integrated Circuit and Biomedical Electronic System, Dalian University of Technology, Dalian 116024, China
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2
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α3β4 Acetylcholine Nicotinic Receptors Are Components of the Secretory Machinery Clusters in Chromaffin Cells. Int J Mol Sci 2022; 23:ijms23169101. [PMID: 36012367 PMCID: PMC9409273 DOI: 10.3390/ijms23169101] [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: 06/06/2022] [Revised: 07/25/2022] [Accepted: 08/11/2022] [Indexed: 11/17/2022] Open
Abstract
The heteromeric assembly of α3 and β4 subunits of acetylcholine nicotinic receptors (nAChRs) seems to mediate the secretory response in bovine chromaffin cells. However, there is no information about the localization of these nAChRs in relationship with the secretory active zones in this cellular model. The present work presents the first evidence that, in fact, a population of these receptors is associated through the F-actin cytoskeleton with exocytotic machinery components, as detected by SNAP-25 labeling. Furthermore, we also prove that, upon stimulation, the probability to find α3β4 nAChRs very close to exocytotic events increases with randomized distributions, thus substantiating the clear dynamic behavior of these receptors during the secretory process. Modeling on secretory dynamics and secretory component distributions supports the idea that α3β4 nAChR cluster mobility could help with improving the efficiency of the secretory response of chromaffin cells. Our study is limited by the use of conventional confocal microscopy; in this sense, a strengthening to our conclusions could come from the use of super-resolution microscopy techniques in the near future.
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3
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Cabrera AP, Stoddard J, Santiago Tierno I, Matisioudis N, Agarwal M, Renner L, Palegar N, Neuringer M, McGill T, Ghosh K. Increased cell stiffness contributes to complement-mediated injury of choroidal endothelial cells in a monkey model of early age-related macular degeneration. J Pathol 2022; 257:314-326. [PMID: 35239183 DOI: 10.1002/path.5892] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 02/03/2022] [Accepted: 03/01/2022] [Indexed: 11/06/2022]
Abstract
Age-related macular degeneration (AMD) is the leading cause of blindness in the aging population. Yet, no therapies exist for approximately 85% of all AMD patients who have the dry form that is marked by degeneration of the retinal pigmented epithelium (RPE) and underlying choroidal vasculature. As the choroidal vessels are crucial for RPE development and maintenance, understanding how they degenerate may lead to effective therapies for dry AMD. One likely causative factor for choroidal vascular loss is the cytolytic membrane attack complex (MAC) of the complement pathway that is abundant on choroidal vessels of humans with early dry AMD. To examine this possibility, we studied the effect of complement activation on choroidal endothelial cells (ECs) isolated from a rhesus monkey model of early AMD that, we report, exhibits MAC deposition and choriocapillaris endothelial loss similar to that seen in human early AMD. Treatment of choroidal ECs from AMD eyes with complement-competent normal human serum caused extensive actin cytoskeletal injury that was significantly less pronounced in choroidal ECs from young normal monkey eyes. We further show that ECs from AMD eyes are significantly stiffer than their younger counterparts and exhibit peripheral actin organization that is distinct from the longitudinal stress fibers in young ECs. Finally, these differences in complement susceptibility and mechanostructural properties were found to be regulated by the differential activity of the small GTPases Rac and Rho, because Rac inhibition in AMD cells led to simultaneous reduction in stiffness and complement susceptibility while Rho inhibition in young cells exacerbated complement injury. Thus, by identifying cell stiffness and cytoskeletal regulators Rac and Rho as important determinants of complement susceptibility, the current findings offer a new mechanistic insight into choroidal vascular loss in early AMD that warrants further investigation for assessment of translational potential. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Andrea P Cabrera
- Department of Bioengineering, University of California, Riverside, CA, USA
| | - Jonathan Stoddard
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Sciences University, Beaverton, OR, USA
| | - Irene Santiago Tierno
- Department of Ophthalmology and Integrated Physiology Interdepartmental PhD Program, University of California, Los Angeles, CA, USA.,Molecular, Cellular, and Integrated Physiology Interdepartmental PhD Program, University of California, Los Angeles, CA, USA.,Doheny Eye Institute, Pasadena, CA, USA
| | | | - Mahesh Agarwal
- Department of Ophthalmology and Integrated Physiology Interdepartmental PhD Program, University of California, Los Angeles, CA, USA.,Doheny Eye Institute, Pasadena, CA, USA
| | - Lauren Renner
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Sciences University, Beaverton, OR, USA
| | - Neha Palegar
- Department of Bioengineering, University of California, Riverside, CA, USA
| | - Martha Neuringer
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Sciences University, Beaverton, OR, USA.,Casey Eye Institute, Oregon Health & Sciences University, Portland, OR, USA
| | - Trevor McGill
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Sciences University, Beaverton, OR, USA.,Casey Eye Institute, Oregon Health & Sciences University, Portland, OR, USA
| | - Kaustabh Ghosh
- Department of Bioengineering, University of California, Riverside, CA, USA.,Department of Ophthalmology and Integrated Physiology Interdepartmental PhD Program, University of California, Los Angeles, CA, USA.,Molecular, Cellular, and Integrated Physiology Interdepartmental PhD Program, University of California, Los Angeles, CA, USA.,Doheny Eye Institute, Pasadena, CA, USA
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4
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Villanueva J, Gimenez-Molina Y, Davletov B, Gutiérrez LM. Vesicle Fusion as a Target Process for the Action of Sphingosine and Its Derived Drugs. Int J Mol Sci 2022; 23:ijms23031086. [PMID: 35163009 PMCID: PMC8834808 DOI: 10.3390/ijms23031086] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 01/13/2022] [Accepted: 01/18/2022] [Indexed: 11/16/2022] Open
Abstract
The fusion of membranes is a central part of the physiological processes involving the intracellular transport and maturation of vesicles and the final release of their contents, such as neurotransmitters and hormones, by exocytosis. Traditionally, in this process, proteins, such SNAREs have been considered the essential components of the fusion molecular machinery, while lipids have been seen as merely structural elements. Nevertheless, sphingosine, an intracellular signalling lipid, greatly increases the release of neurotransmitters in neuronal and neuroendocrine cells, affecting the exocytotic fusion mode through the direct interaction with SNAREs. Moreover, recent studies suggest that FTY-720 (Fingolimod), a sphingosine structural analogue used in the treatment of multiple sclerosis, simulates sphingosine in the promotion of exocytosis. Furthermore, this drug also induces the intracellular fusion of organelles such as dense vesicles and mitochondria causing cell death in neuroendocrine cells. Therefore, the effect of sphingosine and synthetic derivatives on the heterologous and homologous fusion of organelles can be considered as a new mechanism of action of sphingolipids influencing important physiological processes, which could underlie therapeutic uses of sphingosine derived lipids in the treatment of neurodegenerative disorders and cancers of neuronal origin such neuroblastoma.
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Affiliation(s)
- José Villanueva
- Instituto de Neurociencias, CSIC-Universidad Miguel Hernández, Cra de Valencia S/N, Sant Joan d’Alacant, 03550 Alicante, Spain;
- Correspondence: (J.V.); (L.M.G.)
| | - Yolanda Gimenez-Molina
- Instituto de Neurociencias, CSIC-Universidad Miguel Hernández, Cra de Valencia S/N, Sant Joan d’Alacant, 03550 Alicante, Spain;
| | - Bazbek Davletov
- Department of Biomedical Science, University of Sheffield, Sheffield S10 2TN, UK;
| | - Luis M. Gutiérrez
- Instituto de Neurociencias, CSIC-Universidad Miguel Hernández, Cra de Valencia S/N, Sant Joan d’Alacant, 03550 Alicante, Spain;
- Correspondence: (J.V.); (L.M.G.)
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5 ns electric pulses induce Ca 2+-dependent exocytotic release of catecholamine from adrenal chromaffin cells. Bioelectrochemistry 2021; 140:107830. [PMID: 33965669 DOI: 10.1016/j.bioelechem.2021.107830] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Revised: 04/21/2021] [Accepted: 04/23/2021] [Indexed: 12/12/2022]
Abstract
Previously we reported that adrenal chromaffin cells exposed to a 5 ns, 5 MV/m pulse release the catecholamines norepinephrine (NE) and epinephrine (EPI) in a Ca2+-dependent manner. Here we determined that NE and EPI release increased with pulse number (one versus five and ten pulses at 1 Hz), established that release occurs by exocytosis, and characterized the exocytotic response in real-time. Evidence of an exocytotic mechanism was the appearance of dopamine-β-hydroxylase on the plasma membrane, and the demonstration by total internal reflection fluorescence microscopy studies that a train of five or ten pulses at 1 Hz triggered the release of the fluorescent dye acridine orange from secretory granules. Release events were Ca2+-dependent, longer-lived relative to those evoked by nicotinic receptor stimulation, and occurred with a delay of several seconds despite an immediate rise in Ca2+. In complementary studies, cells labeled with the plasma membrane fluorescent dye FM 1-43 and exposed to a train of ten pulses at 1 Hz underwent Ca2+-dependent increases in FM 1-43 fluorescence indicative of granule fusion with the plasma membrane due to exocytosis. These results demonstrate the effectiveness of ultrashort electric pulses for stimulating catecholamine release, signifying their promise as a novel electrostimulation modality for neurosecretion.
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Delavoie F, Royer C, Gasman S, Vitale N, Chasserot-Golaz S. Transmission Electron Microscopy and Tomography on Plasma Membrane Sheets to Study Secretory Docking. Methods Mol Biol 2021; 2233:301-309. [PMID: 33222143 DOI: 10.1007/978-1-0716-1044-2_20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
To study the formation and the architecture of exocytotic site, we generated plasma membrane (PM) sheets on electron microscopy grids to visualize the membrane organization and quantitatively analyze distributions of specific proteins and lipids. This technique allows observing the cytoplasmic face of the plasma membrane by transmission electron microscope. The principle of this approach relies on application of mechanical forces to break open cells. The exposed inner membrane surface can then be visualized with different electron-dense colorations, and specific proteins or lipids can be detected with gold-conjugated probes. Moreover, the membrane sheets are sufficiently resistant to support automated acquisition of multiple-tilt projections, and thus electron tomography allows to obtain three-dimensional (3D) ultrastructural images of secretory granule docked to the plasma membrane.
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Affiliation(s)
- Franck Delavoie
- Centre National de la Recherche Scientifique, Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative, Université de Toulouse, Toulouse, France
| | - Cathy Royer
- Plateforme Imagerie In Vitro, Neuropôle de Strasbourg, Strasbourg, France
| | - Stéphane Gasman
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg, France
| | - Nicolas Vitale
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg, France
| | - Sylvette Chasserot-Golaz
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg, France.
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Mono- and Poly-unsaturated Phosphatidic Acid Regulate Distinct Steps of Regulated Exocytosis in Neuroendocrine Cells. Cell Rep 2020; 32:108026. [DOI: 10.1016/j.celrep.2020.108026] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 06/16/2020] [Accepted: 07/21/2020] [Indexed: 12/21/2022] Open
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8
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Miklavc P, Frick M. Actin and Myosin in Non-Neuronal Exocytosis. Cells 2020; 9:cells9061455. [PMID: 32545391 PMCID: PMC7348895 DOI: 10.3390/cells9061455] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 06/03/2020] [Accepted: 06/06/2020] [Indexed: 12/18/2022] Open
Abstract
Cellular secretion depends on exocytosis of secretory vesicles and discharge of vesicle contents. Actin and myosin are essential for pre-fusion and post-fusion stages of exocytosis. Secretory vesicles depend on actin for transport to and attachment at the cell cortex during the pre-fusion phase. Actin coats on fused vesicles contribute to stabilization of large vesicles, active vesicle contraction and/or retrieval of excess membrane during the post-fusion phase. Myosin molecular motors complement the role of actin. Myosin V is required for vesicle trafficking and attachment to cortical actin. Myosin I and II members engage in local remodeling of cortical actin to allow vesicles to get access to the plasma membrane for membrane fusion. Myosins stabilize open fusion pores and contribute to anchoring and contraction of actin coats to facilitate vesicle content release. Actin and myosin function in secretion is regulated by a plethora of interacting regulatory lipids and proteins. Some of these processes have been first described in non-neuronal cells and reflect adaptations to exocytosis of large secretory vesicles and/or secretion of bulky vesicle cargoes. Here we collate the current knowledge and highlight the role of actomyosin during distinct phases of exocytosis in an attempt to identify unifying molecular mechanisms in non-neuronal secretory cells.
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Affiliation(s)
- Pika Miklavc
- School of Science, Engineering & Environment, University of Salford, Manchester M5 4WT, UK
- Correspondence: (P.M.); (M.F.); Tel.: +44-0161-295-3395 (P.M.); +49-731-500-23115 (M.F.); Fax: +49-731-500-23242 (M.F.)
| | - Manfred Frick
- Institute of General Physiology, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
- Correspondence: (P.M.); (M.F.); Tel.: +44-0161-295-3395 (P.M.); +49-731-500-23115 (M.F.); Fax: +49-731-500-23242 (M.F.)
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9
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Martínez J, Marmisolle I, Tarallo D, Quijano C. Mitochondrial Bioenergetics and Dynamics in Secretion Processes. Front Endocrinol (Lausanne) 2020; 11:319. [PMID: 32528413 PMCID: PMC7256191 DOI: 10.3389/fendo.2020.00319] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 04/27/2020] [Indexed: 12/12/2022] Open
Abstract
Secretion is an energy consuming process that plays a relevant role in cell communication and adaptation to the environment. Among others, endocrine cells producing hormones, immune cells producing cytokines or antibodies, neurons releasing neurotransmitters at synapsis, and more recently acknowledged, senescent cells synthesizing and secreting multiple cytokines, growth factors and proteases, require energy to successfully accomplish the different stages of the secretion process. Calcium ions (Ca2+) act as second messengers regulating secretion in many of these cases. In this setting, mitochondria appear as key players providing ATP by oxidative phosphorylation, buffering Ca2+ concentrations and acting as structural platforms. These tasks also require the concerted actions of the mitochondrial dynamics machinery. These proteins mediate mitochondrial fusion and fission, and are also required for transport and tethering of mitochondria to cellular organelles where the different steps of the secretion process take place. Herein we present a brief overview of mitochondrial energy metabolism, mitochondrial dynamics, and the different steps of the secretion processes, along with evidence of the interaction between these pathways. We also analyze the role of mitochondria in secretion by different cell types in physiological and pathological settings.
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10
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Gimenez-Molina Y, García-Martínez V, Villanueva J, Davletov B, Gutiérrez LM. Multiple sclerosis drug FTY-720 toxicity is mediated by the heterotypic fusion of organelles in neuroendocrine cells. Sci Rep 2019; 9:18471. [PMID: 31804600 PMCID: PMC6895052 DOI: 10.1038/s41598-019-55106-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 11/24/2019] [Indexed: 12/29/2022] Open
Abstract
FTY-720 (Fingolimod) was one of the first compounds authorized for the treatment of multiple sclerosis. Among its other activities, this sphingosine analogue enhances exocytosis in neuroendocrine chromaffin cells, altering the quantal release of catecholamines. Surprisingly, the size of chromaffin granules is reduced within few minutes of treatment, a process that is paralleled by the homotypic fusion of granules and their heterotypic fusion with mitochondria, as witnessed by dynamic confocal and TIRF microscopy. Electron microscopy studies support these observations, revealing the fusion of several vesicles with individual mitochondria to form large, round mixed organelles. This cross-fusion is SNARE-dependent, being partially prevented by the expression of an inactive form of SNAP-25. Fused mitochondria exhibit an altered redox potential, which dramatically enhances cell death. Therefore, the cross-fusion of intracellular organelles appears to be a new mechanism to be borne in mind when considering the effect of FTY-720 on the survival of neuroendocrine cells.
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Affiliation(s)
- Yolanda Gimenez-Molina
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas, Sant Joan d'Alacant, Alicante, 03550, Spain
| | - Virginia García-Martínez
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas, Sant Joan d'Alacant, Alicante, 03550, Spain
| | - José Villanueva
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas, Sant Joan d'Alacant, Alicante, 03550, Spain
| | - Bazbek Davletov
- Department of Biomedical Science, University of Sheffield, Firth Court, Western Bank, Sheffield, S10 2TN, UK
| | - Luis M Gutiérrez
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas, Sant Joan d'Alacant, Alicante, 03550, Spain.
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Chan B, Parreno J, Glogauer M, Wang Y, Kandel R. Adseverin, an actin binding protein, regulates articular chondrocyte phenotype. J Tissue Eng Regen Med 2019; 13:1438-1452. [PMID: 31090208 DOI: 10.1002/term.2898] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 05/08/2019] [Accepted: 05/10/2019] [Indexed: 11/11/2022]
Abstract
Chondrocytes dedifferentiate as a result of monolayer culture for cell number expansion. This is associated with the development of an elongated shape, increased actin polymerization, development of stress fibres, and expression of contractile molecules. Given the changes in actin status with dedifferentiation, the hypothesis of this study was that adseverin, an actin severing and capping protein, plays a role in regulating chondrocyte phenotype and function. This study reports that serial passaging of articular chondrocytes in monolayer culture resulted in loss of adseverin protein expression as early as Day 14 of culture and remained repressed in Passage 2 (P2) cells. Knockdown of adseverin by siRNA in primary chondrocytes promoted an increase in cell size and an elongated shape, actin stress fibres, decreased G-/F-actin ratio, and increased number of actin-free barbed ends. The cells also showed increased expression of the contractile genes and proteins, vinculin and α-smooth muscle actin, and increased ability to contract collagen gels. These are all features of dedifferentiation. These effects were due to adseverin as adseverin overexpression following transfection of the green fluorescent protein-adseverin plasmid partially reversed all of these changes in P2 chondrocytes. Furthermore, sox9 and aggrecan chondrogenic gene expression was upregulated, and collagen type I genes expression was downregulated with adseverin overexpression. The change in aggrecan mRNA expression had functional consequence as these cells exhibited increased total proteoglycan synthesis. These findings demonstrate that adseverin regulates features indicative of redifferentiation in passaged articular chondrocytes through modulation of the actin cytoskeleton status and potentially may regulate the maintenance of phenotype in primary chondrocytes.
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Affiliation(s)
- Byron Chan
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Justin Parreno
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Michael Glogauer
- Faculty of Dentistry, University of Toronto, Toronto, ON, Canada
| | - Yongqiang Wang
- Faculty of Dentistry, University of Toronto, Toronto, ON, Canada
| | - Rita Kandel
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
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12
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Klein O, Sagi-Eisenberg R. Anaphylactic Degranulation of Mast Cells: Focus on Compound Exocytosis. J Immunol Res 2019; 2019:9542656. [PMID: 31011586 PMCID: PMC6442490 DOI: 10.1155/2019/9542656] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2018] [Accepted: 12/26/2018] [Indexed: 01/15/2023] Open
Abstract
Anaphylaxis is a notorious type 2 immune response which may result in a systemic response and lead to death. A precondition for the unfolding of the anaphylactic shock is the secretion of inflammatory mediators from mast cells in response to an allergen, mostly through activation of the cells via the IgE-dependent pathway. While mast cells are specialized secretory cells that can secrete through a variety of exocytic modes, the most predominant mode exerted by the mast cell during anaphylaxis is compound exocytosis-a specialized form of regulated exocytosis where secretory granules fuse to one another. Here, we review the modes of regulated exocytosis in the mast cell and focus on compound exocytosis. We review historical landmarks in the research of compound exocytosis in mast cells and the methods available for investigating compound exocytosis. We also review the molecular mechanisms reported to underlie compound exocytosis in mast cells and expand further with reviewing key findings from other cell types. Finally, we discuss the possible reasons for the mast cell to utilize compound exocytosis during anaphylaxis, the conflicting evidence in different mast cell models, and the open questions in the field which remain to be answered.
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Affiliation(s)
- Ofir Klein
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Ronit Sagi-Eisenberg
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
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Zhang X, Han L, Wang Q, Zhang C, Yu Y, Tian J, Kong Z. The host actin cytoskeleton channels rhizobia release and facilitates symbiosome accommodation during nodulation in Medicago truncatula. THE NEW PHYTOLOGIST 2019; 221:1049-1059. [PMID: 30156704 DOI: 10.1111/nph.15423] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Accepted: 08/02/2018] [Indexed: 05/13/2023]
Abstract
In plants, the actin cytoskeleton plays a central role in regulating intracellular transport and trafficking in the endomembrane system. Work in legumes suggested that during nodulation, the actin cytoskeleton coordinates numerous cellular processes in the development of nitrogen-fixing nodules. However, we lacked live-cell visualizations demonstrating dynamic remodeling of the actin cytoskeleton during infection droplet release and symbiosome development. Here, we generated transgenic Medicago truncatula lines stably expressing the fluorescent actin marker ABD2-GFP, and utilized live-cell imaging to reveal the architecture and dynamics of the actin cytoskeleton during nodule development. Live-cell observations showed that different zones in nitrogen-fixing nodules exhibit distinct actin architectures and infected cells display five characteristic actin architectures during nodule development. Live-cell imaging combined with three-dimensional reconstruction demonstrated that dense filamentous-actin (F-actin) arrays channel the elongation of infection threads and the release of infection droplets, an F-actin network encircles freshly-released rhizobia, and short F-actin fragments and actin dots around radially distributed symbiosomes. Our findings suggest an important role of the actin cytoskeleton in infection droplet release, symbiosome development and maturation, and provide significant insight into the cellular mechanisms underlying nodule development and nitrogen fixation during legume-rhizobia interactions.
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Affiliation(s)
- Xiaxia Zhang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Libo Han
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Qi Wang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Chen Zhang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yanjun Yu
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Juan Tian
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Zhaosheng Kong
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
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14
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Actin Remodeling in Regulated Exocytosis: Toward a Mesoscopic View. Trends Cell Biol 2018; 28:685-697. [DOI: 10.1016/j.tcb.2018.04.004] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 04/05/2018] [Accepted: 04/13/2018] [Indexed: 01/10/2023]
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15
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Garcia-Martinez V, Gimenez-Molina Y, Villanueva J, Darios FD, Davletov B, Gutiérrez LM. Emerging evidence for the modulation of exocytosis by signalling lipids. FEBS Lett 2018; 592:3493-3503. [PMID: 29962039 PMCID: PMC6282582 DOI: 10.1002/1873-3468.13178] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 06/01/2018] [Accepted: 06/27/2018] [Indexed: 01/22/2023]
Abstract
Membrane fusion is a key event in exocytosis of neurotransmitters and hormones stored in intracellular vesicles. In this process, soluble N‐ethylmaleimide sensitive factor attachment protein receptor (SNARE) proteins are essential components of the exocytotic molecular machinery, while lipids have been seen traditionally as structural elements. However, the so‐called signalling lipids, such as sphingosine and arachidonic acid, interact with SNAREs and directly modulate the frequency and mode of fusion events. Interestingly, recent work has proved that the sphingosine analogue FTY‐720, used in the treatment of multiple sclerosis, mimics the effects of signalling lipids. In the present Review, we discuss recent investigations suggesting that endogenous signalling lipids and synthetic analogues can modulate important physiological aspects of secretion, such as quantal release, vesicle recruitment into active sites, vesicle transport and even organelle fusion in the cytosol. Therefore, these compounds are far from being merely structural components of cellular membranes.
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Affiliation(s)
- Virginia Garcia-Martinez
- Instituto de Neurociencias de Alicante, Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández de Elche, Sant Joan d'Alacant, Alicante, Spain
| | - Yolanda Gimenez-Molina
- Instituto de Neurociencias de Alicante, Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández de Elche, Sant Joan d'Alacant, Alicante, Spain
| | - José Villanueva
- Instituto de Neurociencias de Alicante, Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández de Elche, Sant Joan d'Alacant, Alicante, Spain
| | - Frederic D Darios
- Inserm, U1127, CNRS, UMR 7225, Institut du Cerveau et de la Moelle épinière, ICM, Sorbonne Université, Paris, France
| | - Bazbek Davletov
- Department of Biomedical Sciences, University of Sheffield, UK
| | - Luis M Gutiérrez
- Instituto de Neurociencias de Alicante, Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández de Elche, Sant Joan d'Alacant, Alicante, Spain
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16
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Félix-Martínez GJ, Gil A, Segura J, Villanueva J, Gutíerrez LM. Modeling the influence of co-localized intracellular calcium stores on the secretory response of bovine chromaffin cells. Comput Biol Med 2018; 100:165-175. [PMID: 30015013 DOI: 10.1016/j.compbiomed.2018.06.032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 06/26/2018] [Accepted: 06/27/2018] [Indexed: 11/19/2022]
Abstract
Catecholamines secretion from chromaffin cells is mediated by a Ca2+-dependent process in the submembrane space where the exocytotic machinery is located and high-Ca2+ microdomains (HCMDs) are formed by the coordinated activity of a functional triad composed of Ca2+ channels, endoplasmic reticulum (ER) and mitochondria. It has been observed experimentally that subpopulations of cortical mitochondria and ER associate to secretory sites in bovine chromaffin cells. Here, we study the effect of the geometrical distribution of the co-localized cortical organelles both in the formation of HCMDs in the vicinity of Ca2+ channels and on the secretory activity of bovine chromaffin cells in response to a single voltage pulse. Our simulations indicate that co-localized organelles have a dual role in the formation of HCMDs, having, on the one hand, an amplification effect due to the Ca2+-induced Ca2+-release mechanism from the ER and, on the other, acting as physical barriers to Ca2+ diffusion. In addition, our simulations suggest that the increased levels of Ca2+ in the microdomain enhances the secretion of the vesicles co-localized to the Ca2+ channels. As a whole, our results support the idea that the functional triads formed by Ca2+ channels, subplasmalemma ER and mitochondria have a positive effect on the secretion of catecholamines in bovine chromaffin cells.
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Affiliation(s)
- Gerardo J Félix-Martínez
- Depto. de Matemática Aplicada y Ciencias de la Computación, Universidad de Cantabria, 39005, Santander, Spain; Depto. de Ingeniería Eléctrica, Universidad Autónoma Metropolitana, 09340, Mexico City, Mexico.
| | - Amparo Gil
- Depto. de Matemática Aplicada y Ciencias de la Computación, Universidad de Cantabria, 39005, Santander, Spain.
| | - Javier Segura
- Depto. de Matemáticas, Estadística y Computación, Universidad de Cantabria, 39005, Santander, Spain.
| | - José Villanueva
- Instituto de Neurociencias, Centro Mixto Universidad Miguel Hernández-CSIC, Sant Joan d'Alacant, 03550, Alicante, Spain.
| | - Luis M Gutíerrez
- Instituto de Neurociencias, Centro Mixto Universidad Miguel Hernández-CSIC, Sant Joan d'Alacant, 03550, Alicante, Spain.
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Bitter tastant quinine modulates glucagon-like peptide-1 exocytosis from clonal GLUTag enteroendocrine L cells via actin reorganization. Biochem Biophys Res Commun 2018; 500:723-730. [PMID: 29684353 DOI: 10.1016/j.bbrc.2018.04.143] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 04/17/2018] [Indexed: 12/23/2022]
Abstract
Enteroendocrine L cells in the gastrointestinal tract secrete glucagon-like peptide-1 (GLP-1), which plays an important role in glucose homeostasis. Here we investigated the effect of bitter tastant quinine on GLP-1 secretion using clonal GLUTag mouse enteroendocrine L cells. We found that GLUTag cells expressed putative quinine receptors at mRNA levels. Although application of quinine resulted in an increase of intracellular Ca2+ levels, which was mediated by Ca2+ release from the endoplasmic reticulum and Ca2+ influx through voltage-sensitive Ca2+ channels, quinine had little effect on GLP-1 secretion. Total internal reflection fluorescence microscopy and immunocytochemistry revealed that GLP-1-containing vesicles remained unfused with the plasma membrane and facilitated actin polymerization beneath the plasma membrane after application of quinine, respectively. Interestingly, application of forskolin together with quinine induced GLP-1 exocytosis from the cells. These results suggest that quinine does not induce GLP-1 secretion because it facilitates Ca2+ increase and actin reorganization but not cAMP increase, and both Ca2+ and cAMP are essential for GLP-1 secretion.
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18
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Venditti M, Fasano C, Santillo A, Aniello F, Minucci S. First evidence of DAAM1 localization in mouse seminal vesicles and its possible involvement during regulated exocytosis. C R Biol 2018; 341:228-234. [PMID: 29571963 DOI: 10.1016/j.crvi.2018.03.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 03/01/2018] [Accepted: 03/01/2018] [Indexed: 12/26/2022]
Abstract
Dishevelled-associated activator of morphogenesis 1 (DAAM1) is a protein belonging to the formin family, which regulates, together with the small GTPase RhoA, the nucleation and the assembly of actin fibres through Wnt-Dishevelled PCP pathway. Its role has been investigated in essential biological processes, such as cell polarity, movement and adhesion during morphogenesis and organogenesis. In this work, we studied the expression of DAAM1 mRNA and protein by PCR and Western blot analyses and its co-localization with actin in adult mouse seminal vesicles by immunofluorescence. We show that both proteins are cytoplasmic: actin is evident at cell-cell junctions and at cell cortex; DAAM1 had a more diffused localization, but is also prominent at the apical plasmatic membrane of epithelial cells. These findings support our hypothesis of a role of DAAM1 in cytoskeletal rearrangement that occurs during the exocytosis of secretory vesicles, and in particular concerning actin filaments. We were also able to detect DAAM1 and actin association in the smooth muscle cells that surround the epithelium too. In this case, we could only speculate the possible involvement of this formin in muscular cells in the maintenance and the regulation of the contractile structures. The present results strongly suggest that DAAM1 could have a pivotal role in vesicle exocytosis and in the physiology of mouse seminal vesicles.
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Affiliation(s)
- Massimo Venditti
- Dipartimento di Medicina Sperimentale, Sez, Fisiologia Umana e Funzioni Biologiche Integrate, Università degli studi della Campania "Luigi Vanvitelli", Via Costantinopoli, 16, 80138 Napoli, Italy
| | - Chiara Fasano
- Dipartimento di Medicina Sperimentale, Sez, Fisiologia Umana e Funzioni Biologiche Integrate, Università degli studi della Campania "Luigi Vanvitelli", Via Costantinopoli, 16, 80138 Napoli, Italy
| | - Alessandra Santillo
- Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Università degli Studi della Campania "Luigi Vanvitelli", Caserta, Italy
| | - Francesco Aniello
- Dipartimento di Biologia, Università degli Studi di Napoli "Federico II", Napoli, Italy
| | - Sergio Minucci
- Dipartimento di Medicina Sperimentale, Sez, Fisiologia Umana e Funzioni Biologiche Integrate, Università degli studi della Campania "Luigi Vanvitelli", Via Costantinopoli, 16, 80138 Napoli, Italy.
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19
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Steppan D, Pan L, Gross KW, Kurtz A. Analysis of the calcium paradox of renin secretion. Am J Physiol Renal Physiol 2017; 315:F834-F843. [PMID: 29357428 DOI: 10.1152/ajprenal.00554.2017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The secretion of the protease renin from renal juxtaglomerular cells is enhanced by subnormal extracellular calcium concentrations. The mechanisms underlying this atypical effect of calcium have not yet been unraveled. We therefore aimed to characterize the effect of extracellular calcium concentration on calcium handling of juxtaglomerular cells and on renin secretion in more detail. For this purpose, we used a combination of experiments with isolated perfused mouse kidneys and direct calcium measurements in renin-secreting cells in situ. We found that lowering of the extracellular calcium concentration led to a sustained elevation of renin secretion. Electron-microscopical analysis of renin-secreting cells exposed to subnormal extracellular calcium concentrations revealed big omega-shaped structures resulting from the intracellular fusion and subsequent emptying of renin storage vesicles. The calcium concentration dependencies as well as the kinetics of changes were rather similar for renin secretion and for renovascular resistance. Since vascular resistance is fundamentally influenced by myosin light chain kinase (MLCK), myosin light chain phosphatase (MLCP), and Rho-associated protein kinase (Rho-K) activities, we examined the effects of MLCK-, MLCP-, and Rho-K inhibitors on renin secretion. Only MLCK inhibition stimulated renin secretion. Conversely, inhibition of MCLP activity lowered perfusate flow and strongly inhibited renin secretion, which could not be reversed by lowering of the extracellular calcium concentration. Renin-secreting cells and smooth muscle cells of afferent arterioles showed immunoreactivity of MLCK. These findings suggest that the inhibitory effect of calcium on renin secretion could be explained by phosphorylation-dependent processes under control of the MLCK.
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Affiliation(s)
- D Steppan
- Institute of Physiology, University of Regensburg , Regensburg , Germany
| | - L Pan
- Department of Pathology, Brigham and Women's Hospital , Boston, Massachusetts
| | - K W Gross
- Department of Molecular and Cellular Biology, Roswell Park Cancer Institute , Buffalo, New York
| | - A Kurtz
- Institute of Physiology, University of Regensburg , Regensburg , Germany
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20
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Bargi-Souza P, Goulart-Silva F, Nunes MT. Novel aspects of T 3 actions on GH and TSH synthesis and secretion: physiological implications. J Mol Endocrinol 2017; 59:R167-R178. [PMID: 28951438 DOI: 10.1530/jme-17-0068] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 09/26/2017] [Indexed: 12/27/2022]
Abstract
Thyroid hormones (THs) classically regulate the gene expression by transcriptional mechanisms. In pituitary, the encoding genes for growth hormone (GH) and thyroid-stimulating hormone (TSH) are examples of genes regulated by triiodothyronine (T3) in a positive and negative way, respectively. Recent studies have shown a rapid adjustment of GH and TSH synthesis/secretion induced by T3 posttranscriptional actions. In somatotrophs, T3 promotes an increase in Gh mRNA content, poly(A) tail length and binding to the ribosome, associated with a rearrangement of actin cytoskeleton. In thyrotrophs, T3 reduces Tshb mRNA content, poly(A) tail length and its association with the ribosome. In parallel, it promotes a redistribution of TSH secretory granules to more distal regions of the cell periphery, indicating a rapid effect of T3 inhibition of TSH secretion. T3 was shown to affect the content of tubulin and the polymerization of actin and tubulin cytoskeletons in the whole anterior pituitary gland, and to increase intracellular alpha (CGA) content. This review summarizes genomic and non-genomic/posttranscriptional actions of TH on the regulation of several steps of GH and TSH synthesis and secretion. These distinct mechanisms induced by T3 can occur simultaneously, even though non-genomic effects are promptly elicited and precede the genomic actions, coexisting in a functional network within the cells.
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Affiliation(s)
| | | | - M T Nunes
- Department of Physiology and Biophysics of the Institute of Biomedical SciencesUniversity of São Paulo, São Paulo, SP, Brazil
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21
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Gutiérrez LM, Villanueva J. The role of F-actin in the transport and secretion of chromaffin granules: an historic perspective. Pflugers Arch 2017; 470:181-186. [PMID: 28730385 PMCID: PMC5748413 DOI: 10.1007/s00424-017-2040-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 07/13/2017] [Accepted: 07/14/2017] [Indexed: 12/23/2022]
Abstract
Actin is one of the most ubiquitous protein playing fundamental roles in a variety of cellular processes. Since early in the 1980s, it was evident that filamentous actin (F-actin) formed a peripheral cortical barrier that prevented vesicles to access secretory sites in chromaffin cells in culture. Later, around 2000, it was described that the F-actin structure accomplishes a dual role serving both vesicle transport and retentive purposes and undergoing dynamic transient changes during cell stimulation. The complex role of the F-actin cytoskeleton in neuroendocrine secretion was further evidenced when it has been proved to participate in the scaffold structure holding together the secretory machinery at active sites and participate in the generation of mechanical forces that drive the opening of the fusion pore, during the first decade of the present century. The complex vision of the multiple roles of F-actin in secretion we have acquired to date comes largely from studies performed on traditional 2D cultures of primary cells; however, recent evidences suggest that these may not accurately mimic the 3D in vivo environment, and thus, more work is now needed on adrenomedullary cells kept in a more “native” configuration to fully understand the role of F-actin in regulating chromaffin granule transport and secretion under physiological conditions.
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Affiliation(s)
- Luis M Gutiérrez
- Instituto de Neurociencias de Alicante, Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández, Sant Joan d'Alacant, 03550, Alicante, Spain.
| | - José Villanueva
- Instituto de Neurociencias de Alicante, Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández, Sant Joan d'Alacant, 03550, Alicante, Spain
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22
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Papadopulos A. Membrane shaping by actin and myosin during regulated exocytosis. Mol Cell Neurosci 2017; 84:93-99. [PMID: 28536001 DOI: 10.1016/j.mcn.2017.05.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 04/21/2017] [Accepted: 05/19/2017] [Indexed: 12/01/2022] Open
Abstract
The cortical actin network in neurosecretory cells is a dense mesh of actin filaments underlying the plasma membrane. Interaction of actomyosin with vesicular membranes or the plasma membrane is vital for tethering, retention, transport as well as fusion and fission of exo- and endocytic membrane structures. During regulated exocytosis the cortical actin network undergoes dramatic changes in morphology to accommodate vesicle docking, fusion and replenishment. Most of these processes involve plasma membrane Phosphoinositides (PIP) and investigating the interactions between the actin cortex and secretory structures has become a hotbed for research in recent years. Actin remodelling leads to filopodia outgrowth and the creation of new fusion sites in neurosecretory cells and actin, myosin and dynamin actively shape and maintain the fusion pore of secretory vesicles. Changes in viscoelastic properties of the actin cortex can facilitate vesicular transport and lead to docking and priming of vesicle at the plasma membrane. Small GTPase actin mediators control the state of the cortical actin network and influence vesicular access to their docking and fusion sites. These changes potentially affect membrane properties such as tension and fluidity as well as the mobility of embedded proteins and could influence the processes leading to both exo- and endocytosis. Here we discuss the multitudes of actin and membrane interactions that control successive steps underpinning regulated exocytosis.
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Affiliation(s)
- Andreas Papadopulos
- The Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia.
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23
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Gimenez-Molina Y, Villanueva J, Nanclares C, Lopez-Font I, Viniegra S, Francés MDM, Gandia L, Gil A, Gutiérrez LM. The Differential Organization of F-Actin Alters the Distribution of Organelles in Cultured When Compared to Native Chromaffin Cells. Front Cell Neurosci 2017; 11:135. [PMID: 28522964 PMCID: PMC5415619 DOI: 10.3389/fncel.2017.00135] [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] [Received: 02/16/2017] [Accepted: 04/21/2017] [Indexed: 11/17/2022] Open
Abstract
Cultured bovine chromaffin cells have been used extensively as a neuroendocrine model to study regulated secretion. In order to extend such experimental findings to the physiological situation, it is necessary to study mayor cellular structures affecting secretion in cultured cells with their counterparts present in the adrenomedullary tissue. F-actin concentrates in a peripheral ring in cultured cells, as witnessed by phalloidin–rodhamine labeling, while extends throughout the cytoplasm in native cells. This result is also confirmed when studying the localization of α-fodrin, a F-actin-associated protein. Furthermore, as a consequence of this redistribution of F-actin, we observed that chromaffin granules and mitochondria located into two different cortical and internal populations in cultured cells, whereas they are homogeneously distributed throughout the cytoplasm in the adrenomedullary tissue. Nevertheless, secretion from isolated cells and adrenal gland pieces is remarkably similar when measured by amperometry. Finally, we generate mathematical models to consider how the distribution of organelles affects the secretory kinetics of intact and cultured cells. Our results imply that we have to consider F-actin structural changes to interpret functional data obtained in cultured neuroendocrine cells.
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Affiliation(s)
- Yolanda Gimenez-Molina
- Instituto de Neurociencias, Centro Mixto del Consejo Superior de Investigaciones Científicas, Universidad Miguel HernándezAlicante, Spain
| | - José Villanueva
- Instituto de Neurociencias, Centro Mixto del Consejo Superior de Investigaciones Científicas, Universidad Miguel HernándezAlicante, Spain
| | - Carmen Nanclares
- Instituto Teófilo Hernando, Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de MadridMadrid, Spain
| | - Inmaculada Lopez-Font
- Instituto de Neurociencias, Centro Mixto del Consejo Superior de Investigaciones Científicas, Universidad Miguel HernándezAlicante, Spain.,Centro de Investigación Biomédica en Red de Enfermedades NeurodegenerativasAlicante, Spain
| | - Salvador Viniegra
- Instituto de Neurociencias, Centro Mixto del Consejo Superior de Investigaciones Científicas, Universidad Miguel HernándezAlicante, Spain
| | - Maria Del Mar Francés
- Instituto de Neurociencias, Centro Mixto del Consejo Superior de Investigaciones Científicas, Universidad Miguel HernándezAlicante, Spain
| | - Luis Gandia
- Instituto Teófilo Hernando, Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de MadridMadrid, Spain
| | - Amparo Gil
- Department Matemática Aplicada y Ciencias de la Computación, Universidad de CantabriaSantander, Spain
| | - Luis M Gutiérrez
- Instituto de Neurociencias, Centro Mixto del Consejo Superior de Investigaciones Científicas, Universidad Miguel HernándezAlicante, Spain
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Yasen A, Herrera R, Rosbe K, Lien K, Tugizov SM. Release of HIV-1 sequestered in the vesicles of oral and genital mucosal epithelial cells by epithelial-lymphocyte interaction. PLoS Pathog 2017; 13:e1006247. [PMID: 28241053 PMCID: PMC5344537 DOI: 10.1371/journal.ppat.1006247] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 03/09/2017] [Accepted: 02/16/2017] [Indexed: 01/16/2023] Open
Abstract
Oropharyngeal mucosal epithelia of fetuses/neonates/infants and the genital epithelia of adults play a critical role in HIV-1 mother-to-child transmission and sexual transmission of virus, respectively. To study the mechanisms of HIV-1 transmission through mucosal epithelium, we established polarized tonsil, cervical and foreskin epithelial cells. Analysis of HIV-1 transmission through epithelial cells showed that approximately 0.05% of initially inoculated virions transmigrated via epithelium. More than 90% of internalized virions were sequestered in the endosomes of epithelial cells, including multivesicular bodies (MVBs) and vacuoles. Intraepithelial HIV-1 remained infectious for 9 days without viral release. Release of sequestered intraepithelial HIV-1 was induced by the calcium ionophore ionomycin and by cytochalasin D, which increase intracellular calcium and disrupt the cortical actin of epithelial cells, respectively. Cocultivation of epithelial cells containing HIV-1 with activated peripheral blood mononuclear cells and CD4+ T lymphocytes led to the disruption of epithelial cortical actin and spread of virus from epithelial cells to lymphocytes. Treatment of epithelial cells with proinflammatory cytokines tumor necrosis factor-alpha and interferon gamma also induced reorganization of cortical actin and release of virus. Inhibition of MVB formation by small interfering RNA (siRNA)-mediated silencing of its critical protein hepatocyte growth factor-regulated tyrosine kinase substrate (Hrs) expression reduced viral sequestration in epithelial cells and its transmission from epithelial cells to lymphocytes by ~60-70%. Furthermore, inhibition of vacuole formation of epithelial cells by siRNA-inactivated rabankyrin-5 expression also significantly reduced HIV-1 sequestration in epithelial cells and spread of virus from epithelial cells to lymphocytes. Interaction of the intercellular adhesion molecule-1 of epithelial cells with the function-associated antigen-1 of lymphocytes was important for inducing the release of sequestered HIV-1 from epithelial cells and facilitating cell-to-cell spread of virus from epithelial cells to lymphocytes. This mechanism may serve as a pathway of HIV-1 mucosal transmission.
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Affiliation(s)
- Aizezi Yasen
- Department of Medicine, University of California–San Francisco, San Francisco, California, United States of America
| | - Rossana Herrera
- Department of Medicine, University of California–San Francisco, San Francisco, California, United States of America
| | - Kristina Rosbe
- Department of Otolaryngology, University of California–San Francisco, San Francisco, California, United States of America
| | - Kathy Lien
- Department of Medicine, University of California–San Francisco, San Francisco, California, United States of America
| | - Sharof M. Tugizov
- Department of Medicine, University of California–San Francisco, San Francisco, California, United States of America
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25
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Meunier FA, Gutiérrez LM. Captivating New Roles of F-Actin Cortex in Exocytosis and Bulk Endocytosis in Neurosecretory Cells. Trends Neurosci 2016; 39:605-613. [DOI: 10.1016/j.tins.2016.07.003] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 07/01/2016] [Accepted: 07/06/2016] [Indexed: 12/01/2022]
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26
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Gabel M, Delavoie F, Vitale N, Bader MF, Chasserot-Golaz S. [Actin and annexin A2: essential partners for the control of neuroendocrine secretion]. Med Sci (Paris) 2016; 32:553-5. [PMID: 27406755 DOI: 10.1051/medsci/20163206008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Marion Gabel
- Institut des neurosciences cellulaires et intégratives, CNRS - UPR 3212 et université de Strasbourg, 5, rue Blaise Pascal, F-67084, Strasbourg, France
| | - Franck Delavoie
- Laboratoire de biologie moléculaire eucaryote, UMR5099 CNRS-université de Toulouse III Paul Sabatier, 118, route de Narbonne, F-31000, Toulouse, France
| | - Nicolas Vitale
- Institut des neurosciences cellulaires et intégratives, CNRS - UPR 3212 et université de Strasbourg, 5, rue Blaise Pascal, F-67084, Strasbourg, France
| | - Marie-France Bader
- Institut des neurosciences cellulaires et intégratives, CNRS - UPR 3212 et université de Strasbourg, 5, rue Blaise Pascal, F-67084, Strasbourg, France
| | - Sylvette Chasserot-Golaz
- Institut des neurosciences cellulaires et intégratives, CNRS - UPR 3212 et université de Strasbourg, 5, rue Blaise Pascal, F-67084, Strasbourg, France
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27
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Gabel M, Chasserot-Golaz S. Annexin A2, an essential partner of the exocytotic process in chromaffin cells. J Neurochem 2016; 137:890-6. [DOI: 10.1111/jnc.13628] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 03/09/2016] [Accepted: 03/30/2016] [Indexed: 12/30/2022]
Affiliation(s)
- Marion Gabel
- INCI; UPR3212 CNRS; Université de Strasbourg; Strasbourg France
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28
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Villanueva J, Gimenez-Molina Y, Viniegra S, Gutiérrez LM. F-actin cytoskeleton and the fate of organelles in chromaffin cells. J Neurochem 2016; 137:860-6. [PMID: 26843469 DOI: 10.1111/jnc.13560] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 01/21/2016] [Accepted: 01/22/2016] [Indexed: 12/31/2022]
Abstract
In addition to playing a fundamental structural role, the F-actin cytoskeleton in neuroendocrine chromaffin cells has a prominent influence on governing the molecular mechanism and regulating the secretory process. Performing such roles, the F-actin network might be essential to first transport, and later locate the cellular organelles participating in the secretory cycle. Chromaffin granules are transported from the internal cytosolic regions to the cell periphery along microtubular and F-actin structures. Once in the cortical region, they are embedded in the F-actin network where these vesicles experience restrictions in motility. Similarly, mitochondria transport is affected by both microtubule and F-actin inhibitors and suffers increasing motion restrictions when they are located in the cortical region. Therefore, the F-actin cortex is a key factor in defining the existence of two populations of cortical and perinuclear granules and mitochondria which could be distinguished by their different location and mobility. Interestingly, other important organelles for controlling intracellular calcium levels, such as the endoplasmic reticulum network, present clear differences in distribution and much lower mobility than chromaffin vesicles and mitochondria. Nevertheless, both mitochondria and the endoplasmic reticulum appear to distribute in the proximity of secretory sites to fulfill a pivotal role, forming triads with calcium channels ensuring the fine tuning of the secretory response. This review presents the contributions that provide the basis for our current view regarding the influence that F-actin has on the distribution of organelles participating in the release of catecholamines in chromaffin cells, and summarizes this knowledge in simple models. In chromaffin cells, organelles such as granules and mitochondria distribute forming cortical and perinuclear populations whereas others like the ER present homogenous distributions. In the present review we discuss the role of transport systems and the existence of an F-actin cortical structure as the main factors behind the formation of organelle subpopulations in this neuroendocrine cell model. This article is part of a mini review series on Chromaffin cells (ISCCB Meeting, 2015). Cover image for this issue: doi: 10.1111/jnc.13322.
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Affiliation(s)
- José Villanueva
- Instituto de Neurociencias, Centro Mixto Universidad Miguel Hernández-CSIC, Sant Joan d'Alacant (Alicante), Spain
| | - Yolanda Gimenez-Molina
- Instituto de Neurociencias, Centro Mixto Universidad Miguel Hernández-CSIC, Sant Joan d'Alacant (Alicante), Spain
| | - Salvador Viniegra
- Instituto de Neurociencias, Centro Mixto Universidad Miguel Hernández-CSIC, Sant Joan d'Alacant (Alicante), Spain
| | - Luis M Gutiérrez
- Instituto de Neurociencias, Centro Mixto Universidad Miguel Hernández-CSIC, Sant Joan d'Alacant (Alicante), Spain
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Abstract
Actin is the central building block of the actin cytoskeleton, a highly regulated filamentous network enabling dynamic processes of cells and simultaneously providing structure. Mammals have six actin isoforms that are very conserved and thus share common functions. Tissue-specific expression in part underlies their differential roles, but actin isoforms also coexist in various cell types and tissues, suggesting specific functions and preferential interaction partners. Gene deletion models, antibody-based staining patterns, gene silencing effects, and the occurrence of isoform-specific mutations in certain diseases have provided clues for specificity on the subcellular level and its consequences on the organism level. Yet, the differential actin isoform functions are still far from understood in detail. Biochemical studies on the different isoforms in pure form are just emerging, and investigations in cells have to deal with a complex and regulated system, including compensatory actin isoform expression.
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Affiliation(s)
- Christophe Ampe
- Department of Biochemistry, Faculty of Medicine and Health Sciences, Ghent University, A. Baertsoenkaai 3, 9000, Ghent, Belgium.
| | - Marleen Van Troys
- Department of Biochemistry, Faculty of Medicine and Health Sciences, Ghent University, A. Baertsoenkaai 3, 9000, Ghent, Belgium
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Gabel M, Delavoie F, Demais V, Royer C, Bailly Y, Vitale N, Bader MF, Chasserot-Golaz S. Annexin A2-dependent actin bundling promotes secretory granule docking to the plasma membrane and exocytosis. J Cell Biol 2015; 210:785-800. [PMID: 26323692 PMCID: PMC4555831 DOI: 10.1083/jcb.201412030] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Annexin A2, a calcium-, actin-, and lipid-binding protein involved in exocytosis, mediates the formation of lipid microdomains required for the structural and spatial organization of fusion sites at the plasma membrane. To understand how annexin A2 promotes this membrane remodeling, the involvement of cortical actin filaments in lipid domain organization was investigated. 3D electron tomography showed that cortical actin bundled by annexin A2 connected docked secretory granules to the plasma membrane and contributed to the formation of GM1-enriched lipid microdomains at the exocytotic sites in chromaffin cells. When an annexin A2 mutant with impaired actin filament-bundling activity was expressed, the formation of plasma membrane lipid microdomains and the number of exocytotic events were decreased and the fusion kinetics were slower, whereas the pharmacological activation of the intrinsic actin-bundling activity of endogenous annexin A2 had the opposite effects. Thus, annexin A2-induced actin bundling is apparently essential for generating active exocytotic sites.
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Affiliation(s)
- Marion Gabel
- Institut des Neurosciences Cellulaires et Intégratives, UPR3212 Centre National de la Recherche Scientifique, Université de Strasbourg, F-67084 Strasbourg, France
| | - Franck Delavoie
- Laboratoire de Biologie Moléculaire Eucaryote, UMR5099 Centre National de la Recherche Scientifique-Université de Toulouse III Paul Sabatier, F-31000 Toulouse, France
| | - Valérie Demais
- Plateforme Imagerie In Vitro, Neuropôle de Strasbourg, F-67084 Strasbourg, France
| | - Cathy Royer
- Plateforme Imagerie In Vitro, Neuropôle de Strasbourg, F-67084 Strasbourg, France
| | - Yannick Bailly
- Institut des Neurosciences Cellulaires et Intégratives, UPR3212 Centre National de la Recherche Scientifique, Université de Strasbourg, F-67084 Strasbourg, France
| | - Nicolas Vitale
- Institut des Neurosciences Cellulaires et Intégratives, UPR3212 Centre National de la Recherche Scientifique, Université de Strasbourg, F-67084 Strasbourg, France
| | - Marie-France Bader
- Institut des Neurosciences Cellulaires et Intégratives, UPR3212 Centre National de la Recherche Scientifique, Université de Strasbourg, F-67084 Strasbourg, France
| | - Sylvette Chasserot-Golaz
- Institut des Neurosciences Cellulaires et Intégratives, UPR3212 Centre National de la Recherche Scientifique, Université de Strasbourg, F-67084 Strasbourg, France
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31
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Arp2/3-mediated F-actin formation controls regulated exocytosis in vivo. Nat Commun 2015; 6:10098. [PMID: 26639106 PMCID: PMC4686765 DOI: 10.1038/ncomms10098] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 11/02/2015] [Indexed: 02/07/2023] Open
Abstract
The actin cytoskeleton plays crucial roles in many cellular processes, including regulated secretion. However, the mechanisms controlling F-actin dynamics in this process are largely unknown. Through 3D time-lapse imaging in a secreting organ, we show that F-actin is actively disassembled along the apical plasma membrane at the site of secretory vesicle fusion and re-assembled directionally on vesicle membranes. Moreover, we show that fusion pore formation and PIP2 redistribution precedes actin and myosin recruitment to secretory vesicle membranes. Finally, we show essential roles for the branched actin nucleators Arp2/3- and WASp in the process of secretory cargo expulsion and integration of vesicular membranes with the apical plasma membrane. Our results highlight previously unknown roles for branched actin in exocytosis and provide a genetically tractable system to image the temporal and spatial dynamics of polarized secretion in vivo. The cytoskeleton plays a crucial role in secretion. Here Tran et al. demonstrate that cortical actin is rearranged at the site of vesicle fusion and recruited to fused secretory granules in Drosophila salivary glands, and show that branched actin nucleators are required for cargo expulsion.
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32
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Than NG, Balogh A, Romero R, Kárpáti E, Erez O, Szilágyi A, Kovalszky I, Sammar M, Gizurarson S, Matkó J, Závodszky P, Papp Z, Meiri H. Placental Protein 13 (PP13) - A Placental Immunoregulatory Galectin Protecting Pregnancy. Front Immunol 2014; 5:348. [PMID: 25191322 PMCID: PMC4138504 DOI: 10.3389/fimmu.2014.00348] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Accepted: 07/08/2014] [Indexed: 12/16/2022] Open
Abstract
Galectins are glycan-binding proteins that regulate innate and adaptive immune responses, and some confer maternal-fetal immune tolerance in eutherian mammals. A chromosome 19 cluster of galectins has emerged in anthropoid primates, species with deep placentation and long gestation. Three of the five human cluster galectins are solely expressed in the placenta, where they may confer additional immunoregulatory functions to enable deep placentation. One of these is galectin-13, also known as Placental Protein 13 (PP13). It has a "jelly-roll" fold, carbohydrate-recognition domain and sugar-binding preference resembling other mammalian galectins. PP13 is predominantly expressed by the syncytiotrophoblast and released from the placenta into the maternal circulation. Its ability to induce apoptosis of activated T cells in vitro, and to divert and kill T cells as well as macrophages in the maternal decidua in situ, suggests important immune functions. Indeed, mutations in the promoter and an exon of LGALS13 presumably leading to altered or non-functional protein expression are associated with a higher frequency of preeclampsia and other obstetrical syndromes, which involve immune dysregulation. Moreover, decreased placental expression of PP13 and its low concentrations in first trimester maternal sera are associated with elevated risk of preeclampsia. Indeed, PP13 turned to be a good early biomarker to assess maternal risk for the subsequent development of pregnancy complications caused by impaired placentation. Due to the ischemic placental stress in preterm preeclampsia, there is increased trophoblastic shedding of PP13 immunopositive microvesicles starting in the second trimester, which leads to high maternal blood PP13 concentrations. Our meta-analysis suggests that this phenomenon may enable the potential use of PP13 in directing patient management near to or at the time of delivery. Recent findings on the beneficial effects of PP13 on decreasing blood pressure due to vasodilatation in pregnant animals suggest its therapeutic potential in preeclampsia.
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Affiliation(s)
- Nándor Gábor Than
- Perinatology Research Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services , Bethesda, MD, and Detroit, MI , USA ; Department of Obstetrics and Gynecology, Wayne State University School of Medicine , Detroit, MI , USA ; Maternity Private Department, Kútvölgyi Clinical Block, Semmelweis University , Budapest , Hungary ; Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences , Budapest , Hungary
| | - Andrea Balogh
- Department of Immunology, Eötvös Loránd University , Budapest , Hungary
| | - Roberto Romero
- Perinatology Research Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services , Bethesda, MD, and Detroit, MI , USA
| | - Eva Kárpáti
- Department of Immunology, Eötvös Loránd University , Budapest , Hungary
| | - Offer Erez
- Department of Obstetrics and Gynecology, Soroka University Medical Center, Ben-Gurion University of the Negev , Beer-Sheva , Israel
| | - András Szilágyi
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences , Budapest , Hungary
| | - Ilona Kovalszky
- First Department of Pathology and Experimental Cancer Research, Semmelweis University , Budapest , Hungary
| | - Marei Sammar
- Prof. Ephraim Katzir Department of Biotechnology Engineering, ORT Braude College , Karmiel , Israel
| | - Sveinbjorn Gizurarson
- Faculty of Pharmaceutical Sciences, School of Health Science, University of Iceland , Reykjavik , Iceland
| | - János Matkó
- Department of Immunology, Eötvös Loránd University , Budapest , Hungary
| | - Péter Závodszky
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences , Budapest , Hungary
| | - Zoltán Papp
- Maternity Private Department, Kútvölgyi Clinical Block, Semmelweis University , Budapest , Hungary
| | - Hamutal Meiri
- TeleMarpe Ltd. , Tel Aviv , Israel ; Hylabs Ltd. , Rehovot , Israel
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33
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Flores JA, Balseiro-Gomez S, Cabeza JM, Acosta J, Ramirez-Ponce P, Ales E. A new role for myosin II in vesicle fission. PLoS One 2014; 9:e100757. [PMID: 24959909 PMCID: PMC4069105 DOI: 10.1371/journal.pone.0100757] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Accepted: 05/28/2014] [Indexed: 11/19/2022] Open
Abstract
An endocytic vesicle is formed from a flat plasma membrane patch by a sequential process of invagination, bud formation and fission. The scission step requires the formation of a tubular membrane neck (the fission pore) that connects the endocytic vesicle with the plasma membrane. Progress in vesicle fission can be measured by the formation and closure of the fission pore. Live-cell imaging and sensitive biophysical measurements have provided various glimpses into the structure and behaviour of the fission pore. In the present study, the role of non-muscle myosin II (NM-2) in vesicle fission was tested by analyzing the kinetics of the fission pore with perforated-patch clamp capacitance measurements to detect single vesicle endocytosis with millisecond time resolution in peritoneal mast cells. Blebbistatin, a specific inhibitor of NM-2, dramatically increased the duration of the fission pore and also prevented closure during large endocytic events. Using the fluorescent markers FM1-43 and pHrodo Green dextran, we found that NM-2 inhibition greatly arrested vesicle fission in a late phase of the scission event when the pore reached a final diameter of ∼ 5 nm. Our results indicate that loss of the ATPase activity of myosin II drastically reduces the efficiency of membrane scission by making vesicle closure incomplete and suggest that NM-2 might be especially relevant in vesicle fission during compound endocytosis.
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Affiliation(s)
- Juan A. Flores
- Dpto. Fisiología Médica y Biofísica, Facultad de Medicina, Universidad de Sevilla, Seville, Spain
| | - Santiago Balseiro-Gomez
- Dpto. Fisiología Médica y Biofísica, Facultad de Medicina, Universidad de Sevilla, Seville, Spain
| | - Jose M. Cabeza
- Dpto. Fisiología Médica y Biofísica, Facultad de Medicina, Universidad de Sevilla, Seville, Spain
| | - Jorge Acosta
- Dpto. Fisiología Médica y Biofísica, Facultad de Medicina, Universidad de Sevilla, Seville, Spain
| | - Pilar Ramirez-Ponce
- Dpto. Fisiología Médica y Biofísica, Facultad de Medicina, Universidad de Sevilla, Seville, Spain
| | - Eva Ales
- Dpto. Fisiología Médica y Biofísica, Facultad de Medicina, Universidad de Sevilla, Seville, Spain
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34
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Villanueva J, Viniegra S, Gimenez-Molina Y, García-Martinez V, Expósito-Romero G, del Mar Frances M, García-Sancho J, Gutiérrez LM. The distribution of mitochondria and endoplasmic reticulum in relation with secretory sites in chromaffin cells. J Cell Sci 2014; 127:5105-14. [DOI: 10.1242/jcs.160242] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The distribution of mitochondria and ER in relation to exocytotic sites is relevant to understand the influence of these organelles in tuning calcium signals and secretion. Confocal images of probes tagged to mitochondria and F-actin cytoskeleton revealed the existence of two populations of mitochondria, one cortical and the other perinuclear. This mitochondrial distribution was also confirmed by using electron microscopy. In contrast, ER was sparse in the cortex and more abundant in deep cytoplasmic regions. The mitochondrial distribution may be due to organellar transport, which experiences increasing restrictions in the cell cortex. Further study of organelle distribution in relation to SNARE microdomains or the granule fusion sites revealed that 1/3 of the cortical mitochondria co-localized with exocytotic sites whereas another 1/3 located at a distance smaller than 2 vesicle diameters. ER structures were also present in the vicinity of secretory sites but at a lower density. Therefore, mitochondria and ER have a spatial distribution that suggests a specialized role in modulation of exocytosis and fits with cytosolic Ca2+ microdomains described before.
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35
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Bargi-Souza P, Romano RM, Salgado RDM, Goulart-Silva F, Brunetto EL, Zorn TMT, Nunes MT. Triiodothyronine rapidly alters the TSH content and the secretory granules distribution in male rat thyrotrophs by a cytoskeleton rearrangement-independent mechanism. Endocrinology 2013; 154:4908-18. [PMID: 24105481 DOI: 10.1210/en.2013-1508] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Rapid actions of T3 on TSH synthesis in posttranscriptional steps, such as polyadenylation and translation rate, have already been described. The focus of this paper was to characterize rapid actions of T3 on TSH secretion and the involvement of actin and microtubule cytoskeleton in this process. For that, sham-operated (SO) and thyroidectomized (Tx) rats were subjected to acute or chronic treatment with T3. We observed a disarrangement in microtubule and actin cytoskeletons and an increase in Tshb mRNA levels in Tx rats, whereas the total TSH protein content was reduced in the pituitary gland as a whole, but increased in the secretory granules close to the plasma membrane of thyrotrophs, as well as in the extracellular space. The acute T3 dose promoted a rapid increase and redistribution of TSH secretory granules throughout the cytoplasm, as well as a rearrangement in actin and microtubule cytoskeletons. The T3 chronic treatment outcome reinforces the acute effects observed and, additionally, evinces an increase in the α-tubulin content and a rearrangement in microtubule cytoskeleton. Thus, T3 is able to rapidly suppress TSH secretion and, in parallel, to promote a rearrangement in actin and microtubules assembly throughout the pituitary gland, effects that seem to be independent from each other.
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Affiliation(s)
- Paula Bargi-Souza
- PhD, Full Professor, Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Avenue Professor Lineu Prestes, 1524, CEP 05508-000, Sao Paulo, Brazil.
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36
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Handa Y, Durkin CH, Dodding MP, Way M. Vaccinia virus F11 promotes viral spread by acting as a PDZ-containing scaffolding protein to bind myosin-9A and inhibit RhoA signaling. Cell Host Microbe 2013; 14:51-62. [PMID: 23870313 DOI: 10.1016/j.chom.2013.06.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 05/29/2013] [Accepted: 06/13/2013] [Indexed: 11/19/2022]
Abstract
The vaccinia F11 protein promotes viral spread by modulating the cortical actin cytoskeleton by inhibiting RhoA signaling via an unknown mechanism. PDZ domains are widely conserved protein interaction modules whose occurrence in viral proteins is unprecedented. We found that F11 contains a central PDZ-like domain that is required to downregulate RhoA signaling and enhance viral spread. The PDZ-like domain interacts with the PDZ binding motif of the Rho GTPase-activating protein (GAP) Myosin-9A. In the absence of Myosin-9A, RhoA signaling is not inhibited, resulting in fewer actin tails and reduced virus release concomitant with less viral spread. The loss of Myosin-9A GAP activity or its ability to bind F11 also reduces actin tail formation. Furthermore, the ability of Myosin-9A to promote viral spread depends on F11 binding RhoA. Thus, F11 acts as a functional PDZ-containing scaffolding protein to inhibit RhoA signaling by binding Myosin-9A.
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Affiliation(s)
- Yutaka Handa
- Cell Motility Laboratory, Cancer Research UK, London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
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37
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Sasaki S, Yui N, Noda Y. Actin directly interacts with different membrane channel proteins and influences channel activities: AQP2 as a model. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1838:514-20. [PMID: 23770358 DOI: 10.1016/j.bbamem.2013.06.004] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Revised: 06/01/2013] [Accepted: 06/06/2013] [Indexed: 11/26/2022]
Abstract
The interplay between actin and 10 membrane channel proteins that have been shown to directly bind to actin are reviewed. The 10 membrane channel proteins covered in this review are aquaporin 2 (AQP2), cystic fibrosis transmembrane conductance regulator (CFTR), ClC2, short form of ClC3 (sClC3), chloride intracellular channel 1 (CLIC1), chloride intracellular channel 5 (CLIC5), epithelial sodium channel (ENaC), large-conductance calcium-activated potassium channel (Maxi-K), transient receptor potential vanilloid 4 (TRPV4), and voltage-dependent anion channel (VDAC), with particular attention to AQP2. In regard to AQP2, most reciprocal interactions between actin and AQP2 occur during intracellular trafficking, which are largely mediated through indirect binding. Actin and the actin cytoskeleton work as cables, barriers, stabilizers, and force generators for motility. However, as with ENaC, the effects of actin cytoskeleton on channel gating should be investigated further. This article is part of a Special Issue entitled: Reciprocal influences between cell cytoskeleton and membrane channels, receptors and transporters. Guest Editor: Jean Claude Hervé.
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Affiliation(s)
- Sei Sasaki
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo 113-8519, Japan.
| | - Naofumi Yui
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo 113-8519, Japan
| | - Yumi Noda
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo 113-8519, Japan
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38
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Aller MA, Arias JI, Prieto I, Gilsanz C, Arias A, Yang H, Arias J. Surgical inflammatory stress: the embryo takes hold of the reins again. Theor Biol Med Model 2013; 10:6. [PMID: 23374964 PMCID: PMC3577641 DOI: 10.1186/1742-4682-10-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 01/18/2013] [Indexed: 01/07/2023] Open
Abstract
The surgical inflammatory response can be a type of high-grade acute stress response associated with an increasingly complex trophic functional system for using oxygen. This systemic neuro-immune-endocrine response seems to induce the re-expression of 2 extraembryonic-like functional axes, i.e. coelomic-amniotic and trophoblastic-yolk-sac-related, within injured tissues and organs, thus favoring their re-development. Accordingly, through the up-regulation of two systemic inflammatory phenotypes, i.e. neurogenic and immune-related, a gestational-like response using embryonic functions would be induced in the patient's injured tissues and organs, which would therefore result in their repair. Here we establish a comparison between the pathophysiological mechanisms that are produced during the inflammatory response and the physiological mechanisms that are expressed during early embryonic development. In this way, surgical inflammation could be a high-grade stress response whose pathophysiological mechanisms would be based on the recapitulation of ontogenic and phylogenetic-related functions. Thus, the ultimate objective of surgical inflammation, as a gestational process, is creating new tissues/organs for repairing the injured ones. Since surgical inflammation and early embryonic development share common production mechanisms, the factors that hamper the wound healing reaction in surgical patients could be similar to those that impair the gestational process.
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Affiliation(s)
- Maria-Angeles Aller
- Department of Surgery, School of Medicine, Complutense University of Madrid, Madrid, Spain
| | - Jose-Ignacio Arias
- General and Digestive Surgery Unit, Monte Naranco Hospital, Oviedo, Asturias, Spain
| | - Isabel Prieto
- Department of General and Digestive Surgery, La Paz Hospital, Autonomous University, Madrid, Spain
| | - Carlos Gilsanz
- General and Digestive Surgery Unit, Sudeste University Hospital, Arganda del Rey, Madrid, Spain
| | - Ana Arias
- Department of Medicine, Puerta de Hierro Hospital, Autonomous University, Madrid, Spain
| | - Heping Yang
- Division of Gastroenterology and Liver Disease, USC Research Centre for Liver Diseases, Los Angeles, CA, USA
| | - Jaime Arias
- Department of Surgery, School of Medicine, Complutense University of Madrid, Madrid, Spain
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40
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Torregrosa-Hetland CJ, Villanueva J, Garcia-Martínez V, Expósito-Romero G, Francés MDM, Gutiérrez LM. Cortical F-actin affects the localization and dynamics of SNAP-25 membrane clusters in chromaffin cells. Int J Biochem Cell Biol 2012; 45:583-92. [PMID: 23220175 DOI: 10.1016/j.biocel.2012.11.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2012] [Revised: 10/22/2012] [Accepted: 11/28/2012] [Indexed: 10/27/2022]
Abstract
It has been proposed recently that the F-actin cytoskeleton organizes the relative disposition of the SNARE proteins and calcium channels that form part of the secretory machinery in chromaffin cells, a neurosecretory model. To test this idea, we used confocal microscopy do determine if DsRed-SNAP-25 microdomains, which define the final sites of exocytosis along with syntaxin-1, preferentially remain in contact with F-actin cortical structures labelled by lifeact-EGFP. A quantitative analysis showed that in cells over-expressing these constructs there is a preferential colocalization, rather than a random distribution of SNAP-25 patches. To analyze the possible interactions between these proteins, we designed FRET experiments and tested whether treatment with agents that affect F-actin mobility would modify SNAP-25 movement. The significant FRET efficiencies detected suggest that direct molecular interactions occur, whereas dynamic experiments using TIRFM revealed that attenuation of cortical F-actin movement clearly diminishes the mobility of SNAP-25 clusters. Taken together, these data can be explained by a model that associates components of the secretory machinery to the F-actin cortex through flexible links.
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Affiliation(s)
- Cristina J Torregrosa-Hetland
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas, Sant Joan d'Alacant, Carretera Nacional 332 s/n, 03550 Alicante, Spain
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41
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Gil A, Torregrosa-Hetland CJ, González-Vélez V, Villanueva J, Garcia-Martinez V, Viniegra S, Segura J, Gutiérrez LM. Neurite extensions in chromaffin cells: study of the influence of the cytoskeletal structure on calcium dynamics and secretion. FRONTIERS IN LIFE SCIENCE 2012. [DOI: 10.1080/21553769.2012.745452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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42
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Multiple roles for the actin cytoskeleton during regulated exocytosis. Cell Mol Life Sci 2012; 70:2099-121. [PMID: 22986507 DOI: 10.1007/s00018-012-1156-5] [Citation(s) in RCA: 135] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Revised: 08/28/2012] [Accepted: 08/30/2012] [Indexed: 01/01/2023]
Abstract
Regulated exocytosis is the main mechanism utilized by specialized secretory cells to deliver molecules to the cell surface by virtue of membranous containers (i.e., secretory vesicles). The process involves a series of highly coordinated and sequential steps, which include the biogenesis of the vesicles, their delivery to the cell periphery, their fusion with the plasma membrane, and the release of their content into the extracellular space. Each of these steps is regulated by the actin cytoskeleton. In this review, we summarize the current knowledge regarding the involvement of actin and its associated molecules during each of the exocytic steps in vertebrates, and suggest that the overall role of the actin cytoskeleton during regulated exocytosis is linked to the architecture and the physiology of the secretory cells under examination. Specifically, in neurons, neuroendocrine, endocrine, and hematopoietic cells, which contain small secretory vesicles that undergo rapid exocytosis (on the order of milliseconds), the actin cytoskeleton plays a role in pre-fusion events, where it acts primarily as a functional barrier and facilitates docking. In exocrine and other secretory cells, which contain large secretory vesicles that undergo slow exocytosis (seconds to minutes), the actin cytoskeleton plays a role in post-fusion events, where it regulates the dynamics of the fusion pore, facilitates the integration of the vesicles into the plasma membrane, provides structural support, and promotes the expulsion of large cargo molecules.
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