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Klinke N, Meyer H, Ratnavadivel S, Reinhardt M, Heinisch JJ, Malmendal A, Milting H, Paululat A. A Drosophila melanogaster model for TMEM43-related arrhythmogenic right ventricular cardiomyopathy type 5. Cell Mol Life Sci 2022; 79:444. [PMID: 35869176 PMCID: PMC9307560 DOI: 10.1007/s00018-022-04458-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 06/01/2022] [Accepted: 06/28/2022] [Indexed: 11/03/2022]
Abstract
AbstractArrhythmogenic right ventricular cardiomyopathy (ARVC) is a severe cardiac disease that leads to heart failure or sudden cardiac death (SCD). For the pathogenesis of ARVC, various mutations in at least eight different genes have been identified. A rare form of ARVC is associated with the mutation TMEM43 p.S358L, which is a fully penetrant variant in male carriers. TMEM43 p.S358 is homologous to CG8111 p.S333 in Drosophila melanogaster. We established CRISPR/Cas9-mediated CG8111 knock-out mutants in Drosophila, as well as transgenic fly lines carrying an overexpression construct of the CG8111 p.S333L substitution. Knock-out flies developed normally, whereas the overexpression of CG8111 p.S333L caused growth defects, loss of body weight, cardiac arrhythmias, and premature death. An evaluation of a series of model mutants that replaced S333 by selected amino acids proved that the conserved serine is critical for the physiological function of CG8111. Metabolomic and proteomic analyses revealed that the S333 in CG8111 is essential to proper energy homeostasis and lipid metabolism in the fly. Of note, metabolic impairments were also found in the murine Tmem43 disease model, and fibrofatty replacement is a hallmark of human ARVC5. These findings contribute to a more comprehensive understanding of the molecular functions of CG8111 in Drosophila, and can represent a valuable basis to assess the aetiology of the human TMEM43 p.S358L variant in more detail.
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2
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Schiemann R, Buhr A, Cordes E, Walter S, Heinisch JJ, Ferrero P, Milting H, Paululat A, Meyer H. Neprilysins regulate muscle contraction and heart function via cleavage of SERCA-inhibitory micropeptides. Nat Commun 2022; 13:4420. [PMID: 35906206 PMCID: PMC9338278 DOI: 10.1038/s41467-022-31974-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 07/06/2022] [Indexed: 12/26/2022] Open
Abstract
Muscle contraction depends on strictly controlled Ca2+ transients within myocytes. A major player maintaining these transients is the sarcoplasmic/endoplasmic reticulum Ca2+ ATPase, SERCA. Activity of SERCA is regulated by binding of micropeptides and impaired expression or function of these peptides results in cardiomyopathy. To date, it is not known how homeostasis or turnover of the micropeptides is regulated. Herein, we find that the Drosophila endopeptidase Neprilysin 4 hydrolyzes SERCA-inhibitory Sarcolamban peptides in membranes of the sarcoplasmic reticulum, thereby ensuring proper regulation of SERCA. Cleavage is necessary and sufficient to maintain homeostasis and function of the micropeptides. Analyses on human Neprilysin, sarcolipin, and ventricular cardiomyocytes indicates that the regulatory mechanism is evolutionarily conserved. By identifying a neprilysin as essential regulator of SERCA activity and Ca2+ homeostasis in cardiomyocytes, these data contribute to a more comprehensive understanding of the complex mechanisms that control muscle contraction and heart function in health and disease.
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Affiliation(s)
- Ronja Schiemann
- Department of Zoology & Developmental Biology, Osnabrück University, 49076, Osnabrück, Germany
| | - Annika Buhr
- Department of Zoology & Developmental Biology, Osnabrück University, 49076, Osnabrück, Germany
| | - Eva Cordes
- Department of Zoology & Developmental Biology, Osnabrück University, 49076, Osnabrück, Germany
| | - Stefan Walter
- Center of Cellular Nanoanalytics Osnabrück - CellNanOs, 49076, Osnabrück, Germany
| | - Jürgen J Heinisch
- Center of Cellular Nanoanalytics Osnabrück - CellNanOs, 49076, Osnabrück, Germany.,Department of Genetics, Osnabrück University, 49076, Osnabrück, Germany
| | - Paola Ferrero
- Center for Cardiovascular Research - CONICET/National University of La Plata, 1900, La Plata, Argentina
| | - Hendrik Milting
- Heart & Diabetes Center NRW, University of Bochum, Erich & Hanna Klessmann-Institute for Cardiovascular Research and Development, 32545, Bad Oeynhausen, Germany
| | - Achim Paululat
- Department of Zoology & Developmental Biology, Osnabrück University, 49076, Osnabrück, Germany.,Center of Cellular Nanoanalytics Osnabrück - CellNanOs, 49076, Osnabrück, Germany
| | - Heiko Meyer
- Department of Zoology & Developmental Biology, Osnabrück University, 49076, Osnabrück, Germany. .,Center of Cellular Nanoanalytics Osnabrück - CellNanOs, 49076, Osnabrück, Germany.
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3
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Triple gene expressions in yeast, Escherichia coli, and mammalian cells by transferring DNA fragments amplified from a mother yeast expression plasmid. J Biosci Bioeng 2022; 133:587-595. [DOI: 10.1016/j.jbiosc.2022.03.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 02/18/2022] [Accepted: 03/04/2022] [Indexed: 11/22/2022]
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4
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Morin-Poulard I, Destalminil-Letourneau M, Bataillé L, Frendo JL, Lebreton G, Vanzo N, Crozatier M. Identification of Bipotential Blood Cell/Nephrocyte Progenitors in Drosophila: Another Route for Generating Blood Progenitors. Front Cell Dev Biol 2022; 10:834720. [PMID: 35237606 PMCID: PMC8883574 DOI: 10.3389/fcell.2022.834720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 01/24/2022] [Indexed: 11/13/2022] Open
Abstract
The Drosophila lymph gland is the larval hematopoietic organ and is aligned along the anterior part of the cardiovascular system, composed of cardiac cells, that form the cardiac tube and its associated pericardial cells or nephrocytes. By the end of embryogenesis the lymph gland is composed of a single pair of lobes. Two additional pairs of posterior lobes develop during larval development to contribute to the mature lymph gland. In this study we describe the ontogeny of lymph gland posterior lobes during larval development and identify the genetic basis of the process. By lineage tracing we show here that each posterior lobe originates from three embryonic pericardial cells, thus establishing a bivalent blood cell/nephrocyte potential for a subset of embryonic pericardial cells. The posterior lobes of L3 larvae posterior lobes are composed of heterogeneous blood progenitors and their diversity is progressively built during larval development. We further establish that in larvae, homeotic genes and the transcription factor Klf15 regulate the choice between blood cell and nephrocyte fates. Our data underline the sequential production of blood cell progenitors during larval development.
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Affiliation(s)
- Ismaël Morin-Poulard
- Unité de Biologie Moléculaire et Cellulaire et du Développement (MCD), Centre de Biologie Intégrative (CBI), Université de Toulouse UMR 5077/CNRS, Toulouse, France
| | - Manon Destalminil-Letourneau
- Unité de Biologie Moléculaire et Cellulaire et du Développement (MCD), Centre de Biologie Intégrative (CBI), Université de Toulouse UMR 5077/CNRS, Toulouse, France
| | - Laetitia Bataillé
- Unité de Biologie Moléculaire et Cellulaire et du Développement (MCD), Centre de Biologie Intégrative (CBI), Université de Toulouse UMR 5077/CNRS, Toulouse, France.,CNRS, INSERM, IGDR (Institut de Génétique et Développement de Rennes), UMR6290, ERL U1305, Rennes, France
| | - Jean-Louis Frendo
- Unité de Biologie Moléculaire et Cellulaire et du Développement (MCD), Centre de Biologie Intégrative (CBI), Université de Toulouse UMR 5077/CNRS, Toulouse, France.,INSERM U1301, CNRS 5070, Université de Toulouse, Toulouse, France
| | - Gaëlle Lebreton
- Unité de Biologie Moléculaire et Cellulaire et du Développement (MCD), Centre de Biologie Intégrative (CBI), Université de Toulouse UMR 5077/CNRS, Toulouse, France
| | - Nathalie Vanzo
- Unité de Biologie Moléculaire et Cellulaire et du Développement (MCD), Centre de Biologie Intégrative (CBI), Université de Toulouse UMR 5077/CNRS, Toulouse, France
| | - Michèle Crozatier
- Unité de Biologie Moléculaire et Cellulaire et du Développement (MCD), Centre de Biologie Intégrative (CBI), Université de Toulouse UMR 5077/CNRS, Toulouse, France
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5
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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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Abstract
In all kingdoms of life, DNA is used to encode hereditary information. Propagation of the genetic material between generations requires timely and accurate duplication of DNA by semiconservative replication prior to cell division to ensure each daughter cell receives the full complement of chromosomes. DNA synthesis of daughter strands starts at discrete sites, termed replication origins, and proceeds in a bidirectional manner until all genomic DNA is replicated. Despite the fundamental nature of these events, organisms have evolved surprisingly divergent strategies that control replication onset. Here, we discuss commonalities and differences in replication origin organization and recognition in the three domains of life.
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Affiliation(s)
- Babatunde Ekundayo
- Quantitative Biology, Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Franziska Bleichert
- Quantitative Biology, Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
- * E-mail:
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7
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Wilmes AC, Klinke N, Rotstein B, Meyer H, Paululat A. Biosynthesis and assembly of the Collagen IV-like protein Pericardin in Drosophila melanogaster. Biol Open 2018; 7:7/4/bio030361. [PMID: 29685999 PMCID: PMC5936059 DOI: 10.1242/bio.030361] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
In Drosophila, formation of the cardiac extracellular matrix (ECM) starts during embryogenesis. Assembly and incorporation of structural proteins such as Collagen IV, Pericardin, and Laminin A, B1, and B2 into the cardiac ECM is critical to the maintenance of heart integrity and functionality and, therefore, to longevity of the animal. The cardiac ECM connects the heart tube with the alary muscles; thus, the ECM contributes to a flexible positioning of the heart within the animal's body. Moreover, the cardiac ECM holds the larval pericardial nephrocytes in close proximity to the heart tube and the inflow tract, which is assumed to be critical to efficient haemolymph clearance. Mutations in either structural ECM constituents or ECM receptors cause breakdown of the ECM network upon ageing, with disconnection of the heart tube from alary muscles becoming apparent at larval stages. Finally, the heart becomes non-functional. Here, we characterised existing and new pericardin mutants and investigated biosynthesis, secretion, and assembly of Pericardin in matrices. We identified two new pericardin alleles, which turned out to be a null (pericardin3-548) and a hypomorphic allele (pericardin3-21). Both mutants could be rescued with a genomic duplication of a fosmid coding for the pericardin locus. Biochemical analysis revealed that Pericardin is highly glycosylated and forms redox-dependent multimers. Multimer formation is remarkably reduced in animals deficient for the prolyl-4 hydroxylase cluster at 75D3-4. Summary: We identified two new pericardin alleles. Both mutants could be rescued with a genomic duplication of a fosmid coding for the pericardin locus. Biochemical analysis revealed that Pericardin is highly glycosylated and forms redox-dependent multimers.
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Affiliation(s)
- Ariane C Wilmes
- University of Osnabrück, Biology, Department of Zoology and Developmental Biology, Barbarastraße 11, 49076 Osnabrück, Germany
| | - Nora Klinke
- University of Osnabrück, Biology, Department of Zoology and Developmental Biology, Barbarastraße 11, 49076 Osnabrück, Germany
| | - Barbara Rotstein
- University of Osnabrück, Biology, Department of Zoology and Developmental Biology, Barbarastraße 11, 49076 Osnabrück, Germany
| | - Heiko Meyer
- University of Osnabrück, Biology, Department of Zoology and Developmental Biology, Barbarastraße 11, 49076 Osnabrück, Germany
| | - Achim Paululat
- University of Osnabrück, Biology, Department of Zoology and Developmental Biology, Barbarastraße 11, 49076 Osnabrück, Germany
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8
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Rotstein B, Post Y, Reinhardt M, Lammers K, Buhr A, Heinisch JJ, Meyer H, Paululat A. Distinct domains in the matricellular protein Lonely heart are crucial for cardiac extracellular matrix formation and heart function in Drosophila. J Biol Chem 2018; 293:7864-7879. [PMID: 29599288 DOI: 10.1074/jbc.m117.817940] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 03/29/2018] [Indexed: 12/22/2022] Open
Abstract
The biomechanical properties of extracellular matrices (ECMs) are critical to many biological processes, including cell-cell communication and cell migration and function. The correct balance between stiffness and elasticity is essential to the function of numerous tissues, including blood vessels and the lymphatic system, and depends on ECM constituents (the "matrisome") and on their level of interconnection. However, despite its physiological relevance, the matrisome composition and organization remain poorly understood. Previously, we reported that the ADAMTS-like protein Lonely heart (Loh) is critical for recruiting the type IV collagen-like protein Pericardin to the cardiac ECM. Here, we utilized Drosophila as a simple and genetically amenable invertebrate model for studying Loh-mediated recruitment of tissue-specific ECM components such as Pericardin to the ECM. We focused on the functional relevance of distinct Loh domains to protein localization and Pericardin recruitment. Analysis of Loh deletion constructs revealed that one thrombospondin type 1 repeat (TSR1-1), which has an embedded WXXW motif, is critical for anchoring Loh to the ECM. Two other thrombospondin repeats, TSR1-2 and TSR1-4, the latter containing a CXXTCXXG motif, appeared to be dispensable for tethering Loh to the ECM but were crucial for proper interaction with and recruitment of Pericardin. Moreover, our results also suggested that Pericardin in the cardiac ECM primarily ensures the structural integrity of the heart, rather than increasing tissue flexibility. In conclusion, our work provides new insights into the roles of thrombospondin type 1 repeats and advances our understanding of cardiac ECM assembly and function.
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Affiliation(s)
| | - Yanina Post
- From the Departments of Zoology and Developmental Biology and
| | | | - Kay Lammers
- From the Departments of Zoology and Developmental Biology and
| | - Annika Buhr
- From the Departments of Zoology and Developmental Biology and
| | - Jürgen J Heinisch
- Genetics, Faculty of Biology & Chemistry, University of Osnabrück Barbarastrasse 11, 49076 Osnabrück, Germany
| | - Heiko Meyer
- From the Departments of Zoology and Developmental Biology and
| | - Achim Paululat
- From the Departments of Zoology and Developmental Biology and
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9
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Lammers K, Abeln B, Hüsken M, Lehmacher C, Psathaki OE, Alcorta E, Meyer H, Paululat A. Formation and function of intracardiac valve cells in the Drosophila heart. J Exp Biol 2017; 220:1852-1863. [DOI: 10.1242/jeb.156265] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Accepted: 02/26/2017] [Indexed: 01/20/2023]
Abstract
Drosophila harbors a simple tubular heart that ensures hemolymph circulation within the body. The heart is built by a few different cell types, including cardiomyocytes that define the luminal heart channel and ostia cells that constitute openings in the heart wall allowing hemolymph to enter the heart chamber. Regulation of flow directionality within a tube, such as blood flow in arteries or insect hemolymph within the heart lumen, requires a dedicated gate, valve, or flap-like structure that prevents backflow of fluids. In the Drosophila heart, intracardiac valves provide this directionality of hemolymph streaming, with one valve being present in larvae and three valves in the adult fly. Each valve is built by two specialized cardiomyocytes that exhibit a unique histology. We found that the capacity to open and close the heart lumen relies on a unique myofibrillar setting as well as on the presence of large membranous vesicles. These vesicles are of endocytic origin and probably represent unique organelles of valve cells. Moreover, we characterised the working mode of the cells in real time. Valve cells exhibit a highly flexible shape and during each heartbeat, oscillating shape changes result in closing and opening of the heart channel. Finally, we identified a set of novel valve cell markers useful for future in-depth analyses of cell differentiation in wildtype and mutant animals.
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Affiliation(s)
- Kay Lammers
- University of Osnabrück, Department of Zoology and Developmental Biology, Barbarastraße 11, 49076 Osnabrueck, Germany
| | - Bettina Abeln
- University of Osnabrück, Department of Zoology and Developmental Biology, Barbarastraße 11, 49076 Osnabrueck, Germany
| | - Mirko Hüsken
- University of Osnabrück, Department of Zoology and Developmental Biology, Barbarastraße 11, 49076 Osnabrueck, Germany
| | - Christine Lehmacher
- University of Osnabrück, Department of Zoology and Developmental Biology, Barbarastraße 11, 49076 Osnabrueck, Germany
| | | | - Esther Alcorta
- Departamento de Biología Funcional, Facultad de Medicina, Universidad de Oviedo, C/ Julián Clavería s/n, 33.006 Oviedo, Spain
| | - Heiko Meyer
- University of Osnabrück, Department of Zoology and Developmental Biology, Barbarastraße 11, 49076 Osnabrueck, Germany
| | - Achim Paululat
- University of Osnabrück, Department of Zoology and Developmental Biology, Barbarastraße 11, 49076 Osnabrueck, Germany
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10
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Hallier B, Schiemann R, Cordes E, Vitos-Faleato J, Walter S, Heinisch JJ, Malmendal A, Paululat A, Meyer H. Drosophila neprilysins control insulin signaling and food intake via cleavage of regulatory peptides. eLife 2016; 5. [PMID: 27919317 PMCID: PMC5140268 DOI: 10.7554/elife.19430] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 11/14/2016] [Indexed: 12/11/2022] Open
Abstract
Insulin and IGF signaling are critical to numerous developmental and physiological processes, with perturbations being pathognomonic of various diseases, including diabetes. Although the functional roles of the respective signaling pathways have been extensively studied, the control of insulin production and release is only partially understood. Herein, we show that in Drosophila expression of insulin-like peptides is regulated by neprilysin activity. Concomitant phenotypes of altered neprilysin expression included impaired food intake, reduced body size, and characteristic changes in the metabolite composition. Ectopic expression of a catalytically inactive mutant did not elicit any of the phenotypes, which confirms abnormal peptide hydrolysis as a causative factor. A screen for corresponding substrates of the neprilysin identified distinct peptides that regulate insulin-like peptide expression, feeding behavior, or both. The high functional conservation of neprilysins and their substrates renders the characterized principles applicable to numerous species, including higher eukaryotes and humans. DOI:http://dx.doi.org/10.7554/eLife.19430.001 The hormone insulin and similar molecules called insulin-like peptides act as signals to control many processes in the body, including growth, stress responses and aging. Disrupting these signaling pathways can cause many diseases, with diabetes being the most common of these. Although the roles of the signaling pathways have been well studied, it is less clear how the body controls the production of insulin and insulin-like peptides. Neprilysins are enzymes that can cut other proteins and peptides by a process known as hydrolysis. Their targets (known as “substrates”) include peptides that regulate a range of cell processes, and neprilysins have therefore been linked with many diseases. Fruit flies have at least five different neprilysin enzymes, but their substrates have not yet been identified. One of these, known as Nep4A, is produced in muscle tissue and appears to be important for muscles to work properly. Hallier, Schiemann et al. reveal that Nep4A regulates the production of insulin-like peptides. The experiments used fruit fly larvae that had been genetically engineered so that the level of Nep4A could be altered in muscle tissue. Larvae with very high or very low levels of Nep4A eat less food, have smaller bodies and produce different amounts of insulin-like peptides compared to normal larvae. Further experiments show that Nep4A can hydrolyze a number of peptides that regulate the production and the release of insulin-like peptides. This suggests that the enzymatic activity of neprilysins plays a direct role in controlling the production of insulin. The next challenge is to find out whether these findings apply to humans and other animals that also have neprilysins. DOI:http://dx.doi.org/10.7554/eLife.19430.002
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Affiliation(s)
- Benjamin Hallier
- Department of Developmental Biology, University of Osnabrück, Osnabrück, Germany
| | - Ronja Schiemann
- Department of Developmental Biology, University of Osnabrück, Osnabrück, Germany
| | - Eva Cordes
- Department of Developmental Biology, University of Osnabrück, Osnabrück, Germany
| | - Jessica Vitos-Faleato
- Department of Biomedical Research, Institute for Research in Biomedicine, Barcelona, Spain
| | - Stefan Walter
- Department of Microbiology, University of Osnabrück, Osnabrück, Germany
| | | | - Anders Malmendal
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Achim Paululat
- Department of Developmental Biology, University of Osnabrück, Osnabrück, Germany
| | - Heiko Meyer
- Department of Developmental Biology, University of Osnabrück, Osnabrück, Germany
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11
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A Drosophila Model of Epidermolysis Bullosa Simplex. J Invest Dermatol 2015; 135:2031-2039. [PMID: 25830653 PMCID: PMC4519992 DOI: 10.1038/jid.2015.129] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 03/16/2015] [Accepted: 03/24/2015] [Indexed: 12/03/2022]
Abstract
The blistering skin disorder Epidermolysis bullosa simplex (EBS) results from dominant mutations in K5 or K14 genes, encoding the intermediate filament network of basal epidermal keratinocytes. The mechanisms governing keratin network formation and collapse due to EBS mutations remain incompletely understood. Drosophila lacks cytoplasmic intermediate filaments, providing a ‚null’ environment to examine the formation of keratin networks and determine mechanisms by which mutant keratins cause pathology. Here, we report that ubiquitous co-expression of transgenes encoding wild-type human K14 and K5 resulted in the formation of extensive keratin networks in Drosophila epithelial and non-epithelial tissues, causing no overt phenotype. Similar to mammalian cells, treatment of transgenic fly tissues with phosphatase inhibitors caused keratin network collapse, validating Drosophila as a genetic model system to investigate keratin dynamics. Co-expression of K5 and a K14R125C mutant that causes the most severe form of EBS resulted in widespread formation of EBS-like cytoplasmic keratin aggregates in epithelial and non-epithelial fly tissues. Expression of K14R125C/K5 caused semi-lethality; adult survivors developed wing blisters and were flightless due to lack of intercellular adhesion during wing heart development. This Drosophila model of EBS is valuable for the identification of pathways altered by mutant keratins and for development of EBS therapies.
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12
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Manivannan SN, Lai LB, Gopalan V, Simcox A. Transcriptional control of an essential ribozyme in Drosophila reveals an ancient evolutionary divide in animals. PLoS Genet 2015; 11:e1004893. [PMID: 25569672 PMCID: PMC4287351 DOI: 10.1371/journal.pgen.1004893] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 11/13/2014] [Indexed: 11/19/2022] Open
Abstract
Ribonuclease P (RNase P) is an essential enzyme required for 5'-maturation of tRNA. While an RNA-free, protein-based form of RNase P exists in eukaryotes, the ribonucleoprotein (RNP) form is found in all domains of life. The catalytic component of the RNP is an RNA known as RNase P RNA (RPR). Eukaryotic RPR genes are typically transcribed by RNA polymerase III (pol III). Here we showed that the RPR gene in Drosophila, which is annotated in the intron of a pol II-transcribed protein-coding gene, lacks signals for transcription by pol III. Using reporter gene constructs that include the RPR-coding intron from Drosophila, we found that the intron contains all the sequences necessary for production of mature RPR but is dependent on the promoter of the recipient gene for expression. We also demonstrated that the intron-coded RPR copurifies with RNase P and is required for its activity. Analysis of RPR genes in various animal genomes revealed a striking divide in the animal kingdom that separates insects and crustaceans into a single group in which RPR genes lack signals for independent transcription and are embedded in different protein-coding genes. Our findings provide evidence for a genetic event that occurred approximately 500 million years ago in the arthropod lineage, which switched the control of the transcription of RPR from pol III to pol II.
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Affiliation(s)
- Sathiya N. Manivannan
- Molecular Cellular Developmental Biology Program, Ohio State University, Columbus, Ohio, United States of America
- Department of Molecular Genetics, Ohio State University, Columbus, Ohio, United States of America
| | - Lien B. Lai
- Department of Chemistry and Biochemistry, Ohio State University, Columbus, Ohio, United States of America
- Center for RNA Biology, Ohio State University, Columbus, Ohio, United States of America
| | - Venkat Gopalan
- Molecular Cellular Developmental Biology Program, Ohio State University, Columbus, Ohio, United States of America
- Department of Chemistry and Biochemistry, Ohio State University, Columbus, Ohio, United States of America
- Center for RNA Biology, Ohio State University, Columbus, Ohio, United States of America
- * E-mail: (VG); (AS)
| | - Amanda Simcox
- Molecular Cellular Developmental Biology Program, Ohio State University, Columbus, Ohio, United States of America
- Department of Molecular Genetics, Ohio State University, Columbus, Ohio, United States of America
- * E-mail: (VG); (AS)
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Rosemeyer H, Paululat A, Heinisch JJ. 'Yeast mail': a novel Saccharomyces application (NSA) to encrypt messages. Chem Biodivers 2014; 11:1364-73. [PMID: 25238077 DOI: 10.1002/cbdv.201400160] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Indexed: 11/10/2022]
Abstract
The universal genetic code is used by all life forms to encode biological information. It can also be used to encrypt semantic messages and convey them within organisms without anyone but the sender and recipient knowing, i.e., as a means of steganography. Several theoretical, but comparatively few experimental, approaches have been dedicated to this subject, so far. Here, we describe an experimental system to stably integrate encrypted messages within the yeast genome using a polymerase chain reaction (PCR)-based, one-step homologous recombination system. Thus, DNA sequences encoding alphabetical and/or numerical information will be inherited by yeast propagation and can be sent in the form of dried yeast. Moreover, due to the availability of triple shuttle vectors, Saccharomyces cerevisiae can also be used as an intermediate construction device for transfer of information to either Drosophila or mammalian cells as steganographic containers. Besides its classical use in alcoholic fermentation and its modern use for heterologous gene expression, we here show that baker's yeast can thus be employed in a novel Saccharomyces application (NSA) as a simple steganographic container to hide and convey messages.
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Affiliation(s)
- Helmut Rosemeyer
- Organic Chemistry I - Bioorganic Chemistry, Institute of Chemistry of New Materials, University of Osnabrück, Barbarastrasse 7, D-49069 Osnabrück.
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