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Dornan AJ, Halberg KV, Beuter LK, Davies SA, Dow JAT. Compromised junctional integrity phenocopies age-dependent renal dysfunction in Drosophila Snakeskin mutants. J Cell Sci 2023; 136:jcs261118. [PMID: 37694602 PMCID: PMC10565245 DOI: 10.1242/jcs.261118] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 09/05/2023] [Indexed: 09/12/2023] Open
Abstract
Transporting epithelia provide a protective barrier against pathogenic insults while allowing the controlled exchange of ions, solutes and water with the external environment. In invertebrates, these functions depend on formation and maintenance of 'tight' septate junctions (SJs). However, the mechanism by which SJs affect transport competence and tissue homeostasis, and how these are modulated by ageing, remain incompletely understood. Here, we demonstrate that the Drosophila renal (Malpighian) tubules undergo an age-dependent decline in secretory capacity, which correlates with mislocalisation of SJ proteins and progressive degeneration in cellular morphology and tissue homeostasis. Acute loss of the SJ protein Snakeskin in adult tubules induced progressive changes in cellular and tissue architecture, including altered expression and localisation of junctional proteins with concomitant loss of cell polarity and barrier integrity, demonstrating that compromised junctional integrity is sufficient to replicate these ageing-related phenotypes. Taken together, our work demonstrates a crucial link between epithelial barrier integrity, tubule transport competence, renal homeostasis and organismal viability, as well as providing novel insights into the mechanisms underpinning ageing and renal disease.
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Affiliation(s)
- Anthony J. Dornan
- School of Molecular Biosciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Kenneth V. Halberg
- Section for Cell and Neurobiology, Department of Biology, University of Copenhagen, Universitetsparken 15, Copenhagen DK-2100, Denmark
| | - Liesa-Kristin Beuter
- School of Molecular Biosciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
- Department of Animal Ecology and Systematics, Justus-Liebig-University Giessen, Giessen D-35392, Germany
| | - Shireen-Anne Davies
- School of Molecular Biosciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Julian A. T. Dow
- School of Molecular Biosciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
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2
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Zhang XQ, Yang R, Jin L, Li GQ. Requirement of Snakeskin for normal functions of midgut and Malpighian tubules in Henosepilachna vigintioctopunctata. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2023; 114:e22033. [PMID: 37401505 DOI: 10.1002/arch.22033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 06/12/2023] [Accepted: 06/14/2023] [Indexed: 07/05/2023]
Abstract
Septate junctions (SJs) are located between epithelial cells and play crucial roles in epithelial barrier formation and epithelia cell homeostasis. Nevertheless, the molecular constituents, especially those related to smooth SJs (sSJs), have not been well explored in non-Drosophilid insects. A putative integral membrane protein Snakeskin (Ssk) was identified in a Coleoptera foliar pest Henosepilachna vigintioctopunctata. RNA interference-aided knockdown of Hvssk at the third-instar larval stage arrested larval development. Most resultant larvae failed to shed larval exuviae until their death. Silence of Hvssk at the fourth-instar larvae inhibited the growth and reduced foliage consumption. Dissection and microscopic observation revealed that compromised expression of Hvssk caused obvious phenotypic defects in the midgut. A great number of morphologically abnormal columnar epithelial cells accumulated throughout the midgut lumen. Moreover, numerous vesicles were observed in the malformed cells of the Malpighian tubules (Mt). All the Hvssk depleted larvae remained as prepupae; they gradually darkened and eventually died. Furthermore, depletion of Hvssk at the pupal stage suppressed adult feeding and shortened adult lifespan. These findings demonstrated that Ssk plays a vital role in the integrity and function of both midguts and Mt, and established the conservative roles of Ssk in the formation of epithelial barrier and the homeostasis of epithelial cells in H. vigintioctopunctata.
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Affiliation(s)
- Xiao-Qing Zhang
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests/State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Rui Yang
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests/State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Lin Jin
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests/State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Guo-Qing Li
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests/State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
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3
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Mei X, Qiao P, Ma H, Qin S, Song X, Zhao Q, Shen D. Bombyx mori Tetraspanin A (BmTsp.A) is a facilitator in BmNPV invasion by regulating apoptosis. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2023; 146:104736. [PMID: 37207976 DOI: 10.1016/j.dci.2023.104736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Revised: 05/15/2023] [Accepted: 05/17/2023] [Indexed: 05/21/2023]
Abstract
BmTsp.A (Bombyx mori Tetraspanin A) is one of the four transmembrane proteins which are capable to regulate multiple aspects of the immune response and are involved in various stages of viral invasion of the hosts. This study focused on the sequence features, analysis of expression pattern, as well as the effect of BmTsp.A on BmNPV (Bombyx mori nucleopolyhedrovirus) infection in the apoptotic pathway. BmTsp.A features the typical tetraspanins family, including four transmembrane domains and a major large extracellular loop domain. It is highly expressed specifically in the malpighian tubes, and its expression is increased by BmNPV induction for 48 h and 72 h. Overexpression and RNAi (RNA interference) mediated by siRNA reveal that BmTsp.A can promote the infection and replication of the virus. In addition, the overexpression of BmTsp.A regulates BmNPV-induced apoptosis, leading to changes in the expression of apoptosis-related genes and thus affecting viral proliferation. When subjected to stimulation by BmNPV infection, on the one hand, BmTsp.A inhibits Bmp53 through a Caspase-dependent pathway, which consequently promotes the expression of Bmbuffy, thereby activating BmICE to inhibit apoptosis and causing the promotion of viral proliferation. On the other hand, BmTsp.A inhibits the expression of BmPTEN and BmPkc through the phosphatidylinositol 3 kinase (PI3K)/protein kinaseB(AKT) signaling pathway, thus affecting the regulation of apoptosis. To summarize, our results demonstrate that BmTsp.A promotes viral infection and replication by inhibiting apoptosis, which is fundamental for understanding the pathogenesis of BmNPV and the immune defense mechanism of silkworm.
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Affiliation(s)
- Xianghan Mei
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, 212018, China; Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture and Rural Affairs, Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, 212018, China.
| | - Peitong Qiao
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, 212018, China; Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture and Rural Affairs, Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, 212018, China.
| | - Hengheng Ma
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, 212018, China; Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture and Rural Affairs, Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, 212018, China.
| | - Siyu Qin
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, 212018, China; Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture and Rural Affairs, Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, 212018, China.
| | - Xia Song
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, 212018, China; Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture and Rural Affairs, Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, 212018, China.
| | - Qiaoling Zhao
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, 212018, China; Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture and Rural Affairs, Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, 212018, China.
| | - Dongxu Shen
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, 212018, China; Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture and Rural Affairs, Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, 212018, China.
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Jonusaite S, Oulhen N, Izumi Y, Furuse M, Yamamoto T, Sakamoto N, Wessel G, Heyland A. Identification of the genes encoding candidate septate junction components expressed during early development of the sea urchin, Strongylocentrotus purpuratus, and evidence of a role for Mesh in the formation of the gut barrier. Dev Biol 2023; 495:21-34. [PMID: 36587799 DOI: 10.1016/j.ydbio.2022.12.007] [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: 07/07/2022] [Revised: 12/20/2022] [Accepted: 12/22/2022] [Indexed: 12/30/2022]
Abstract
Septate junctions (SJs) evolved as cell-cell junctions that regulate the paracellular barrier and integrity of epithelia in invertebrates. Multiple morphological variants of SJs exist specific to different epithelia and/or phyla but the biological significance of varied SJ morphology is unclear because the knowledge of the SJ associated proteins and their functions in non-insect invertebrates remains largely unknown. Here we report cell-specific expression of nine candidate SJ genes in the early life stages of the sea urchin Strongylocentrotus purpuratus. By use of in situ RNA hybridization and single cell RNA-seq we found that the expression of selected genes encoding putatively SJ associated transmembrane and cytoplasmic scaffold molecules was dynamically regulated during epithelial development in the embryos and larvae with different epithelia expressing different cohorts of SJ genes. We focused a functional analysis on SpMesh, a homolog of the Drosophila smooth SJ component Mesh, which was highly enriched in the endodermal epithelium of the mid- and hindgut. Functional perturbation of SpMesh by both CRISPR/Cas9 mutagenesis and vivo morpholino-mediated knockdown shows that loss of SpMesh does not disrupt the formation of the gut epithelium during gastrulation. However, loss of SpMesh resulted in a severely reduced gut-paracellular barrier as quantitated by increased permeability to 3-5 kDa FITC-dextran. Together, these studies provide a first look at the molecular SJ physiology during the development of a marine organism and suggest a shared role for Mesh-homologous proteins in forming an intestinal barrier in invertebrates. Results have implications for consideration of the traits underlying species-specific sensitivity of marine larvae to climate driven ocean change.
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Affiliation(s)
- Sima Jonusaite
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada.
| | - Nathalie Oulhen
- Department of Molecular and Cell Biology and Biochemistry, Brown University, Providence, RI, 02912, United States
| | - Yasushi Izumi
- Division of Cell Structure, National Institute for Physiological Sciences, Okazaki, 444-8787, Japan
| | - Mikio Furuse
- Division of Cell Structure, National Institute for Physiological Sciences, Okazaki, 444-8787, Japan; Nagoya University Graduate School of Medicine, Aichi, 464-8601, Japan
| | - Takashi Yamamoto
- Division of Integrated Sciences for Life, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, 739-8526, Japan
| | - Naoaki Sakamoto
- Division of Integrated Sciences for Life, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, 739-8526, Japan
| | - Gary Wessel
- Department of Molecular and Cell Biology and Biochemistry, Brown University, Providence, RI, 02912, United States
| | - Andreas Heyland
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada
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5
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Meyer C, Breitsprecher L, Bataille L, Vincent AJM, Drechsler M, Meyer H, Paululat A. Formation and function of a highly specialised type of organelle in cardiac valve cells. Development 2022; 149:276991. [DOI: 10.1242/dev.200701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 08/23/2022] [Indexed: 11/06/2022]
Abstract
ABSTRACT
Within a cell, vesicles play a crucial role in the transport of membrane material and proteins to a given target membrane, and thus regulate a variety of cellular functions. Vesicular transport occurs by means of, among others, endocytosis, where cargoes are taken up by the cell and are processed further upon vesicular trafficking, i.e. transported back to the plasma membrane via recycling endosomes or the degraded by fusion of the vesicles with lysosomes. During evolution, a variety of vesicles with individual functions arose, with some of them building up highly specialised subcellular compartments. In this study, we have analysed the biosynthesis of a new vesicular compartment present in the valve cells of Drosophila melanogaster. We show that the compartment is formed by invaginations of the plasma membrane and grows via re-routing of the recycling endosomal pathway. This is achieved by inactivation of other membrane-consuming pathways and a plasma membrane-like molecular signature of the compartment in these highly specialised heart cells.
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Affiliation(s)
- Christian Meyer
- University of Osnabrück 1 , Department of Biology and Chemistry, Zoology and Developmental Biology, Barbarastraße 11, 49076 Osnabrück , Germany
| | - Leonhard Breitsprecher
- University of Osnabrück 1 , Department of Biology and Chemistry, Zoology and Developmental Biology, Barbarastraße 11, 49076 Osnabrück , Germany
- Center of Cellular Nanoanalytics (CellNanOs), integrated Bioimaging Facility (iBiOs), University of Osnabrück 2 , Barbarastrasse 11, 49076 Osnabrück , Germany
| | - Laetitia Bataille
- Unité de Biologie Moléculaire et Cellulaire et du Développement (MCD), Centre de Biologie Intégrative (CBI) 3 , Université de Toulouse UMR 5077/CNRS, F-31062 Toulouse , France
| | - Alain J. M. Vincent
- Unité de Biologie Moléculaire et Cellulaire et du Développement (MCD), Centre de Biologie Intégrative (CBI) 3 , Université de Toulouse UMR 5077/CNRS, F-31062 Toulouse , France
| | - Maik Drechsler
- University of Osnabrück 1 , Department of Biology and Chemistry, Zoology and Developmental Biology, Barbarastraße 11, 49076 Osnabrück , Germany
| | - Heiko Meyer
- University of Osnabrück 1 , Department of Biology and Chemistry, Zoology and Developmental Biology, Barbarastraße 11, 49076 Osnabrück , Germany
- Center of Cellular Nanoanalytics (CellNanOs), integrated Bioimaging Facility (iBiOs), University of Osnabrück 2 , Barbarastrasse 11, 49076 Osnabrück , Germany
| | - Achim Paululat
- University of Osnabrück 1 , Department of Biology and Chemistry, Zoology and Developmental Biology, Barbarastraße 11, 49076 Osnabrück , Germany
- Center of Cellular Nanoanalytics (CellNanOs), integrated Bioimaging Facility (iBiOs), University of Osnabrück 2 , Barbarastrasse 11, 49076 Osnabrück , Germany
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6
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Dow JAT, Simons M, Romero MF. Drosophila melanogaster: a simple genetic model of kidney structure, function and disease. Nat Rev Nephrol 2022; 18:417-434. [PMID: 35411063 DOI: 10.1038/s41581-022-00561-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/07/2022] [Indexed: 12/27/2022]
Abstract
Although the genetic basis of many kidney diseases is being rapidly elucidated, their experimental study remains problematic owing to the lack of suitable models. The fruitfly Drosophila melanogaster provides a rapid, ethical and cost-effective model system of the kidney. The unique advantages of D. melanogaster include ease and low cost of maintenance, comprehensive availability of genetic mutants and powerful transgenic technologies, and less onerous regulation, as compared with mammalian systems. Renal and excretory functions in D. melanogaster reside in three main tissues - the transporting renal (Malpighian) tubules, the reabsorptive hindgut and the endocytic nephrocytes. Tubules contain multiple cell types and regions and generate a primary urine by transcellular transport rather than filtration, which is then subjected to selective reabsorption in the hindgut. By contrast, the nephrocytes are specialized for uptake of macromolecules and equipped with a filtering slit diaphragm resembling that of podocytes. Many genes with key roles in the human kidney have D. melanogaster orthologues that are enriched and functionally relevant in fly renal tissues. This similarity has allowed investigations of epithelial transport, kidney stone formation and podocyte and proximal tubule function. Furthermore, a range of unique quantitative phenotypes are available to measure function in both wild type and disease-modelling flies.
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Affiliation(s)
- Julian A T Dow
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.
| | - Matias Simons
- INSERM UMR1163, Laboratory of Epithelial Biology and Disease, Imagine Institute, Université de Paris, Hôpital Necker-Enfants Malades, Paris, France
- Institute of Human Genetics, University Hospital Heidelberg, Heidelberg, Germany
| | - Michael F Romero
- Department of Physiology and Biomedical Engineering, Division of Nephrology and Hypertension, Mayo Clinic College of Medicine and Science, Rochester, MN, USA
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7
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Psathaki OE, Paululat A. Preparation of Drosophila Tissues and Organs for Transmission Electron Microscopy. Methods Mol Biol 2022; 2540:361-385. [PMID: 35980589 DOI: 10.1007/978-1-0716-2541-5_19] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Transmission electron microscopy (TEM) is the method of choice to image the ultrastructure of cells or tissues. TEM allows the visualization of molecular complexes up to an atomic resolution. Thus, TEM data have led to important conclusions about cellular processes and supported findings obtained by functional analyses. In this chapter, we describe the preparation of Drosophila tissues for TEM and provide reliable step-by-step protocols for applying classical chemical fixation or high-pressure freezing-freeze substitution (HPF-FS) to preserve cellular structures.
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Affiliation(s)
- Olympia-Ekaterini Psathaki
- University of Osnabrück, Department of Zoology and Developmental Biology, Osnabrück, Germany
- University of Osnabrück, Center of Cellular Nanoanalytics, Integrated Bioimaging Facility Osnabrück (iBiOs), Osnabrück, Germany
| | - Achim Paululat
- University of Osnabrück, Department of Zoology and Developmental Biology, Osnabrück, Germany.
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8
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Dow JAT, Krause SA, Herzyk P. Updates on ion and water transport by the Malpighian tubule. CURRENT OPINION IN INSECT SCIENCE 2021; 47:31-37. [PMID: 33705976 PMCID: PMC9586879 DOI: 10.1016/j.cois.2021.02.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 02/26/2021] [Accepted: 02/27/2021] [Indexed: 05/29/2023]
Abstract
The Malpighian (renal) tubule is capable of transporting fluid at remarkable rates. This review will focus on recent insights into the mechanisms by which these high rates are achieved and controlled, with particular reference to the tubules of Drosophila melanogaster, in which the combination of physiology and genetics has led to particularly rapid progress. Like many vertebrate epithelia, the Drosophila tubule has specialized cell types, with active cation transport confined to a large, metabolically active principal cell; whereas the smaller intercalated stellate cell controls chloride and water shunts to achieve net fluid secretion. Recently, the genes underlying many of these processes have been identified, functionally validated and localized within the tubule. The imminent arrival of new types of post-genomic data (notably single cell sequencing) will herald an exciting era of new discovery.
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Affiliation(s)
- Julian A T Dow
- Institute of Molecular, Cell & Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK.
| | - Sue Ann Krause
- Institute of Molecular, Cell & Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Pawel Herzyk
- Institute of Molecular, Cell & Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
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9
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Jonusaite S, Rodan AR. Molecular basis for epithelial morphogenesis and ion transport in the Malpighian tubule. CURRENT OPINION IN INSECT SCIENCE 2021; 47:7-11. [PMID: 33581351 PMCID: PMC8353009 DOI: 10.1016/j.cois.2021.02.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2021] [Revised: 01/28/2021] [Accepted: 02/01/2021] [Indexed: 05/04/2023]
Abstract
During development, the insect Malpighian tubule undergoes several programmed morphogenetic events that give rise to the tubule's ability to transport ions and water at unparalleled speed. Studies in Diptera, in particular, have greatly increased our understanding of the molecular pathways underlying embryonic tubule development. In this review, we discuss recent work that has revealed new insights into the molecular players required for the development and maintenance of structurally and functionally intact adult Malpighian tubules. We highlight the contribution of the smooth septate junction (sSJ) proteins to the morphogenesis and transport function of the epithelial cells of the Drosophila melanogaster Malpighian tubule and also discuss new findings on the role of the GATAe transcription factor. We also consider the roles of sSJ proteins in the fly midgut, as compared to the Malpighian tubule, and the importance of cellular context for the functions of these proteins.
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Affiliation(s)
- Sima Jonusaite
- Department of Internal Medicine, Division of Nephrology and Hypertension, and Molecular Medicine Program, University of Utah, Salt Lake City, UT 84112, USA; Department of Integrative Biology, University of Guelph, Guelph, Ontario NIG 2W1, Canada
| | - Aylin R Rodan
- Department of Internal Medicine, Division of Nephrology and Hypertension, and Molecular Medicine Program, University of Utah, Salt Lake City, UT 84112, USA; Medical Service, Veterans Affairs Salt Lake City Health Care System, Salt Lake City, UT, USA.
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10
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Izumi Y, Furuse K, Furuse M. The novel membrane protein Hoka regulates septate junction organization and stem cell homeostasis in the Drosophila gut. J Cell Sci 2021; 134:jcs.257022. [PMID: 33589496 DOI: 10.1242/jcs.257022] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 02/01/2021] [Indexed: 12/16/2022] Open
Abstract
Smooth septate junctions (sSJs) regulate the paracellular transport in the intestinal tract in arthropods. In Drosophila, the organization and physiological function of sSJs are regulated by at least three sSJ-specific membrane proteins: Ssk, Mesh and Tsp2A. Here, we report a novel sSJ membrane protein, Hoka, which has a single membrane-spanning segment with a short extracellular region, and a cytoplasmic region with Tyr-Thr-Pro-Ala motifs. The larval midgut in hoka mutants shows a defect in sSJ structure. Hoka forms a complex with Ssk, Mesh and Tsp2A, and is required for the correct localization of these proteins to sSJs. Knockdown of hoka in the adult midgut leads to intestinal barrier dysfunction and stem cell overproliferation. In hoka-knockdown midguts, aPKC is upregulated in the cytoplasm and the apical membrane of epithelial cells. The depletion of aPKC and yki in hoka-knockdown midguts results in reduced stem cell overproliferation. These findings indicate that Hoka cooperates with the sSJ proteins Ssk, Mesh and Tsp2A to organize sSJs, and is required for maintaining intestinal stem cell homeostasis through the regulation of aPKC and Yki activities in the Drosophila midgut.
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Affiliation(s)
- Yasushi Izumi
- Division of Cell Structure, National Institute for Physiological Sciences, Okazaki 444-8787, Japan .,Department of Physiological Sciences, The Graduate University of Advanced Studies, SOKENDAI, Okazaki 444-8585, Japan
| | - Kyoko Furuse
- Division of Cell Structure, National Institute for Physiological Sciences, Okazaki 444-8787, Japan
| | - Mikio Furuse
- Division of Cell Structure, National Institute for Physiological Sciences, Okazaki 444-8787, Japan.,Department of Physiological Sciences, The Graduate University of Advanced Studies, SOKENDAI, Okazaki 444-8585, Japan
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11
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Rouka E, Gourgoulianni N, Lüpold S, Hatzoglou C, Gourgoulianis K, Blanckenhorn WU, Zarogiannis SG. The Drosophila septate junctions beyond barrier function: Review of the literature, prediction of human orthologs of the SJ-related proteins and identification of protein domain families. Acta Physiol (Oxf) 2021; 231:e13527. [PMID: 32603029 DOI: 10.1111/apha.13527] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 06/20/2020] [Accepted: 06/22/2020] [Indexed: 12/20/2022]
Abstract
The involvement of Septate Junctions (SJs) in critical cellular functions that extend beyond their role as diffusion barriers in the epithelia and the nervous system has made the fruit fly an ideal model for the study of human diseases associated with impaired Tight Junction (TJ) function. In this study, we summarized current knowledge of the Drosophila melanogaster SJ-related proteins, focusing on their unconventional functions. Additionally, we sought to identify human orthologs of the corresponding genes as well as protein domain families. The systematic literature search was performed in PubMed and Scopus databases using relevant key terms. Orthologs were predicted using the DIOPT tool and aligned protein regions were determined from the Pfam database. 3-D models of the smooth SJ proteins were built on the Phyre2 and DMPFold protein structure prediction servers. A total of 30 proteins were identified as relatives to the SJ cellular structure. Key roles of these proteins, mainly in the regulation of morphogenetic events and cellular signalling, were highlighted. The investigation of protein domain families revealed that the SJ-related proteins contain conserved domains that are required not only for cell-cell interactions and cell polarity but also for cellular signalling and immunity. DIOPT analysis of orthologs identified novel human genes as putative functional homologs of the fruit fly SJ genes. A gap in our knowledge was identified regarding the domains that occur in the proteins encoded by eight SJ-associated genes. Future investigation of these domains is needed to provide functional information.
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Affiliation(s)
- Erasmia Rouka
- Department of Physiology Faculty of Medicine School of Health Sciences University of ThessalyBIOPOLIS Larissa Greece
| | - Natalia Gourgoulianni
- Department of Evolutionary Biology and Environmental Studies University of Zurich Zurich Switzerland
| | - Stefan Lüpold
- Department of Evolutionary Biology and Environmental Studies University of Zurich Zurich Switzerland
| | - Chrissi Hatzoglou
- Department of Physiology Faculty of Medicine School of Health Sciences University of ThessalyBIOPOLIS Larissa Greece
- Department of Respiratory Medicine Faculty of Medicine School of Health Sciences University of ThessalyBIOPOLIS Larissa Greece
| | - Konstantinos Gourgoulianis
- Department of Respiratory Medicine Faculty of Medicine School of Health Sciences University of ThessalyBIOPOLIS Larissa Greece
| | - Wolf U. Blanckenhorn
- Department of Evolutionary Biology and Environmental Studies University of Zurich Zurich Switzerland
| | - Sotirios G. Zarogiannis
- Department of Physiology Faculty of Medicine School of Health Sciences University of ThessalyBIOPOLIS Larissa Greece
- Department of Respiratory Medicine Faculty of Medicine School of Health Sciences University of ThessalyBIOPOLIS Larissa Greece
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Dehnen L, Janz M, Verma JK, Psathaki OE, Langemeyer L, Fröhlich F, Heinisch JJ, Meyer H, Ungermann C, Paululat A. A trimeric metazoan Rab7 GEF complex is crucial for endocytosis and scavenger function. J Cell Sci 2020; 133:jcs247080. [PMID: 32499409 DOI: 10.1242/jcs.247080] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 05/20/2020] [Indexed: 12/12/2022] Open
Abstract
Endosome biogenesis in eukaryotic cells is critical for nutrient uptake and plasma membrane integrity. Early endosomes initially contain Rab5, which is replaced by Rab7 on late endosomes prior to their fusion with lysosomes. Recruitment of Rab7 to endosomes requires the Mon1-Ccz1 guanine-nucleotide-exchange factor (GEF). Here, we show that full function of the Drosophila Mon1-Ccz1 complex requires a third stoichiometric subunit, termed Bulli (encoded by CG8270). Bulli localises to Rab7-positive endosomes, in agreement with its function in the GEF complex. Using Drosophila nephrocytes as a model system, we observe that absence of Bulli results in (i) reduced endocytosis, (ii) Rab5 accumulation within non-acidified enlarged endosomes, (iii) defective Rab7 localisation and (iv) impaired endosomal maturation. Moreover, longevity of animals lacking bulli is affected. Both the Mon1-Ccz1 dimer and a Bulli-containing trimer display Rab7 GEF activity. In summary, this suggests a key role for Bulli in the Rab5 to Rab7 transition during endosomal maturation rather than a direct influence on the GEF activity of Mon1-Ccz1.
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Affiliation(s)
- Lena Dehnen
- Department of Biology and Chemistry, Zoology and Developmental Biology, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany
| | - Maren Janz
- Department of Biology and Chemistry, Zoology and Developmental Biology, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany
| | - Jitender Kumar Verma
- Department of Biology and Chemistry, Biochemistry, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany
| | - Olympia Ekaterini Psathaki
- Center of Cellular Nanoanalytics, Integrated Bioimaging Facility Osnabrück (iBiOs), University of Osnabrück, 49076 Osnabrück, Germany
| | - Lars Langemeyer
- Department of Biology and Chemistry, Biochemistry, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany
| | - Florian Fröhlich
- Department of Biology and Chemistry, Molecular Membrane Biology, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany
| | - Jürgen J Heinisch
- Department of Biology and Chemistry, Genetics, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany
- Center of Cellular Nanoanalytics, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany
| | - Heiko Meyer
- Department of Biology and Chemistry, Zoology and Developmental Biology, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany
- Center of Cellular Nanoanalytics, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany
| | - Christian Ungermann
- Department of Biology and Chemistry, Biochemistry, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany
- Center of Cellular Nanoanalytics, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany
| | - Achim Paululat
- Department of Biology and Chemistry, Zoology and Developmental Biology, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany
- Center of Cellular Nanoanalytics, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany
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