1
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Higashi T, Saito AC, Chiba H. Damage control of epithelial barrier function in dynamic environments. Eur J Cell Biol 2024; 103:151410. [PMID: 38579602 DOI: 10.1016/j.ejcb.2024.151410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Revised: 03/27/2024] [Accepted: 03/30/2024] [Indexed: 04/07/2024] Open
Abstract
Epithelial tissues cover the surfaces and lumens of the internal organs of multicellular animals and crucially contribute to internal environment homeostasis by delineating distinct compartments within the body. This vital role is known as epithelial barrier function. Epithelial cells are arranged like cobblestones and intricately bind together to form an epithelial sheet that upholds this barrier function. Central to the restriction of solute and fluid diffusion through intercellular spaces are occluding junctions, tight junctions in vertebrates and septate junctions in invertebrates. As part of epithelial tissues, cells undergo constant renewal, with older cells being replaced by new ones. Simultaneously, the epithelial tissue undergoes relative rearrangement, elongating, and shifting directionally as a whole. The movement or shape changes within the epithelial sheet necessitate significant deformation and reconnection of occluding junctions. Recent advancements have shed light on the intricate mechanisms through which epithelial cells sustain their barrier function in dynamic environments. This review aims to introduce these noteworthy findings and discuss some of the questions that remain unanswered.
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Affiliation(s)
- Tomohito Higashi
- Department of Basic Pathology, Fukushima Medical University, Fukushima 960-1295, Japan.
| | - Akira C Saito
- Department of Basic Pathology, Fukushima Medical University, Fukushima 960-1295, Japan
| | - Hideki Chiba
- Department of Basic Pathology, Fukushima Medical University, Fukushima 960-1295, Japan
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2
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Schleutker R, Luschnig S. Palmitoylation of proteolipid protein M6 promotes tricellular junction assembly in epithelia of Drosophila. J Cell Sci 2024; 137:jcs261916. [PMID: 38345097 DOI: 10.1242/jcs.261916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 02/02/2024] [Indexed: 03/21/2024] Open
Abstract
Tricellular junctions (TCJs) seal epithelial cell vertices and are essential for tissue integrity and physiology, but how TCJs are assembled and maintained is poorly understood. In Drosophila, the transmembrane proteins Anakonda (Aka, also known as Bark), Gliotactin (Gli) and M6 organize occluding TCJs. Aka and M6 localize in an interdependent manner to vertices and act jointly to localize Gli, but how these proteins interact to assemble TCJs was not previously known. Here, we show that the proteolipid protein M6 physically interacts with Aka and with itself, and that M6 is palmitoylated on conserved juxta-membrane cysteine residues. This modification promotes vertex localization of M6 and binding to Aka, but not to itself, and becomes essential when TCJ protein levels are reduced. Abolishing M6 palmitoylation leads to delayed localization of M6 and Aka but does not affect the rate of TCJ growth or mobility of M6 or Aka. Our findings suggest that palmitoylation-dependent recruitment of Aka by M6 promotes initiation of TCJ assembly, whereas subsequent TCJ growth relies on different mechanisms that are independent of M6 palmitoylation.
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Affiliation(s)
- Raphael Schleutker
- Institute of Integrative Cell Biology and Physiology, Cells in Motion (CiM) Interfaculty Centre, University of Münster, D-48149 Münster, Germany
| | - Stefan Luschnig
- Institute of Integrative Cell Biology and Physiology, Cells in Motion (CiM) Interfaculty Centre, University of Münster, D-48149 Münster, Germany
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3
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Esmangart de Bournonville T, Jaglarz MK, Durel E, Le Borgne R. ESCRT-III-dependent adhesive and mechanical changes are triggered by a mechanism detecting alteration of septate junction integrity in Drosophila epithelial cells. eLife 2024; 13:e91246. [PMID: 38305711 PMCID: PMC10959524 DOI: 10.7554/elife.91246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 02/01/2024] [Indexed: 02/03/2024] Open
Abstract
Barrier functions of proliferative epithelia are constantly challenged by mechanical and chemical constraints. How epithelia respond to and cope with disturbances of barrier functions to allow tissue integrity maintenance is poorly characterised. Cellular junctions play an important role in this process and intracellular traffic contribute to their homeostasis. Here, we reveal that, in Drosophila pupal notum, alteration of the bi- or tricellular septate junctions (SJs) triggers a mechanism with two prominent outcomes. On one hand, there is an increase in the levels of E-cadherin, F-actin, and non-muscle myosin II in the plane of adherens junctions. On the other hand, β-integrin/Vinculin-positive cell contacts are reinforced along the lateral and basal membranes. We found that the weakening of SJ integrity, caused by the depletion of bi- or tricellular SJ components, alters ESCRT-III/Vps32/Shrub distribution, reduces degradation and instead favours recycling of SJ components, an effect that extends to other recycled transmembrane protein cargoes including Crumbs, its effector β-Heavy Spectrin Karst, and β-integrin. We propose a mechanism by which epithelial cells, upon sensing alterations of the SJ, reroute the function of Shrub to adjust the balance of degradation/recycling of junctional cargoes and thereby compensate for barrier junction defects to maintain epithelial integrity.
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Affiliation(s)
- Thomas Esmangart de Bournonville
- Univ Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes) – UMR 6290RennesFrance
- Global Health Institute, School of Life Science, Ecole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland
| | - Mariusz K Jaglarz
- Department of Developmental Biology and Invertebrate Morphology, Institute of Zoology and Biomedical Research, Jagiellonian University in KrakowKrakowPoland
| | - Emeline Durel
- Univ Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes) – UMR 6290RennesFrance
| | - Roland Le Borgne
- Univ Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes) – UMR 6290RennesFrance
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4
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Hodge RA, Ghannam M, Edmond E, de la Torre F, D’Alterio C, Kaya NH, Resnik-Docampo M, Reiff T, Jones DL. The septate junction component bark beetle is required for Drosophila intestinal barrier function and homeostasis. iScience 2023; 26:106901. [PMID: 37332603 PMCID: PMC10276166 DOI: 10.1016/j.isci.2023.106901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 04/19/2023] [Accepted: 05/12/2023] [Indexed: 06/20/2023] Open
Abstract
Age-related loss of intestinal barrier function has been documented across species, but the causes remain unknown. The intestinal barrier is maintained by tight junctions (TJs) in mammals and septate junctions (SJs) in insects. Specialized TJs/SJs, called tricellular junctions (TCJs), are located at the nexus of three adjacent cells, and we have shown that aging results in changes to TCJs in intestines of adult Drosophila melanogaster. We now demonstrate that localization of the TCJ protein bark beetle (Bark) decreases in aged flies. Depletion of bark from enterocytes in young flies led to hallmarks of intestinal aging and shortened lifespan, whereas depletion of bark in progenitor cells reduced Notch activity, biasing differentiation toward the secretory lineage. Our data implicate Bark in EC maturation and maintenance of intestinal barrier integrity. Understanding the assembly and maintenance of TCJs to ensure barrier integrity may lead to strategies to improve tissue integrity when function is compromised.
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Affiliation(s)
- Rachel A. Hodge
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Mirna Ghannam
- Institute of Genetics, Heinrich-Heine-University, Düsseldorf, Germany
| | - Emma Edmond
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Fernando de la Torre
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Cecilia D’Alterio
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Nida Hatice Kaya
- Institute of Genetics, Heinrich-Heine-University, Düsseldorf, Germany
| | - Martin Resnik-Docampo
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Tobias Reiff
- Institute of Genetics, Heinrich-Heine-University, Düsseldorf, Germany
| | - D. Leanne Jones
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA 90095, USA
- Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, CA 90095, USA
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143, USA
- Department of Medicine, Division of Geriatrics, University of California, San Francisco, San Francisco, CA 94143, USA
- Bakar Aging Research Institute, University of California, San Francisco, San Francisco, CA 94143, USA
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5
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Glashauser J, Camelo C, Hollmann M, Backer W, Jacobs T, Sanchez JI, Schleutker R, Förster D, Berns N, Riechmann V, Luschnig S. Acute manipulation and real-time visualization of membrane trafficking and exocytosis in Drosophila. Dev Cell 2023; 58:709-723.e7. [PMID: 37023749 DOI: 10.1016/j.devcel.2023.03.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 01/05/2023] [Accepted: 03/07/2023] [Indexed: 04/08/2023]
Abstract
Intracellular trafficking of secretory proteins plays key roles in animal development and physiology, but so far, tools for investigating the dynamics of membrane trafficking have been limited to cultured cells. Here, we present a system that enables acute manipulation and real-time visualization of membrane trafficking through the reversible retention of proteins in the endoplasmic reticulum (ER) in living multicellular organisms. By adapting the "retention using selective hooks" (RUSH) approach to Drosophila, we show that trafficking of GPI-linked, secreted, and transmembrane proteins can be controlled with high temporal precision in intact animals and cultured organs. We demonstrate the potential of this approach by analyzing the kinetics of ER exit and apical secretion and the spatiotemporal dynamics of tricellular junction assembly in epithelia of living embryos. Furthermore, we show that controllable ER retention enables tissue-specific depletion of secretory protein function. The system is broadly applicable to visualizing and manipulating membrane trafficking in diverse cell types in vivo.
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Affiliation(s)
- Jade Glashauser
- Institute of Integrative Cell Biology and Physiology, Faculty of Biology and Cells in Motion (CiM) Interfaculty Center, University of Münster, 48149 Münster, Germany
| | - Carolina Camelo
- Institute of Integrative Cell Biology and Physiology, Faculty of Biology and Cells in Motion (CiM) Interfaculty Center, University of Münster, 48149 Münster, Germany
| | - Manuel Hollmann
- Institute of Integrative Cell Biology and Physiology, Faculty of Biology and Cells in Motion (CiM) Interfaculty Center, University of Münster, 48149 Münster, Germany
| | - Wilko Backer
- Institute of Integrative Cell Biology and Physiology, Faculty of Biology and Cells in Motion (CiM) Interfaculty Center, University of Münster, 48149 Münster, Germany
| | - Thea Jacobs
- Institute of Integrative Cell Biology and Physiology, Faculty of Biology and Cells in Motion (CiM) Interfaculty Center, University of Münster, 48149 Münster, Germany
| | - Jone Isasti Sanchez
- Institute of Integrative Cell Biology and Physiology, Faculty of Biology and Cells in Motion (CiM) Interfaculty Center, University of Münster, 48149 Münster, Germany
| | - Raphael Schleutker
- Institute of Integrative Cell Biology and Physiology, Faculty of Biology and Cells in Motion (CiM) Interfaculty Center, University of Münster, 48149 Münster, Germany
| | - Dominique Förster
- Institute of Integrative Cell Biology and Physiology, Faculty of Biology and Cells in Motion (CiM) Interfaculty Center, University of Münster, 48149 Münster, Germany
| | - Nicola Berns
- Department of Cell and Molecular Biology, Medical Faculty Mannheim, Heidelberg University, 68167 Mannheim, Germany
| | - Veit Riechmann
- Department of Cell and Molecular Biology, Medical Faculty Mannheim, Heidelberg University, 68167 Mannheim, Germany
| | - Stefan Luschnig
- Institute of Integrative Cell Biology and Physiology, Faculty of Biology and Cells in Motion (CiM) Interfaculty Center, University of Münster, 48149 Münster, Germany.
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6
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Ikawa K, Ishihara S, Tamori Y, Sugimura K. Attachment and detachment of cortical myosin regulates cell junction exchange during cell rearrangement in the Drosophila wing epithelium. Curr Biol 2023; 33:263-275.e4. [PMID: 36543168 DOI: 10.1016/j.cub.2022.11.067] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 08/12/2022] [Accepted: 11/29/2022] [Indexed: 12/24/2022]
Abstract
Epithelial cells remodel cell adhesion and change their neighbors to shape a tissue. This cellular rearrangement proceeds in three steps: the shrinkage of a junction, exchange of junctions, and elongation of the newly generated junction. Herein, by combining live imaging and physical modeling, we showed that the formation of myosin-II (myo-II) cables around the cell vertices underlies the exchange of junctions in the Drosophila wing epithelium. The local and transient detachment of myo-II from the cell cortex is regulated by the LIM domain-containing protein Jub and the tricellular septate junction protein M6. Moreover, we found that M6 shifts to the adherens junction plane on jub RNAi and that Jub is persistently retained at reconnecting junctions in m6 RNAi cells. This interplay between Jub and M6 can depend on the junction length and thereby couples the detachment of cortical myo-II cables and the shrinkage/elongation of the junction during cell rearrangement. Furthermore, we developed a mechanical model based on the wetting theory and clarified how the physical properties of myo-II cables are integrated with the junction geometry to induce the transition between the attached and detached states and support the unidirectionality of cell rearrangement. Collectively, this study elucidates the orchestration of geometry, mechanics, and signaling for exchanging junctions.
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Affiliation(s)
- Keisuke Ikawa
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo 113-0032, Japan; Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University, Kyoto 606-8501, Japan; Division of Biological Science, Graduate School of Science, Nagoya University, Aichi 464-8602, Japan.
| | - Shuji Ishihara
- Department of Integrated Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo 153-8902, Japan; Universal Biology Institute, The University of Tokyo, Tokyo 113-0033, Japan
| | - Yoichiro Tamori
- Department of Molecular Oncology, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan
| | - Kaoru Sugimura
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo 113-0032, Japan; Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University, Kyoto 606-8501, Japan; Universal Biology Institute, The University of Tokyo, Tokyo 113-0033, Japan; Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8561, Japan.
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7
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Chen J, St Johnston D. Epithelial Cell Polarity During Drosophila Midgut Development. Front Cell Dev Biol 2022; 10:886773. [PMID: 35846367 PMCID: PMC9281564 DOI: 10.3389/fcell.2022.886773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 05/30/2022] [Indexed: 11/23/2022] Open
Abstract
The adult Drosophila midgut epithelium is derived from a group of stem cells called adult midgut precursors (AMPs) that are specified during the migration of the endoderm in early embryogenesis. AMPs are maintained and expanded in AMP nests that lie on the basal side of the larval midgut throughout the larval development. During metamorphosis, the larval midgut undergoes histolysis and programmed cell death, while the central cells in the AMP nests form the future adult midgut and the peripheral cells form the transient pupal midgut. Here we review what is known about how cells polarise in the embryonic, larval, pupal and adult midgut, and discuss the open questions about the mechanisms that control the changes in cell arrangements, cell shape and cell polarity during midgut development.
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Affiliation(s)
| | - Daniel St Johnston
- Gurdon Institute and the Department of Genetics, University of Cambridge, Cambridge, United Kingdom
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8
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Sugawara T, Furuse K, Otani T, Wakayama T, Furuse M. Angulin-1 seals tricellular contacts independently of tricellulin and claudins. J Cell Biol 2021; 220:e202005062. [PMID: 34269802 PMCID: PMC8289698 DOI: 10.1083/jcb.202005062] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 04/24/2021] [Accepted: 06/21/2021] [Indexed: 12/24/2022] Open
Abstract
Tricellular tight junctions (tTJs) are specialized tight junctions (TJs) that seal the intercellular space at tricellular contacts (TCs), where the vertices of three epithelial cells meet. Tricellulin and angulin family membrane proteins are known constituents of tTJs, but the molecular mechanism of tTJ formation remains elusive. Here, we investigated the roles of angulin-1 and tricellulin in tTJ formation in MDCK II cells by genome editing. Angulin-1-deficient cells lost the plasma membrane contact at TCs with impaired epithelial barrier function. The C terminus of angulin-1 bound to the TJ scaffold protein ZO-1, and disruption of their interaction influenced the localization of claudins at TCs, but not the tricellular sealing. Strikingly, the plasma membrane contact at TCs was formed in tricellulin- or claudin-deficient cells. These findings demonstrate that angulin-1 is responsible for the plasma membrane seal at TCs independently of tricellulin and claudins.
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Affiliation(s)
- Taichi Sugawara
- Division of Cell Structure, National Institute for Physiological Sciences, National Institute of Natural Sciences, Okazaki, Aichi, Japan
- Department of Physiological Sciences, The Graduate University for Advanced Studies, SOKENDAI, Okazaki, Aichi, Japan
- Department of Histology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Kyoko Furuse
- Division of Cell Structure, National Institute for Physiological Sciences, National Institute of Natural Sciences, Okazaki, Aichi, Japan
| | - Tetsuhisa Otani
- Division of Cell Structure, National Institute for Physiological Sciences, National Institute of Natural Sciences, Okazaki, Aichi, Japan
- Department of Physiological Sciences, The Graduate University for Advanced Studies, SOKENDAI, Okazaki, Aichi, Japan
| | - Tomohiko Wakayama
- Department of Histology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Mikio Furuse
- Division of Cell Structure, National Institute for Physiological Sciences, National Institute of Natural Sciences, Okazaki, Aichi, Japan
- Department of Physiological Sciences, The Graduate University for Advanced Studies, SOKENDAI, Okazaki, Aichi, Japan
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9
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Isasti-Sanchez J, Münz-Zeise F, Lancino M, Luschnig S. Transient opening of tricellular vertices controls paracellular transport through the follicle epithelium during Drosophila oogenesis. Dev Cell 2021; 56:1083-1099.e5. [PMID: 33831351 DOI: 10.1016/j.devcel.2021.03.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 12/22/2020] [Accepted: 03/15/2021] [Indexed: 10/21/2022]
Abstract
Paracellular permeability is regulated to allow solute transport or cell migration across epithelial or endothelial barriers. However, how cell-cell junction dynamics controls paracellular permeability is poorly understood. Here, we describe patency, a developmentally regulated process in Drosophila oogenesis, during which cell vertices in the follicular epithelium open transiently to allow paracellular transport of yolk proteins for uptake by the oocyte. We show that the sequential removal of E-cadherin, N-cadherin, NCAM/Fasciclin 2, and Sidekick from vertices precedes their basal-to-apical opening, while the subsequent assembly of tricellular occluding junctions marks the termination of patency and seals the paracellular barrier. E-cadherin-based adhesion is required to limit paracellular channel size, whereas stabilized adherens junctions, prolonged NCAM/Fasciclin 2 expression, blocked endocytosis, or increased actomyosin contractility prevent patency. Our findings reveal a key role of cell vertices as gateways controlling paracellular transport and demonstrate that dynamic regulation of adhesion and actomyosin contractility at vertices governs epithelial barrier properties.
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Affiliation(s)
- Jone Isasti-Sanchez
- Institute of Animal Physiology, University of Münster, Schlossplatz 8, 48143 Münster, Germany; Cells in Motion (CiM) Interfaculty Center, 48149 Münster, Germany
| | - Fenja Münz-Zeise
- Institute of Animal Physiology, University of Münster, Schlossplatz 8, 48143 Münster, Germany; Cells in Motion (CiM) Interfaculty Center, 48149 Münster, Germany
| | - Mylène Lancino
- Institute of Animal Physiology, University of Münster, Schlossplatz 8, 48143 Münster, Germany; Cells in Motion (CiM) Interfaculty Center, 48149 Münster, Germany
| | - Stefan Luschnig
- Institute of Animal Physiology, University of Münster, Schlossplatz 8, 48143 Münster, Germany; Cells in Motion (CiM) Interfaculty Center, 48149 Münster, Germany.
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10
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Rice C, De O, Alhadyian H, Hall S, Ward RE. Expanding the Junction: New Insights into Non-Occluding Roles for Septate Junction Proteins during Development. J Dev Biol 2021; 9:11. [PMID: 33801162 PMCID: PMC8006247 DOI: 10.3390/jdb9010011] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 03/15/2021] [Accepted: 03/17/2021] [Indexed: 12/17/2022] Open
Abstract
The septate junction (SJ) provides an occluding function for epithelial tissues in invertebrate organisms. This ability to seal the paracellular route between cells allows internal tissues to create unique compartments for organ function and endows the epidermis with a barrier function to restrict the passage of pathogens. Over the past twenty-five years, numerous investigators have identified more than 30 proteins that are required for the formation or maintenance of the SJs in Drosophila melanogaster, and have determined many of the steps involved in the biogenesis of the junction. Along the way, it has become clear that SJ proteins are also required for a number of developmental events that occur throughout the life of the organism. Many of these developmental events occur prior to the formation of the occluding junction, suggesting that SJ proteins possess non-occluding functions. In this review, we will describe the composition of SJs, taking note of which proteins are core components of the junction versus resident or accessory proteins, and the steps involved in the biogenesis of the junction. We will then elaborate on the functions that core SJ proteins likely play outside of their role in forming the occluding junction and describe studies that provide some cell biological perspectives that are beginning to provide mechanistic understanding of how these proteins function in developmental contexts.
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Affiliation(s)
- Clinton Rice
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS 66045, USA; (C.R.); (H.A.)
| | - Oindrila De
- Department of Biology, Case Western Reserve University, Cleveland, OH 44106, USA;
| | - Haifa Alhadyian
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS 66045, USA; (C.R.); (H.A.)
| | | | - Robert E. Ward
- Department of Biology, Case Western Reserve University, Cleveland, OH 44106, USA;
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11
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Comoletti D, Trobiani L, Chatonnet A, Bourne Y, Marchot P. Comparative mapping of selected structural determinants on the extracellular domains of cholinesterase-like cell-adhesion molecules. Neuropharmacology 2020; 184:108381. [PMID: 33166544 DOI: 10.1016/j.neuropharm.2020.108381] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 09/10/2020] [Accepted: 10/29/2020] [Indexed: 11/18/2022]
Abstract
Cell adhesion generally involves formation of homophilic or heterophilic protein complexes between two cells to form transcellular junctions. Neural cell-adhesion members of the α/β-hydrolase fold superfamily of proteins use their extracellular or soluble cholinesterase-like domain to bind cognate partners across cell membranes, as illustrated by the neuroligins. These cell-adhesion molecules currently comprise the synaptic organizers neuroligins found in all animal phyla, along with three proteins found only in invertebrates: the guidance molecule neurotactin, the glia-specific gliotactin, and the basement membrane protein glutactin. Although these proteins share a cholinesterase-like fold, they lack one or more residues composing the catalytic triad responsible for the enzymatic activity of the cholinesterases. Conversely, they are found in various subcellular localisations and display specific disulfide bonding and N-glycosylation patterns, along with individual surface determinants possibly associated with recognition and binding of protein partners. Formation of non-covalent dimers typical of the cholinesterases is documented for mammalian neuroligins, yet whether invertebrate neuroligins and their neurotactin, gliotactin and glutactin relatives also form dimers in physiological conditions is unknown. Here we provide a brief overview of the localization, function, evolution, and conserved versus individual structural determinants of these cholinesterase-like cell-adhesion proteins. This article is part of the special issue entitled 'Acetylcholinesterase Inhibitors: From Bench to Bedside to Battlefield'.
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Affiliation(s)
- Davide Comoletti
- School of Biological Sciences, Victoria University of Wellington, Wellington, 6012, New Zealand; Child Health Institute of New Jersey, New Brunswick, NJ 08901, USA; Department of Neuroscience and Cell Biology Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ 08901, USA.
| | - Laura Trobiani
- School of Biological Sciences, Victoria University of Wellington, Wellington, 6012, New Zealand
| | - Arnaud Chatonnet
- Lab 'Dynamique Musculaire et Métabolisme', Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement (INRAE) / Université Montpellier, Montpellier, France
| | - Yves Bourne
- Lab 'Architecture et Fonction des Macromolécules Biologiques (AFMB)', Centre National de la Recherche Scientifique (CNRS)/Aix-Marseille Univ, Faculté des Sciences - Campus Luminy, Marseille, France
| | - Pascale Marchot
- Lab 'Architecture et Fonction des Macromolécules Biologiques (AFMB)', Centre National de la Recherche Scientifique (CNRS)/Aix-Marseille Univ, Faculté des Sciences - Campus Luminy, Marseille, France.
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