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Ben-Hur S, Sernik S, Afar S, Kolpakova A, Politi Y, Gal L, Florentin A, Golani O, Sivan E, Dezorella N, Morgenstern D, Pietrokovski S, Schejter E, Yacobi-Sharon K, Arama E. Egg multivesicular bodies elicit an LC3-associated phagocytosis-like pathway to degrade paternal mitochondria after fertilization. Nat Commun 2024; 15:5715. [PMID: 38977659 PMCID: PMC11231261 DOI: 10.1038/s41467-024-50041-5] [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: 09/20/2023] [Accepted: 06/27/2024] [Indexed: 07/10/2024] Open
Abstract
Mitochondria are maternally inherited, but the mechanisms underlying paternal mitochondrial elimination after fertilization are far less clear. Using Drosophila, we show that special egg-derived multivesicular body vesicles promote paternal mitochondrial elimination by activating an LC3-associated phagocytosis-like pathway, a cellular defense pathway commonly employed against invading microbes. Upon fertilization, these egg-derived vesicles form extended vesicular sheaths around the sperm flagellum, promoting degradation of the sperm mitochondrial derivative and plasma membrane. LC3-associated phagocytosis cascade of events, including recruitment of a Rubicon-based class III PI(3)K complex to the flagellum vesicular sheaths, its activation, and consequent recruitment of Atg8/LC3, are all required for paternal mitochondrial elimination. Finally, lysosomes fuse with strings of large vesicles derived from the flagellum vesicular sheaths and contain degrading fragments of the paternal mitochondrial derivative. Given reports showing that in some mammals, the paternal mitochondria are also decorated with Atg8/LC3 and surrounded by multivesicular bodies upon fertilization, our findings suggest that a similar pathway also mediates paternal mitochondrial elimination in other flagellated sperm-producing organisms.
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Affiliation(s)
- Sharon Ben-Hur
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Shoshana Sernik
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Sara Afar
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Alina Kolpakova
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Yoav Politi
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Liron Gal
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Anat Florentin
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
- Department of Microbiology and Molecular Genetics, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Ofra Golani
- Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, Israel
| | - Ehud Sivan
- Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, Israel
| | - Nili Dezorella
- Department of Chemical Research Support, Weizmann Institute of Science, Rehovot, Israel
| | - David Morgenstern
- de Botton Institute for Protein Profiling, The Nancy and Stephen Grand Israel National Center for Personalised Medicine, Weizmann Institute of Science, Rehovot, Israel
| | - Shmuel Pietrokovski
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Eyal Schejter
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Keren Yacobi-Sharon
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Eli Arama
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel.
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2
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Banerjee S, Bongu S, Hughes SP, Gaboury EK, Carver CE, Luo X, Bessert DA, Thummel R. Hypomyelinated vps16 Mutant Zebrafish Exhibit Systemic and Neurodevelopmental Pathologies. Int J Mol Sci 2024; 25:7260. [PMID: 39000367 PMCID: PMC11242861 DOI: 10.3390/ijms25137260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Revised: 06/22/2024] [Accepted: 06/27/2024] [Indexed: 07/16/2024] Open
Abstract
Homotypic Fusion and Protein Sorting (HOPS) and Class C-core Vacuole/Endosome Tethering (CORVET) complexes regulate the correct fusion of endolysosomal bodies. Mutations in core proteins (VPS11, VPS16, VPS18, and VPS33) have been linked with multiple neurological disorders, including mucopolysaccharidosis (MPS), genetic leukoencephalopathy (gLE), and dystonia. Mutations in human Vacuolar Protein Sorting 16 (VPS16) have been associated with MPS and dystonia. In this study, we generated and characterized a zebrafish vps16(-/-) mutant line using immunohistochemical and behavioral approaches. The loss of Vps16 function caused multiple systemic defects, hypomyelination, and increased neuronal cell death. Behavioral analysis showed a progressive loss of visuomotor response and reduced motor response and habituation to acoustic/tap stimuli in mutants. Finally, using a novel multiple-round acoustic/tap stimuli test, mutants showed intermediate memory deficits. Together, these data demonstrate that zebrafish vps16(-/-) mutants show systemic defects, neurological and motor system pathologies, and cognitive impairment. This is the first study to report behavior abnormalities and memory deficiencies in a zebrafish vps16(-/-) mutant line. Finally, we conclude that the deficits observed in vps16(-/-) zebrafish mutants do not mimic pathologies associated with dystonia, but more align to abnormalities associated with MPS and gLE.
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Affiliation(s)
- Shreya Banerjee
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Shivani Bongu
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Sydney P Hughes
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Emma K Gaboury
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Chelsea E Carver
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Xixia Luo
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Denise A Bessert
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Ryan Thummel
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48201, USA
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3
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Laczkó-Dobos H, Bhattacharjee A, Maddali AK, Kincses A, Abuammar H, Sebők-Nagy K, Páli T, Dér A, Hegedűs T, Csordás G, Juhász G. PtdIns4P is required for the autophagosomal recruitment of STX17 (syntaxin 17) to promote lysosomal fusion. Autophagy 2024; 20:1639-1650. [PMID: 38411137 PMCID: PMC11210929 DOI: 10.1080/15548627.2024.2322493] [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: 08/31/2023] [Accepted: 02/20/2024] [Indexed: 02/28/2024] Open
Abstract
The autophagosomal SNARE STX17 (syntaxin 17) promotes lysosomal fusion and degradation, but its autophagosomal recruitment is incompletely understood. Notably, PtdIns4P is generated on autophagosomes and promotes fusion through an unknown mechanism. Here we show that soluble recombinant STX17 is spontaneously recruited to negatively charged liposomes and adding PtdIns4P to liposomes containing neutral lipids is sufficient for its recruitment. Consistently, STX17 colocalizes with PtdIns4P-positive autophagosomes in cells, and specific inhibition of PtdIns4P synthesis on autophagosomes prevents its loading. Molecular dynamics simulations indicate that C-terminal positively charged amino acids establish contact with membrane bilayers containing negatively charged PtdIns4P. Accordingly, Ala substitution of Lys and Arg residues in the C terminus of STX17 abolishes membrane binding and impairs its autophagosomal recruitment. Finally, only wild type but not Ala substituted STX17 expression rescues the autophagosome-lysosome fusion defect of STX17 loss-of-function cells. We thus identify a key step of autophagosome maturation that promotes lysosomal fusion.Abbreviations: Cardiolipin: 1',3'-bis[1-palmitoyl-2-oleoyl-sn-glycero-3-phospho]-glycerol; DMSO: dimethyl sulfoxide; GST: glutathione S-transferase; GUV: giant unilamellar vesicles; LAMP1: lysosomal associated membrane protein 1; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; PA: 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphate; PC/POPC: 1-palmitoyl-2-oleoyl-glycero-3-phosphocholine; PG: 1-palmitoyl-2-linoleoyl-sn-glycero-3-phospho-(1'-rac-glycerol); PI: L-α-phosphatidylinositol; PI4K2A: phosphatidylinositol 4-kinase type 2 alpha; PIK3C3/VPS34: phosphatidylinositol 3-kinase catalytic subunit type 3; POPE/PE: 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine; PS: 1-stearoyl-2-linoleoyl-sn-glycero-3-phospho-L-serine; PtdIns(3,5)P2: 1,2-dioleoyl-sn-glycero-3-phospho-(1"-myo-inositol-3',5'-bisphosphate); PtdIns3P: 1,2- dioleoyl-sn-glycero-3-phospho-(1'-myo-inositol-3'-phosphate); PtdIns4P: 1,2-dioleoyl-sn-glycero-3-phospho-(1"-myo-inositol-4'-phosphate); SDS-PAGE: sodium dodecyl sulfate-polyacrylamide gel electrophoresis; STX17: syntaxin 17.
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Affiliation(s)
| | | | - Asha Kiran Maddali
- Institute of Genetics, HUN-REN Biological Research Centre Szeged, Szeged, Hungary
- Doctoral School of Biology, University of Szeged, Szeged, Hungary
| | - András Kincses
- Institute of Biophysics, HUN-REN Biological Research Centre Szeged, Szeged, Hungary
| | - Hussein Abuammar
- Institute of Genetics, HUN-REN Biological Research Centre Szeged, Szeged, Hungary
- Doctoral School of Biology, University of Szeged, Szeged, Hungary
| | - Krisztina Sebők-Nagy
- Institute of Biophysics, HUN-REN Biological Research Centre Szeged, Szeged, Hungary
| | - Tibor Páli
- Institute of Biophysics, HUN-REN Biological Research Centre Szeged, Szeged, Hungary
| | - András Dér
- Institute of Biophysics, HUN-REN Biological Research Centre Szeged, Szeged, Hungary
| | - Tamás Hegedűs
- Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
- HUN-REN Biophysical Virology Research Group, Budapest, Hungary
| | - Gábor Csordás
- Institute of Genetics, HUN-REN Biological Research Centre Szeged, Szeged, Hungary
| | - Gábor Juhász
- Institute of Genetics, HUN-REN Biological Research Centre Szeged, Szeged, Hungary
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
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4
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Davis GH, Zaya A, Pearce MMP. Impairment of the Glial Phagolysosomal System Drives Prion-Like Propagation in a Drosophila Model of Huntington's Disease. J Neurosci 2024; 44:e1256232024. [PMID: 38589228 PMCID: PMC11097281 DOI: 10.1523/jneurosci.1256-23.2024] [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: 07/06/2023] [Revised: 01/31/2024] [Accepted: 02/26/2024] [Indexed: 04/10/2024] Open
Abstract
Protein misfolding, aggregation, and spread through the brain are primary drivers of neurodegenerative disease pathogenesis. Phagocytic glia are responsible for regulating the load of pathological proteins in the brain, but emerging evidence suggests that glia may also act as vectors for aggregate spread. Accumulation of protein aggregates could compromise the ability of glia to eliminate toxic materials from the brain by disrupting efficient degradation in the phagolysosomal system. A better understanding of phagocytic glial cell deficiencies in the disease state could help to identify novel therapeutic targets for multiple neurological disorders. Here, we report that mutant huntingtin (mHTT) aggregates impair glial responsiveness to injury and capacity to degrade neuronal debris in male and female adult Drosophila expressing the gene that causes Huntington's disease (HD). mHTT aggregate formation in neurons impairs engulfment and clearance of injured axons and causes accumulation of phagolysosomes in glia. Neuronal mHTT expression induces upregulation of key innate immunity and phagocytic genes, some of which were found to regulate mHTT aggregate burden in the brain. A forward genetic screen revealed Rab10 as a novel component of Draper-dependent phagocytosis that regulates mHTT aggregate transmission from neurons to glia. These data suggest that glial phagocytic defects enable engulfed mHTT aggregates to evade lysosomal degradation and acquire prion-like characteristics. Together, our findings uncover new mechanisms that enhance our understanding of the beneficial and harmful effects of phagocytic glia in HD and other neurodegenerative diseases.
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Affiliation(s)
- Graham H Davis
- Department of Biological and Biomedical Sciences, Rowan University, Glassboro, New Jersey 08028
- Department of Biology, Saint Joseph's University, Philadelphia, Pennsylvania 19131
- Department of Biological Sciences, University of the Sciences, Philadelphia, Pennsylvania 19104
| | - Aprem Zaya
- Department of Biological Sciences, University of the Sciences, Philadelphia, Pennsylvania 19104
| | - Margaret M Panning Pearce
- Department of Biological and Biomedical Sciences, Rowan University, Glassboro, New Jersey 08028
- Department of Biology, Saint Joseph's University, Philadelphia, Pennsylvania 19131
- Department of Biological Sciences, University of the Sciences, Philadelphia, Pennsylvania 19104
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5
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Muñoz-Oreja M, Sandoval A, Bruland O, Perez-Rodriguez D, Fernandez-Pelayo U, de Arbina AL, Villar-Fernandez M, Hernández-Eguiazu H, Hernández I, Park Y, Goicoechea L, Pascual-Frías N, Garcia-Ruiz C, Fernandez-Checa J, Martí-Carrera I, Gil-Bea FJ, Hasan MT, Gegg ME, Bredrup C, Knappskog PM, Gereñu-Lopetegui G, Varhaug KN, Bindoff LA, Spinazzola A, Yoon WH, Holt IJ. Elevated cholesterol in ATAD3 mutants is a compensatory mechanism that leads to membrane cholesterol aggregation. Brain 2024; 147:1899-1913. [PMID: 38242545 PMCID: PMC11068212 DOI: 10.1093/brain/awae018] [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: 07/20/2023] [Revised: 10/29/2023] [Accepted: 12/16/2023] [Indexed: 01/21/2024] Open
Abstract
Aberrant cholesterol metabolism causes neurological disease and neurodegeneration, and mitochondria have been linked to perturbed cholesterol homeostasis via the study of pathological mutations in the ATAD3 gene cluster. However, whether the cholesterol changes were compensatory or contributory to the disorder was unclear, and the effects on cell membranes and the wider cell were also unknown. Using patient-derived cells, we show that cholesterol perturbation is a conserved feature of pathological ATAD3 variants that is accompanied by an expanded lysosome population containing membrane whorls characteristic of lysosomal storage diseases. Lysosomes are also more numerous in Drosophila neural progenitor cells expressing mutant Atad3, which exhibit abundant membrane-bound cholesterol aggregates, many of which co-localize with lysosomes. By subjecting the Drosophila Atad3 mutant to nutrient restriction and cholesterol supplementation, we show that the mutant displays heightened cholesterol dependence. Collectively, these findings suggest that elevated cholesterol enhances tolerance to pathological ATAD3 variants; however, this comes at the cost of inducing cholesterol aggregation in membranes, which lysosomal clearance only partly mitigates.
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Affiliation(s)
- Mikel Muñoz-Oreja
- Department of Neurosciences, Biogipuzkoa Health Research Institute, 20014 San Sebastian, Spain
- University of the Basque Country—Bizkaia Campus, 48940 Bilbao, Spain
- CIBERNED (Center for Networked Biomedical Research on Neurodegenerative Diseases, Ministry of Economy and Competitiveness, Institute Carlos III), 28031 Madrid, Spain
| | - Abigail Sandoval
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
| | - Ove Bruland
- Department of Medical Genetics, Haukeland University Hospital, Bergen 5021, Norway
| | - Diego Perez-Rodriguez
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Royal Free Campus, London NW3 2PF, UK
| | - Uxoa Fernandez-Pelayo
- Department of Neurosciences, Biogipuzkoa Health Research Institute, 20014 San Sebastian, Spain
| | - Amaia Lopez de Arbina
- Department of Neurosciences, Biogipuzkoa Health Research Institute, 20014 San Sebastian, Spain
| | - Marina Villar-Fernandez
- Department of Neurosciences, Biogipuzkoa Health Research Institute, 20014 San Sebastian, Spain
| | | | - Ixiar Hernández
- University of the Basque Country—Bizkaia Campus, 48940 Bilbao, Spain
| | - Yohan Park
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
| | - Leire Goicoechea
- Department of Cell Death and Proliferation, Institute of Biomedical Research of Barcelona (IIBB), CSIC, 08036 Barcelona, Spain
- Liver Unit, Hospital Clinic i Provincial de Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain
- Centro de Investigación Biomédica en Red (CIBEREHD), 08036 Barcelona, Spain
| | - Nerea Pascual-Frías
- Department of Neurosciences, Biogipuzkoa Health Research Institute, 20014 San Sebastian, Spain
- Center for Cooperative Research in Biomaterials (CIC BiomaGUNE), Basque Research and Technology Alliance (BRTA), 20014 San Sebastian, Spain
| | - Carmen Garcia-Ruiz
- Department of Cell Death and Proliferation, Institute of Biomedical Research of Barcelona (IIBB), CSIC, 08036 Barcelona, Spain
- Liver Unit, Hospital Clinic i Provincial de Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain
- Centro de Investigación Biomédica en Red (CIBEREHD), 08036 Barcelona, Spain
| | - Jose Fernandez-Checa
- Department of Cell Death and Proliferation, Institute of Biomedical Research of Barcelona (IIBB), CSIC, 08036 Barcelona, Spain
- Liver Unit, Hospital Clinic i Provincial de Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain
- Centro de Investigación Biomédica en Red (CIBEREHD), 08036 Barcelona, Spain
- Research Center for ALPD, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Itxaso Martí-Carrera
- Department of Neurosciences, Biogipuzkoa Health Research Institute, 20014 San Sebastian, Spain
- University of the Basque Country—Bizkaia Campus, 48940 Bilbao, Spain
- CIBERNED (Center for Networked Biomedical Research on Neurodegenerative Diseases, Ministry of Economy and Competitiveness, Institute Carlos III), 28031 Madrid, Spain
- Pediatric Neurology, Hospital Universitario Donostia, 20014 San Sebastián, Spain
| | | | - Mazahir T Hasan
- Laboratory of Brain Circuits Therapeutics, Achucarro Basque Center for Neuroscience, Barrio Sarriena, s/n, E-48940 Leioa, Spain
- IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain
| | - Matthew E Gegg
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Royal Free Campus, London NW3 2PF, UK
| | - Cecilie Bredrup
- Department of Ophthalmology, Haukeland University Hospital, Bergen 5021, Norway
- Department of Clinical Medicine (K1), University of Bergen, Bergen 5020, Norway
| | | | - Gorka Gereñu-Lopetegui
- Department of Neurosciences, Biogipuzkoa Health Research Institute, 20014 San Sebastian, Spain
- University of the Basque Country—Bizkaia Campus, 48940 Bilbao, Spain
- CIBERNED (Center for Networked Biomedical Research on Neurodegenerative Diseases, Ministry of Economy and Competitiveness, Institute Carlos III), 28031 Madrid, Spain
- IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain
| | - Kristin N Varhaug
- Department of Clinical Medicine (K1), University of Bergen, Bergen 5020, Norway
- Department of Neurology, Haukeland University Hospital, Bergen 5021, Norway
| | - Laurence A Bindoff
- Department of Ophthalmology, Haukeland University Hospital, Bergen 5021, Norway
- Department of Clinical Medicine (K1), University of Bergen, Bergen 5020, Norway
- Department of Neurology, Haukeland University Hospital, Bergen 5021, Norway
| | - Antonella Spinazzola
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Royal Free Campus, London NW3 2PF, UK
| | - Wan Hee Yoon
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
| | - Ian J Holt
- Department of Neurosciences, Biogipuzkoa Health Research Institute, 20014 San Sebastian, Spain
- University of the Basque Country—Bizkaia Campus, 48940 Bilbao, Spain
- CIBERNED (Center for Networked Biomedical Research on Neurodegenerative Diseases, Ministry of Economy and Competitiveness, Institute Carlos III), 28031 Madrid, Spain
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Royal Free Campus, London NW3 2PF, UK
- IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain
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6
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Yi S, Wang L, Ho MS, Zhang S. The autophagy protein Atg9 functions in glia and contributes to parkinsonian symptoms in a Drosophila model of Parkinson's disease. Neural Regen Res 2024; 19:1150-1155. [PMID: 37862221 PMCID: PMC10749615 DOI: 10.4103/1673-5374.382259] [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: 03/08/2023] [Revised: 05/31/2023] [Accepted: 07/10/2023] [Indexed: 10/22/2023] Open
Abstract
Parkinson's disease is a progressive neurodegenerative disease characterized by motor deficits, dopaminergic neuron loss, and brain accumulation of α-synuclein aggregates called Lewy bodies. Dysfunction in protein degradation pathways, such as autophagy, has been demonstrated in neurons as a critical mechanism for eliminating protein aggregates in Parkinson's disease. However, it is less well understood how protein aggregates are eliminated in glia, the other cell type in the brain. In the present study, we show that autophagy-related gene 9 (Atg9), the only transmembrane protein in the autophagy machinery, is highly expressed in Drosophila glia from adult brain. Results from immunostaining and live cell imaging analysis reveal that a portion of Atg9 localizes to the trans-Golgi network, autophagosomes, and lysosomes in glia. Atg9 is persistently in contact with these organelles. Lacking glial atg9 reduces the number of omegasomes and autophagosomes, and impairs autophagic substrate degradation. This suggests that glial Atg9 participates in the early steps of autophagy, and hence the control of autophagic degradation. Importantly, loss of glial atg9 induces parkinsonian symptoms in Drosophila including progressive loss of dopaminergic neurons, locomotion deficits, and glial activation. Our findings identify a functional role of Atg9 in glial autophagy and establish a potential link between glial autophagy and Parkinson's disease. These results may provide new insights on the underlying mechanism of Parkinson's disease.
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Affiliation(s)
- Shuanglong Yi
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Linfang Wang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Margaret S. Ho
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Shiping Zhang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
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7
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Zhang P, Catterson JH, Grönke S, Partridge L. Inhibition of S6K lowers age-related inflammation and increases lifespan through the endolysosomal system. NATURE AGING 2024; 4:491-509. [PMID: 38413780 PMCID: PMC11031405 DOI: 10.1038/s43587-024-00578-3] [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: 09/09/2022] [Accepted: 01/24/2024] [Indexed: 02/29/2024]
Abstract
Suppression of target of rapamycin complex 1 (TORC1) by rapamycin ameliorates aging in diverse species. S6 kinase (S6K) is an essential mediator, but the mechanisms involved are unclear. Here we show that activation of S6K specifically in Drosophila fat-body blocked extension of lifespan by rapamycin, induced accumulation of multilamellar lysosomes and blocked age-associated hyperactivation of the NF-κB-like immune deficiency (IMD) pathway, indicative of reduced inflammaging. Syntaxin 13 mediated the effects of TORC1-S6K signaling on lysosome morphology and inflammaging, suggesting they may be linked. Inflammaging depended on the IMD receptor regulatory isoform PGRP-LC, and repression of the IMD pathway from midlife extended lifespan. Age-related inflammaging was higher in females than in males and was not lowered in males by rapamycin treatment or lowered S6K. Rapamycin treatment also elevated Syntaxin 12/13 levels in mouse liver and prevented age-related increase in noncanonical NF-κB signaling, suggesting that the effect of TORC1 on inflammaging is conserved from flies to mammals.
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Affiliation(s)
- Pingze Zhang
- Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - James H Catterson
- Institute of Healthy Ageing, Department of Genetics, Evolution and Environment, University College London, London, UK
- Centre for Discovery Brain Sciences, UK Dementia Research Institute, University of Edinburgh, Edinburgh, UK
| | | | - Linda Partridge
- Max Planck Institute for Biology of Ageing, Cologne, Germany.
- Institute of Healthy Ageing, Department of Genetics, Evolution and Environment, University College London, London, UK.
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8
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Clémot M, D’Alterio C, Kwang AC, Jones DL. mTORC1 is required for differentiation of germline stem cells in the Drosophila melanogaster testis. PLoS One 2024; 19:e0300337. [PMID: 38512882 PMCID: PMC10956854 DOI: 10.1371/journal.pone.0300337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 02/26/2024] [Indexed: 03/23/2024] Open
Abstract
Metabolism participates in the control of stem cell function and subsequent maintenance of tissue homeostasis. How this is achieved in the context of adult stem cell niches in coordination with other local and intrinsic signaling cues is not completely understood. The Target of Rapamycin (TOR) pathway is a master regulator of metabolism and plays essential roles in stem cell maintenance and differentiation. In the Drosophila male germline, mTORC1 is active in germline stem cells (GSCs) and early germ cells. Targeted RNAi-mediated downregulation of mTor in early germ cells causes a block and/or a delay in differentiation, resulting in an accumulation of germ cells with GSC-like features. These early germ cells also contain unusually large and dysfunctional autolysosomes. In addition, downregulation of mTor in adult male GSCs and early germ cells causes non-autonomous activation of mTORC1 in neighboring cyst cells, which correlates with a disruption in the coordination of germline and somatic differentiation. Our study identifies a previously uncharacterized role of the TOR pathway in regulating male germline differentiation.
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Affiliation(s)
- Marie Clémot
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA, United States of America
- Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, CA, United States of America
| | - Cecilia D’Alterio
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA, United States of America
| | - Alexa C. Kwang
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA, United States of America
| | - D. Leanne Jones
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA, United States of America
- Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, CA, United States of America
- Departments of Anatomy, Division of Geriatrics, University of California, San Francisco, San Francisco, CA, United States of America
- Departments of Medicine, Division of Geriatrics, University of California, San Francisco, San Francisco, CA, United States of America
- Eli and Edythe Broad Center for Regeneration Medicine, University of California, San Francisco, San Francisco, CA, United States of America
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9
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Hewson L, Choo A, Webber DL, Trim PJ, Snel MF, Fedele AO, Hopwood JJ, Hemsley KM, O'Keefe LV. Drosophila melanogaster models of MPS IIIC (Hgsnat-deficiency) highlight the role of glia in disease presentation. J Inherit Metab Dis 2024; 47:340-354. [PMID: 38238109 DOI: 10.1002/jimd.12712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 12/18/2023] [Accepted: 12/21/2023] [Indexed: 03/16/2024]
Abstract
Sanfilippo syndrome (Mucopolysaccharidosis type III or MPS III) is a recessively inherited neurodegenerative lysosomal storage disorder. Mutations in genes encoding enzymes in the heparan sulphate degradation pathway lead to the accumulation of partially degraded heparan sulphate, resulting ultimately in the development of neurological deficits. Mutations in the gene encoding the membrane protein heparan-α-glucosaminide N-acetyltransferase (HGSNAT; EC2.3.1.78) cause MPS IIIC (OMIM#252930), typified by impaired cognition, sleep-wake cycle changes, hyperactivity and early death, often before adulthood. The precise disease mechanism that causes symptom emergence remains unknown, posing a significant challenge in the development of effective therapeutics. As HGSNAT is conserved in Drosophila melanogaster, we now describe the creation and characterisation of the first Drosophila models of MPS IIIC. Flies with either an endogenous insertion mutation or RNAi-mediated knockdown of hgsnat were confirmed to have a reduced level of HGSNAT transcripts and age-dependent accumulation of heparan sulphate leading to engorgement of the endo/lysosomal compartment. This resulted in abnormalities at the pre-synapse, defective climbing and reduced overall activity. Altered circadian rhythms (shift in peak morning activity) were seen in hgsnat neuronal knockdown lines. Further, when hgsnat was knocked down in specific glial subsets (wrapping, cortical, astrocytes or subperineural glia), impaired climbing or reduced activity was noted, implying that hgsnat function in these specific glial subtypes contributes significantly to this behaviour and targeting treatments to these cell groups may be necessary to ameliorate or prevent symptom onset. These novel models of MPS IIIC provide critical research tools for delineating the key cellular pathways causal in the onset of neurodegeneration in this presently untreatable disorder.
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Affiliation(s)
- Laura Hewson
- Department of Molecular and Biomedical Science, School of Biological Sciences, The University of Adelaide, Adelaide, South Australia, Australia
| | - Amanda Choo
- Department of Molecular and Biomedical Science, School of Biological Sciences, The University of Adelaide, Adelaide, South Australia, Australia
| | - Dani L Webber
- Department of Molecular and Biomedical Science, School of Biological Sciences, The University of Adelaide, Adelaide, South Australia, Australia
| | - Paul J Trim
- Proteomics, Metabolomics & MS-Imaging Core, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
| | - Marten F Snel
- Proteomics, Metabolomics & MS-Imaging Core, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
| | - Anthony O Fedele
- Hopwood Centre for Neurobiology, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
| | - John J Hopwood
- Hopwood Centre for Neurobiology, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
| | - Kim M Hemsley
- Childhood Dementia Research Group, Flinders Health and Medical Research Institute, Flinders University, Bedford Park, South Australia, Australia
| | - Louise V O'Keefe
- Department of Molecular and Biomedical Science, School of Biological Sciences, The University of Adelaide, Adelaide, South Australia, Australia
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10
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Li K, Guo Y, Wang Y, Zhu R, Chen W, Cheng T, Zhang X, Jia Y, Liu T, Zhang W, Jan LY, Jan YN. Drosophila TMEM63 and mouse TMEM63A are lysosomal mechanosensory ion channels. Nat Cell Biol 2024; 26:393-403. [PMID: 38388853 PMCID: PMC10940159 DOI: 10.1038/s41556-024-01353-7] [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: 04/13/2023] [Accepted: 01/10/2024] [Indexed: 02/24/2024]
Abstract
Cells sense physical forces and convert them into electrical or chemical signals, a process known as mechanotransduction. Whereas extensive studies focus on mechanotransduction at the plasma membrane, little is known about whether and how intracellular organelles sense mechanical force and the physiological functions of organellar mechanosensing. Here we identify the Drosophila TMEM63 (DmTMEM63) ion channel as an intrinsic mechanosensor of the lysosome, a major degradative organelle. Endogenous DmTMEM63 proteins localize to lysosomes, mediate lysosomal mechanosensitivity and modulate lysosomal morphology and function. Tmem63 mutant flies exhibit impaired lysosomal degradation, synaptic loss, progressive motor deficits and early death, with some of these mutant phenotypes recapitulating symptoms of TMEM63-associated human diseases. Importantly, mouse TMEM63A mediates lysosomal mechanosensitivity in Neuro-2a cells, indicative of functional conservation in mammals. Our findings reveal DmTMEM63 channel function in lysosomes and its physiological roles in vivo and provide a molecular basis to explore the mechanosensitive process in subcellular organelles.
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Affiliation(s)
- Kai Li
- Department of Physiology, University of California at San Francisco, San Francisco, CA, USA
- Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, CA, USA
| | - Yanmeng Guo
- Department of Physiology, University of California at San Francisco, San Francisco, CA, USA
- Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, CA, USA
| | - Yayu Wang
- Department of Physiology, University of California at San Francisco, San Francisco, CA, USA
- Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, CA, USA
| | - Ruijun Zhu
- Department of Physiology, University of California at San Francisco, San Francisco, CA, USA
- Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, CA, USA
| | - Wei Chen
- Department of Physiology, University of California at San Francisco, San Francisco, CA, USA
- Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, CA, USA
| | - Tong Cheng
- Department of Physiology, University of California at San Francisco, San Francisco, CA, USA
- Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, CA, USA
| | - Xiaofan Zhang
- Department of Physiology, University of California at San Francisco, San Francisco, CA, USA
- Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, CA, USA
| | - Yinjun Jia
- School of Life Sciences, Tsinghua-Peking Center for Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing, China
| | - Ting Liu
- School of Life Sciences, Tsinghua-Peking Center for Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing, China
| | - Wei Zhang
- School of Life Sciences, Tsinghua-Peking Center for Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing, China
| | - Lily Yeh Jan
- Department of Physiology, University of California at San Francisco, San Francisco, CA, USA
- Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, CA, USA
| | - Yuh Nung Jan
- Department of Physiology, University of California at San Francisco, San Francisco, CA, USA.
- Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, CA, USA.
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11
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Davis GH, Zaya A, Pearce MMP. Impairment of the glial phagolysosomal system drives prion-like propagation in a Drosophila model of Huntington's disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.10.04.560952. [PMID: 38370619 PMCID: PMC10871239 DOI: 10.1101/2023.10.04.560952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Protein misfolding, aggregation, and spread through the brain are primary drivers of neurodegenerative diseases pathogenesis. Phagocytic glia are responsible for regulating the load of pathogenic protein aggregates in the brain, but emerging evidence suggests that glia may also act as vectors for aggregate spread. Accumulation of protein aggregates could compromise the ability of glia to eliminate toxic materials from the brain by disrupting efficient degradation in the phagolysosomal system. A better understanding of phagocytic glial cell deficiencies in the disease state could help to identify novel therapeutic targets for multiple neurological disorders. Here, we report that mutant huntingtin (mHTT) aggregates impair glial responsiveness to injury and capacity to degrade neuronal debris in male and female adult Drosophila expressing the gene that causes Huntington's disease (HD). mHTT aggregate formation in neurons impairs engulfment and clearance of injured axons and causes accumulation of phagolysosomes in glia. Neuronal mHTT expression induces upregulation of key innate immunity and phagocytic genes, some of which were found to regulate mHTT aggregate burden in the brain. Finally, a forward genetic screen revealed Rab10 as a novel component of Draper-dependent phagocytosis that regulates mHTT aggregate transmission from neurons to glia. These data suggest that glial phagocytic defects enable engulfed mHTT aggregates to evade lysosomal degradation and acquire prion-like characteristics. Together, our findings reveal new mechanisms that enhance our understanding of the beneficial and potentially harmful effects of phagocytic glia in HD and potentially other neurodegenerative diseases.
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Affiliation(s)
- Graham H. Davis
- Rowan University, Department of Biological and Biomedical Sciences, Glassboro, NJ 08028
- Saint Joseph’s University, Department of Biology, Philadelphia, PA 19131
- University of the Sciences, Department of Biological Sciences, Philadelphia, PA 19104
| | - Aprem Zaya
- University of the Sciences, Department of Biological Sciences, Philadelphia, PA 19104
| | - Margaret M. Panning Pearce
- Rowan University, Department of Biological and Biomedical Sciences, Glassboro, NJ 08028
- Saint Joseph’s University, Department of Biology, Philadelphia, PA 19131
- University of the Sciences, Department of Biological Sciences, Philadelphia, PA 19104
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12
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Thomsen M, Lange LM, Zech M, Lohmann K. Genetics and Pathogenesis of Dystonia. ANNUAL REVIEW OF PATHOLOGY 2024; 19:99-131. [PMID: 37738511 DOI: 10.1146/annurev-pathmechdis-051122-110756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/24/2023]
Abstract
Dystonia is a clinically and genetically highly heterogeneous neurological disorder characterized by abnormal movements and postures caused by involuntary sustained or intermittent muscle contractions. A number of groundbreaking genetic and molecular insights have recently been gained. While they enable genetic testing and counseling, their translation into new therapies is still limited. However, we are beginning to understand shared pathophysiological pathways and molecular mechanisms. It has become clear that dystonia results from a dysfunctional network involving the basal ganglia, cerebellum, thalamus, and cortex. On the molecular level, more than a handful of, often intertwined, pathways have been linked to pathogenic variants in dystonia genes, including gene transcription during neurodevelopment (e.g., KMT2B, THAP1), calcium homeostasis (e.g., ANO3, HPCA), striatal dopamine signaling (e.g., GNAL), endoplasmic reticulum stress response (e.g., EIF2AK2, PRKRA, TOR1A), autophagy (e.g., VPS16), and others. Thus, different forms of dystonia can be molecularly grouped, which may facilitate treatment development in the future.
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Affiliation(s)
- Mirja Thomsen
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany;
| | - Lara M Lange
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany;
| | - Michael Zech
- Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany
- Institute of Human Genetics, School of Medicine, Technical University of Munich, Munich, Germany
| | - Katja Lohmann
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany;
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13
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Tsarouhas V, Liu D, Tsikala G, Engström Y, Strigini M, Samakovlis C. A surfactant lipid layer of endosomal membranes facilitates airway gas filling in Drosophila. Curr Biol 2023; 33:5132-5146.e5. [PMID: 37992718 DOI: 10.1016/j.cub.2023.10.058] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 09/14/2023] [Accepted: 10/26/2023] [Indexed: 11/24/2023]
Abstract
The mechanisms underlying the construction of an air-liquid interface in respiratory organs remain elusive. Here, we use live imaging and genetic analysis to describe the morphogenetic events generating an extracellular lipid lining of the Drosophila airways required for their gas filing and animal survival. We show that sequential Rab39/Syx1A/Syt1-mediated secretion of lysosomal acid sphingomyelinase (Drosophila ASM [dASM]) and Rab11/35/Syx1A/Rop-dependent exosomal secretion provides distinct components for lipid film assembly. Tracheal inactivation of Rab11 or Rab35 or loss of Rop results in intracellular accumulation of exosomal, multi-vesicular body (MVB)-derived vesicles. On the other hand, loss of dASM or Rab39 causes luminal bubble-like accumulations of exosomal membranes and liquid retention in the airways. Inactivation of the exosomal secretion in dASM mutants counteracts this phenotype, arguing that the exosomal secretion provides the lipid vesicles and that secreted lysosomal dASM organizes them into a continuous film. Our results reveal the coordinated functions of extracellular vesicle and lysosomal secretions in generating a lipid layer crucial for airway gas filling and survival.
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Affiliation(s)
- Vasilios Tsarouhas
- Stockholm University, Department of Molecular Biosciences, The Wenner-Gren Institute, 10691 Stockholm, Sweden; Science for Life Laboratory, SciLifeLab, 171 65 Stockholm, Sweden.
| | - Dan Liu
- Stockholm University, Department of Molecular Biosciences, The Wenner-Gren Institute, 10691 Stockholm, Sweden
| | - Georgia Tsikala
- Stockholm University, Department of Molecular Biosciences, The Wenner-Gren Institute, 10691 Stockholm, Sweden; IMBB, 70013 Heraklion, Crete, Greece
| | - Ylva Engström
- Stockholm University, Department of Molecular Biosciences, The Wenner-Gren Institute, 10691 Stockholm, Sweden
| | | | - Christos Samakovlis
- Stockholm University, Department of Molecular Biosciences, The Wenner-Gren Institute, 10691 Stockholm, Sweden; Science for Life Laboratory, SciLifeLab, 171 65 Stockholm, Sweden; ECCPS, Justus Liebig University of Giessen, 35390 Giessen, Germany.
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14
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Thakur RS, O’Connor-Giles KM. PDZD8 promotes autophagy at ER-Lysosome contact sites to regulate synaptogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.30.564828. [PMID: 37961523 PMCID: PMC10634952 DOI: 10.1101/2023.10.30.564828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Building synaptic connections, which are often far from the soma, requires coordinating a host of cellular activities from transcription to protein turnover, placing a high demand on intracellular communication. Membrane contact sites (MCSs) formed between cellular organelles have emerged as key signaling hubs for coordinating an array of cellular activities. We have found that the endoplasmic reticulum (ER) MCS tethering protein PDZD8 is required for activity-dependent synaptogenesis. PDZD8 is sufficient to drive ectopic synaptic bouton formation through an autophagy-dependent mechanism and required for basal synapse formation when autophagy biogenesis is limited. PDZD8 functions at ER-late endosome/lysosome (LEL) MCSs to promote lysosome maturation and accelerate autophagic flux. Mutational analysis of PDZD8's SMP domain further suggests a role for lipid transfer at ER-LEL MCSs. We propose that PDZD8-dependent lipid transfer from ER to LELs promotes lysosome maturation to increase autophagic flux during periods of high demand, including activity-dependent synapse formation.
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Affiliation(s)
- Rajan S. Thakur
- Department of Neuroscience, Brown University, Providence, RI
| | - Kate M. O’Connor-Giles
- Department of Neuroscience, Brown University, Providence, RI
- Carney Institute for Brain Science, Providence, RI
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15
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Neophytou C, Soteriou E, Pitsouli C. The Sterol Transporter Npc2c Controls Intestinal Stem Cell Mitosis and Host-Microbiome Interactions in Drosophila. Metabolites 2023; 13:1084. [PMID: 37887409 PMCID: PMC10609107 DOI: 10.3390/metabo13101084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 10/05/2023] [Accepted: 10/12/2023] [Indexed: 10/28/2023] Open
Abstract
Cholesterol is necessary for all cells to function. The intracellular cholesterol transporters Npc1 and Npc2 control sterol trafficking and their malfunction leads to Neimann-Pick Type C disease, a rare disorder affecting the nervous system and the intestine. Unlike humans that encode single Npc1 and Npc2 transporters, flies encompass two Npc1 (Npc1a-1b) and eight Npc2 (Npc2a-2h) members, and most of the Npc2 family genes remain unexplored. Here, we focus on the intestinal function of Npc2c in the adult. We find that Npc2c is necessary for intestinal stem cell (ISC) mitosis, maintenance of the ISC lineage, survival upon pathogenic infection, as well as tumor growth. Impaired mitosis of Npc2c-silenced midguts is accompanied by reduced expression of Cyclin genes, and genes encoding ISC regulators, such as Delta, unpaired1 and Socs36E. ISC-specific Npc2c silencing induces Attacin-A expression, a phenotype reminiscent of Gram-negative bacteria overabundance. Metagenomic analysis of Npc2c-depleted midguts indicates intestinal dysbiosis, whereby decreased commensal complexity is accompanied by increased gamma-proteobacteria. ISC-specific Npc2c silencing also results in increased cholesterol aggregation. Interestingly, administration of the non-steroidal ecdysone receptor agonist, RH5849, rescues mitosis of Npc2c-silenced midguts and increases expression of the ecdysone response gene Broad, underscoring the role of Npc2c and sterols in ecdysone signaling. Assessment of additional Npc2 family members indicates potential redundant roles with Npc2c in ISC control and response to ecdysone signaling. Our results highlight a previously unidentified essential role of Npc2c in ISC mitosis, as well as an important role in ecdysone signaling and microbiome composition in the Drosophila midgut.
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Affiliation(s)
| | | | - Chrysoula Pitsouli
- Department of Biological Sciences, University of Cyprus, 1 University Avenue, 2109 Aglantzia, Cyprus; (C.N.); (E.S.)
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16
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Hossain MS, Yao A, Qiao X, Shi W, Xie T, Chen C, Zhang YQ. Gbb glutathionylation promotes its proteasome-mediated degradation to inhibit synapse growth. J Cell Biol 2023; 222:e202202068. [PMID: 37389657 PMCID: PMC10316630 DOI: 10.1083/jcb.202202068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 04/20/2023] [Accepted: 06/13/2023] [Indexed: 07/01/2023] Open
Abstract
Glutathionylation is a posttranslational modification involved in various molecular and cellular processes. However, it remains unknown whether and how glutathionylation regulates nervous system development. To identify critical regulators of synapse growth and development, we performed an RNAi screen and found that postsynaptic knockdown of glutathione transferase omega 1 (GstO1) caused significantly more synaptic boutons at the Drosophila neuromuscular junctions. Genetic and biochemical analysis revealed an increased level of glass boat bottom (Gbb), the Drosophila homolog of mammalian bone morphogenetic protein (BMP), in GstO1 mutants. Further experiments showed that GstO1 is a critical regulator of Gbb glutathionylation at cysteines 354 and 420, which promoted its degradation via the proteasome pathway. Moreover, the E3 ligase Ctrip negatively regulated the Gbb protein level by preferentially binding to glutathionylated Gbb. These results unveil a novel regulatory mechanism in which glutathionylation of Gbb facilitates its ubiquitin-mediated degradation. Taken together, our findings shed new light on the crosstalk between glutathionylation and ubiquitination of Gbb in synapse development.
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Affiliation(s)
- Md Shafayat Hossain
- Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Aiyu Yao
- Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Xinhua Qiao
- Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Wenwen Shi
- Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Ting Xie
- Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Chang Chen
- Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yong Q. Zhang
- Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
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17
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Demir E, Kacew S. Drosophila as a Robust Model System for Assessing Autophagy: A Review. TOXICS 2023; 11:682. [PMID: 37624187 PMCID: PMC10458868 DOI: 10.3390/toxics11080682] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 08/07/2023] [Accepted: 08/07/2023] [Indexed: 08/26/2023]
Abstract
Autophagy is the process through which a body breaks down and recycles its own cellular components, primarily inside lysosomes. It is a cellular response to starvation and stress, which plays decisive roles in various biological processes such as senescence, apoptosis, carcinoma, and immune response. Autophagy, which was first discovered as a survival mechanism during starvation in yeast, is now known to serve a wide range of functions in more advanced organisms. It plays a vital role in how cells respond to stress, starvation, and infection. While research on yeast has led to the identification of many key components of the autophagy process, more research into autophagy in more complex systems is still warranted. This review article focuses on the use of the fruit fly Drosophila melanogaster as a robust testing model in further research on autophagy. Drosophila provides an ideal environment for exploring autophagy in a living organism during its development. Additionally, Drosophila is a well-suited compact tool for genetic analysis in that it serves as an intermediate between yeast and mammals because evolution conserved the molecular machinery required for autophagy in this species. Experimental tractability of host-pathogen interactions in Drosophila also affords great convenience in modeling human diseases on analogous structures and tissues.
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Affiliation(s)
- Esref Demir
- Massachusetts General Hospital, Harvard Medical School, Boston, MA 02129, USA
- F.M. Kirby Neurobiology Center, Boston Children’s Hospital, 300 Longwood Avenue, Boston, MA 02115, USA
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
- Medical Laboratory Techniques Program, Department of Medical Services and Techniques, Vocational School of Health Services, Antalya Bilim University, 07190 Antalya, Turkey
| | - Sam Kacew
- R. Samuel McLaughllin Center for Population Health Risk Assessment, Institute of Population Health, University of Ottawa, 1 Stewart (320), Ottawa, ON K1N 6N5, Canada;
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18
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Szabó Á, Vincze V, Chhatre AS, Jipa A, Bognár S, Varga KE, Banik P, Harmatos-Ürmösi A, Neukomm LJ, Juhász G. LC3-associated phagocytosis promotes glial degradation of axon debris after injury in Drosophila models. Nat Commun 2023; 14:3077. [PMID: 37248218 DOI: 10.1038/s41467-023-38755-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 05/09/2023] [Indexed: 05/31/2023] Open
Abstract
Glial engulfment of neuron-derived debris after trauma, during development, and in neurodegenerative diseases supports nervous system functions. However, mechanisms governing the efficiency of debris degradation in glia have remained largely unexplored. Here we show that LC3-associated phagocytosis (LAP), an engulfment pathway assisted by certain autophagy factors, promotes glial phagosome maturation in the Drosophila wing nerve. A LAP-specific subset of autophagy-related genes is required in glia for axon debris clearance, encoding members of the Atg8a (LC3) conjugation system and the Vps34 lipid kinase complex including UVRAG and Rubicon. Phagosomal Rubicon and Atg16 WD40 domain-dependent conjugation of Atg8a mediate proper breakdown of internalized axon fragments, and Rubicon overexpression in glia accelerates debris elimination. Finally, LAP promotes survival following traumatic brain injury. Our results reveal a role of glial LAP in the clearance of neuronal debris in vivo, with potential implications for the recovery of the injured nervous system.
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Affiliation(s)
- Áron Szabó
- Biological Research Center, Institute of Genetics, Eötvös Loránd Research Network (ELKH), Szeged, H-6726, Hungary.
| | - Virág Vincze
- Biological Research Center, Institute of Genetics, Eötvös Loránd Research Network (ELKH), Szeged, H-6726, Hungary
| | - Aishwarya Sanjay Chhatre
- Biological Research Center, Institute of Genetics, Eötvös Loránd Research Network (ELKH), Szeged, H-6726, Hungary
- Doctoral School of Biology, University of Szeged, Szeged, Hungary
| | - András Jipa
- Biological Research Center, Institute of Genetics, Eötvös Loránd Research Network (ELKH), Szeged, H-6726, Hungary
| | - Sarolta Bognár
- Biological Research Center, Institute of Genetics, Eötvös Loránd Research Network (ELKH), Szeged, H-6726, Hungary
| | - Katalin Eszter Varga
- Biological Research Center, Institute of Genetics, Eötvös Loránd Research Network (ELKH), Szeged, H-6726, Hungary
| | - Poulami Banik
- Biological Research Center, Institute of Genetics, Eötvös Loránd Research Network (ELKH), Szeged, H-6726, Hungary
| | - Adél Harmatos-Ürmösi
- Biological Research Center, Institute of Genetics, Eötvös Loránd Research Network (ELKH), Szeged, H-6726, Hungary
| | - Lukas J Neukomm
- Department of Fundamental Neurosciences, University of Lausanne, CH-1005, Lausanne, Switzerland
| | - Gábor Juhász
- Biological Research Center, Institute of Genetics, Eötvös Loránd Research Network (ELKH), Szeged, H-6726, Hungary.
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, H-1117, Hungary.
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19
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Liu RJY, Al-Molieh Y, Chen SZ, Drobac M, Urban D, Chen CH, Yao HHY, Geng RSQ, Li L, Pluthero FG, Benlekbir S, Rubinstein JL, Kahr WHA. The Sec1/Munc18 protein VPS33B forms a uniquely bidirectional complex with VPS16B. J Biol Chem 2023; 299:104718. [PMID: 37062417 DOI: 10.1016/j.jbc.2023.104718] [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: 01/08/2023] [Revised: 03/03/2023] [Accepted: 04/07/2023] [Indexed: 04/18/2023] Open
Abstract
Loss of function variants of VPS33B and VIPAS39 (encoding VPS16B) are causative for arthrogryposis, renal dysfunction and cholestasis (ARC) syndrome, where early lethality of patients indicates that VPS33B and VPS16B play essential cellular roles. VPS33B is a member of the Sec1/Munc18 (SM) protein family, and thus thought to facilitate vesicular fusion via interaction with SNARE complexes, as does its paralog VPS33A in the homotypic fusion and vacuole sorting (HOPS) complex. VPS33B and VPS16B have been shown to associate, but little is known about the composition, structure or function of the VPS33B/VPS16B complex. We show here that human VPS33B/VPS16B is a high molecular weight complex, which we expressed in yeast to obtain material for structural, composition and stability analysis. Circular dichroism data indicate VPS33B/VPS16B has a well-folded α-helical secondary structure, for which size exclusion chromatography-multi angle light scattering revealed a MW of ∼315 kDa. Quantitative immunoblotting indicated the complex has a VPS33B:VPS16B ratio of 2:3. Expression of ARC syndrome-causing VPS33B missense variants showed that L30P disrupts complex formation, but not S243F or H344D. Truncated VPS16B containing amino acids 143-316 was sufficient to form a complex with VPS33B. Small angle X-ray scattering and negative staining electron microscopy revealed a two-lobed shape for VPS33B/VPS16B. Avidin tagging indicated that each lobe contains a VPS33B molecule, and they are oriented in opposite directions. From this we propose a structure for VPS33B/VPS16B that allows the copies of VPS33B at each end to interact with separate SNARE bundles and/or SNAREpins, plus their associated membrane components. Thus our observations reveal the only known potentially bidirectional SM protein complex.
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Affiliation(s)
- Richard J Y Liu
- Department of Biochemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Yusef Al-Molieh
- Department of Biochemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Shao Z Chen
- Department of Biochemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Marko Drobac
- Department of Biochemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Denisa Urban
- Department of Biochemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Chang H Chen
- Department of Biochemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Helen H Y Yao
- Department of Biochemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Ryan S Q Geng
- Department of Biochemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Ling Li
- Cell Biology Program, Research Institute, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - Fred G Pluthero
- Cell Biology Program, Research Institute, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - Samir Benlekbir
- Molecular Medicine Program, Research Institute, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - John L Rubinstein
- Department of Biochemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada; Molecular Medicine Program, Research Institute, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - Walter H A Kahr
- Department of Biochemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada; Cell Biology Program, Research Institute, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada; Division of Haematology/Oncology, Department of Paediatrics, University of Toronto and The Hospital for Sick Children, Toronto, ON, M5G 1X8, Canada.
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20
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Scholl A, Ndoja I, Dhakal N, Morante D, Ivan A, Newman D, Mossington T, Clemans C, Surapaneni S, Powers M, Jiang L. The Osiris family genes function as novel regulators of the tube maturation process in the Drosophila trachea. PLoS Genet 2023; 19:e1010571. [PMID: 36689473 PMCID: PMC9870157 DOI: 10.1371/journal.pgen.1010571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 12/14/2022] [Indexed: 01/24/2023] Open
Abstract
Drosophila trachea is a premier model to study tube morphogenesis. After the formation of continuous tubes, tube maturation follows. Tracheal tube maturation starts with an apical secretion pulse that deposits extracellular matrix components to form a chitin-based apical luminal matrix (aECM). This aECM is then cleared and followed by the maturation of taenidial folds. Finally, air fills the tubes. Meanwhile, the cellular junctions are maintained to ensure tube integrity. Previous research has identified several key components (ER, Golgi, several endosomes) of protein trafficking pathways that regulate the secretion and clearance of aECM, and the maintenance of cellular junctions. The Osiris (Osi) gene family is located at the Triplo-lethal (Tpl) locus on chromosome 3R 83D4-E3 and exhibits dosage sensitivity. Here, we show that three Osi genes (Osi9, Osi15, Osi19), function redundantly to regulate adherens junction (AJ) maintenance, luminal clearance, taenidial fold formation, tube morphology, and air filling during tube maturation. The localization of Osi proteins in endosomes (Rab7-containing late endosomes, Rab11-containing recycling endosomes, Lamp-containing lysosomes) and the reduction of these endosomes in Osi mutants suggest the possible role of Osi genes in tube maturation through endosome-mediated trafficking. We analyzed tube maturation in zygotic rab11 and rab7 mutants, respectively, to determine whether endosome-mediated trafficking is required. Interestingly, similar tube maturation defects were observed in rab11 but not in rab7 mutants, suggesting the involvement of Rab11-mediated trafficking, but not Rab7-mediated trafficking, in this process. To investigate whether Osi genes regulate tube maturation primarily through the maintenance of Rab11-containing endosomes, we overexpressed rab11 in Osi mutant trachea. Surprisingly, no obvious rescue was observed. Thus, increasing endosome numbers is not sufficient to rescue tube maturation defects in Osi mutants. These results suggest that Osi genes regulate other aspects of endosome-mediated trafficking, or regulate an unknown mechanism that converges or acts in parallel with Rab11-mediated trafficking during tube maturation.
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Affiliation(s)
- Aaron Scholl
- Department of Biological Sciences, Oakland University, Rochester, Michigan, United States of America
| | - Istri Ndoja
- Department of Biological Sciences, Oakland University, Rochester, Michigan, United States of America
| | - Niraj Dhakal
- Department of Biological Sciences, Oakland University, Rochester, Michigan, United States of America
| | - Doria Morante
- Department of Biological Sciences, Oakland University, Rochester, Michigan, United States of America
| | - Abigail Ivan
- Department of Biological Sciences, Oakland University, Rochester, Michigan, United States of America
| | - Darren Newman
- Department of Biological Sciences, Oakland University, Rochester, Michigan, United States of America
| | - Thomas Mossington
- Department of Biological Sciences, Oakland University, Rochester, Michigan, United States of America
| | - Christian Clemans
- Department of Biological Sciences, Oakland University, Rochester, Michigan, United States of America
| | - Sruthi Surapaneni
- Department of Biological Sciences, Oakland University, Rochester, Michigan, United States of America
| | - Michael Powers
- Department of Biological Sciences, Oakland University, Rochester, Michigan, United States of America
| | - Lan Jiang
- Department of Biological Sciences, Oakland University, Rochester, Michigan, United States of America
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21
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Boda A, Varga LP, Nagy A, Szenci G, Csizmadia T, Lőrincz P, Juhász G. Rab26 controls secretory granule maturation and breakdown in Drosophila. Cell Mol Life Sci 2023; 80:24. [PMID: 36600084 PMCID: PMC9813115 DOI: 10.1007/s00018-022-04674-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 11/29/2022] [Accepted: 12/13/2022] [Indexed: 01/06/2023]
Abstract
At the onset of Drosophila metamorphosis, plenty of secretory glue granules are released from salivary gland cells and the glue is deposited on the ventral side of the forming (pre)pupa to attach it to a dry surface. Prior to this, a poorly understood maturation process takes place during which secretory granules gradually grow via homotypic fusions, and their contents are reorganized. Here we show that the small GTPase Rab26 localizes to immature (smaller, non-acidic) glue granules and its presence prevents vesicle acidification. Rab26 mutation accelerates the maturation, acidification and release of these secretory vesicles as well as the lysosomal breakdown (crinophagy) of residual, non-released glue granules. Strikingly, loss of Mon1, an activator of the late endosomal and lysosomal fusion factor Rab7, results in Rab26 remaining associated even with the large glue granules and a concomitant defect in glue release, similar to the effects of Rab26 overexpression. Our data thus identify Rab26 as a key regulator of secretory vesicle maturation that promotes early steps (vesicle growth) and inhibits later steps (lysosomal transport, acidification, content reorganization, release, and breakdown), which is counteracted by Mon1.
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Affiliation(s)
- Attila Boda
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Luca Petra Varga
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Anikó Nagy
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Győző Szenci
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Tamás Csizmadia
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Péter Lőrincz
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Gábor Juhász
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary.
- Institute of Genetics, Biological Research Centre, Szeged, Hungary.
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22
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Milosavljevic J, Lempicki C, Lang K, Heinkele H, Kampf LL, Leroy C, Chen M, Gerstner L, Spitz D, Wang M, Knob AU, Kayser S, Helmstädter M, Walz G, Pollak MR, Hermle T. Nephrotic Syndrome Gene TBC1D8B Is Required for Endosomal Maturation and Nephrin Endocytosis in Drosophila. J Am Soc Nephrol 2022; 33:2174-2193. [PMID: 36137753 PMCID: PMC9731638 DOI: 10.1681/asn.2022030275] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 09/01/2022] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Variants in TBC1D8B cause nephrotic syndrome. TBC1D8B is a GTPase-activating protein for Rab11 (RAB11-GAP) that interacts with nephrin, but how it controls nephrin trafficking or other podocyte functions remains unclear. METHODS We generated a stable deletion in Tbc1d8b and used microhomology-mediated end-joining for genome editing. Ex vivo functional assays utilized slit diaphragms in podocyte-like Drosophila nephrocytes. Manipulation of endocytic regulators and transgenesis of murine Tbc1d8b provided a comprehensive functional analysis of Tbc1d8b. RESULTS A null allele of Drosophila TBC1D8B exhibited a nephrocyte-restricted phenotype of nephrin mislocalization, similar to patients with isolated nephrotic syndrome who have variants in the gene. The protein was required for rapid nephrin turnover in nephrocytes and for endocytosis of nephrin induced by excessive Rab5 activity. The protein expressed from the Tbc1d8b locus bearing the edited tag predominantly localized to mature early and late endosomes. Tbc1d8b was required for endocytic cargo processing and degradation. Silencing Hrs, a regulator of endosomal maturation, phenocopied loss of Tbc1d8b. Low-level expression of murine TBC1D8B rescued loss of the Drosophila gene, indicating evolutionary conservation. Excessive murine TBC1D8B selectively disturbed nephrin dynamics. Finally, we discovered four novel TBC1D8B variants within a cohort of 363 patients with FSGS and validated a functional effect of two variants in Drosophila, suggesting a personalized platform for TBC1D8B-associated FSGS. CONCLUSIONS Variants in TBC1D8B are not infrequent among patients with FSGS. TBC1D8B, functioning in endosomal maturation and degradation, is essential for nephrin trafficking.
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Affiliation(s)
- Julian Milosavljevic
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Camille Lempicki
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Konrad Lang
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Helena Heinkele
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Lina L. Kampf
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Claire Leroy
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Mengmeng Chen
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Lea Gerstner
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Dominik Spitz
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Minxian Wang
- Division of Nephrology, Beth Israel Deaconess Medical Center, Boston, Massachusetts
- Department of Medicine, Harvard Medical School, Boston, Massachusetts
| | - Andrea U. Knob
- Division of Nephrology, Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Séverine Kayser
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Martin Helmstädter
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Gerd Walz
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
- CIBSS–Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Martin R. Pollak
- Division of Nephrology, Beth Israel Deaconess Medical Center, Boston, Massachusetts
- Department of Medicine, Harvard Medical School, Boston, Massachusetts
| | - Tobias Hermle
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
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23
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Csizmadia T, Dósa A, Farkas E, Csikos BV, Kriska EA, Juhász G, Lőw P. Developmental program-independent secretory granule degradation in larval salivary gland cells of Drosophila. Traffic 2022; 23:568-586. [PMID: 36353974 PMCID: PMC10099382 DOI: 10.1111/tra.12871] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 10/26/2022] [Accepted: 11/03/2022] [Indexed: 11/11/2022]
Abstract
Both constitutive and regulated secretion require cell organelles that are able to store and release the secretory cargo. During development, the larval salivary gland of Drosophila initially produces high amount of glue-containing small immature secretory granules, which then fuse with each other and reach their normal 3-3.5 μm in size. Following the burst of secretion, obsolete glue granules directly fuse with late endosomes or lysosomes by a process called crinophagy, which leads to fast degradation and recycling of the secretory cargo. However, hindering of endosome-to-TGN retrograde transport in these cells causes abnormally small glue granules which are not able to fuse with each other. Here, we show that loss of function of the SNARE genes Syntaxin 16 (Syx16) and Synaptobrevin (Syb), the small GTPase Rab6 and the GARP tethering complex members Vps53 and Scattered (Vps54) all involved in retrograde transport cause intense early degradation of immature glue granules via crinophagy independently of the developmental program. Moreover, silencing of these genes also provokes secretory failure and accelerated crinophagy during larval development. Our results provide a better understanding of the relations among secretion, secretory granule maturation and degradation and paves the way for further investigation of these connections in other metazoans.
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Affiliation(s)
- Tamás Csizmadia
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Anna Dósa
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Erika Farkas
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Belián Valentin Csikos
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Eszter Adél Kriska
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Gábor Juhász
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary.,Institute of Genetics, Biological Research Centre, Eötvös Loránd Research Network, Szeged, Hungary
| | - Péter Lőw
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
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24
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Park SY, Muschalik N, Chadwick J, Munro S. In vivo characterization of Drosophila golgins reveals redundancy and plasticity of vesicle capture at the Golgi apparatus. Curr Biol 2022; 32:4549-4564.e6. [PMID: 36103876 PMCID: PMC9849145 DOI: 10.1016/j.cub.2022.08.054] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 06/29/2022] [Accepted: 08/18/2022] [Indexed: 01/26/2023]
Abstract
The Golgi is the central sorting station in the secretory pathway and thus the destination of transport vesicles arriving from the endoplasmic reticulum and endosomes and from within the Golgi itself. Cell viability, therefore, requires that the Golgi accurately receives multiple classes of vesicle. One set of proteins proposed to direct vesicle arrival at the Golgi are the golgins, long coiled-coil proteins localized to specific parts of the Golgi stack. In mammalian cells, three of the golgins, TMF, golgin-84, and GMAP-210, can capture intra-Golgi transport vesicles when placed in an ectopic location. However, the individual golgins are not required for cell viability, and mouse knockout mutants only have defects in specific tissues. To further illuminate this system, we examine the Drosophila orthologs of these three intra-Golgi golgins. We show that ectopic forms can capture intra-Golgi transport vesicles, but strikingly, the cargo present in the vesicles captured by each golgin varies between tissues. Loss-of-function mutants show that the golgins are individually dispensable, although the loss of TMF recapitulates the male fertility defects observed in mice. However, the deletion of multiple golgins results in defects in glycosylation and loss of viability. Examining the vesicles captured by a particular golgin when another golgin is missing reveals that the vesicle content in one tissue changes to resemble that of a different tissue. This reveals a plasticity in Golgi organization between tissues, providing an explanation for why the Golgi is sufficiently robust to tolerate the loss of many of the individual components of its membrane traffic machinery.
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Affiliation(s)
- Sung Yun Park
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Nadine Muschalik
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Jessica Chadwick
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Sean Munro
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK.
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25
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Nagy A, Szenci G, Boda A, Al-Lami M, Csizmadia T, Lőrincz P, Juhász G, Lőw P. Ecdysone receptor isoform specific regulation of secretory granule acidification in the larval Drosophila salivary gland. Eur J Cell Biol 2022; 101:151279. [PMID: 36306596 DOI: 10.1016/j.ejcb.2022.151279] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 10/21/2022] [Accepted: 10/21/2022] [Indexed: 12/14/2022] Open
Abstract
Bulk production and release of glue containing secretory granules takes place in the larval salivary gland during Drosophila development in order to attach the metamorphosing animal to a dry surface. These granules undergo a maturation process to prepare glue for exocytosis, which includes homotypic fusions to increase the size of granules, vesicle acidification and ion uptake. The steroid hormone 20-hydroxyecdysone is known to be required for the first and last steps of this process: glue synthesis and secretion, respectively. Here we show that the B1 isoform of Ecdysone receptor (EcR), together with its binding partner Ultraspiracle, are also necessary for the maturation of glue granules by promoting their acidification via regulation of Vha55 expression, which encodes an essential subunit of the V-ATPase proton pump. This is antagonized by the EcR-A isoform, overexpression of which decreases EcR-B1 and Vha55 expression and glue granule acidification. Our data shed light on a previously unknown, ecdysone receptor isoform-specific regulation of glue granule maturation.
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Affiliation(s)
- Anikó Nagy
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Győző Szenci
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Attila Boda
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Muna Al-Lami
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Tamás Csizmadia
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Péter Lőrincz
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Gábor Juhász
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary; Institute of Genetics, Biological Research Centre, Szeged, Hungary.
| | - Péter Lőw
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
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26
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Linnemannstöns K, Karuna M P, Witte L, Choezom D, Honemann‐Capito M, Lagurin AS, Schmidt CV, Shrikhande S, Steinmetz L, Wiebke M, Lenz C, Gross JC. Microscopic and biochemical monitoring of endosomal trafficking and extracellular vesicle secretion in an endogenous in vivo model. J Extracell Vesicles 2022; 11:e12263. [PMID: 36103151 PMCID: PMC9473323 DOI: 10.1002/jev2.12263] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 02/17/2022] [Accepted: 05/22/2022] [Indexed: 11/10/2022] Open
Abstract
Extracellular vesicle (EV) secretion enables cell-cell communication in multicellular organisms. During development, EV secretion and the specific loading of signalling factors in EVs contributes to organ development and tissue differentiation. Here, we present an in vivo model to study EV secretion using the fat body and the haemolymph of the fruit fly, Drosophila melanogaster. The system makes use of tissue-specific EV labelling and is amenable to genetic modification by RNAi. This allows the unique combination of microscopic visualisation of EVs in different organs and quantitative biochemical purification to study how EVs are generated within the cells and which factors regulate their secretion in vivo. Characterisation of the system revealed that secretion of EVs from the fat body is mainly regulated by Rab11 and Rab35, highlighting the importance of recycling Rab GTPase family members for EV secretion. We furthermore discovered a so far unknown function of Rab14 along with the kinesin Klp98A in EV biogenesis and secretion.
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Affiliation(s)
- Karen Linnemannstöns
- Developmental BiochemistryUniversity Medical Center GoettingenGoettingenGermany
- Hematology and OncologyUniversity Medical Center GoettingenGoettingenGermany
- Molecular OncologyUniversity Medical Center GoettingenGoettingenGermany
| | - Pradhipa Karuna M
- Developmental BiochemistryUniversity Medical Center GoettingenGoettingenGermany
| | - Leonie Witte
- Developmental BiochemistryUniversity Medical Center GoettingenGoettingenGermany
| | - Dolma Choezom
- Developmental BiochemistryUniversity Medical Center GoettingenGoettingenGermany
| | | | - Alex Simon Lagurin
- Developmental BiochemistryUniversity Medical Center GoettingenGoettingenGermany
| | | | - Shreya Shrikhande
- Developmental BiochemistryUniversity Medical Center GoettingenGoettingenGermany
| | | | - Möbius Wiebke
- Electron Microscopy Core Unit, Department of NeurogeneticsMax Planck Institute of Experimental MedicineGöttingenGermany
| | - Christof Lenz
- Institute of Clinical ChemistryUniversity Medical Center GöttingenGöttingenGermany
- Bioanalytical Mass Spectrometry GroupMax Planck Institute for Biophysical ChemistryGöttingenGermany
| | - Julia Christina Gross
- Developmental BiochemistryUniversity Medical Center GoettingenGoettingenGermany
- Hematology and OncologyUniversity Medical Center GoettingenGoettingenGermany
- Department of MedicineHealth and Medical UniversityPotsdamGermany
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27
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Zohar-Fux M, Ben-Hamo-Arad A, Arad T, Volin M, Shklyar B, Hakim-Mishnaevski K, Porat-Kuperstein L, Kurant E, Toledano H. The phagocytic cyst cells in Drosophila testis eliminate germ cell progenitors via phagoptosis. SCIENCE ADVANCES 2022; 8:eabm4937. [PMID: 35714186 PMCID: PMC9205596 DOI: 10.1126/sciadv.abm4937] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 05/04/2022] [Indexed: 06/15/2023]
Abstract
Phagoptosis is a frequently occurring nonautonomous cell death pathway in which phagocytes eliminate viable cells. While it is thought that phosphatidylserine (PS) "eat-me" signals on target cells initiate the process, the precise sequence of events is largely unknown. Here, we show that in Drosophila testes, progenitor germ cells are spontaneously removed by neighboring cyst cells through phagoptosis. Using live imaging with multiple markers, we demonstrate that cyst cell-derived early/late endosomes and lysosomes fused around live progenitors to acidify them, before DNA fragmentation and substantial PS exposure on the germ cell surface. Furthermore, the phagocytic receptor Draper is expressed on cyst cell membranes and is necessary for phagoptosis. Significantly, germ cell death is blocked by knockdown of either the endosomal component Rab5 or the lysosomal associated protein Lamp1, within the cyst cells. These data ascribe an active role for phagocytic cyst cells in removal of live germ cell progenitors.
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Affiliation(s)
- Maayan Zohar-Fux
- Department of Human Biology, Faculty of Natural Sciences, University of Haifa, 199 Aba Hushi Avenue, Mount Carmel, Haifa 3498838, Israel
| | - Aya Ben-Hamo-Arad
- Department of Human Biology, Faculty of Natural Sciences, University of Haifa, 199 Aba Hushi Avenue, Mount Carmel, Haifa 3498838, Israel
| | - Tal Arad
- Department of Human Biology, Faculty of Natural Sciences, University of Haifa, 199 Aba Hushi Avenue, Mount Carmel, Haifa 3498838, Israel
| | - Marina Volin
- Department of Human Biology, Faculty of Natural Sciences, University of Haifa, 199 Aba Hushi Avenue, Mount Carmel, Haifa 3498838, Israel
| | - Boris Shklyar
- Bioimaging Unit, Faculty of Natural Sciences, University of Haifa, 199 Aba Hushi Avenue, Mount Carmel, Haifa 3498838, Israel
| | - Ketty Hakim-Mishnaevski
- Department of Human Biology, Faculty of Natural Sciences, University of Haifa, 199 Aba Hushi Avenue, Mount Carmel, Haifa 3498838, Israel
| | - Lilach Porat-Kuperstein
- Department of Human Biology, Faculty of Natural Sciences, University of Haifa, 199 Aba Hushi Avenue, Mount Carmel, Haifa 3498838, Israel
| | - Estee Kurant
- Department of Human Biology, Faculty of Natural Sciences, University of Haifa, 199 Aba Hushi Avenue, Mount Carmel, Haifa 3498838, Israel
| | - Hila Toledano
- Department of Human Biology, Faculty of Natural Sciences, University of Haifa, 199 Aba Hushi Avenue, Mount Carmel, Haifa 3498838, Israel
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28
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Rong Y, Zhang S, Nandi N, Wu Z, Li L, Liu Y, Wei Y, Zhao Y, Yuan W, Zhou C, Xiao G, Levine B, Yan N, Mou S, Deng L, Tang Z, Liu X, Kramer H, Zhong Q. STING controls energy stress-induced autophagy and energy metabolism via STX17. J Biophys Biochem Cytol 2022; 221:213198. [PMID: 35510944 PMCID: PMC9082627 DOI: 10.1083/jcb.202202060] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 03/07/2022] [Accepted: 03/08/2022] [Indexed: 01/07/2023] Open
Abstract
The stimulator of interferon genes (STING) plays a critical role in innate immunity. Emerging evidence suggests that STING is important for DNA or cGAMP-induced non-canonical autophagy, which is independent of a large part of canonical autophagy machineries. Here, we report that, in the absence of STING, energy stress-induced autophagy is upregulated rather than downregulated. Depletion of STING in Drosophila fat cells enhances basal- and starvation-induced autophagic flux. During acute exercise, STING knockout mice show increased autophagy flux, exercise endurance, and altered glucose metabolism. Mechanistically, these observations could be explained by the STING-STX17 interaction. STING physically interacts with STX17, a SNARE that is essential for autophagosome biogenesis and autophagosome-lysosome fusion. Energy crisis and TBK1-mediated phosphorylation both disrupt the STING-STX17 interaction, allow different pools of STX17 to translocate to phagophores and mature autophagosomes, and promote autophagic flux. Taken together, we demonstrate a heretofore unexpected function of STING in energy stress-induced autophagy through spatial regulation of autophagic SNARE STX17.
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Affiliation(s)
- Yueguang Rong
- Department of Pathogen Biology, School of Basic Medicine, Huazhong University of Science and Technology, Wuhan, China
| | - Shen Zhang
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Nilay Nandi
- Department of Neuroscience and Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX
| | - Zhe Wu
- Department of Pathogen Biology, School of Basic Medicine, Huazhong University of Science and Technology, Wuhan, China
| | - Linsen Li
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yang Liu
- Center for Autophagy Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX
| | - Yuehan Wei
- Department of Nephrology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yuan Zhao
- Department of Pathogen Biology, School of Basic Medicine, Huazhong University of Science and Technology, Wuhan, China
| | - Weigang Yuan
- Department of Pathogen Biology, School of Basic Medicine, Huazhong University of Science and Technology, Wuhan, China
| | - Chuchu Zhou
- Department of Pathogen Biology, School of Basic Medicine, Huazhong University of Science and Technology, Wuhan, China
| | - Guanghua Xiao
- Quantitative Biomedical Research Center, Department of Clinical Sciences, University of Texas Southwestern Medical Center, Dallas, TX
| | - Beth Levine
- Center for Autophagy Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX
| | - Nan Yan
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX
| | - Shan Mou
- Department of Nephrology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Liufu Deng
- Department of Immunology and Microbiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zaiming Tang
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiaoxia Liu
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Helmut Kramer
- Department of Neuroscience and Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX,Helmut Kramer:
| | - Qing Zhong
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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Nassari S, Lacarrière-Keïta C, Lévesque D, Boisvert FM, Jean S. Rab21 in enterocytes participates in intestinal epithelium maintenance. Mol Biol Cell 2022; 33:ar32. [PMID: 35171715 PMCID: PMC9250356 DOI: 10.1091/mbc.e21-03-0139] [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] [Indexed: 11/11/2022] Open
Abstract
Membrane trafficking is defined as the vesicular transport of proteins into, out of, and throughout the cell. In intestinal enterocytes, defects in endocytic/recycling pathways result in impaired function and are linked to diseases. However, how these trafficking pathways regulate intestinal tissue homeostasis is poorly understood. Using the Drosophila intestine as an in vivo system, we investigated enterocyte-specific functions for the early endosomal machinery. We focused on Rab21, which regulates specific steps in early endosomal trafficking. Depletion of Rab21 in enterocytes led to abnormalities in intestinal morphology, with deregulated cellular equilibrium associated with a gain in mitotic cells and increased cell death. Increases in apoptosis and Yorkie signaling were responsible for compensatory proliferation and tissue inflammation. Using an RNAi screen, we identified regulators of autophagy and membrane trafficking that phenocopied Rab21 knockdown. We further showed that Rab21 knockdown-induced hyperplasia was rescued by inhibition of epidermal growth factor receptor signaling. Moreover, quantitative proteomics identified proteins affected by Rab21 depletion. Of these, we validated changes in apolipoprotein ApoLpp and the trehalose transporter Tret1-1, indicating roles for enterocyte Rab21 in lipid and carbohydrate homeostasis, respectively. Our data shed light on an important role for early endosomal trafficking, and Rab21, in enterocyte-mediated intestinal epithelium maintenance. [Media: see text] [Media: see text].
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Affiliation(s)
- Sonya Nassari
- Faculté de Médecine et des Sciences de la Santé, Department of Immunology and Cell Biology, Université de Sherbrooke, 3201 Rue Jean Mignault, Sherbrooke, Québec J1E 4K8, Canada
| | - Camille Lacarrière-Keïta
- Faculté de Médecine et des Sciences de la Santé, Department of Immunology and Cell Biology, Université de Sherbrooke, 3201 Rue Jean Mignault, Sherbrooke, Québec J1E 4K8, Canada
| | - Dominique Lévesque
- Faculté de Médecine et des Sciences de la Santé, Department of Immunology and Cell Biology, Université de Sherbrooke, 3201 Rue Jean Mignault, Sherbrooke, Québec J1E 4K8, Canada
| | - François-Michel Boisvert
- Faculté de Médecine et des Sciences de la Santé, Department of Immunology and Cell Biology, Université de Sherbrooke, 3201 Rue Jean Mignault, Sherbrooke, Québec J1E 4K8, Canada
| | - Steve Jean
- Faculté de Médecine et des Sciences de la Santé, Department of Immunology and Cell Biology, Université de Sherbrooke, 3201 Rue Jean Mignault, Sherbrooke, Québec J1E 4K8, Canada
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30
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Camelo C, Körte A, Jacobs T, Luschnig S. Tracheal tube fusion in Drosophila involves release of extracellular vesicles from multivesicular bodies. J Cell Sci 2022; 135:274235. [PMID: 35019140 DOI: 10.1242/jcs.259590] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 12/22/2021] [Indexed: 11/20/2022] Open
Abstract
Extracellular vesicles (EVs) comprise diverse types of cell-released membranous structures that are thought to play important roles in intercellular communication. While the formation and functions of EVs have been investigated extensively in cultured cells, studies of EVs in vivo have remained scarce. We report here that EVs are present in the developing lumen of tracheal tubes in Drosophila embryos. We defined two distinct EV subpopulations, one of which contains the Munc13-4 homologue Staccato (Stac) and is spatially and temporally associated with tracheal tube fusion (anastomosis) events. The formation of Stac-positive luminal EVs depends on the tracheal tip-cell-specific GTPase Arl3, which is also required for the formation of Stac-positive multivesicular bodies, suggesting that Stac-EVs derive from fusion of Stac-MVBs with the luminal membrane in tip cells during anastomosis formation. The GTPases Rab27 and Rab35 cooperate downstream of Arl3 to promote Stac-MVB formation and tube fusion. We propose that Stac-MVBs act as membrane reservoirs that facilitate tracheal lumen fusion in a process regulated by Arl3, Rab27, Rab35, and Stac/Munc13-4.
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Affiliation(s)
- Carolina Camelo
- Institute of Integrative Cell Biology and Physiology, University of Münster, D-48143 Münster, Germany.,Cells in Motion (CiM) Interfaculty Centre, D-48149 Münster, Germany
| | - Anna Körte
- Institute of Integrative Cell Biology and Physiology, University of Münster, D-48143 Münster, Germany.,Cells in Motion (CiM) Interfaculty Centre, D-48149 Münster, Germany
| | - Thea Jacobs
- Institute of Integrative Cell Biology and Physiology, University of Münster, D-48143 Münster, Germany.,Cells in Motion (CiM) Interfaculty Centre, D-48149 Münster, Germany
| | - Stefan Luschnig
- Institute of Integrative Cell Biology and Physiology, University of Münster, D-48143 Münster, Germany.,Cells in Motion (CiM) Interfaculty Centre, D-48149 Münster, Germany
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31
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Hernandez-Diaz S, Ghimire S, Sanchez-Mirasierra I, Montecinos-Oliva C, Swerts J, Kuenen S, Verstreken P, Soukup SF. Endophilin-B regulates autophagy during synapse development and neurodegeneration. Neurobiol Dis 2021; 163:105595. [PMID: 34933093 DOI: 10.1016/j.nbd.2021.105595] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Revised: 12/13/2021] [Accepted: 12/17/2021] [Indexed: 01/18/2023] Open
Abstract
Synapses are critical for neuronal communication and brain function. To maintain neuronal homeostasis, synapses rely on autophagy. Autophagic alterations cause neurodegeneration and synaptic dysfunction is a feature in neurodegenerative diseases. In Parkinson's disease (PD), where the loss of synapses precedes dopaminergic neuron loss, various PD-causative proteins are involved in the regulation of autophagy. So far only a few factors regulating autophagy at the synapse have been identified and the molecular mechanisms underlying autophagy at the synapse is only partially understood. Here, we describe Endophilin-B (EndoB) as a novel player in the regulation of synaptic autophagy in health and disease. We demonstrate that EndoB is required for autophagosome biogenesis at the synapse, whereas the loss of EndoB blocks the autophagy induction promoted by the PD mutation LRRK2G2019S. We show that EndoB is required to prevent neuronal loss. Moreover, loss of EndoB in the Drosophila visual system leads to an increase in synaptic contacts between photoreceptor terminals and their post-synaptic synapses. These data confirm the role of autophagy in synaptic contact formation and neuronal survival.
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Affiliation(s)
| | - Saurav Ghimire
- Univ. Bordeaux, CNRS, IMN, UMR 5293, F-33000 Bordeaux, France
| | | | | | - Jef Swerts
- VIB Center for the Biology of Disease, Belgium; KU Leuven, Department for Human Genetics, Leuven Institute for Neurodegenerative Disease (LIND), 3000 Leuven, Belgium
| | - Sabine Kuenen
- VIB Center for the Biology of Disease, Belgium; KU Leuven, Department for Human Genetics, Leuven Institute for Neurodegenerative Disease (LIND), 3000 Leuven, Belgium
| | - Patrik Verstreken
- VIB Center for the Biology of Disease, Belgium; KU Leuven, Department for Human Genetics, Leuven Institute for Neurodegenerative Disease (LIND), 3000 Leuven, Belgium
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32
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Valko A, Perez-Pandolfo S, Sorianello E, Brech A, Wappner P, Melani M. Adaptation to hypoxia in Drosophila melanogaster requires autophagy. Autophagy 2021; 18:909-920. [PMID: 34793268 DOI: 10.1080/15548627.2021.1991191] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Macroautophagy/autophagy, a mechanism of degradation of intracellular material required to sustain cellular homeostasis, is exacerbated under stress conditions like nutrient deprivation, protein aggregation, organelle senescence, pathogen invasion, and hypoxia, among others. Detailed in vivo description of autophagic responses triggered by hypoxia is limited. We have characterized the autophagic response induced by hypoxia in Drosophila melanogaster. We found that this process is essential for Drosophila adaptation and survival because larvae with impaired autophagy are hypersensitive to low oxygen levels. Hypoxia triggers a bona fide autophagic response, as evaluated by several autophagy markers including Atg8, LysoTracker, Lamp1, Pi3K59F/Vps34 activity, transcriptional induction of Atg genes, as well as by transmission electron microscopy. Autophagy occurs in waves of autophagosome formation and maturation as hypoxia exposure is prolonged. Hypoxia-triggered autophagy is induced cell autonomously, and different tissues are sensitive to hypoxic treatments. We found that hypoxia-induced autophagy depends on the basic autophagy machinery but not on the hypoxia master regulator sima/HIF1A. Overall, our studies lay the foundation for using D. melanogaster as a model system for studying autophagy under hypoxic conditions, which, in combination with the potency of genetic manipulations available in this organism, provides a platform for studying the involvement of autophagy in hypoxia-associated pathologies and developmentally regulated processes.Abbreviations: Atg: autophagy-related; FYVE: zinc finger domain from Fab1 (yeast ortholog of PIKfyve); GFP: green fluorescent protein; HIF: hypoxia-inducible factor; hsf: heat shock factor; Hx: hypoxia; mCh: mCherry; PtdIns: phosphatidylinositol; PtdIns3P: phosphatidylinositol-3-phosphate; Rheb: Ras homolog enriched in brain; sima: similar; Stv: Starvation; TEM: transmission electron microscopy; Tor: target of rapamycin; UAS: upstream activating sequence; Vps: vacuolar protein sorting.
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Affiliation(s)
- Ayelén Valko
- Fundación Instituto Leloir, Buenos Aires, Argentina
| | - Sebastián Perez-Pandolfo
- Fundación Instituto Leloir, Buenos Aires, Argentina.,Consejo Nacional De Investigaciones Científicas Y Técnicas (CONICET), Buenos Aires, Argentina
| | - Eleonora Sorianello
- Consejo Nacional De Investigaciones Científicas Y Técnicas (CONICET), Buenos Aires, Argentina.,Laboratorio De Regulación Hipofisaria, Instituto De Medicina Y Biología Experimental (Ibyme-conicet), Buenos Aires, Argentina
| | - Andreas Brech
- Centre for Cancer Cell Reprogramming, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway.,Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
| | - Pablo Wappner
- Fundación Instituto Leloir, Buenos Aires, Argentina.,Consejo Nacional De Investigaciones Científicas Y Técnicas (CONICET), Buenos Aires, Argentina.,Departamento De Fisiología, Biología Molecular Y Celular, Facultad De Ciencias Exactas Y Naturales, Universidad De Buenos Aires, Buenos Aires, Argentina
| | - Mariana Melani
- Fundación Instituto Leloir, Buenos Aires, Argentina.,Consejo Nacional De Investigaciones Científicas Y Técnicas (CONICET), Buenos Aires, Argentina.,Departamento De Fisiología, Biología Molecular Y Celular, Facultad De Ciencias Exactas Y Naturales, Universidad De Buenos Aires, Buenos Aires, Argentina
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33
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Mesquita A, Glenn J, Jenny A. Differential activation of eMI by distinct forms of cellular stress. Autophagy 2021; 17:1828-1840. [PMID: 32559125 PMCID: PMC8386722 DOI: 10.1080/15548627.2020.1783833] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 06/03/2020] [Accepted: 06/08/2020] [Indexed: 12/11/2022] Open
Abstract
As one of the major, highly conserved catabolic pathways, autophagy delivers cytosolic components to lysosomes for degradation. It is essential for development, cellular homeostasis, and coping with stress. Reduced autophagy increases susceptibility to protein aggregation diseases and leads to phenotypes associated with aging. Of the three major forms of autophagy, macroautophagy (MA) can degrade organelles or aggregated proteins, and chaperone-mediated autophagy is specific for soluble proteins containing KFERQ-related targeting motifs. During endosomal microautophagy (eMI), cytoplasmic proteins are engulfed into late endosomes in an ESCRT machinery-dependent manner. eMI can be KFERQ-specific or occur in bulk and be induced by prolonged starvation. Its physiological regulation and function, however, are not understood. Here, we show that eMI in the Drosophila fat body, akin to the mammalian liver, is induced upon oxidative or genotoxic stress in an ESCRT and partially Hsc70-4-dependent manner. Interestingly, eMI activation is selective, as ER stress fails to elicit a response. Intriguingly, we find that reducing MA leads to a compensatory enhancement of eMI, suggesting a tight interplay between these degradative processes. Furthermore, we show that mutations in DNA damage response genes are sufficient to trigger eMI and that the response to oxidative stress is under the control of MAPK/JNK signaling. Our data suggest that, controlled by various signaling pathways, eMI allows an organ to react and adapt to specific types of stress and is thus likely critical to prevent disease.Abbreviations:Atg: autophagy-related; CMA: chaperone-mediated autophagy; DDR: DNA damage repair; Df: deficiency (deletion); (E)GFP: (enhanced) green fluorescent protein; eMI: endosomal microautophagy; ER: endoplasmatic reticulum; ESCRT: endosomal sorting complexes required for transport; Eto: etoposide; FLP: flipase; Hsc: heat shock cognate protein; LAMP2A: lysosomal-associated membrane protein 2A; LE: late endosome; MA: macroautophagy; MI: microautophagy; MVB: multivesicular body; PA: photoactivatable; Para: paraquat; ROS: reactive oxygen species; SEM: standard error of means; Tor: target of rapamycin [serine/threonine kinase]; UPR: unfolded protein response; Vps: vacuolar protein sorting.
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Affiliation(s)
- Ana Mesquita
- Department of Developmental and Molecular Biology, Marion Bessin Liver Research Center, Albert Einstein College of Medicine, New York, NY, US
| | - James Glenn
- Department of Developmental and Molecular Biology, Marion Bessin Liver Research Center, Albert Einstein College of Medicine, New York, NY, US
| | - Andreas Jenny
- Department of Developmental and Molecular Biology, Marion Bessin Liver Research Center, Albert Einstein College of Medicine, New York, NY, US
- Department of Genetics, Marion Bessin Liver Research Center, Albert Einstein College of Medicine, New York, NY, US
- Marion Bessin Liver Research Center, Albert Einstein College of Medicine, New York, NY, US
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34
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Yıldız Y, Koşukcu C, Aygün D, Akçaboy M, Öztek Çelebi FZ, Taşcı Yıldız Y, Şahin G, Aytekin C, Yüksel D, Lay İ, Özgül RK, Dursun A. Homozygous missense VPS16 variant is associated with a novel disease, resembling mucopolysaccharidosis-plus syndrome in two siblings. Clin Genet 2021; 100:308-317. [PMID: 34013567 DOI: 10.1111/cge.14002] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 05/12/2021] [Accepted: 05/18/2021] [Indexed: 12/17/2022]
Abstract
Disorders of intracellular trafficking are a group of inherited disorders, which often display multisystem phenotypes. Vacuolar protein sorting (VPS) subunit C, composed of VPS11, VPS18, VPS16, and VPS33A proteins, is involved in tethering of endosomes, lysosomes, and autophagosomes. Our group and others have previously described patients with a specific homozygous missense VPS33A variant, exhibiting a storage disease phenotype resembling mucopolysaccharidosis (MPS), termed "MPS-plus syndrome." Here, we report two siblings from a consanguineous Turkish-Arabic family, who have overlapping features of MPS and intracellular trafficking disorders, including short stature, coarse facies, developmental delay, peripheral neuropathy, splenomegaly, spondylar dysplasia, congenital neutropenia, and high-normal glycosaminoglycan excretion. Whole exome sequencing and familial segregation analyses led to the homozygous NM_022575.3:c.540G>T; p.Trp180Cys variant in VPS16 in both siblings. Multiple bioinformatic methods supported the pathogenicity of this variant. Different monoallelic null VPS16 variants and a homozygous missense VPS16 variant had been previously associated with dystonia. A biallelic intronic, probably splice-altering variant in VPS16, causing an MPS-plus syndrome-like disease has been very recently reported in two individuals. The siblings presented herein display no dystonia, but have features of a multisystem storage disorder, representing a novel MPS-plus syndrome-like disease, associated for the first time with VPS16 missense variants.
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Affiliation(s)
- Yılmaz Yıldız
- Division of Pediatric Metabolism, Department of Pediatrics, Faculty of Medicine, Hacettepe University, Ankara, Turkey.,Department of Pediatric Metabolic Diseases, Dr. Sami Ulus Training and Research Hospital for Maternity and Child Health, Ankara, Turkey
| | - Can Koşukcu
- Division of Pediatric Metabolism, Department of Pediatrics, Faculty of Medicine, Hacettepe University, Ankara, Turkey.,Department of Bioinformatics, Institute of Health Sciences, Hacettepe University, Ankara, Turkey
| | - Damla Aygün
- Division of Pediatric Metabolism, Department of Pediatrics, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Meltem Akçaboy
- Department of Pediatrics, Dr. Sami Ulus Training and Research Hospital for Maternity and Child Health, Ankara, Turkey
| | - Fatma Zehra Öztek Çelebi
- Department of Pediatrics, Dr. Sami Ulus Training and Research Hospital for Maternity and Child Health, Ankara, Turkey
| | - Yasemin Taşcı Yıldız
- Department of Pediatric Radiology, Dr. Sami Ulus Training and Research Hospital for Maternity and Child Health, Ankara, Turkey
| | - Gülseren Şahin
- Department of Pediatric Gastroenterology, Dr. Sami Ulus Training and Research Hospital for Maternity and Child Health, Ankara, Turkey
| | - Caner Aytekin
- Department of Pediatric Allergy and Immunology, Dr. Sami Ulus Training and Research Hospital for Maternity and Child Health, Ankara, Turkey
| | - Deniz Yüksel
- Department of Pediatric Neurology, Dr. Sami Ulus Training and Research Hospital for Maternity and Child Health, Ankara, Turkey
| | - İncilay Lay
- Department of Medical Biochemistry, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Rıza Köksal Özgül
- Division of Pediatric Metabolism, Department of Pediatrics, Faculty of Medicine, Hacettepe University, Ankara, Turkey.,Institute of Child Health, Hacettepe University, Ankara, Turkey
| | - Ali Dursun
- Division of Pediatric Metabolism, Department of Pediatrics, Faculty of Medicine, Hacettepe University, Ankara, Turkey
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35
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A parasitoid wasp of Drosophila employs preemptive and reactive strategies to deplete its host's blood cells. PLoS Pathog 2021; 17:e1009615. [PMID: 34048506 PMCID: PMC8191917 DOI: 10.1371/journal.ppat.1009615] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 06/10/2021] [Accepted: 05/05/2021] [Indexed: 11/19/2022] Open
Abstract
The wasps Leptopilina heterotoma parasitize and ingest their Drosophila hosts. They produce extracellular vesicles (EVs) in the venom that are packed with proteins, some of which perform immune suppressive functions. EV interactions with blood cells of host larvae are linked to hematopoietic depletion, immune suppression, and parasite success. But how EVs disperse within the host, enter and kill hematopoietic cells is not well understood. Using an antibody marker for L. heterotoma EVs, we show that these parasite-derived structures are readily distributed within the hosts’ hemolymphatic system. EVs converge around the tightly clustered cells of the posterior signaling center (PSC) of the larval lymph gland, a small hematopoietic organ in Drosophila. The PSC serves as a source of developmental signals in naïve animals. In wasp-infected animals, the PSC directs the differentiation of lymph gland progenitors into lamellocytes. These lamellocytes are needed to encapsulate the wasp egg and block parasite development. We found that L. heterotoma infection disassembles the PSC and PSC cells disperse into the disintegrating lymph gland lobes. Genetically manipulated PSC-less lymph glands remain non-responsive and largely intact in the face of L. heterotoma infection. We also show that the larval lymph gland progenitors use the endocytic machinery to internalize EVs. Once inside, L. heterotoma EVs damage the Rab7- and LAMP-positive late endocytic and phagolysosomal compartments. Rab5 maintains hematopoietic and immune quiescence as Rab5 knockdown results in hematopoietic over-proliferation and ectopic lamellocyte differentiation. Thus, both aspects of anti-parasite immunity, i.e., (a) phagocytosis of the wasp’s immune-suppressive EVs, and (b) progenitor differentiation for wasp egg encapsulation reside in the lymph gland. These results help explain why the lymph gland is specifically and precisely targeted for destruction. The parasite’s simultaneous and multipronged approach to block cellular immunity not only eliminates blood cells, but also tactically blocks the genetic programming needed for supplementary hematopoietic differentiation necessary for host success. In addition to its known functions in hematopoiesis, our results highlight a previously unrecognized phagocytic role of the lymph gland in cellular immunity. EV-mediated virulence strategies described for L. heterotoma are likely to be shared by other parasitoid wasps; their understanding can improve the design and development of novel therapeutics and biopesticides as well as help protect biodiversity. Parasitoid wasps serve as biological control agents of agricultural insect pests and are worthy of study. Many parasitic wasps develop inside their hosts to emerge as free-living adults. To overcome the resistance of their hosts, parasitic wasps use varied and ingenious strategies such as mimicry, evasion, bioactive venom, virus-like particles, viruses, and extracellular vesicles (EVs). We describe the effects of a unique class of EVs containing virulence proteins and produced in the venom of wasps that parasitize fruit flies of Drosophila species. EVs from Leptopilina heterotoma are widely distributed throughout the Drosophila hosts’ circulatory system after infection. They enter and kill macrophages by destroying the very same subcellular machinery that facilitates their uptake. An important protein in this process, Rab5, is needed to maintain the identity of the macrophage; when Rab5 function is reduced, macrophages turn into a different cell type called lamellocytes. Activities in the EVs can eliminate lamellocytes as well. EVs also interfere with the hosts’ genetic program that promotes lamellocyte differentiation needed to block parasite development. Thus, wasps combine specific preemptive and reactive strategies to deplete their hosts of the very cells that would otherwise sequester and kill them. These findings have applied value in agricultural pest control and medical therapeutics.
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36
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Genetic analysis of the Drosophila ESCRT-III complex protein, VPS24, reveals a novel function in lysosome homeostasis. PLoS One 2021; 16:e0251184. [PMID: 33956855 PMCID: PMC8101729 DOI: 10.1371/journal.pone.0251184] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 04/21/2021] [Indexed: 12/28/2022] Open
Abstract
The ESCRT pathway is evolutionarily conserved across eukaryotes and plays key roles in a variety of membrane remodeling processes. A new Drosophila mutant recovered in our forward genetic screens for synaptic transmission mutants mapped to the vps24 gene encoding a subunit of the ESCRT-III complex. Molecular characterization indicated a loss of VPS24 function, however the mutant is viable and thus loss of VPS24 may be studied in a developed multicellular organism. The mutant exhibits deficits in locomotion and lifespan and, notably, these phenotypes are rescued by neuronal expression of wild-type VPS24. At the cellular level, neuronal and muscle cells exhibit marked expansion of a ubiquitin-positive lysosomal compartment, as well as accumulation of autophagic intermediates, and these phenotypes are rescued cell-autonomously. Moreover, VPS24 expression in glia suppressed the mutant phenotype in muscle, indicating a cell-nonautonomous function for VPS24 in protective intercellular signaling. Ultrastructural analysis of neurons and muscle indicated marked accumulation of the lysosomal compartment in the vps24 mutant. In the neuronal cell body, this included characteristic lysosomal structures associated with an expansive membrane compartment with a striking tubular network morphology. These findings further define the in vivo roles of VPS24 and the ESCRT pathway in lysosome homeostasis and their potential contributions to neurodegenerative diseases characterized by defective ESCRT or lysosome function.
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37
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Götz TWB, Puchkov D, Lysiuk V, Lützkendorf J, Nikonenko AG, Quentin C, Lehmann M, Sigrist SJ, Petzoldt AG. Rab2 regulates presynaptic precursor vesicle biogenesis at the trans-Golgi. J Cell Biol 2021; 220:211946. [PMID: 33822845 PMCID: PMC8025234 DOI: 10.1083/jcb.202006040] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 02/08/2021] [Accepted: 02/26/2021] [Indexed: 11/22/2022] Open
Abstract
Reliable delivery of presynaptic material, including active zone and synaptic vesicle proteins from neuronal somata to synaptic terminals, is prerequisite for successful synaptogenesis and neurotransmission. However, molecular mechanisms controlling the somatic assembly of presynaptic precursors remain insufficiently understood. We show here that in mutants of the small GTPase Rab2, both active zone and synaptic vesicle proteins accumulated in the neuronal cell body at the trans-Golgi and were, consequently, depleted at synaptic terminals, provoking neurotransmission deficits. Ectopic presynaptic material accumulations consisted of heterogeneous vesicles and short tubules of 40 × 60 nm, segregating in subfractions either positive for active zone or synaptic vesicle proteins and LAMP1, a lysosomal membrane protein. Genetically, Rab2 acts upstream of Arl8, a lysosomal adaptor controlling axonal export of precursors. Collectively, we identified a Golgi-associated assembly sequence of presynaptic precursor biogenesis dependent on a Rab2-regulated protein export and sorting step at the trans-Golgi.
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Affiliation(s)
- Torsten W B Götz
- Freie Universität Berlin, Institute for Biology and Genetics, Berlin, Germany
| | - Dmytro Puchkov
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie im Forschungsverbund Berlin e.V., Campus Berlin-Buch, Berlin, Germany
| | - Veronika Lysiuk
- Freie Universität Berlin, Institute for Biology and Genetics, Berlin, Germany
| | - Janine Lützkendorf
- Freie Universität Berlin, Institute for Biology and Genetics, Berlin, Germany
| | | | - Christine Quentin
- Freie Universität Berlin, Institute for Biology and Genetics, Berlin, Germany
| | - Martin Lehmann
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie im Forschungsverbund Berlin e.V., Campus Berlin-Buch, Berlin, Germany
| | - Stephan J Sigrist
- Freie Universität Berlin, Institute for Biology and Genetics, Berlin, Germany.,NeuroCure, Charité, Berlin, Germany
| | - Astrid G Petzoldt
- Freie Universität Berlin, Institute for Biology and Genetics, Berlin, Germany
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38
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Duan X, Tong C. Autophagy in Drosophila and Zebrafish. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1208:333-356. [PMID: 34260032 DOI: 10.1007/978-981-16-2830-6_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Autophagy is a highly conserved cellular process that delivers cellular contents to the lysosome for degradation. It not only serves as a bulk degradation system for various cytoplasmic components but also functions selectively to clear damaged organelles, aggregated proteins, and invading pathogens (Feng et al., Cell Res 24:24-41, 2014; Galluzzi et al., EMBO J 36:1811-36, 2017; Klionsky et al., Autophagy 12:1-222, 2016). The malfunction of autophagy leads to multiple developmental defects and diseases (Mizushima et al., Nature 451:1069-75, 2008). Drosophila and zebrafish are higher metazoan model systems with sophisticated genetic tools readily available, which make it possible to dissect the autophagic processes and to understand the physiological functions of autophagy (Lorincz et al., Cells 6:22, 2017a; Mathai et al., Cells 6:21, 2017; Zhang and Baehrecke, Trends Cell Biol 25:376-87, 2015). In this chapter, we will discuss recent progress that has been made in the autophagic field by using these animal models. We will focus on the protein machineries required for autophagosome formation and maturation as well as the physiological roles of autophagy in both Drosophila and zebrafish.
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Affiliation(s)
- Xiuying Duan
- MOE Key Laboratory for Biosystems Homeostasis and Protection and Innovation Center for Cell Signaling Network, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang, China
| | - Chao Tong
- MOE Key Laboratory for Biosystems Homeostasis and Protection and Innovation Center for Cell Signaling Network, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang, China. .,The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.
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Cunningham KM, Maulding K, Ruan K, Senturk M, Grima JC, Sung H, Zuo Z, Song H, Gao J, Dubey S, Rothstein JD, Zhang K, Bellen HJ, Lloyd TE. TFEB/Mitf links impaired nuclear import to autophagolysosomal dysfunction in C9-ALS. eLife 2020; 9:59419. [PMID: 33300868 PMCID: PMC7758070 DOI: 10.7554/elife.59419] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 12/09/2020] [Indexed: 12/13/2022] Open
Abstract
Disrupted nucleocytoplasmic transport (NCT) has been implicated in neurodegenerative disease pathogenesis; however, the mechanisms by which disrupted NCT causes neurodegeneration remain unclear. In a Drosophila screen, we identified ref(2)P/p62, a key regulator of autophagy, as a potent suppressor of neurodegeneration caused by the GGGGCC hexanucleotide repeat expansion (G4C2 HRE) in C9orf72 that causes amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). We found that p62 is increased and forms ubiquitinated aggregates due to decreased autophagic cargo degradation. Immunofluorescence and electron microscopy of Drosophila tissues demonstrate an accumulation of lysosome-like organelles that precedes neurodegeneration. These phenotypes are partially caused by cytoplasmic mislocalization of Mitf/TFEB, a key transcriptional regulator of autophagolysosomal function. Additionally, TFEB is mislocalized and downregulated in human cells expressing GGGGCC repeats and in C9-ALS patient motor cortex. Our data suggest that the C9orf72-HRE impairs Mitf/TFEB nuclear import, thereby disrupting autophagy and exacerbating proteostasis defects in C9-ALS/FTD.
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Affiliation(s)
- Kathleen M Cunningham
- Cellular and Molecular Medicine Program, School of Medicine, Johns Hopkins University, Baltimore, United States
| | - Kirstin Maulding
- Cellular and Molecular Medicine Program, School of Medicine, Johns Hopkins University, Baltimore, United States
| | - Kai Ruan
- Department of Neurology, School of Medicine, Johns Hopkins University, Baltimore, United States
| | - Mumine Senturk
- Program in Developmental Biology, Baylor College of Medicine (BCM), Houston, United States
| | - Jonathan C Grima
- Brain Science Institute, School of Medicine, Johns Hopkins University, Baltimore, United States.,Solomon H. Snyder Department of Neuroscience, School of Medicine, Johns Hopkins University, Baltimore, United States
| | - Hyun Sung
- Department of Neurology, School of Medicine, Johns Hopkins University, Baltimore, United States
| | - Zhongyuan Zuo
- Department of Molecular and Human Genetics, BCM, Houston, United States
| | - Helen Song
- Department of Neurology, School of Medicine, Johns Hopkins University, Baltimore, United States
| | - Junli Gao
- Department of Neuroscience, Mayo Clinic, Jacksonville, United States
| | - Sandeep Dubey
- Department of Neurology, School of Medicine, Johns Hopkins University, Baltimore, United States
| | - Jeffrey D Rothstein
- Cellular and Molecular Medicine Program, School of Medicine, Johns Hopkins University, Baltimore, United States.,Department of Neurology, School of Medicine, Johns Hopkins University, Baltimore, United States.,Brain Science Institute, School of Medicine, Johns Hopkins University, Baltimore, United States.,Solomon H. Snyder Department of Neuroscience, School of Medicine, Johns Hopkins University, Baltimore, United States
| | - Ke Zhang
- Department of Neuroscience, Mayo Clinic, Jacksonville, United States
| | - Hugo J Bellen
- Program in Developmental Biology, Baylor College of Medicine (BCM), Houston, United States.,Department of Molecular and Human Genetics, BCM, Houston, United States.,Department of Neuroscience, BCM, Houston, United States.,Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, United States.,Howard Hughes Medical Institute, Houston, United States
| | - Thomas E Lloyd
- Cellular and Molecular Medicine Program, School of Medicine, Johns Hopkins University, Baltimore, United States.,Department of Neurology, School of Medicine, Johns Hopkins University, Baltimore, United States.,Solomon H. Snyder Department of Neuroscience, School of Medicine, Johns Hopkins University, Baltimore, United States
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40
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Ceder MM, Aggarwal T, Hosseini K, Maturi V, Patil S, Perland E, Williams MJ, Fredriksson R. CG4928 Is Vital for Renal Function in Fruit Flies and Membrane Potential in Cells: A First In-Depth Characterization of the Putative Solute Carrier UNC93A. Front Cell Dev Biol 2020; 8:580291. [PMID: 33163493 PMCID: PMC7591606 DOI: 10.3389/fcell.2020.580291] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Accepted: 09/16/2020] [Indexed: 01/23/2023] Open
Abstract
The number of transporter proteins that are not fully characterized is immense. Here, we used Drosophila melanogaster and human cell lines to perform a first in-depth characterization of CG4928, an ortholog to the human UNC93A, of which little is known. Solute carriers regulate and maintain biochemical pathways important for the body, and malfunctioning transport is associated with multiple diseases. Based on phylogenetic analysis, CG4928 is closely related to human UNC93A and has a secondary and a tertiary protein structure and folding similar to major facilitator superfamily transporters. Ubiquitous knockdown of CG4928 causes flies to have a reduced secretion rate from the Malpighian tubules; altering potassium content in the body and in the Malpighian tubules, homologous to the renal system; and results in the development of edema. The edema could be rescued by using amiloride, a common diuretic, and by maintaining the flies on ion-free diets. CG4928-overexpressing cells did not facilitate the transport of sugars and amino acids; however, proximity ligation assay revealed that CG4928 co-localized with TASK1 channels. Overexpression of CG4928 resulted in induced apoptosis and cytotoxicity, which could be restored when cells were kept in high-sodium media. Furthermore, the basal membrane potential was observed to be disrupted. Taken together, the results indicate that CG4928 is of importance for generating the cellular membrane potential by an unknown manner. However, we speculate that it most likely acts as a regulator or transporter of potassium flows over the membrane.
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Affiliation(s)
- Mikaela M Ceder
- Department of Pharmaceutical Biosciences, Molecular Neuropharmacology, Uppsala University, Uppsala, Sweden
| | - Tanya Aggarwal
- Department of Pharmaceutical Biosciences, Molecular Neuropharmacology, Uppsala University, Uppsala, Sweden
| | - Kimia Hosseini
- Department of Pharmaceutical Biosciences, Molecular Neuropharmacology, Uppsala University, Uppsala, Sweden
| | - Varun Maturi
- Department of Pharmacy, Drug Delivery, Uppsala University, Uppsala, Sweden
| | - Sourabh Patil
- Department of Pharmaceutical Biosciences, Molecular Neuropharmacology, Uppsala University, Uppsala, Sweden
| | - Emelie Perland
- Department of Pharmaceutical Biosciences, Molecular Neuropharmacology, Uppsala University, Uppsala, Sweden
| | - Michael J Williams
- Department of Neuroscience, Functional Pharmacology, Uppsala University, Uppsala, Sweden
| | - Robert Fredriksson
- Department of Pharmaceutical Biosciences, Molecular Neuropharmacology, Uppsala University, Uppsala, Sweden
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Steel D, Zech M, Zhao C, Barwick KES, Burke D, Demailly D, Kumar KR, Zorzi G, Nardocci N, Kaiyrzhanov R, Wagner M, Iuso A, Berutti R, Škorvánek M, Necpál J, Davis R, Wiethoff S, Mankad K, Sudhakar S, Ferrini A, Sharma S, Kamsteeg EJ, Tijssen MA, Verschuuren C, van Egmond ME, Flowers JM, McEntagart M, Tucci A, Coubes P, Bustos BI, Gonzalez-Latapi P, Tisch S, Darveniza P, Gorman KM, Peall KJ, Bötzel K, Koch JC, Kmieć T, Plecko B, Boesch S, Haslinger B, Jech R, Garavaglia B, Wood N, Houlden H, Gissen P, Lubbe SJ, Sue CM, Cif L, Mencacci NE, Anderson G, Kurian MA, Winkelmann J. Loss-of-Function Variants in HOPS Complex Genes VPS16 and VPS41 Cause Early Onset Dystonia Associated with Lysosomal Abnormalities. Ann Neurol 2020; 88:867-877. [PMID: 32808683 DOI: 10.1002/ana.25879] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 07/31/2020] [Accepted: 08/09/2020] [Indexed: 02/02/2023]
Abstract
OBJECTIVES The majority of people with suspected genetic dystonia remain undiagnosed after maximal investigation, implying that a number of causative genes have not yet been recognized. We aimed to investigate this paucity of diagnoses. METHODS We undertook weighted burden analysis of whole-exome sequencing (WES) data from 138 individuals with unresolved generalized dystonia of suspected genetic etiology, followed by additional case-finding from international databases, first for the gene implicated by the burden analysis (VPS16), and then for other functionally related genes. Electron microscopy was performed on patient-derived cells. RESULTS Analysis revealed a significant burden for VPS16 (Fisher's exact test p value, 6.9 × 109 ). VPS16 encodes a subunit of the homotypic fusion and vacuole protein sorting (HOPS) complex, which plays a key role in autophagosome-lysosome fusion. A total of 18 individuals harboring heterozygous loss-of-function VPS16 variants, and one with a microdeletion, were identified. These individuals experienced early onset progressive dystonia with predominant cervical, bulbar, orofacial, and upper limb involvement. Some patients had a more complex phenotype with additional neuropsychiatric and/or developmental comorbidities. We also identified biallelic loss-of-function variants in VPS41, another HOPS-complex encoding gene, in an individual with infantile-onset generalized dystonia. Electron microscopy of patient-derived lymphocytes and fibroblasts from both patients with VPS16 and VPS41 showed vacuolar abnormalities suggestive of impaired lysosomal function. INTERPRETATION Our study strongly supports a role for HOPS complex dysfunction in the pathogenesis of dystonia, although variants in different subunits display different phenotypic and inheritance characteristics. ANN NEUROL 2020;88:867-877.
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Affiliation(s)
- Dora Steel
- Department of Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London, UK.,Department of Neurology, Great Ormond Street Hospital, London, UK
| | - Michael Zech
- Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany.,Institute of Human Genetics, Technical University of Munich, Munich, Germany
| | - Chen Zhao
- Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany
| | - Katy E S Barwick
- Department of Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Derek Burke
- Enzyme Laboratory, Great Ormond Street Hospital for Children, London, UK
| | - Diane Demailly
- Unités des Pathologies Cérébrales Résistantes, Département de Neurochirurgie, Centre Hospitalier Universitaire, Montpellier, France
| | - Kishore R Kumar
- Department of Neurogenetics, Kolling Institute of Medical Research, University of Sydney and Northern Sydney Local Health District, Sydney, New South Wales, Australia.,Molecular Medicine Laboratory, Concord Repatriation General Hospital, Concord, New South Wales, Australia.,Translational Genomics, Kinghorn Centre for Clinical Genomics, Garvan Institute for Medical Research, Sydney, New South Wales, Australia.,Department of Neurogenetics, University of Sydney and Northern Sydney Local Health District, Sydney, New South Wales, Australia
| | - Giovanna Zorzi
- Department of Child Neurology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Nardo Nardocci
- Department of Child Neurology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Rauan Kaiyrzhanov
- Department of Neuromuscular Diseases, University College London, Queen Square, Institute of Neurology, London, UK
| | - Matias Wagner
- Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany.,Institute of Human Genetics, Technical University of Munich, Munich, Germany
| | - Arcangela Iuso
- Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany.,Institute of Human Genetics, Technical University of Munich, Munich, Germany
| | - Riccardo Berutti
- Institute of Human Genetics, Technical University of Munich, Munich, Germany
| | - Matej Škorvánek
- Department of Neurology, P. J. Safarik University, Kosice, Slovak Republic.,Department of Neurology, University Hospital of L. Pasteur, Kosice, Slovak Republic
| | - Ján Necpál
- Department of Neurology, Zvolen Hospital, Zvolen, Slovakia
| | - Ryan Davis
- Department of Neurogenetics, Kolling Institute of Medical Research, University of Sydney and Northern Sydney Local Health District, Sydney, New South Wales, Australia.,Translational Genomics, Kinghorn Centre for Clinical Genomics, Garvan Institute for Medical Research, Sydney, New South Wales, Australia.,Department of Neurogenetics, University of Sydney and Northern Sydney Local Health District, Sydney, New South Wales, Australia
| | - Sarah Wiethoff
- UCL Queen Square Institute of Neurology, London, UK.,Department of Neurodegenerative Disease, Hertie-Institute for Clinical Brain Research and Center for Neurology, University of Tübingen, Tübingen, Germany
| | - Kshitij Mankad
- Department of Radiology, Great Ormond Street Hospital for Children, London, UK
| | - Sniya Sudhakar
- Department of Radiology, Great Ormond Street Hospital for Children, London, UK
| | - Arianna Ferrini
- Department of Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Suvasini Sharma
- Neurology Division, Department of Pediatrics, Lady Hardinge Medical College and Associated Kalawati Saran Children's Hospital, New Delhi, India
| | - Erik-Jan Kamsteeg
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Marina A Tijssen
- Department of Neurology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Corien Verschuuren
- Expertise Center Movement Disorders Groningen, University Medical Center Groningen, Groningen, The Netherlands.,Department of Genetics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Martje E van Egmond
- Department of Neurology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.,Expertise Center Movement Disorders Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | | | | | | | - Philippe Coubes
- Unités des Pathologies Cérébrales Résistantes, Département de Neurochirurgie, Centre Hospitalier Universitaire, Montpellier, France
| | - Bernabe I Bustos
- Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Paulina Gonzalez-Latapi
- Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Stephen Tisch
- Department of Neurology, St. Vincent's Hospital, Sydney, Australia
| | - Paul Darveniza
- Department of Neurology, St. Vincent's Hospital, Sydney, Australia
| | - Kathleen M Gorman
- Department of Neurology and Clinical Neurophysiology, Children's Health Ireland at Temple Street, Dublin, Ireland.,UCD School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
| | | | - Kai Bötzel
- Department of Neurology, Ludwig Maximilian University, Munich, Germany
| | - Jan C Koch
- Department of Neurology, University Medical Center Göttingen, Göttingen, Germany
| | - Tomasz Kmieć
- Department of Neurology and Epileptology, Children's Memorial Health Institute, Warsaw, Poland
| | - Barbara Plecko
- Department of Pediatrics and Adolescent Medicine, Division of General Pediatrics, Medical University of Graz, Graz, Austria
| | - Sylvia Boesch
- Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
| | - Bernhard Haslinger
- Klinik und Poliklinik für Neurologie, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Robert Jech
- Department of Neurology, Charles University, 1st Faculty of Medicine and General University Hospital in Prague, Prague, Czech Republic
| | - Barbara Garavaglia
- Department of Child Neurology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Nick Wood
- UCL Queen Square Institute of Neurology, London, UK
| | - Henry Houlden
- Department of Neuromuscular Diseases, University College London, Queen Square, Institute of Neurology, London, UK
| | - Paul Gissen
- Genetics and Genomic Medicine, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Steven J Lubbe
- Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Carolyn M Sue
- Department of Neurogenetics, Kolling Institute of Medical Research, University of Sydney and Northern Sydney Local Health District, Sydney, New South Wales, Australia.,Translational Genomics, Kinghorn Centre for Clinical Genomics, Garvan Institute for Medical Research, Sydney, New South Wales, Australia.,Department of Neurogenetics, University of Sydney and Northern Sydney Local Health District, Sydney, New South Wales, Australia.,Department of Neurology, Royal North Shore Hospital, Northern Sydney Local Health District, Sydney, New South Wales, Australia
| | - Laura Cif
- Unités des Pathologies Cérébrales Résistantes, Département de Neurochirurgie, Centre Hospitalier Universitaire, Montpellier, France
| | - Niccolò E Mencacci
- Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Glenn Anderson
- Department of Histopathology, Great Ormond Street Hospital for Children, London, UK
| | - Manju A Kurian
- Department of Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London, UK.,Department of Neurology, Great Ormond Street Hospital, London, UK
| | - Juliane Winkelmann
- Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany.,Institute of Human Genetics, Technical University of Munich, Munich, Germany.,Lehrstuhl für Neurogenetik, Technische Universität München, Munich, Germany.,Munich Cluster for Systems Neurology, Munich, Germany
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Mechanism of platelet α-granule biogenesis: study of cargo transport and the VPS33B-VPS16B complex in a model system. Blood Adv 2020; 3:2617-2626. [PMID: 31501156 DOI: 10.1182/bloodadvances.2018028969] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 07/30/2019] [Indexed: 12/29/2022] Open
Abstract
Platelet α-granules play important roles in platelet function. They contain hundreds of proteins that are synthesized by the megakaryocyte or taken up by endocytosis. The trafficking pathways that mediate platelet α-granule biogenesis are incompletely understood, especially with regard to cargo synthesized by the megakaryocyte. Vacuolar-protein sorting 33B (VPS33B) and VPS16B are essential proteins for α-granule biogenesis, but they are largely uncharacterized. Here, we adapted a powerful method to directly map the pathway followed by newly synthesized cargo proteins to reach α-granules. Using this method, we revealed the recycling endosome as a key intermediate compartment in α-granule biogenesis. We then used CRISPR/Cas9 gene editing to knock out VPS33B in pluripotent stem cell-derived immortalized megakaryocyte cells (imMKCLs). Consistent with the observations in platelets from patients with VPS33B mutation, VPS33B-knockout (KO) imMKCLs have drastically reduced levels of α-granule proteins platelet factor 4, von Willebrand factor, and P-selectin. VPS33B and VPS16B form a distinct and small complex in imMKCLs with the same hydrodynamic radius as the recombinant VPS33B-VPS16B heterodimer purified from bacteria. Mechanistically, the VPS33B-VPS16B complex ensures the correct trafficking of α-granule proteins. VPS33B deficiency results in α-granule cargo degradation in lysosomes. VPS16B steady-state levels are significantly lower in VPS33B-KO imMKCLs, suggesting that VPS16B is destabilized in the absence of its partner. Exogenous expression of green fluorescent protein-VPS33B in VPS33B-KO imMKCLs reconstitutes the complex, which localizes to the recycling endosome, further defining this compartment as a key intermediate in α-granule biogenesis. These results advance our understanding of platelet α-granule biogenesis and open new avenues for the study of these organelles.
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Zhang J, Tracy C, Pasare C, Zeng J, Krämer H. Hypersensitivity of Vps33B mutant flies to non-pathogenic infections is dictated by aberrant activation of p38b MAP kinase. Traffic 2020; 21:578-589. [PMID: 32677257 DOI: 10.1111/tra.12756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 07/10/2020] [Accepted: 07/12/2020] [Indexed: 11/29/2022]
Abstract
Loss of the arthrogryposis-renal dysfunction-cholestasis (ARC) syndrome-linked Vps33B protein results in exaggerated inflammatory responses upon activation of receptors of the innate immune system in both vertebrates and flies. However, little is known about the signaling elements downstream of these receptors that are critical for the hypersensitivity of Vps33B mutants. Here, we show that p38b MAP kinase contributes to the enhanced inflammatory responses in flies lacking Vps33B. Loss of p38b mitogen-activated protein kinase (MAPK) reduces enhanced inflammatory responses and prolongs the survival of infected Vps33B deficient flies. The function of p38 MAPK is not limited to its proinflammatory effects downstream of the PGRP-LC receptor as p38 also modulates endosomal trafficking of PGRP-LC and phagocytosis of bacteria. Expression of constitutively active p38b MAPK, but not dominant negative p38b MAPK enhances accumulation of endocytosed PGRP-LC receptors or phagocytosed bacteria within cells. Moreover, p38 MAPK is required for induction of macropinocytosis, an alternate pathway for the downregulation of immune receptors. Together, our data indicate that p38 MAPK activates multiple pathways that can contribute to the dysregulation of innate immune signaling in ARC syndrome.
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Affiliation(s)
- Jian Zhang
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, Texas, USA.,Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangdong Provincial Key Laboratory for Diagnosis and Treatment of Major Neurological Diseases, National Key Clinical Department and Key Discipline of Neurology, Guangzhou, China
| | - Charles Tracy
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Chandrashekhar Pasare
- Division of Immunobiology and Center for Inflammation and Tolerance, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.,Department of Pediatrics, University of Cincinnati, College of Medicine, Cincinnati, Ohio, USA
| | - Jinsheng Zeng
- Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangdong Provincial Key Laboratory for Diagnosis and Treatment of Major Neurological Diseases, National Key Clinical Department and Key Discipline of Neurology, Guangzhou, China
| | - Helmut Krämer
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, Texas, USA.,Department of Cell Biology, UT Southwestern Medical Center, Dallas, Texas, USA
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Bowman SL, Bi-Karchin J, Le L, Marks MS. The road to lysosome-related organelles: Insights from Hermansky-Pudlak syndrome and other rare diseases. Traffic 2020; 20:404-435. [PMID: 30945407 DOI: 10.1111/tra.12646] [Citation(s) in RCA: 120] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 04/02/2019] [Accepted: 04/02/2019] [Indexed: 12/11/2022]
Abstract
Lysosome-related organelles (LROs) comprise a diverse group of cell type-specific, membrane-bound subcellular organelles that derive at least in part from the endolysosomal system but that have unique contents, morphologies and functions to support specific physiological roles. They include: melanosomes that provide pigment to our eyes and skin; alpha and dense granules in platelets, and lytic granules in cytotoxic T cells and natural killer cells, which release effectors to regulate hemostasis and immunity; and distinct classes of lamellar bodies in lung epithelial cells and keratinocytes that support lung plasticity and skin lubrication. The formation, maturation and/or secretion of subsets of LROs are dysfunctional or entirely absent in a number of hereditary syndromic disorders, including in particular the Hermansky-Pudlak syndromes. This review provides a comprehensive overview of LROs in humans and model organisms and presents our current understanding of how the products of genes that are defective in heritable diseases impact their formation, motility and ultimate secretion.
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Affiliation(s)
- Shanna L Bowman
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia Research Institute, Philadelphia, Pennsylvania.,Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Jing Bi-Karchin
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia Research Institute, Philadelphia, Pennsylvania.,Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Linh Le
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia Research Institute, Philadelphia, Pennsylvania.,Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Michael S Marks
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia Research Institute, Philadelphia, Pennsylvania.,Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
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45
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Donnelly KM, DeLorenzo OR, Zaya ADA, Pisano GE, Thu WM, Luo L, Kopito RR, Panning Pearce MM. Phagocytic glia are obligatory intermediates in transmission of mutant huntingtin aggregates across neuronal synapses. eLife 2020; 9:e58499. [PMID: 32463364 PMCID: PMC7297539 DOI: 10.7554/elife.58499] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Accepted: 05/22/2020] [Indexed: 12/12/2022] Open
Abstract
Emerging evidence supports the hypothesis that pathogenic protein aggregates associated with neurodegenerative diseases spread from cell to cell through the brain in a manner akin to infectious prions. Here, we show that mutant huntingtin (mHtt) aggregates associated with Huntington disease transfer anterogradely from presynaptic to postsynaptic neurons in the adult Drosophila olfactory system. Trans-synaptic transmission of mHtt aggregates is inversely correlated with neuronal activity and blocked by inhibiting caspases in presynaptic neurons, implicating synaptic dysfunction and cell death in aggregate spreading. Remarkably, mHtt aggregate transmission across synapses requires the glial scavenger receptor Draper and involves a transient visit to the glial cytoplasm, indicating that phagocytic glia act as obligatory intermediates in aggregate spreading between synaptically-connected neurons. These findings expand our understanding of phagocytic glia as double-edged players in neurodegeneration-by clearing neurotoxic protein aggregates, but also providing an opportunity for prion-like seeds to evade phagolysosomal degradation and propagate further in the brain.
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Affiliation(s)
- Kirby M Donnelly
- Department of Biological Sciences, University of the SciencesPhiladelphiaUnited States
| | - Olivia R DeLorenzo
- Program in Neuroscience, University of the SciencesPhiladelphiaUnited States
| | - Aprem DA Zaya
- Department of Biological Sciences, University of the SciencesPhiladelphiaUnited States
| | - Gabrielle E Pisano
- Department of Biological Sciences, University of the SciencesPhiladelphiaUnited States
| | - Wint M Thu
- Department of Biological Sciences, University of the SciencesPhiladelphiaUnited States
| | - Liqun Luo
- Department of Biology, Stanford UniversityStanfordUnited States
- Howard Hughes Medical Institute, Stanford UniversityStanfordUnited States
| | - Ron R Kopito
- Department of Biology, Stanford UniversityStanfordUnited States
| | - Margaret M Panning Pearce
- Department of Biological Sciences, University of the SciencesPhiladelphiaUnited States
- Program in Neuroscience, University of the SciencesPhiladelphiaUnited States
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Griffiths NW, Del Bel LM, Wilk R, Brill JA. Cellular homeostasis in the Drosophila retina requires the lipid phosphatase Sac1. Mol Biol Cell 2020; 31:1183-1199. [PMID: 32186963 PMCID: PMC7353163 DOI: 10.1091/mbc.e20-02-0161] [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] [Indexed: 11/21/2022] Open
Abstract
The complex functions of cellular membranes, and thus overall cell physiology, depend on the distribution of crucial lipid species. Sac1 is an essential, conserved, ER-localized phosphatase whose substrate, phosphatidylinositol 4-phosphate (PI4P), coordinates secretory trafficking and plasma membrane function. PI4P from multiple pools is delivered to Sac1 by oxysterol-binding protein and related proteins in exchange for other lipids and sterols, which places Sac1 at the intersection of multiple lipid distribution pathways. However, much remains unknown about the roles of Sac1 in subcellular homeostasis and organismal development. Using a temperature-sensitive allele (Sac1ts), we show that Sac1 is required for structural integrity of the Drosophila retinal floor. The βps-integrin Myospheroid, which is necessary for basal cell adhesion, is mislocalized in Sac1ts retinas. In addition, the adhesion proteins Roughest and Kirre, which coordinate apical retinal cell patterning at an earlier stage, accumulate within Sac1ts retinal cells due to impaired endo-lysosomal degradation. Moreover, Sac1 is required for ER homeostasis in Drosophila retinal cells. Together, our data illustrate the importance of Sac1 in regulating multiple aspects of cellular homeostasis during tissue development.
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Affiliation(s)
- Nigel W Griffiths
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Lauren M Del Bel
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Ronit Wilk
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Julie A Brill
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
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Takáts S, Lévay L, Boda A, Tóth S, Simon-Vecsei Z, Rubics A, Varga Á, Lippai M, Lőrincz P, Glatz G, Juhász G. The Warburg Micro Syndrome-associated Rab3GAP-Rab18 module promotes autolysosome maturation through the Vps34 Complex I. FEBS J 2020; 288:190-211. [PMID: 32248620 DOI: 10.1111/febs.15313] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Revised: 02/10/2020] [Accepted: 03/26/2020] [Indexed: 12/23/2022]
Abstract
Warburg micro syndrome (WMS) is a hereditary autosomal neuromuscular disorder in humans caused by mutations in Rab18, Rab3GAP1, or Rab3GAP2 genes. Rab3GAP1/2 forms a heterodimeric complex, which acts as a guanosine nucleotide exchange factor and activates Rab18. Although the genetic causes of WMS are known, it is still unclear whether loss of the Rab3GAP-Rab18 module affects neuronal or muscle cell physiology or both, and how. In this work, we characterize a Rab3GAP2 mutant Drosophila line to establish a novel animal model for WMS. Similarly to symptoms of WMS, loss of Rab3GAP2 leads to highly decreased motility in Drosophila that becomes more serious with age. We demonstrate that these mutant flies are defective for autophagic degradation in multiple tissues including fat cells and muscles. Loss of Rab3GAP-Rab18 module members leads to perturbed autolysosome morphology due to destabilization of Rab7-positive autophagosomal and late endosomal compartments and perturbation of lysosomal biosynthetic transport. Importantly, overexpression of UVRAG or loss of Atg14, two alternative subunits of the Vps34/PI3K (vacuole protein sorting 34/phosphatidylinositol 3-kinase) complexes in fat cells, mimics the autophagic phenotype of Rab3GAP-Rab18 module loss. We find that GTP-bound Rab18 binds to Atg6/Beclin1, a permanent subunit of Vps34 complexes. Finally, we show that Rab3GAP2 and Rab18 are present on autophagosomal and autolysosomal membranes and colocalize with Vps34 Complex I subunits. Our data suggest that the Rab3GAP-Rab18 module regulates autolysosomal maturation through its interaction with the Vps34 Complex I, and perturbed autophagy due to loss of the Rab3GAP-Rab18 module may contribute to the development of WMS.
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Affiliation(s)
- Szabolcs Takáts
- Department of Anatomy, Cell and Developmental Biology, ELTE Eötvös Loránd University, Budapest, Hungary.,Premium Postdoctorate Research Program, Hungarian Academy of Sciences, Budapest, Hungary
| | - Luca Lévay
- Department of Anatomy, Cell and Developmental Biology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Attila Boda
- Department of Anatomy, Cell and Developmental Biology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Sarolta Tóth
- Department of Anatomy, Cell and Developmental Biology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Zsófia Simon-Vecsei
- Department of Anatomy, Cell and Developmental Biology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - András Rubics
- Department of Anatomy, Cell and Developmental Biology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Ágnes Varga
- Department of Anatomy, Cell and Developmental Biology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Mónika Lippai
- Department of Anatomy, Cell and Developmental Biology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Péter Lőrincz
- Department of Anatomy, Cell and Developmental Biology, ELTE Eötvös Loránd University, Budapest, Hungary.,Premium Postdoctorate Research Program, Hungarian Academy of Sciences, Budapest, Hungary
| | - Gábor Glatz
- Department of Anatomy, Cell and Developmental Biology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Gábor Juhász
- Department of Anatomy, Cell and Developmental Biology, ELTE Eötvös Loránd University, Budapest, Hungary.,Institute of Genetics, Biological Research Centre of the Hungarian Academy of Sciences, Szeged, Hungary
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Lőrincz P, Juhász G. Autophagosome-Lysosome Fusion. J Mol Biol 2020; 432:2462-2482. [DOI: 10.1016/j.jmb.2019.10.028] [Citation(s) in RCA: 98] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 10/11/2019] [Accepted: 10/15/2019] [Indexed: 12/26/2022]
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49
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Yang WK, Chien CT. Beyond being innervated: the epidermis actively shapes sensory dendritic patterning. Open Biol 2020; 9:180257. [PMID: 30914004 PMCID: PMC6451362 DOI: 10.1098/rsob.180257] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Sensing environmental cues requires well-built neuronal circuits linked to the body surface. Sensory neurons generate dendrites to innervate surface epithelium, thereby making it the largest sensory organ in the body. Previous studies have illustrated that neuronal type, physiological function and branching patterns are determined by intrinsic factors. Perhaps for effective sensation or protection, sensory dendrites bind to or are surrounded by the substrate epidermis. Recent studies have shed light on the mechanisms by which dendrites interact with their substrates. These interactions suggest that substrates can regulate dendrite guidance, arborization and degeneration. In this review, we focus on recent studies of Drosophila and Caenorhabditis elegans that demonstrate how epidermal cells can regulate dendrites in several aspects.
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Affiliation(s)
- Wei-Kang Yang
- Institute of Molecular Biology, Academia Sinica , Taipei 115 , Taiwan
| | - Cheng-Ting Chien
- Institute of Molecular Biology, Academia Sinica , Taipei 115 , Taiwan
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Csizmadia T, Juhász G. Crinophagy mechanisms and its potential role in human health and disease. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2020; 172:239-255. [PMID: 32620244 DOI: 10.1016/bs.pmbts.2020.02.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Autophagic-lysosomal degradation is essential for the maintenance of normal homeostasis in eukaryotic cells. Several types of such self-degradative and recycling pathways have been identified. From these, probably the least known autophagic process is crinophagy, during which unnecessary or obsolete secretory granules directly fuse with late endosomes/lysosomes as a means of rapid elimination of unused secretory material from the cytoplasm. This process was identified in 1966, but we are only beginning to understand the molecular mechanisms and regulation of crinophagy. In this review, we summarize the current examination methods and possible model systems, discuss the recently identified factors that are required for crinophagy, and give an overview of the potential medical relevance of this process.
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Affiliation(s)
- Tamás Csizmadia
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary
| | - Gábor Juhász
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary; Institute of Genetics, Biological Research Centre, Szeged, Hungary.
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